Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating activities:
Net income (loss)	$ 40,118	$ (41,722)
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Realized loss on sales of investments, net	0	23,315
Unrealized loss (gain) on investments, net	70,024	(57,120)
(Gain) loss on derivative instruments, net	(124,635)	67,267
Amortization of investment premiums, net	14,059	19,642
Other amortization and depreciation, net	501	585
Share-based compensation expense	4,270	1,010
Decrease (increase) in accrued interest receivable	828	(1,974)
Decrease in accrued interest payable	(17,522)	(3,644)
Change in other assets and liabilities, net	(4,747)	(3,622)
Net cash (used in) provided by operating activities	(17,104)	3,737
Investing activities:
Purchases of investments	0	(310,352)
Principal payments received on trading securities	78,131	30,233
Principal payments received on available-for-sale investments	18,874	22,318
Principal payments received on mortgage loans held for investment	307	279
Net receipts (payments) on derivatives, including terminations	172,784	(101,425)
(Decrease) increase in cash collateral posted by counterparties	(37,494)	26,690
Net cash provided by (used in) investing activities	232,602	(332,257)
Financing activities:
Borrowings under repurchase agreements	12,273,321	5,428,877
Repayments of repurchase agreement borrowings	(12,369,717)	(5,136,158)
Proceeds from issuance of common stock	86,806	2,771
Payments related to tax withholding for share-based compensation	(527)	(276)
Dividends paid	(24,916)	(22,949)
Net cash (used in) provided by financing activities	(35,033)	272,265
Net increase (decrease) in cash, including cash posted to counterparties	180,465	(56,255)
Cash including cash posted to counterparties at beginning of period	237,864	449,877
Cash including cash posted to counterparties at end of period	418,329	393,622
Supplemental Disclosure of Cash Activity:
Cash paid for interest	$ 92,239	$ 34,952