Employee Benefit Plans - Schedule of Change in Benefit Obligation and Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Plan
Change in benefit obligation:
Benefit obligation, beginning balance	$ 312,440	$ 263,826
Acquired	0	0
Service cost	8,044	7,985	$ 6,494
Interest cost	7,317	7,608	8,569
Actuarial (gain) loss	(9,023)	40,281
Benefits paid	(8,362)	(7,260)
Benefit obligation, ending balance	310,416	312,440	263,826
Change in plan assets:
Fair value of plan assets, beginning balance	411,907	356,347
Actuarial return on plan assets	53,587	50,820
Employer contributions	35,000	12,000
Benefits paid	(8,362)	(7,260)
Fair value of plan assets, ending balance	492,132	411,907	356,347
Funded status at end of year	181,716	99,467
RIM Plan
Change in benefit obligation:
Benefit obligation, beginning balance	16,530	13,696
Acquired	0	0
Service cost	398	267	210
Interest cost	343	405	466
Actuarial (gain) loss	(1,292)	2,506
Benefits paid	(329)	(344)
Benefit obligation, ending balance	15,650	16,530	13,696
Change in plan assets:
Fair value of plan assets, beginning balance	0	0
Actuarial return on plan assets	0	0
Employer contributions	329	344
Benefits paid	(329)	(344)
Fair value of plan assets, ending balance	0	0	0
Funded status at end of year	(15,650)	(16,530)
Post-retirement Plan
Change in benefit obligation:
Benefit obligation, beginning balance	30,621	24,603
Acquired	0	0
Service cost	520	394	339
Interest cost	562	683	826
Actuarial (gain) loss	(4,805)	5,506
Benefits paid	(563)	(565)
Benefit obligation, ending balance	26,335	30,621	24,603
Change in plan assets:
Fair value of plan assets, beginning balance	0	0
Actuarial return on plan assets	0	0
Employer contributions	563	565
Benefits paid	(563)	(565)
Fair value of plan assets, ending balance	0	0	0
Funded status at end of year	(26,335)	(30,621)
Split-Dollar Life Insurance
Change in benefit obligation:
Benefit obligation, beginning balance	19,981	14,100
Acquired	0	1,981
Service cost	562	467	354
Interest cost	500	507	457
Actuarial (gain) loss	(903)	3,137
Benefits paid	0	(211)
Benefit obligation, ending balance	20,140	19,981	14,100
Change in plan assets:
Fair value of plan assets, beginning balance	0	0
Actuarial return on plan assets	0	0
Employer contributions	0	211
Benefits paid	0	(211)
Fair value of plan assets, ending balance	0	0	$ 0
Funded status at end of year	$ (20,140)	$ (19,981)