v3.26.1
Shareholder Report, Holdings (Details)
Jun. 30, 2026
Schwab Prime Advantage Money Fund - Investor Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 71.40%
Schwab Prime Advantage Money Fund - Investor Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
Schwab Prime Advantage Money Fund - Investor Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.00%
Schwab Prime Advantage Money Fund - Investor Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.40%
Schwab Prime Advantage Money Fund - Investor Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.80%
Schwab Prime Advantage Money Fund - Investor Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.40%
Schwab Prime Advantage Money Fund - Investor Shares | Repurchase Agreements Other [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.00%
Schwab Prime Advantage Money Fund - Investor Shares | Certificates of Deposit [Member]  
Holdings [Line Items]  
Percent of Total Investments 23.70%
Schwab Prime Advantage Money Fund - Investor Shares | Commercial Paper Asset Backed [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.40%
Schwab Prime Advantage Money Fund - Investor Shares | Commercial Paper Financial Company [Member]  
Holdings [Line Items]  
Percent of Total Investments 10.40%
Schwab Prime Advantage Money Fund - Investor Shares | Commercial Paper Non-Financial Company [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.40%
Schwab Prime Advantage Money Fund - Investor Shares | Non-Negotiable Time Deposits [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.70%
Schwab Prime Advantage Money Fund - Investor Shares | Other Instruments [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.30%
Schwab Prime Advantage Money Fund - Investor Shares | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 46.00%
Schwab Prime Advantage Money Fund - Investor Shares | Repurchase Agreements U.S. Government Agency [Member]  
Holdings [Line Items]  
Percent of Total Investments 19.70%
Schwab Prime Advantage Money Fund - Investor Shares | Repurchase Agreements U.S. Treasury [Member]  
Holdings [Line Items]  
Percent of Total Investments 19.30%
Schwab Prime Advantage Money Fund - Investor Shares | Variable Rate Demand Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.80%
Schwab Prime Advantage Money Fund - Investor Shares | Commercial Paper [Member]  
Holdings [Line Items]  
Percent of Total Investments 19.20%
Schwab Prime Advantage Money Fund - Ultra Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 71.40%
Schwab Prime Advantage Money Fund - Ultra Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
Schwab Prime Advantage Money Fund - Ultra Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.00%
Schwab Prime Advantage Money Fund - Ultra Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.40%
Schwab Prime Advantage Money Fund - Ultra Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.80%
Schwab Prime Advantage Money Fund - Ultra Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.40%
Schwab Prime Advantage Money Fund - Ultra Shares | Repurchase Agreements Other [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.00%
Schwab Prime Advantage Money Fund - Ultra Shares | Certificates of Deposit [Member]  
Holdings [Line Items]  
Percent of Total Investments 23.70%
Schwab Prime Advantage Money Fund - Ultra Shares | Commercial Paper Asset Backed [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.40%
Schwab Prime Advantage Money Fund - Ultra Shares | Commercial Paper Financial Company [Member]  
Holdings [Line Items]  
Percent of Total Investments 10.40%
Schwab Prime Advantage Money Fund - Ultra Shares | Commercial Paper Non-Financial Company [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.40%
Schwab Prime Advantage Money Fund - Ultra Shares | Non-Negotiable Time Deposits [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.70%
Schwab Prime Advantage Money Fund - Ultra Shares | Other Instruments [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.30%
Schwab Prime Advantage Money Fund - Ultra Shares | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 46.00%
Schwab Prime Advantage Money Fund - Ultra Shares | Repurchase Agreements U.S. Government Agency [Member]  
Holdings [Line Items]  
Percent of Total Investments 19.70%
Schwab Prime Advantage Money Fund - Ultra Shares | Repurchase Agreements U.S. Treasury [Member]  
Holdings [Line Items]  
Percent of Total Investments 19.30%
Schwab Prime Advantage Money Fund - Ultra Shares | Variable Rate Demand Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.80%
Schwab Prime Advantage Money Fund - Ultra Shares | Commercial Paper [Member]  
Holdings [Line Items]  
Percent of Total Investments 19.20%
Schwab Government Money Fund - Sweep Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 78.10%
Schwab Government Money Fund - Sweep Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.70%
Schwab Government Money Fund - Sweep Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
Schwab Government Money Fund - Sweep Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.70%
Schwab Government Money Fund - Sweep Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.10%
Schwab Government Money Fund - Sweep Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 12.00%
Schwab Government Money Fund - Sweep Shares | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 62.60%
