v3.25.4
Shareholder Report, Holdings (Details)
Dec. 31, 2025
Schwab Government Money Market Portfolio | 1 to 7 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 74.30%
Schwab Government Money Market Portfolio | 8 to 30 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.60%
Schwab Government Money Market Portfolio | 31 to 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.00%
Schwab Government Money Market Portfolio | 91 to 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.40%
Schwab Government Money Market Portfolio | 61 to 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.40%
Schwab Government Money Market Portfolio | Over 180 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.30%
Schwab Government Money Market Portfolio | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 53.40%
Schwab Government Money Market Portfolio | Repurchase Agreements U.S. Government Agency [Member]  
Holdings [Line Items]  
Percent of Total Investments 24.60%
Schwab Government Money Market Portfolio | Repurchase Agreements U.S. Treasury [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.80%
Schwab Government Money Market Portfolio | U.S. Government Agency Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 37.40%
Schwab Government Money Market Portfolio | U.S.Treasury Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.90%
Schwab Government Money Market Portfolio | Variable Rate Demand Notes [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.30%
Schwab Government Money Market Portfolio | Short-Term Investments [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.00% [1],[2]
Schwab S&P 500 Index Portfolio | Apple, Inc. [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.80%
Schwab S&P 500 Index Portfolio | Microsoft Corp. [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.10%
Schwab S&P 500 Index Portfolio | Amazon.com, Inc. [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Schwab S&P 500 Index Portfolio | Alphabet, Inc., Class A [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.10%
Schwab S&P 500 Index Portfolio | Broadcom, Inc. [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Schwab S&P 500 Index Portfolio | Alphabet, Inc., Class C [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Schwab S&P 500 Index Portfolio | Meta Platforms, Inc., Class A [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Schwab S&P 500 Index Portfolio | Tesla, Inc. [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Schwab S&P 500 Index Portfolio | Berkshire Hathaway, Inc., Class B [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Schwab S&P 500 Index Portfolio | NVIDIA Corp. [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Schwab S&P 500 Index Portfolio | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Total Investments 34.40% [3]
Schwab S&P 500 Index Portfolio | Financials Sector [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.40% [3]
Schwab S&P 500 Index Portfolio | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Total Investments 10.60% [3]
Schwab S&P 500 Index Portfolio | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Total Investments 10.40% [3]
Schwab S&P 500 Index Portfolio | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.60% [3]
Schwab S&P 500 Index Portfolio | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.20% [3]
Schwab S&P 500 Index Portfolio | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.70% [3]
Schwab S&P 500 Index Portfolio | Energy Sector [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.80% [3]
Schwab S&P 500 Index Portfolio | Utilities Sector [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.20% [3]
Schwab S&P 500 Index Portfolio | Materials Sector [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80% [3]
Schwab S&P 500 Index Portfolio | Real Estate Sector [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80% [3]
Schwab S&P 500 Index Portfolio | Investment Companies [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10% [3]
Schwab VIT Balanced Portfolio | Schwab Short-Term U.S. Treasury ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.00%
Schwab VIT Balanced Portfolio | Schwab U.S. TIPS ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Schwab VIT Balanced Portfolio | Schwab International Equity ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.00%
Schwab VIT Balanced Portfolio | Schwab U.S. Aggregate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 36.30%
Schwab VIT Balanced Portfolio | Schwab U.S. Small-Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Schwab VIT Balanced Portfolio | Schwab U.S. REIT ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
Schwab VIT Balanced Portfolio | Schwab Emerging Markets Equity ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Schwab VIT Balanced Portfolio | Schwab International Small-Cap Equity ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Schwab VIT Balanced Portfolio | Schwab Government Money Fund, Ultra Shares [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.50%
Schwab VIT Balanced Portfolio | Schwab U.S. Large-Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 25.90%
Schwab VIT Balanced Portfolio | Fixed Income - Treasury Bond [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.00%
Schwab VIT Balanced Portfolio | Fixed Income - Inflation-Protected Bond [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.70%
