CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash Flows From Operating Activities:
Net income	$ 152,824	$ 159,479
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sales of MBS and U.S. Treasury securities	(5,998)	(2,953)
Other-than-temporary impairment charges	0	1,200
Accretion of purchase discounts on MBS	(28,762)	(19,322)
Amortization of purchase premiums on MBS	31,301	23,302
Depreciation and amortization on fixed assets and other assets	2,160	1,322
Equity-based compensation expense	2,186	2,581
Unrealized gains and other on Linked Transactions	(466)	(6,145)
Decrease/(increase) in interest receivable	3,142	(939)
(Increase)/decrease in prepaid and other assets	(12,088)	251
Increase/(decrease) in accrued expenses and other liabilities, and excise tax and interest	1,720	(2,332)
(Decrease)/increase in accrued interest payable on financial instruments	(4,773)	4,290
Net cash provided by operating activities	141,246	160,734
Cash Flows From Investing Activities:
Principal payments on MBS	1,483,476	1,222,662
Proceeds from sale of MBS and U.S. Treasury securities	216,079	71,103
Purchases of MBS	(1,251,726)	(1,603,202)
Additions to leasehold improvements, furniture and fixtures	(135)	(301)
Net cash provided by/(used in) investing activities	447,694	(309,738)
Cash Flows From Financing Activities:
Principal payments on repurchase agreements	(39,284,004)	(31,191,396)
Proceeds from borrowings under repurchase agreements	39,440,815	31,746,644
Proceeds from issuance of securitized debt	0	186,691
Principal payments on securitized debt	(203,068)	(200,956)
Payments made on obligation to return securities obtained as collateral	(300,119)	0
Payments made for resecuritization related costs	0	(1,814)
Proceeds from issuance of Senior Notes	0	100,000
Payments made for Senior Notes related costs	0	(3,415)
Cash disbursements on financial instruments underlying Linked Transactions	(114,903)	(439,243)
Cash received from financial instruments underlying Linked Transactions	117,554	328,515
Payments made for margin calls on repurchase agreements and interest rate swaps (“Swaps”)	(3)	(2,390)
Proceeds from reverse margin calls on repurchase agreements and Swaps	2,000	8,890
Proceeds from issuances of common stock	40,398	3,795
Payments made for redemption of Series A Preferred Stock	(96,000)	0
Proceeds from issuance of Series B Preferred Stock	200,000	0
Payments made for preferred stock offering costs	(6,684)	0
Dividends paid on preferred stock	(6,250)	(4,080)
Dividends paid on common stock and DERs	(331,687)	(182,883)
Net cash (used in)/provided by financing activities	(541,951)	348,358
Net increase in cash and cash equivalents	46,989	199,354
Cash and cash equivalents at beginning of period	401,293	394,022
Cash and cash equivalents at end of period	448,282	593,376
Non-cash Investing and Financing Activities:
MBS recorded upon de-linking of Linked Transactions	0	158,379
Net increase in securities obtained as collateral/obligation to return securities obtained as collateral	200,098	206,506
Dividends and DERs declared and unpaid	$ 80,440	$ 83,263