Consolidated Statement Of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS:
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		$ (15,702)	$ 38,429	$ 59,949
Reconciliation of the net increase (decrease) in equity resulting from operations to net cash provided by (used in) operating activities:
Net realized (gain) loss on investments, financial derivatives, and foreign currency transactions		35,498	(23,454)	(6,008)
Change in net unrealized (gain) loss on investments and financial derivatives, and foreign currency translation		13,664	48,649	3,564
Amortization of premiums and accretion of discounts (net)		24,573	21,815	(9,131)
Purchase of investments		(2,246,552)	(3,381,699)	(5,298,446)
Proceeds from disposition of investments		2,032,219	3,570,304	4,755,862
Proceeds from principal payments of investments		276,880	284,166	186,094
Proceeds from investments sold short		1,430,898	1,461,459	1,606,561
Repurchase of investments sold short		(1,573,705)	(2,031,578)	(1,215,239)
Payments on financial derivatives	[1]	(354,814)	(505,956)	(191,469)
Proceeds from financial derivatives	[1]	394,038	416,103	173,013
Shares issued in connection with incentive fee payment		0	0	449
Share-based LTIP expense		400	393	267
Repurchase agreements		(79,119)	66,301	(144,039)
(Increase) decrease in assets:
Receivable for securities sold and financial derivatives		260,636	531,844	(354,587)
Due from brokers		47,954	5,360	(64,394)
Interest and principal receivable		(1,260)	167	(13,780)
Restricted cash		4,202	(4,857)	0
Other assets		1,910	(3,295)	(565)
Increase (decrease) in liabilities:
Due to brokers		(102,017)	92,573	2,462
Payable for securities purchased and financial derivatives		(80,197)	66,618	(94,300)
Accounts payable and accrued expenses		(299)	846	1,205
Incentive fee payable		0	0	(3,091)
Other liabilities		(811)	828	0
Interest and dividends payable		1,654	(580)	865
Base management fee payable		(357)	(190)	599
Net cash provided by (used in) operating activities		69,693	654,246	(604,159)
Cash flows provided by (used in) financing activities:
Proceeds from the issuance of shares		0	0	188,400
Contributions from non-controlling interests		5,552	2,153	1,793
Shares repurchased		(14,028)	(5,639)	0
Offering costs paid		0	(56)	(288)
Dividends paid		(65,148)	(83,460)	(86,449)
Distributions to non-controlling interests		(5,249)	(1,468)	(1,667)
Proceeds from issuance of securitized debt		40,921	0	0
Principal payments on securitized debt		(295)	(763)	(246)
Borrowings under reverse repurchase agreements		5,762,742	9,758,474	23,414,375
Repayments of reverse repurchase agreements		(5,854,823)	(10,253,718)	(22,981,108)
Net cash provided by (used in) financing activities		(130,328)	(584,477)	534,810
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS		(60,635)	69,769	(69,349)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD		183,909	114,140	183,489
CASH AND CASH EQUIVALENTS, END OF PERIOD		123,274	183,909	114,140
Supplemental disclosure of cash flow information:
Interest paid		15,296	12,112	9,544
Shares issued in connection with incentive fee payment (non-cash)		0	0	449
Share-based LTIP awards (non-cash)		400	393	267
Aggregate TBA trade activity (buys sells) (non-cash)		22,923,388	36,357,456	30,136,820
Purchase of investments (non-cash)		(44,914)	0	0
Proceeds from principal payments of investments (non-cash)		10,365	0	0
Proceeds from the disposition of investments (non-cash)		96,131	0	0
Payments on financial derivatives (non-cash)		(4,000)	0	0
Proceeds from financial derivatives (non-cash)		7,486	0	0
Proceeds from issuance of securitized debt (non-cash)		13,088	0	0
Principal payments on securitized debt (non-cash)		(29,629)	0	0
Repayments of reverse repurchase agreements (non-cash)		$ (48,527)	$ 0	$ 0

[1] Conformed to current period presentation.