Schwab VIT Balanced Portfolio | U.S. Stocks - Large-Cap [Member]  
Holdings [Line Items]  
Percent of Total Investments 26.00%
Schwab VIT Balanced Portfolio | International Stocks - Developed Markets [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.10%
Schwab VIT Balanced Portfolio | Fixed Income - Intermediate-Term Bond [Member]  
Holdings [Line Items]  
Percent of Total Investments 36.50%
Schwab VIT Balanced Portfolio | U.S. Stocks - Small-Cap [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.90%
Schwab VIT Balanced Portfolio | Real Estate - U.S. REITs [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.30%
Schwab VIT Balanced Portfolio | International Stocks - Emerging Markets [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
Schwab VIT Balanced Portfolio | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.50%
Schwab VIT Balanced with Growth Portfolio | Schwab Short-Term U.S. Treasury ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Schwab VIT Balanced with Growth Portfolio | Schwab U.S. TIPS ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Schwab VIT Balanced with Growth Portfolio | Schwab International Equity ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 16.10%
Schwab VIT Balanced with Growth Portfolio | Schwab U.S. Aggregate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 26.10%
Schwab VIT Balanced with Growth Portfolio | Schwab U.S. Small-Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Schwab VIT Balanced with Growth Portfolio | Schwab U.S. REIT ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.60%
Schwab VIT Balanced with Growth Portfolio | Schwab Emerging Markets Equity ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Schwab VIT Balanced with Growth Portfolio | Schwab International Small-Cap Equity ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.00%
Schwab VIT Balanced with Growth Portfolio | Schwab Government Money Fund, Ultra Shares [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Schwab VIT Balanced with Growth Portfolio | Schwab U.S. Large-Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 33.90%
Schwab VIT Balanced with Growth Portfolio | Fixed Income - Treasury Bond [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.90%
Schwab VIT Balanced with Growth Portfolio | Fixed Income - Inflation-Protected Bond [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.00%
Schwab VIT Balanced with Growth Portfolio | U.S. Stocks - Large-Cap [Member]  
Holdings [Line Items]  
Percent of Total Investments 34.30%
Schwab VIT Balanced with Growth Portfolio | International Stocks - Developed Markets [Member]  
Holdings [Line Items]  
Percent of Total Investments 19.20%
Schwab VIT Balanced with Growth Portfolio | Fixed Income - Intermediate-Term Bond [Member]  
Holdings [Line Items]  
Percent of Total Investments 26.30%
Schwab VIT Balanced with Growth Portfolio | U.S. Stocks - Small-Cap [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.20%
Schwab VIT Balanced with Growth Portfolio | Real Estate - U.S. REITs [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.70%
Schwab VIT Balanced with Growth Portfolio | International Stocks - Emerging Markets [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.20%
Schwab VIT Balanced with Growth Portfolio | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.20%
Schwab VIT Growth Portfolio | Schwab International Equity ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.00%
Schwab VIT Growth Portfolio | Schwab U.S. Aggregate Bond ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.00%
Schwab VIT Growth Portfolio | Schwab U.S. Small-Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.30%
Schwab VIT Growth Portfolio | Schwab U.S. REIT ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.00%
Schwab VIT Growth Portfolio | Schwab Emerging Markets Equity ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Schwab VIT Growth Portfolio | Schwab International Small-Cap Equity ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Schwab VIT Growth Portfolio | Schwab Government Money Fund, Ultra Shares [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.50%
Schwab VIT Growth Portfolio | Schwab U.S. Large-Cap ETF [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 39.50%
Schwab VIT Growth Portfolio | U.S. Stocks - Large-Cap [Member]  
Holdings [Line Items]  
Percent of Total Investments 39.80%
Schwab VIT Growth Portfolio | International Stocks - Developed Markets [Member]  
Holdings [Line Items]  
Percent of Total Investments 24.90%
Schwab VIT Growth Portfolio | Fixed Income - Intermediate-Term Bond [Member]  
Holdings [Line Items]  
Percent of Total Investments 14.10%
Schwab VIT Growth Portfolio | U.S. Stocks - Small-Cap [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.30%
Schwab VIT Growth Portfolio | Real Estate - U.S. REITs [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.00%
Schwab VIT Growth Portfolio | International Stocks - Emerging Markets [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.40%
Schwab VIT Growth Portfolio | Money Market Funds [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.50%
[1] Includes the fund’s position in money market mutual funds registered under the Investment Company Act of 1940, as amended.
[2] Less than 0.05%.
[3] Excludes derivatives.