Employee Benefits - Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	$ 263,906	$ 229,701
Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	166,063	18,102
Redeemable preferred stock
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	2,946
Liquid assets separate account fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	4,475	0
Core plus bond separate account fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	16,768
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	53,981	134,663
U.S. property separate account fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	25,407	28,468
Arbitrage fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	10,831
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	785	5,356
United Life annuity
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	13,195	12,567
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	263,906	229,701	$ 283,940
Pension Benefits | U.S. property separate account fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	25,407	28,468	$ 27,328
Recurring | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	250,698	217,126
Recurring | Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	54,753	142,957
Recurring | Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	195,945	45,701
Recurring | Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	28,468
Recurring | Pension Benefits | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	166,063	18,102
Recurring | Pension Benefits | Corporate bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	0
Recurring | Pension Benefits | Corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	166,063	18,102
Recurring | Pension Benefits | Corporate bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	0
Recurring | Pension Benefits | Redeemable preferred stock
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		2,946
Recurring | Pension Benefits | Redeemable preferred stock | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		2,946
Recurring | Pension Benefits | Redeemable preferred stock | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		0
Recurring | Pension Benefits | Redeemable preferred stock | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		0
Recurring | Pension Benefits | Liquid assets separate account fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	4,475
Recurring | Pension Benefits | Liquid assets separate account fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0
Recurring | Pension Benefits | Liquid assets separate account fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	4,475
Recurring | Pension Benefits | Liquid assets separate account fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0
Recurring | Pension Benefits | Core plus bond separate account fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		16,768
Recurring | Pension Benefits | Core plus bond separate account fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		0
Recurring | Pension Benefits | Core plus bond separate account fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		16,768
Recurring | Pension Benefits | Core plus bond separate account fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		0
Recurring | Pension Benefits | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	53,981	134,663
Recurring | Pension Benefits | Equity Securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	53,981	134,663
Recurring | Pension Benefits | Equity Securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	0
Recurring | Pension Benefits | Equity Securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	0
Recurring | Pension Benefits | U.S. property separate account fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	25,407	28,468
Recurring | Pension Benefits | U.S. property separate account fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	0
Recurring | Pension Benefits | U.S. property separate account fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	25,407	0
Recurring | Pension Benefits | U.S. property separate account fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		28,468
Recurring | Pension Benefits | Arbitrage fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		10,831
Recurring | Pension Benefits | Arbitrage fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		0
Recurring | Pension Benefits | Arbitrage fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		10,831
Recurring | Pension Benefits | Arbitrage fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value		0
Recurring | Pension Benefits | Money market funds
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	772	5,348
Recurring | Pension Benefits | Money market funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	772	5,348
Recurring | Pension Benefits | Money market funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	0
Recurring | Pension Benefits | Money market funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	$ 0	$ 0