Other Comprehensive Income - Schedule of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 3,428,052	$ 1,600,153
Other comprehensive (loss) income before reclassifications	(73,997)	57,599
Less: Amounts reclassified from accumulated other comprehensive income	6,429	2,332
Net current-period other comprehensive income	(80,426)	55,267
Ending balance	3,387,045	1,662,734
Accumulated Other Comprehensive Income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	54,234	(43,847)
Ending balance	(26,192)	11,420
Defined Benefit Pension Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(21,253)	(81,269)
Other comprehensive (loss) income before reclassifications	0	0
Less: Amounts reclassified from accumulated other comprehensive income	(426)	0
Net current-period other comprehensive income	426	0
Ending balance	(20,827)	(81,269)
Unrealized Gains and (Losses) on Cash Flow Hedges \| Unrealized Gains and (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	29,815	15,624
Other comprehensive (loss) income before reclassifications	0	31,312
Less: Amounts reclassified from accumulated other comprehensive income	5,948	2,237
Net current-period other comprehensive income	(5,948)	29,075
Ending balance	23,867	44,699
Unrealized Gains and (Losses) on Available for Sale Securities \| Unrealized Gains and (Losses) on Available for Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	45,672	21,798
Other comprehensive (loss) income before reclassifications	(73,997)	26,287
Less: Amounts reclassified from accumulated other comprehensive income	907	95
Net current-period other comprehensive income	(74,904)	26,192
Ending balance	$ (29,232)	$ 47,990

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount before tax and reclassification adjustments of other comprehensive income (loss) attributable to parent.

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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