CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities :
Net income	$ 27,353	$ 33,957
Noncash items:
Amortization of investment premiums	26,011	25,078
Amortization of equity-based awards	745	724
Other depreciation and amortization	32	33
Change in measurable hedge ineffectiveness related to interest rate swap agreements designated as cash flow hedges	393	185
Net change in receivables, other assets, accounts payable and accrued expenses	(5,740)	(1,131)
Net cash provided by operating activities	48,794	58,846
Investing activities:
Purchases of residential mortgage investments	(462,759)	(959,548)
Interest receivable acquired with the purchase of residential mortgage investments	(696)	(1,534)
Principal collections on residential mortgage investments, including changes in mortgage securities principal remittance receivable	768,187	703,688
Redemption of Federal Home Loan Bank stock	30,000	0
Net cash provided by (used in) investing activities	334,732	(257,394)
Financing activities:
Proceeds from repurchase arrangements and similar borrowings	29,191,066	29,887,321
Principal payments on repurchase arrangements and similar borrowings	(27,400,760)	(29,755,657)
Proceeds from other secured borrowings	1,175,000	0
Principal payments on other secured borrowings	(3,300,000)	0
Increase in cash collateral receivable from interest rate swap counterparties	(21,844)	(8,530)
Proceeds from issuance of preferred shares	200	10,651
Other capital stock transactions	(57)	(429)
Dividends paid	(29,262)	(36,719)
Net cash (used in) provided by financing activities	(385,657)	96,637
Net change in cash and cash equivalents	(2,131)	(101,911)
Cash and cash equivalents at beginning of period	54,185	307,526
Cash and cash equivalents at end of period	$ 52,054	$ 205,615