Net Assets C000017880 [Member] Schwab Government Money Market Portfolio Investment Company, Portfolio Turnover C000017882 [Member] Schwab S&P 500 Index Portfolio C000111125 [Member] Schwab VIT Balanced Portfolio C000111126 [Member] Schwab VIT Balanced with Growth Portfolio C000111127 [Member] Schwab VIT Growth Portfolio VIT Growth Composite Index [Member] VIT Balanced with Growth Composite Index [Member] VIT Balanced Composite Index [Member] Bloomberg US Aggregate Bond Index [Member] Standard & Poor's 500 Index [Member] Investment Type [Axis] U.S. Stocks - Large-Cap [Member] International Stocks - Developed Markets [Member] Fixed Income - Intermediate-Term Bond [Member] U.S. Stocks - Small-Cap [Member] Real Estate - U.S. REITs [Member] International Stocks - Emerging Markets [Member] Money Market Funds [Member] Schwab International Equity ETF [Member] Schwab U.S. Aggregate Bond ETF [Member] Schwab U.S. Small-Cap ETF [Member] Schwab U.S. REIT ETF [Member] Schwab Emerging Markets Equity ETF [Member] Schwab International Small-Cap Equity ETF [Member] Schwab Government Money Fund, Ultra Shares [Member] Schwab U.S. Large-Cap ETF [Member] Fixed Income - Treasury Bond [Member] Fixed Income - Inflation-Protected Bond [Member] Schwab Short-Term U.S. Treasury ETF [Member] Schwab U.S. TIPS ETF [Member] Financials Sector [Member] Healthcare Sector [Member] Energy Sector [Member] Real Estate Sector [Member] Investment Companies [Member] Apple, Inc. [Member] Microsoft Corp. [Member] Amazon.com, Inc. [Member] Alphabet, Inc., Class A [Member] Broadcom, Inc. [Member] Alphabet, Inc., Class C [Member] Meta Platforms, Inc., Class A [Member] Tesla, Inc. [Member] Berkshire Hathaway, Inc., Class B [Member] NVIDIA Corp. [Member] Repurchase Agreements [Member] Repurchase Agreements US Government Agency [Member] Repurchase Agreements U.S. Government Agency [Member] Repurchase Agreements US Treasury [Member] Repurchase Agreements U.S. Treasury [Member] US Government Agency Debt [Member] U.S. Government Agency Debt [Member] U.S.Treasury Debt [Member] Variable Rate Demand Notes [Member] Short-Term Investments [Member] 1 to 7 Days [Member] 8 to 30 Days [Member] 31 to 60 Days [Member] 91 to 180 Days [Member] 61 to 90 Days [Member] Over 180 Days [Member]