S000010793 [Member] Average Annual Total Returns	12 Months Ended	15 Months Ended	60 Months Ended	120 Months Ended	158 Months Ended	239 Months Ended	284 Months Ended
S000010793 [Member] Average Annual Total Returns	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025
Russell 2000® Value Index (reflects no deductions for fees, expenses or taxes)
Prospectus [Line Items]
Average Annual Return, Percent	12.59%		8.88%	9.27%
Russell 3000® Index (reflects no deductions for fees, expenses or taxes)
Prospectus [Line Items]
Average Annual Return, Percent	17.15%		13.15%	14.29%
C000122580 [Member]
Prospectus [Line Items]
Average Annual Return, Percent	8.41%		9.98%	9.35%
Performance Inception Date					Nov. 08, 2012
C000029858 [Member]
Prospectus [Line Items]
Average Annual Return, Percent	7.65%		9.22%	8.59%
Performance Inception Date						Jan. 23, 2006
C000253705 [Member]
Prospectus [Line Items]
Average Annual Return, Percent	8.25%		9.57%	8.90%
Performance Inception Date		Oct. 02, 2024
C000029855 [Member]
Prospectus [Line Items]
Average Annual Return, Percent	1.72%		8.21%	8.22%
Performance Inception Date							May 01, 2002
C000029855 [Member] \| After Taxes on Distributions
Prospectus [Line Items]
Average Annual Return, Percent	(2.09%)		4.66%	5.66%
Performance Inception Date							May 01, 2002
C000029855 [Member] \| After Taxes on Distributions and Sales
Prospectus [Line Items]
Average Annual Return, Percent	3.20%		5.98%	6.17%
Performance Inception Date							May 01, 2002
C000029859 [Member]
Prospectus [Line Items]
Average Annual Return, Percent	8.24%		9.78%	9.14%
Performance Inception Date							May 01, 2002
C000122579 [Member]
Prospectus [Line Items]
Average Annual Return, Percent	8.36%		9.93%	9.30%
Performance Inception Date					Nov. 08, 2012