S000001578 [Member] Average Annual Total Returns	12 Months Ended	60 Months Ended	120 Months Ended
S000001578 [Member] Average Annual Total Returns	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025
Bloomberg U.S. Universal Index (reflects no deduction for fees, expenses or taxes)
Prospectus [Line Items]
Average Annual Return, Percent	7.58%	0.06%	2.44%
Conservative Strategy Linked Composite Index (reflects no deduction for fees, expenses or taxes)
Prospectus [Line Items]
Average Annual Return, Percent	9.99%	2.54%	4.51%
Class R5
Prospectus [Line Items]
Average Annual Return, Percent	8.93%	1.46%	2.91%
Class M
Prospectus [Line Items]
Average Annual Return, Percent	9.43%	1.82%	3.29%
Class A
Prospectus [Line Items]
Average Annual Return, Percent	2.97%	0.43%	2.47%
Class C
Prospectus [Line Items]
Average Annual Return, Percent	8.36%	0.88%	2.31%
Class S
Prospectus [Line Items]
Average Annual Return, Percent	9.43%	1.82%	3.29%
Class S \| After Taxes on Distributions
Prospectus [Line Items]
Average Annual Return, Percent	7.76%	0.56%	2.05%
Class S \| After Taxes on Distributions and Sales
Prospectus [Line Items]
Average Annual Return, Percent	5.66%	0.96%	2.12%
Class R1
Prospectus [Line Items]
Average Annual Return, Percent	9.55%	1.93%	3.42%