Repurchase Agreements - Repurchase Agreements by Maturity Period (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Assets Sold under Agreements to Repurchase [Line Items]
Haircut percentage	3.32%	3.45%
Balance	$ 8,250,066	$ 3,948,037
Weighted Average Contractual Rate		0.12%
Weighted Average Maturity in days		29 days
Agency Securities
Assets Sold under Agreements to Repurchase [Line Items]
Balance	$ 8,250,066	$ 3,849,037
Weighted Average Contractual Rate	2.78%	0.13%
Weighted Average Maturity in days	14 days	29 days
Agency Securities | Within 30 days
Assets Sold under Agreements to Repurchase [Line Items]
Balance	$ 7,247,587	$ 2,565,743
Weighted Average Contractual Rate	2.72%	0.13%
Weighted Average Maturity in days	11 days	13 days
Agency Securities | 31 days to 60 days
Assets Sold under Agreements to Repurchase [Line Items]
Balance		$ 647,584
Weighted Average Contractual Rate		0.13%
Weighted Average Maturity in days		35 days
Agency Securities | 31 days to 90 days
Assets Sold under Agreements to Repurchase [Line Items]
Balance	$ 1,002,479
Weighted Average Contractual Rate	3.15%
Weighted Average Maturity in days	34 days
Agency Securities | 61 days to 90 days
Assets Sold under Agreements to Repurchase [Line Items]
Balance		$ 635,710
Weighted Average Contractual Rate		0.11%
Weighted Average Maturity in days		89 days
U.S. Treasury Securities | Within 30 days
Assets Sold under Agreements to Repurchase [Line Items]
Balance		$ 99,000
Weighted Average Contractual Rate		0.12%
Weighted Average Maturity in days		3 days