| Label | Element | Value |
|---|---|---|
| Class 2 | Mortgage-Backed Securities [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Total Investments | oef_PctOfTotalInv | 79.30% |
| Class 2 | U.S. Government and Agency Securities [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Total Investments | oef_PctOfTotalInv | 14.90% |
| Class 2 | Corporate Bonds [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Total Investments | oef_PctOfTotalInv | 1.90% |
| Class 2 | Short-Term Investments [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Total Investments | oef_PctOfTotalInv | 3.90% |