CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net income	$ 19,420	$ 22,701
Noncash items:
Amortization of investment premiums	25,620	30,385
Amortization of equity-based awards	415	637
Other depreciation and amortization	26	29
Change in recorded measureable hedge ineffectiveness on interest rate swap agreements designated as cash flow hedges		182
Net change in receivables, other assets, accounts payable and accrued expenses	1,290	(2,453)
Net cash provided by operating activities	46,771	51,481
Investing activities:
Purchases of residential mortgage investments	(461,381)	(1,036,560)
Interest receivable acquired with the purchase of residential mortgage investments	(798)	(1,722)
Principal collections on residential mortgage investments, including changes in mortgage securities principal remittance receivable	812,524	933,699
Net cash provided by (used in) investing activities	350,345	(104,583)
Financing activities:
Proceeds from repurchase arrangements and similar borrowings	48,138,234	36,205,044
Principal payments on repurchase arrangements and similar borrowings	(48,524,450)	(36,062,662)
Decrease (increase) in cash collateral receivable from interest rate swap counterparties	5,920	(15,265)
Net proceeds from interest rate swap settlements	21,324	20,070
Proceeds from issuance of preferred shares		299
Common stock repurchases	(29,062)
Other capital stock transactions	(72)	(261)
Dividends paid	(23,002)	(26,217)
Net cash (used in) provided by financing activities	(411,108)	121,008
Net change in cash and cash equivalents	(13,992)	67,906
Cash and cash equivalents at beginning of period	103,907	56,732
Cash and cash equivalents at end of period	$ 89,915	$ 124,638