CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating activities:
Net income	$ 41,088	$ 57,002
Noncash items:
Amortization of investment premiums	88,293	98,996
Amortization of equity-based awards	1,477	1,671
Other depreciation and amortization	79	89
Change in recorded measureable hedge ineffectiveness on interest rate swap agreements designated as cash flow hedges		36
Net change in receivables, other assets, accounts payable and accrued expenses	6,461	1,877
Net cash provided by operating activities	137,398	159,671
Investing activities:
Purchases of residential mortgage investments	(2,158,970)	(3,380,199)
Interest receivable acquired with the purchase of residential mortgage investments	(4,167)	(5,410)
Principal collections on residential mortgage investments, including changes in mortgage securities principal remittance receivable	2,739,267	2,972,002
Net cash provided by (used in) investing activities	576,130	(413,607)
Financing activities:
Proceeds from repurchase arrangements and similar borrowings	137,810,441	126,991,975
Principal payments on repurchase arrangements and similar borrowings	(138,521,532)	(126,669,933)
Increase (decrease) in cash collateral receivable from interest rate swap counterparties	16,213	(17,590)
Net proceeds from interest rate swap settlements	10,906	8,842
Proceeds from issuance of preferred shares		52,051
Common stock repurchases	(41,313)
Other capital stock transactions	(72)	(261)
Dividends paid	(60,353)	(74,426)
Net cash (used in) provided by financing activities	(785,710)	290,658
Net change in cash and cash equivalents	(72,182)	36,722
Cash and cash equivalents at beginning of period	103,907	56,732
Cash and cash equivalents at end of period	$ 31,725	$ 93,454