Retirement Benefit Plans - Summary of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 0
Interest cost	5,565	4,663	6,511
Expected return on plan assets	(14,675)	(14,385)	(13,522)
Amortization of actuarial loss (gain)	2,224	4,102	4,027
Net periodic benefit cost (benefit)	(6,886)	(5,620)	(2,984)
SERP
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0
Interest cost	107	30	46
Expected return on plan assets	0	0	0
Amortization of actuarial loss (gain)	26	38	23
Net periodic benefit cost (benefit)	133	68	69
OPEB
Defined Benefit Plan Disclosure [Line Items]
Service cost	34	0	0
Interest cost	652	19	46
Expected return on plan assets	0	0	0
Amortization of actuarial loss (gain)	(40)	(38)	(74)
Net periodic benefit cost (benefit)	$ 646	$ (19)	$ (28)