Pension Plans and Other Postretirement Benefits Financial Assets Accounted for at Fair Value on Recurring Basis (Details) - Pension Plans - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 700,247	$ 683,469
Quoted Prices in Active Markets for Identical Items (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	522,870	527,104
Quoted Prices in Active Markets for Identical Items (Level 1) | Domestic Equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	129,139	140,548
Quoted Prices in Active Markets for Identical Items (Level 1) | International Equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	103,554	113,174
Quoted Prices in Active Markets for Identical Items (Level 1) | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	290,177	270,589
Quoted Prices in Active Markets for Identical Items (Level 1) | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		2,793
Quoted Prices in Active Markets for Similar Items (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	81,064	77,578
Quoted Prices in Active Markets for Similar Items (Level 2) | Domestic Equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	807	1,732
Quoted Prices in Active Markets for Similar Items (Level 2) | International Equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	24,799	26,437
Quoted Prices in Active Markets for Similar Items (Level 2) | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	55,458	49,409
Quoted Prices in Active Markets for Similar Items (Level 2) | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Unobservable Inputs (Level 3) | Domestic Equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Unobservable Inputs (Level 3) | International Equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Unobservable Inputs (Level 3) | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Unobservable Inputs (Level 3) | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Absolute Return Measured at Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	96,313	78,787
Fair Value, Inputs, Level 1, 2 and 3 | Domestic Equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	129,946	142,280
Fair Value, Inputs, Level 1, 2 and 3 | International Equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	128,353	139,611
Fair Value, Inputs, Level 1, 2 and 3 | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 345,635	319,998
Fair Value, Inputs, Level 1, 2 and 3 | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 2,793