Schwab Government Money Fund - Sweep Shares | Repurchase Agreements U.S. Government Agency [Member]  
Holdings [Line Items]  
Percent of Total Investments 41.70%
Schwab Government Money Fund - Sweep Shares | Repurchase Agreements U.S. Treasury [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.90%
Schwab Government Money Fund - Sweep Shares | U.S. Government Agency Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.20%
Schwab Government Money Fund - Sweep Shares | U.S. Treasury Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.00%
Schwab Government Money Fund - Sweep Shares | Variable Rate Demand Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.20%
Schwab Government Money Fund - Investor Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 78.10%
Schwab Government Money Fund - Investor Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.70%
Schwab Government Money Fund - Investor Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
Schwab Government Money Fund - Investor Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.70%
Schwab Government Money Fund - Investor Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.10%
Schwab Government Money Fund - Investor Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 12.00%
Schwab Government Money Fund - Investor Shares | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 62.60%
Schwab Government Money Fund - Investor Shares | Repurchase Agreements U.S. Government Agency [Member]  
Holdings [Line Items]  
Percent of Total Investments 41.70%
Schwab Government Money Fund - Investor Shares | Repurchase Agreements U.S. Treasury [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.90%
Schwab Government Money Fund - Investor Shares | U.S. Government Agency Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.20%
Schwab Government Money Fund - Investor Shares | U.S. Treasury Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.00%
Schwab Government Money Fund - Investor Shares | Variable Rate Demand Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.20%
Schwab Government Money Fund - Ultra Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 78.10%
Schwab Government Money Fund - Ultra Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.70%
Schwab Government Money Fund - Ultra Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
Schwab Government Money Fund - Ultra Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.70%
Schwab Government Money Fund - Ultra Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.10%
Schwab Government Money Fund - Ultra Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 12.00%
Schwab Government Money Fund - Ultra Shares | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 62.60%
Schwab Government Money Fund - Ultra Shares | Repurchase Agreements U.S. Government Agency [Member]  
Holdings [Line Items]  
Percent of Total Investments 41.70%
Schwab Government Money Fund - Ultra Shares | Repurchase Agreements U.S. Treasury [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.90%
Schwab Government Money Fund - Ultra Shares | U.S. Government Agency Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.20%
Schwab Government Money Fund - Ultra Shares | U.S. Treasury Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.00%
Schwab Government Money Fund - Ultra Shares | Variable Rate Demand Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.20%
Schwab U.S. Treasury Money Fund - Investor Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 23.10%
Schwab U.S. Treasury Money Fund - Investor Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 31.30%
Schwab U.S. Treasury Money Fund - Investor Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 27.70%
Schwab U.S. Treasury Money Fund - Investor Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.30%
Schwab U.S. Treasury Money Fund - Investor Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.10%
Schwab U.S. Treasury Money Fund - Investor Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.50%
Schwab U.S. Treasury Money Fund - Investor Shares | U.S. Treasury Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
Schwab U.S. Treasury Money Fund - Ultra Shares [Member] | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 23.10%
Schwab U.S. Treasury Money Fund - Ultra Shares [Member] | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 31.30%
Schwab U.S. Treasury Money Fund - Ultra Shares [Member] | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 27.70%
Schwab U.S. Treasury Money Fund - Ultra Shares [Member] | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.30%
Schwab U.S. Treasury Money Fund - Ultra Shares [Member] | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.10%
Schwab U.S. Treasury Money Fund - Ultra Shares [Member] | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.50%
Schwab U.S. Treasury Money Fund - Ultra Shares [Member] | U.S. Treasury Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
Schwab Treasury Obligations Money Fund - Investor Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 77.40%
Schwab Treasury Obligations Money Fund - Investor Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.70%
Schwab Treasury Obligations Money Fund - Investor Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
Schwab Treasury Obligations Money Fund - Investor Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.90%
Schwab Treasury Obligations Money Fund - Investor Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.20%
