Accumulated Other Comprehensive Income - Schedule of Components of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
AOCI [Roll Forward]
Beginning Balance	$ 3,336,728	$ 3,566,498	$ 3,736,191	$ 3,779,386
OCI before reclassifications			(99,324)	(64,867)
Amounts reclassified from AOCI			0	(37,116)
Other comprehensive income (loss)	(58,369)	(37,538)	(99,324)	(101,983)
Ending Balance	2,972,999	3,627,431	2,972,999	3,627,431
Unrealized gains (losses) on available-for-sale securities, net
AOCI [Roll Forward]
Beginning Balance			405,054	558,096
OCI before reclassifications			(99,324)	(64,867)
Amounts reclassified from AOCI			0	(37,116)
Other comprehensive income (loss)			(99,324)	(101,983)
Ending Balance	305,730	456,113	305,730	456,113
Total Accumulated OCI Balance
AOCI [Roll Forward]
Beginning Balance	364,099	493,651	405,054	558,096
Other comprehensive income (loss)	(58,369)	(37,538)	(99,324)	(101,983)
Ending Balance	$ 305,730	$ 456,113	$ 305,730	$ 456,113