Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
AOCI Attributable to Parent, Net of Tax
Balance, beginning	$ 2,934,193	$ 2,295,385	$ 3,177,622	$ 2,307,041
Other comprehensive (loss) income before reclassifications			(354,300)	(51,728)
Total other comprehensive (loss) income, net of tax	(79,403)	10,522	(354,571)	(52,648)
Balance, ending	2,896,239	2,353,955	2,896,239	2,353,955
Gains (Losses) on Available-For-Sale and Transferred Debt Securities
AOCI Attributable to Parent, Net of Tax
Balance, beginning			27,038	143,443
Other comprehensive (loss) income before reclassifications			(357,192)	(52,064)
Total other comprehensive (loss) income, net of tax			(357,462)	(52,984)
Balance, ending	(330,424)	90,459	(330,424)	90,459
(Losses) Gains on Derivatives Used for Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax
Balance, beginning			321	(353)
Other comprehensive (loss) income before reclassifications			2,892	336
Total other comprehensive (loss) income, net of tax			2,891	336
Balance, ending	3,212	(17)	3,212	(17)
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			(573)	(278)
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			(572)	(278)
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			(1)	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			302	(642)
Accumulated Other Compre- hensive Income (loss)
AOCI Attributable to Parent, Net of Tax
Balance, beginning	(247,809)	79,920	27,359	143,090
Total other comprehensive (loss) income, net of tax	(79,403)	10,522	(354,571)	(52,648)
Balance, ending	$ (327,212)	$ 90,442	$ (327,212)	$ 90,442