CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities:
Net (loss) income	$ (129,573)	$ (35,338)	$ 50,072
Adjustments to reconcile net (loss) income to cash provided by operating activities:
Amortization of investment premiums	77,560	73,740	115,333
Amortization of equity-based awards	3,234	2,724	1,783
Amortization of unrealized loss (gain) on de-designated hedges	529	(14,712)
Loss on sale of mortgage investments	67,820	1,365
Loss on derivative instruments (net)	142,483	112,834
Other depreciation and amortization	124	110	110
Net change in receivables, other assets, accounts payable and accrued expenses	(3,834)	14,331	(2,102)
Net cash provided by operating activities	158,343	155,054	165,196
Investing activities:
Purchases of residential mortgage investments	(3,173,342)	(3,316,158)	(2,302,656)
Proceeds from sales of residential mortgage investments	2,558,871	303,991
Interest receivable acquired with the purchase of residential mortgage investments	(5,024)	(6,422)	(4,476)
Principal collections on residential mortgage investments, including changes in mortgage securities principal remittance receivable	3,772,086	3,751,570	3,607,459
Redemption of lending counterparty investment		5,000
Net cash provided by investing activities	3,152,591	737,981	1,300,327
Financing activities:
Proceeds from repurchase arrangements and similar borrowings	82,969,163	138,721,910	173,854,358
Principal payments on repurchase arrangements and similar borrowings	(85,924,578)	(139,425,767)	(175,205,622)
(Increase) decrease in cash collateral receivable from interest rate swap counterparties	(8,934)	(33,680)	10,709
Net payments on interest rate swap settlements	(130,793)	(130,802)	(8,734)
Common stock repurchases			(84,594)
Issuance of common stock	12,882	75,195
Other capital stock transactions	(108)	(106)	(72)
Dividends paid	(76,783)	(54,677)	(75,186)
Net cash used in financing activities	(3,159,151)	(847,927)	(1,509,141)
Net change in cash and cash equivalents	151,783	45,108	(43,618)
Cash and cash equivalents at beginning of year	105,397	60,289	103,907
Cash and cash equivalents at end of year	$ 257,180	$ 105,397	$ 60,289