Accumulated Other Comprehensive Loss - Summary of Changes in Accumulated Other Comprehensive Loss by Component (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (22,234)
Transition adjustment	(1,062,442)		$ (1,088,105)
Transition adjustment	(20,392)		$ (29,080)
Ending balance	6,206
Interest Rate Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(9,363)	$ (27,819)
Gains arising during period	8,189	176
Amounts reclassified from accumulated other comprehensive loss	6,124	8,111
Net other comprehensive income (loss)	14,313	8,287
Ending balance	4,950	(19,532)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(16,419)	(26,623)
Gains arising during period	(6,437)	8,324
Amounts reclassified from accumulated other comprehensive loss	707	588
Net other comprehensive income (loss)	(5,730)	8,912
Ending balance	(22,149)	(17,711)
Accumulated Other-than-Temporary Impairment of Investment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(3,298)	(3,509)
Amounts reclassified from accumulated other comprehensive loss	105	105
Net other comprehensive income (loss)	105	105
Ending balance	(3,193)	(3,404)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(29,080)	(57,951)
Gains arising during period	1,752	8,500
Amounts reclassified from accumulated other comprehensive loss	6,936	8,804
Net other comprehensive income (loss)	8,688	17,304
Ending balance	$ (20,392)	$ (40,647)