Qualified Employee Benefit Plans - Valuation of our Retirement Plan Assets by Pricing Observability Levels (Details) - Retirement Plan - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	$ 95,990	$ 130,939	$ 125,022
Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	78,923	108,466
Level 1
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	40,592	76,111
Level 2
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	38,331	32,355
Level 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	0	0
NAV Expedient
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	17,067	22,473
Cash | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	1,441	47
Cash | Level 1
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	1,441	47
Cash | Level 2
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	0	0
Cash | Level 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	0	0
U.S. Treasury Strips | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	15,634	32,355
U.S. Treasury Strips | Level 1
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	0	0
U.S. Treasury Strips | Level 2
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	15,634	32,355
U.S. Treasury Strips | Level 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	0	0
Fixed income mutual funds | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	2,149	17,477
Fixed income mutual funds | Level 1
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	2,149	17,477
Fixed income mutual funds | Level 2
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	0	0
Fixed income mutual funds | Level 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	0	0
Fixed income securities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	22,478
Fixed income securities | Level 1
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	0
Fixed income securities | Level 2
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	22,478
Fixed income securities | Level 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	0
Equity mutual funds | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	26,074	43,786
Equity mutual funds | Level 1
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	26,074	43,786
Equity mutual funds | Level 2
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	0	0
Equity mutual funds | Level 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	0	0
Equity securities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	11,147	14,801
Equity securities | Level 1
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	10,928	14,801
Equity securities | Level 2
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	219	0
Equity securities | Level 3
Defined Benefit Plan, Assets [Abstract]
Total assets measured at fair value	$ 0	$ 0