Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities:
Net income (loss)	$ 74,170	$ 96,359
Unrealized Gain (Loss) on Derivatives and Commodity Contracts	(54,861)	204,130
Adjustments to reconcile net income to cash provided by operating activities:
Realized gain on sale of investments, net	(6,705)	(277,882)
Unrealized (gain) loss on investments, net	(104)	40
Amortization of investment premiums, net	60,123	63,789
Other amortization and depreciation, net	1,106	959
Share-based compensation expense	995	731
Decrease in accrued interest receivable	332	9,589
Decrease in accrued interest payable	(1,005)	(14,678)
Change in other assets and liabilities, net	(6,197)	432
Net cash provided by operating activities	67,854	83,469
Investing activities:
Purchase of investments	(1,052,490)	(2,818,863)
Principal payments received on investments	223,706	249,766
Proceeds from sales of investments	474,657	4,226,321
Principal payments received on mortgage loans held for investment	1,171	1,519
Net receipts (payments) on derivatives, including terminations	425,889	(210,712)
Increase (Decrease) Cash Collateral from Counterparties	1,645	394
Net cash provided by investing activities	74,578	1,448,425
Financing activities:
Borrowings under repurchase agreements	7,955,673	23,686,649
Repayments of repurchase agreement borrowings	(8,071,793)	(25,124,006)
Principal payments on non-recourse collateralized financing	(118)	(1,467)
Proceeds from issuance of preferred stock	0	107,988
Proceeds from issuance of common stock	196,452	0
Payments for Repurchase of Redeemable Preferred Stock	(69,708)	(100,000)
Cash paid for stock issuance costs	(313)	0
Payments for Repurchase of Common Stock	0	372
Payments related to tax withholding for share-based compensation	(853)	(235)
Dividends paid	(27,409)	(27,894)
Net cash used in financing activities	(18,069)	(1,459,337)
Net increase in cash including cash posted to counterparties	124,363	72,557
Cash including cash posted to counterparties at beginning of period	310,360	134,230
Cash including cash posted to counterparties at end of period	434,723	206,787
Supplemental Disclosure of Cash Activity:
Cash paid for interest	$ 3,906	$ 41,613