CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Cash Flows From Operating Activities:
Net income	$ 82,173	$ 76,188
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sales of MBS	(6,435)	(3,571)
Other-than-temporary impairment charges	407	0
Accretion of purchase discounts on MBS and CRT securities and residential whole loans	(25,254)	(27,434)
Amortization of purchase premiums on MBS	9,122	10,215
Depreciation and amortization on real estate, fixed assets and other assets	115	327
Equity-based compensation expense	912	1,484
Unrealized gain on residential whole loans at fair value	(602)	0
Unrealized gains on derivative instruments	0	(2,076)
Increase in interest receivable	(364)	(863)
Increase in prepaid and other assets	(12,939)	(9,644)
Decrease in accrued expenses and other liabilities, and excise tax and interest	(5,365)	(3,745)
Increase in accrued interest payable on financial instruments	10,058	7,384
Net cash provided by operating activities	51,828	48,265
Cash Flows From Investing Activities:
Principal payments on MBS and CRT securities	588,088	438,149
Proceeds from sale of MBS	10,845	15,501
Purchases of MBS and CRT securities	(518,127)	(888,106)
Purchases of residential whole loans	(40,168)	0
Principal payments on residential whole loans	6,260	0
Additions to leasehold improvements, furniture and fixtures	(158)	(85)
Net cash provided by/(used in) investing activities	46,740	(434,541)
Cash Flows From Financing Activities:
Principal payments on repurchase agreements	(25,536,927)	(20,203,589)
Proceeds from borrowings under repurchase agreements	25,559,532	20,470,421
Principal payments on securitized debt	(19,186)	(73,262)
Cash disbursements on financial instruments underlying Linked Transactions	0	(374,073)
Cash received from financial instruments underlying Linked Transactions	0	344,504
Payments made for margin calls on repurchase agreements and Swaps	(98,000)	(29,000)
Proceeds from reverse margin calls on repurchase agreements and Swaps	60,000	30,000
Proceeds from issuances of common stock	312	7,616
Dividends paid on preferred stock	(3,750)	(3,750)
Dividends paid on common stock and DERs	(74,269)	(73,289)
Net cash (used in)/provided by financing activities	(112,288)	95,578
Net decrease in cash and cash equivalents	(13,720)	(290,698)
Cash and cash equivalents at beginning of period	182,437	565,370
Cash and cash equivalents at end of period	168,717	274,672
Non-cash Investing and Financing Activities:
MBS and CRT securities recorded upon adoption of revised accounting standard for repurchase agreement financing	1,917,813	0
Repurchase agreements recorded upon adoption of revised accounting standard for repurchase agreement financing	1,519,593	0
Net increase in securities obtained as collateral/obligation to return securities obtained as collateral	20,990	47,768
Transfer from residential whole loans to real estate owned	3,448	0
Dividends and DERs declared and unpaid	$ 74,581	$ 73,875