Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Operating activities
Net income	$ 82,212	$ (124,168)
Adjustments to reconcile net income to net cash provided by operating activities:
Net amortization of premium related to mortgage-backed securities	76,374	139,205
Reclassification of deferred swap loss	67,413
Amortization related to interest rate swap agreements	184	239
Share based compensation expense	2,592	1,893
Hedge ineffectiveness		(205)
Net (gain) loss on sale of mortgage-backed securities	(3,089)	214,333
Impairment loss on mortgage-backed securities		8,102
Net loss on derivative instruments	61,445	44,593
Changes in operating assets and liabilities:
Decrease in accrued interest receivable	2,399	14,192
Increase in other assets	(13,211)	(658)
Decrease in accrued interest payable	(5,438)	(3,691)
Increase (decrease) in accounts payable and other liabilities	(814)	842
Net cash provided by operating activities	270,067	294,677
Investing activities
Purchases of mortgage-backed securities	(3,541,220)	(8,521,002)
Principal repayments on mortgage-backed securities	2,559,882	4,823,759
Sales of mortgage-backed securities	1,942,004	8,027,113
Net payments on derivative instruments	(46,532)
Purchase of equity investment	(6,000)
Purchase of broker/dealer	(1,349)
Net cash provided by investing activities	906,785	4,329,870
Financing activities
Repurchase of common stock	(1,912)	(21,063)
Cash dividends paid	(161,258)	(223,978)
Proceeds from repurchase agreements	122,704,915	186,080,168
Principal repayments on repurchase agreements	(123,913,639)	(190,116,826)
Proceeds from dollar roll financing	241,121
Repayments on dollar roll financing	(592,947)
(Increase) decrease in restricted cash margin on derivatives	(1,385)	39,168
Payment on termination of interest rate swaps		(2,904)
Net cash used in financing activities	(1,725,105)	(4,245,435)
Net increase (decrease) in cash and cash equivalents	(548,253)	379,112
Cash and cash equivalents, beginning of period	763,326	168,424
Cash and cash equivalents, end of period	215,073	547,536
Supplemental disclosure of cash flow information
Cash paid during the period for interest	131,614	52,471
Supplemental schedule of non-cash investing and financing activities
Obligation to brokers for purchase of unsettled mortgage-backed securities	45,571	986,828
Receivable for securities sold		548,942
Dividend payable	52,988
Preferred Stock
Supplemental schedule of non-cash investing and financing activities
Dividend payable	4,628	4,628
Common Stock
Supplemental schedule of non-cash investing and financing activities
Dividend payable	$ 48,360	$ 53,850