Retirement Benefit Plans - Schedule of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 5	$ 4
Interest cost	553	689
Expected return on plan assets	(1,581)	(1,452)
Amortization of net (gain)/loss	542	508
Net periodic benefit cost	(481)	(251)
Supplemental Employee Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	369	305
Interest cost	205	236
Amortization of prior service cost	413	317
Amortization of net (gain)/loss	318	158
Recognition of settlement	0	188
Net periodic benefit cost	$ 1,305	$ 1,204