Accumulated Other Comprehensive Income (Loss) - Components of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 5,984,612	$ 5,837,218
Other comprehensive income (loss)	85,635	(304,544)
Ending balance	6,309,331	5,703,456
Debt Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(694,815)	(85,703)
Net unrealized (losses) gains arising during the period	44,275	(281,361)
Amounts reclassified from AOCI	9,806	1,411
Other comprehensive income (loss)	54,081	(279,950)
Ending balance	(640,734)	(365,653)
Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(49,531)	257
Net unrealized (losses) gains arising during the period	21,086	(23,227)
Amounts reclassified from AOCI	7,527	(1,496)
Other comprehensive income (loss)	28,613	(24,723)
Ending balance	(20,918)	(24,466)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(21,283)	(4,935)
Net unrealized (losses) gains arising during the period	2,941	129
Amounts reclassified from AOCI	0	0
Other comprehensive income (loss)	2,941	129
Ending balance	(18,342)	(4,806)
AOCI, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(765,629)	(90,381)
Net unrealized (losses) gains arising during the period	68,302	(304,459)
Amounts reclassified from AOCI	17,333	(85)
Other comprehensive income (loss)	85,635	(304,544)
Ending balance	$ (679,994)	$ (394,925)