Schwab Treasury Obligations Money Fund - Investor Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 12.80%
Schwab Treasury Obligations Money Fund - Investor Shares | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 63.30%
Schwab Treasury Obligations Money Fund - Investor Shares | Repurchase Agreements U.S. Treasury [Member]  
Holdings [Line Items]  
Percent of Total Investments 63.30%
Schwab Treasury Obligations Money Fund - Investor Shares | U.S. Treasury Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 36.70%
Schwab Treasury Obligations Money Fund - Ultra Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 77.40%
Schwab Treasury Obligations Money Fund - Ultra Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.70%
Schwab Treasury Obligations Money Fund - Ultra Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
Schwab Treasury Obligations Money Fund - Ultra Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.90%
Schwab Treasury Obligations Money Fund - Ultra Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.20%
Schwab Treasury Obligations Money Fund - Ultra Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 12.80%
Schwab Treasury Obligations Money Fund - Ultra Shares | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 63.30%
Schwab Treasury Obligations Money Fund - Ultra Shares | Repurchase Agreements U.S. Treasury [Member]  
Holdings [Line Items]  
Percent of Total Investments 63.30%
Schwab Treasury Obligations Money Fund - Ultra Shares | U.S. Treasury Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 36.70%
Schwab Retirement Government Money Fund | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 81.00%
Schwab Retirement Government Money Fund | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.50%
Schwab Retirement Government Money Fund | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80%
Schwab Retirement Government Money Fund | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
Schwab Retirement Government Money Fund | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.20%
Schwab Retirement Government Money Fund | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.50%
Schwab Retirement Government Money Fund | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 60.20%
Schwab Retirement Government Money Fund | Repurchase Agreements U.S. Government Agency [Member]  
Holdings [Line Items]  
Percent of Total Investments 39.70%
Schwab Retirement Government Money Fund | Repurchase Agreements U.S. Treasury [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.50%
Schwab Retirement Government Money Fund | U.S. Government Agency Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 29.70%
Schwab Retirement Government Money Fund | U.S. Treasury Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.10%
Schwab Retirement Government Money Fund | Variable Rate Demand Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.00%
Schwab Municipal Money Fund - Investor Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 72.30%
Schwab Municipal Money Fund - Investor Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.10%
Schwab Municipal Money Fund - Investor Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.90%
Schwab Municipal Money Fund - Investor Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.00%
Schwab Municipal Money Fund - Investor Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.10%
Schwab Municipal Money Fund - Investor Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.60%
Schwab Municipal Money Fund - Investor Shares | FLORIDA  
Holdings [Line Items]  
Percent of Total Investments 5.10%
Schwab Municipal Money Fund - Investor Shares | ILLINOIS  
Holdings [Line Items]  
Percent of Total Investments 4.20%
Schwab Municipal Money Fund - Investor Shares | TEXAS  
Holdings [Line Items]  
Percent of Total Investments 20.60%
Schwab Municipal Money Fund - Investor Shares | NEW YORK  
Holdings [Line Items]  
Percent of Total Investments 10.40%
Schwab Municipal Money Fund - Investor Shares | Multiple States [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.60%
Schwab Municipal Money Fund - Investor Shares | Tender Option Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 21.70%
Schwab Municipal Money Fund - Investor Shares | Variable Rate Demand Obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 39.50%
Schwab Municipal Money Fund - Investor Shares | Fixed Rate Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.80%
Schwab Municipal Money Fund - Investor Shares | Variable Rate Demand Preferred Shares [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.30%
Schwab Municipal Money Fund - Investor Shares | Commercial Paper [Member]  
Holdings [Line Items]  
Percent of Total Investments 21.10%
Schwab Municipal Money Fund - Investor Shares | Put Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.60%
Schwab Municipal Money Fund - Ultra Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 72.30%
Schwab Municipal Money Fund - Ultra Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.10%
Schwab Municipal Money Fund - Ultra Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.90%
Schwab Municipal Money Fund - Ultra Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.00%
Schwab Municipal Money Fund - Ultra Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.10%
Schwab Municipal Money Fund - Ultra Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.60%
