Retirement Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jan. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Weighted-average expected long-term rate of return			5.50%
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	1,441	1,166	4,198	3,498
Expected return on plan assets	(3,669)	(3,595)	(11,006)	(10,786)
Amortization of actuarial loss (gain)	821	1,019	1,667	3,058
Net periodic benefit (income) cost	(1,407)	(1,410)	(5,141)	(4,230)
Pension Plan | Sterling
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations assumed					$ 30,500
SERP
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	17	7	49	20
Expected return on plan assets	0	0	0	0
Amortization of actuarial loss (gain)	7	8	20	25
Net periodic benefit (income) cost	24	15	69	45
OPEB
Defined Benefit Plan Disclosure [Line Items]
Service cost	9	0	24	0
Interest cost	194	4	551	12
Expected return on plan assets	0	0	0	0
Amortization of actuarial loss (gain)	7	(20)	(30)	(60)
Net periodic benefit (income) cost	$ 210	$ (16)	$ 545	$ (48)