State Street Total Return VIS Fund Average Annual Total Returns	12 Months Ended	60 Months Ended	120 Months Ended
	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025
S&P 500 Index (reflects no deduction for fees, expenses or taxes)[Member]
Prospectus [Line Items]
Average Annual Return, Percent	17.88%	14.42%	14.82%
Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)[Member]
Prospectus [Line Items]
Average Annual Return, Percent	7.30%	(0.36%)	2.01%
Class 1 [Member] \| S&P 500 Index (reflects no deduction for fees, expenses or taxes)[Member]
Prospectus [Line Items]
Average Annual Return, Percent	17.88%	14.42%	14.82%
Class 1 [Member] \| MSCI ACWI ex USA Index (reflects no deduction for fees, expenses or taxes other than withholding taxes on reinvested dividends)[Member]
Prospectus [Line Items]
Average Annual Return, Percent	32.39%	7.91%	8.42%
Class 1 [Member] \| Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)[Member]
Prospectus [Line Items]
Average Annual Return, Percent	7.30%	(0.36%)	2.01%
Class 1 [Member] \| Class 1
Prospectus [Line Items]
Average Annual Return, Percent	15.86%	7.12%	7.19%