S000010796 [Member] Average Annual Total Returns	12 Months Ended	60 Months Ended	120 Months Ended	239 Months Ended	351 Months Ended
S000010796 [Member] Average Annual Total Returns	Jan. 31, 2026	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025
S000010796 New Blended Benchmark [Member]
Prospectus [Line Items]
Average Annual Return, Percent	12.65%	4.50%	6.44%
S000010796 Bloomberg US Aggregate Bond Index [Member]
Prospectus [Line Items]
Average Annual Return, Percent	7.30%	(0.36%)	2.01%
S000010796 Russell 3000 Index [Member]
Prospectus [Line Items]
Average Annual Return, Percent	17.15%	13.15%	14.29%
S000010796 Former Blended Benchmark [Member]
Prospectus [Line Items]
Average Annual Return, Percent	11.86%	4.43%	6.11%
C000029869 [Member]
Prospectus [Line Items]
Average Annual Return, Percent	6.27%	3.02%	4.90%
Performance Inception Date					Oct. 15, 1996
C000029869 [Member] \| After Taxes on Distributions
Prospectus [Line Items]
Average Annual Return, Percent	4.87%	1.39%	3.34%
Performance Inception Date					Oct. 15, 1996
C000029869 [Member] \| After Taxes on Distributions and Sales
Prospectus [Line Items]
Average Annual Return, Percent	3.90%	1.81%	3.34%
Performance Inception Date					Oct. 15, 1996
C000029871 [Member]
Prospectus [Line Items]
Average Annual Return, Percent	11.00%	3.47%	4.73%
Performance Inception Date					Oct. 15, 1996
C000029872 [Member]
Prospectus [Line Items]
Average Annual Return, Percent	12.49%	3.99%	5.26%
Performance Inception Date				Jan. 23, 2006
C000029873 [Member]
Prospectus [Line Items]
Average Annual Return, Percent	13.16%	4.52%	5.79%
Performance Inception Date					Oct. 15, 1996