Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating activities:
Net (loss) income	$ (30,435)	$ 99,872
Adjustments to reconcile net (loss) income to cash provided by operating activities:
Realized loss on sale of investments, net	74,916	89,517
Unrealized loss on investments, net	121,491	245,551
Gain on derivative instruments, net	(195,698)	(423,570)
Amortization of investment premiums, net	58,102	77,403
Other amortization and depreciation, net	1,739	1,709
Share-based compensation expense	3,600	4,031
Increase in accrued interest receivable	(11,496)	(1,906)
Increase in accrued interest payable	26,718	3,544
Change in other assets and liabilities, net	(3,308)	127
Net cash provided by operating activities	45,629	96,278
Investing activities:
Purchases of investments	(3,208,774)	(1,537,663)
Principal payments received on trading securities	70,155	87,136
Principal payments received on available-for-sale investments	152,339	195,855
Proceeds from sales of trading securities	348,091	327,700
Principal payments received on mortgage loans held for investment	701	1,163
Net receipts on derivatives, including terminations	209,209	656,172
Decrease (increase) in cash collateral posted by counterparties	24,192	(1,834)
Net cash used in investing activities	(2,404,087)	(271,471)
Financing activities:
Borrowings under repurchase agreements	16,345,414	12,735,123
Repayments of repurchase agreement borrowings	(13,987,589)	(12,575,770)
Proceeds from issuance of common stock	36,676	154,483
Payments related to tax withholding for share-based compensation	(446)	(1,346)
Dividends paid	(69,038)	(52,051)
Net cash provided by financing activities	2,325,017	260,439
Net (decrease) increase in cash including cash posted to counterparties	(33,441)	85,246
Cash including cash posted to counterparties at beginning of period	449,877	421,307
Cash including cash posted to counterparties at end of period	416,436	506,553
Supplemental Disclosure of Cash Activity:
Cash paid for interest	$ 115,266	$ 15,748