Consolidated Statement Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011
INCREASE IN CASH AND CASH EQUIVALENTS:
NET INCREASE IN SHAREHOLDERS' EQUITY RESULTING FROM OPERATINGS	$ 72,360		$ 8,626
Reconciliation of the net increase in shareholders' equity resulting from operations to net cash provided by (used in) operating activities:
Change in net unrealized (gain) loss on investments and financial derivatives	(69,972)		40,685
Net realized (gain) loss on investments and financial derivatives	18,126		(15,662)
Amortization of premiums and accretion of discounts (net)	(8,904)		(7,857)
Purchase of investments	(1,763,718)		(2,695,989)
Proceeds from disposition of investments	1,802,659		2,582,023
Proceeds from principal payments of investments	103,733		75,595
Proceeds from investments sold short	576,851		980,116
Repurchase of investments sold short	(600,777)		(1,226,418)
Payments made to open financial derivatives	(78,043)		(119,933)
Proceeds received to close financial derivatives	111,235		224,232
Proceeds received to open financial derivatives	40,248		25,878
Payments made to close financial derivatives	(53,439)		(27,540)
Shares issued in connection with incentive fee payment	231		203
Share-based LTIP expense	89		116
(Increase) decrease in assets:
Decrease in repurchase agreements	1,970		7,649
(Increase) decrease in receivable for securities sold	9,175		(91,287)
(Increase) decrease in deposits with dealers held as collateral	8,969		(16,275)
Increase in interest and principal receivable	(460)		(1,689)
Increase in other assets	(229)		(157)
Increase (decrease) in liabilities:
Decrease in due to brokers on margin accounts	(45,171)		(74,345)
Increase in payable for securities purchased	50,936		269,450
Decrease in accounts payable and accrued expenses	(313)		(204)
Increase (decrease) in incentive fee payable	9,491		(1,422)
Increase (decrease) in interest and dividends payable	(261)		88
Increase (decrease) in base management fee payable	517		(107)
Net cash provided by (used in) operating activities	185,303		(64,224)
Cash flows provided by (used in) financing activities:
Net proceeds from issuance of shares	88,142	[1]	0	[1]
Shares repurchased	0		(309)
Offering costs paid	(280)		(469)
Dividends paid	(32,766)		(35,634)
Proceeds from issuance of securitized debt	1,522		0
Principal payments on securitized debt	(158)		0
Reverse repurchase agreements, net of repayments	(235,277)		106,456
Net cash provided by (used in) financing activities	(178,817)		70,044
NET INCREASE IN CASH AND CASH EQUIVALENTS	6,486		5,820
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	62,737		35,791
CASH AND CASH EQUIVALENTS, END OF PERIOD	69,223		41,611
Supplemental disclosure of cash flow information:
Interest paid	6,009		4,714
Shares issued in connection with incentive fee payment (non-cash)	231		203
Share-based LTIP awards (non-cash)	89		116
Aggregate TBA trade activity (buys + sells) (non-cash)	$ 11,882,119		$ 16,291,487

[1] Proceeds from the issuance of shares are net of placement fees in the amount of $1,852.