Other Comprehensive Income - Schedule of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 2,579,123	$ 3,008,392	$ 2,471,790	$ 3,406,352
Other comprehensive (loss) income before reclassifications			(50,539)	(599,294)
Less: Amounts reclassified from accumulated other comprehensive loss			(272,749)	5,173
Net current-period other comprehensive income (loss)			222,210	(604,467)
Ending balance	2,526,772	2,718,396	2,526,772	2,718,396
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(609,864)	(412,654)	(923,192)	(56,696)
Ending balance	(700,982)	(661,163)	(700,982)	(661,163)
Unrealized Gains and (Losses) on Available for Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			(880,156)	(58,586)
Other comprehensive (loss) income before reclassifications	(58,486)	(246,850)	(24,995)	(600,374)
Less: Amounts reclassified from accumulated other comprehensive loss	0	(75)	(258,540)	(1,574)
Net current-period other comprehensive income (loss)			233,545	(598,800)
Ending balance	(646,611)	(657,386)	(646,611)	(657,386)
Unrealized Gains and (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			(50,159)	7,361
Other comprehensive (loss) income before reclassifications	(40,832)	1,080	(25,544)	1,080
Less: Amounts reclassified from accumulated other comprehensive loss	(8,561)	2,691	(14,951)	6,500
Net current-period other comprehensive income (loss)			(10,593)	(5,420)
Ending balance	(60,752)	1,941	(60,752)	1,941
Defined Benefit Pension Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			7,123	(5,471)
Other comprehensive (loss) income before reclassifications			0	0
Less: Amounts reclassified from accumulated other comprehensive loss			742	247
Net current-period other comprehensive income (loss)			(742)	(247)
Ending balance	$ 6,381	$ (5,718)	$ 6,381	$ (5,718)