Employee Benefits - Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	$ 229,701	$ 283,940
Fixed maturity securities - corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	18,102	21,683
Redeemable preferred stock
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	2,946	4,633
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	134,663	178,766
Core plus bond separate account fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	16,768	23,916
U.S. property separate account fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	28,468	27,328
Arbitrage fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	10,831	10,588
United Life annuity
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	12,567	11,968
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	5,356	5,058
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	229,701	283,940	$ 248,735
Pension Benefits | U.S. property separate account fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	28,468	27,328	$ 22,269
Recurring | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	217,126	271,967
Recurring | Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	142,957	188,452
Recurring | Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	45,701	56,187
Recurring | Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	28,468	27,328
Recurring | Pension Benefits | Fixed maturity securities - corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	18,102	21,683
Recurring | Pension Benefits | Fixed maturity securities - corporate bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	0
Recurring | Pension Benefits | Fixed maturity securities - corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	18,102	21,683
Recurring | Pension Benefits | Fixed maturity securities - 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	4,633
Recurring | Pension Benefits | Redeemable preferred stock | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	2,946	4,633
Recurring | Pension Benefits | Redeemable preferred stock | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	0
Recurring | Pension Benefits | Redeemable preferred stock | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	0
Recurring | Pension Benefits | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	134,663	178,766
Recurring | Pension Benefits | Equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	134,663	178,766
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 | Core plus bond separate account fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	16,768	23,916
Recurring | Pension Benefits | Core plus bond separate account fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	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	23,916
Recurring | Pension Benefits | Core plus bond separate account fund | 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	28,468	27,328
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	0	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	27,328
Recurring | Pension Benefits | Arbitrage fund
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	10,831	10,588
Recurring | Pension Benefits | Arbitrage fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	0
Recurring | Pension Benefits | Arbitrage fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	10,831	10,588
Recurring | Pension Benefits | Arbitrage fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	0	0
Recurring | Pension Benefits | Money market funds
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	5,348	5,053
Recurring | Pension Benefits | Money market funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets measured at fair value	5,348	5,053
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