Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
AOCI Attributable to Parent, Net of Tax
Balance, beginning	$ 2,843,305	$ 3,177,622
Other comprehensive (loss) income before reclassifications	57,863	(274,077)
Total other comprehensive income (loss), net of tax	58,564	(275,168)
Balance, ending	2,926,904	2,934,193
(Losses) Gains on Available-For-Sale and Transferred Debt Securities
AOCI Attributable to Parent, Net of Tax
Balance, beginning	(474,338)	27,038
Other comprehensive (loss) income before reclassifications	57,890	(276,295)
Total other comprehensive income (loss), net of tax	59,319	(277,386)
Balance, ending	(415,019)	(250,348)
(Losses) Gains on Derivatives Used for Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax
Balance, beginning	5,546	321
Other comprehensive (loss) income before reclassifications	(27)	2,218
Total other comprehensive income (loss), net of tax	(755)	2,218
Balance, ending	4,791	2,539
Reclassification adjustments for gains and transfers included in net income
AOCI Attributable to Parent, Net of Tax
Reclassification adjustments for gains and transfers included in net income	(704)	(507)
Reclassification adjustments for gains and transfers included in net income, debt securities
AOCI Attributable to Parent, Net of Tax
Reclassification adjustments for gains and transfers included in net income	24	(507)
Reclassification adjustments for gains and transfers included in net income, cash flow hedges
AOCI Attributable to Parent, Net of Tax
Reclassification adjustments for gains and transfers included in net income	(728)	0
Reclassification adjustments for amortization included in net income for transferred securities
AOCI Attributable to Parent, Net of Tax
Reclassification adjustments for gains and transfers included in net income	1,405	(584)
Accumulated Other Compre- hensive (Loss) Income
AOCI Attributable to Parent, Net of Tax
Balance, beginning	(468,792)	27,359
Total other comprehensive income (loss), net of tax	58,564	(275,168)
Balance, ending	$ (410,228)	$ (247,809)