Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Operating activities
Net income	$ 4,321	$ 137,978
Adjustments to reconcile net income to net cash provided by operating activities:
Net amortization of premium related to mortgage-backed securities	46,961	92,058
Reclassification of deferred swap loss	47,607
Amortization related to interest rate swap agreements	130	163
Share based compensation expense	1,702	1,256
Hedge ineffectiveness		(96)
Net gain on sale of mortgage-backed securities	(2,852)	(11,302)
Net (gain) loss on derivative instruments	96,875	(5,536)
Changes in operating assets and liabilities:
Decrease in accrued interest receivable	2,578	3,156
Increase in other assets	(1,182)	(730)
Decrease in accrued interest payable	(5,131)	(2,819)
Increase (decrease) in accounts payable and other liabilities	(186)	1,122
Net cash provided by operating activities	190,823	215,250
Investing activities
Purchases of mortgage-backed securities	(2,144,633)	(6,029,805)
Principal repayments on mortgage-backed securities	1,561,297	3,180,421
Sales of mortgage-backed securities	1,699,029	2,361,380
Net payments on derivative instruments	(34,380)
Purchase of equity investment	(6,000)
Purchase of broker/dealer	(1,349)
Net cash provided by (used in) investing activities	1,073,964	(488,004)
Financing activities
Repurchase of common stock	(1,912)
Cash dividends paid	(107,519)	(149,317)
Proceeds from repurchase agreements	83,196,430	126,103,804
Principal repayments on repurchase agreements	(84,306,233)	(125,892,981)
Proceeds from dollar roll liability	241,121
Repayments on dollar roll liability	(592,947)
(Increase) decrease in restricted cash margin on derivatives	(79,703)	131,811
Net cash provided by (used in) financing activities	(1,650,763)	193,317
Net decrease in cash and cash equivalents	(385,976)	(79,437)
Cash and cash equivalents, beginning of period	763,326	168,424
Cash and cash equivalents, end of period	377,350	88,987
Supplemental disclosure of cash flow information
Cash paid during the period for interest	90,139	108,123
Supplemental schedule of non-cash investing and financing activities
Obligation to brokers for purchase of unsettled mortgage-backed securities	59,811	1,042,436
Receivable for securities sold	152,177	7,251
Dividend payable	52,886
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	$ 48,258	$ 69,181