Schwab Municipal Money Fund - Ultra Shares | FLORIDA  
Holdings [Line Items]  
Percent of Total Investments 5.10%
Schwab Municipal Money Fund - Ultra Shares | ILLINOIS  
Holdings [Line Items]  
Percent of Total Investments 4.20%
Schwab Municipal Money Fund - Ultra Shares | TEXAS  
Holdings [Line Items]  
Percent of Total Investments 20.60%
Schwab Municipal Money Fund - Ultra Shares | NEW YORK  
Holdings [Line Items]  
Percent of Total Investments 10.40%
Schwab Municipal Money Fund - Ultra Shares | Multiple States [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.60%
Schwab Municipal Money Fund - Ultra Shares | Tender Option Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 21.70%
Schwab Municipal Money Fund - Ultra Shares | Variable Rate Demand Obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 39.50%
Schwab Municipal Money Fund - Ultra Shares | Fixed Rate Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.80%
Schwab Municipal Money Fund - Ultra Shares | Variable Rate Demand Preferred Shares [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.30%
Schwab Municipal Money Fund - Ultra Shares | Commercial Paper [Member]  
Holdings [Line Items]  
Percent of Total Investments 21.10%
Schwab Municipal Money Fund - Ultra Shares | Put Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.60%
Schwab AMT Tax-Free Money Fund - Investor Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 71.80%
Schwab AMT Tax-Free Money Fund - Investor Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.30%
Schwab AMT Tax-Free Money Fund - Investor Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.40%
Schwab AMT Tax-Free Money Fund - Investor Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.20%
Schwab AMT Tax-Free Money Fund - Investor Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.70%
Schwab AMT Tax-Free Money Fund - Investor Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.60%
Schwab AMT Tax-Free Money Fund - Investor Shares | TEXAS  
Holdings [Line Items]  
Percent of Total Investments 22.00%
Schwab AMT Tax-Free Money Fund - Investor Shares | NEW YORK  
Holdings [Line Items]  
Percent of Total Investments 8.80%
Schwab AMT Tax-Free Money Fund - Investor Shares | Multiple States [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.30%
Schwab AMT Tax-Free Money Fund - Investor Shares | ALABAMA  
Holdings [Line Items]  
Percent of Total Investments 4.90%
Schwab AMT Tax-Free Money Fund - Investor Shares | PENNSYLVANIA  
Holdings [Line Items]  
Percent of Total Investments 4.50%
Schwab AMT Tax-Free Money Fund - Investor Shares | Tender Option Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 37.50%
Schwab AMT Tax-Free Money Fund - Investor Shares | Variable Rate Demand Obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 24.10%
Schwab AMT Tax-Free Money Fund - Investor Shares | Fixed Rate Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.20%
Schwab AMT Tax-Free Money Fund - Investor Shares | Variable Rate Demand Preferred Shares [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.10%
Schwab AMT Tax-Free Money Fund - Investor Shares | Commercial Paper [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.90%
Schwab AMT Tax-Free Money Fund - Investor Shares | Put Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.20%
Schwab AMT Tax-Free Money Fund - Ultra Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 71.80%
Schwab AMT Tax-Free Money Fund - Ultra Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.30%
Schwab AMT Tax-Free Money Fund - Ultra Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.40%
Schwab AMT Tax-Free Money Fund - Ultra Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.20%
Schwab AMT Tax-Free Money Fund - Ultra Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.70%
Schwab AMT Tax-Free Money Fund - Ultra Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.60%
Schwab AMT Tax-Free Money Fund - Ultra Shares | TEXAS  
Holdings [Line Items]  
Percent of Total Investments 22.00%
Schwab AMT Tax-Free Money Fund - Ultra Shares | NEW YORK  
Holdings [Line Items]  
Percent of Total Investments 8.80%
Schwab AMT Tax-Free Money Fund - Ultra Shares | Multiple States [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.30%
Schwab AMT Tax-Free Money Fund - Ultra Shares | ALABAMA  
Holdings [Line Items]  
Percent of Total Investments 4.90%
Schwab AMT Tax-Free Money Fund - Ultra Shares | PENNSYLVANIA  
Holdings [Line Items]  
Percent of Total Investments 4.50%
Schwab AMT Tax-Free Money Fund - Ultra Shares | Tender Option Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 37.50%
Schwab AMT Tax-Free Money Fund - Ultra Shares | Variable Rate Demand Obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 24.10%
Schwab AMT Tax-Free Money Fund - Ultra Shares | Fixed Rate Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.20%
Schwab AMT Tax-Free Money Fund - Ultra Shares | Variable Rate Demand Preferred Shares [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.10%
Schwab AMT Tax-Free Money Fund - Ultra Shares | Commercial Paper [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.90%
Schwab AMT Tax-Free Money Fund - Ultra Shares | Put Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.20%
Schwab California Municipal Money Fund - Investor Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 65.40%
Schwab California Municipal Money Fund - Investor Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.30%
Schwab California Municipal Money Fund - Investor Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 14.00%
Schwab California Municipal Money Fund - Investor Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.30%
Schwab California Municipal Money Fund - Investor Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.50%
Schwab California Municipal Money Fund - Investor Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.50%
Schwab California Municipal Money Fund - Investor Shares | Tender Option Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 14.70%
Schwab California Municipal Money Fund - Investor Shares | Variable Rate Demand Obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 38.50%
Schwab California Municipal Money Fund - Investor Shares | Fixed Rate Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.90%
Schwab California Municipal Money Fund - Investor Shares | Variable Rate Demand Preferred Shares [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.50%
Schwab California Municipal Money Fund - Investor Shares | Commercial Paper [Member]  
Holdings [Line Items]  
Percent of Total Investments 35.40%
Schwab California Municipal Money Fund - Ultra Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 65.40%
Schwab California Municipal Money Fund - Ultra Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.30%
Schwab California Municipal Money Fund - Ultra Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 14.00%
Schwab California Municipal Money Fund - Ultra Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.30%
Schwab California Municipal Money Fund - Ultra Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.50%
Schwab California Municipal Money Fund - Ultra Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.50%
Schwab California Municipal Money Fund - Ultra Shares | Tender Option Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 14.70%
Schwab California Municipal Money Fund - Ultra Shares | Variable Rate Demand Obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 38.50%
Schwab California Municipal Money Fund - Ultra Shares | Fixed Rate Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.90%
Schwab California Municipal Money Fund - Ultra Shares | Variable Rate Demand Preferred Shares [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.50%
Schwab California Municipal Money Fund - Ultra Shares | Commercial Paper [Member]  
Holdings [Line Items]  
Percent of Total Investments 35.40%
Schwab New York Municipal Money Fund - Investor Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 82.90%
Schwab New York Municipal Money Fund - Investor Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.90%
Schwab New York Municipal Money Fund - Investor Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.60%
Schwab New York Municipal Money Fund - Investor Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.10%
Schwab New York Municipal Money Fund - Investor Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
Schwab New York Municipal Money Fund - Investor Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.50%
Schwab New York Municipal Money Fund - Investor Shares | Tender Option Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 39.50%
Schwab New York Municipal Money Fund - Investor Shares | Variable Rate Demand Obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 36.10%
Schwab New York Municipal Money Fund - Investor Shares | Fixed Rate Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.60%
Schwab New York Municipal Money Fund - Investor Shares | Variable Rate Demand Preferred Shares [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.30%
Schwab New York Municipal Money Fund - Investor Shares | Commercial Paper [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.10%
Schwab New York Municipal Money Fund - Investor Shares | Put Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
Schwab New York Municipal Money Fund - Ultra Shares | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 82.90%
Schwab New York Municipal Money Fund - Ultra Shares | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.90%
Schwab New York Municipal Money Fund - Ultra Shares | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.60%
Schwab New York Municipal Money Fund - Ultra Shares | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.10%
Schwab New York Municipal Money Fund - Ultra Shares | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
Schwab New York Municipal Money Fund - Ultra Shares | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.50%
Schwab New York Municipal Money Fund - Ultra Shares | Tender Option Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 39.50%
Schwab New York Municipal Money Fund - Ultra Shares | Variable Rate Demand Obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 36.10%
Schwab New York Municipal Money Fund - Ultra Shares | Fixed Rate Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.60%
Schwab New York Municipal Money Fund - Ultra Shares | Variable Rate Demand Preferred Shares [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.30%
Schwab New York Municipal Money Fund - Ultra Shares | Commercial Paper [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.10%
Schwab New York Municipal Money Fund - Ultra Shares | Put Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%