Consolidated Statement Of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS:
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		$ 35,964	$ (15,702)	$ 38,429
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		17,860	35,498	(23,454)
Change in net unrealized (gain) loss on investments and financial derivatives, and foreign currency translation		(13,750)	13,664	48,649
Amortization of premiums and accretion of discounts (net)		32,764	24,573	21,815
Purchase of investments		(2,849,027)	(2,246,552)	(3,381,699)
Proceeds from disposition of investments		1,962,711	2,032,219	3,570,304
Proceeds from principal payments of investments		286,426	276,880	284,166
Proceeds from investments sold short		1,718,668	1,430,898	1,461,459
Repurchase of investments sold short		(1,674,760)	(1,573,705)	(2,031,578)
Payments on financial derivatives		(103,499)	(354,814)	(505,956)
Proceeds from financial derivatives		109,496	394,038	416,103
Amortization of deferred debt issuance costs		97	0	0
Share-based long term incentive plan unit expense		385	400	393
Interest income related to consolidated securitization trust	[1]	(1,175)	0	0
Interest expense related to consolidated securitization trust	[1]	794	0	0
Debt issuance costs related to debt carried at fair value	[1]	1,679	0	0
Repurchase agreements		28,870	(79,119)	66,301
(Increase) decrease in assets:
Receivable for securities sold and financial derivatives		(30,888)	260,636	531,844
Due from brokers		(46,753)	47,954	5,360
Interest and principal receivable		(7,984)	(1,260)	167
Restricted cash		230	4,202	(4,857)
Other assets		(40,411)	1,910	(3,295)
Increase (decrease) in liabilities:
Due to brokers		(11,059)	(102,017)	92,573
Payable for securities purchased and financial derivatives		117,535	(80,197)	66,618
Accounts payable and accrued expenses		558	(299)	846
Other liabilities		424	(811)	828
Interest and dividends payable		2,444	1,654	(580)
Base management fee payable to affiliate		(303)	(357)	(190)
Net cash provided by (used in) operating activities		(462,704)	69,693	654,246
Cash flows provided by (used in) financing activities:
Contributions from non-controlling interests		20,707	5,552	2,153
Shares repurchased		(14,642)	(14,028)	(5,639)
Dividends paid		(57,636)	(65,148)	(83,460)
Distributions to non-controlling interests		(8,594)	(5,249)	(1,468)
Offering costs paid		0	0	(56)
Proceeds from issuance of Other secured borrowings		111,338	40,921	0
Principal payments on Other secured borrowings		(28,839)	(295)	(763)
Proceeds from issuance of Other secured borrowings, at fair value		106,590	0	0
Debt issuance costs related to Other secured borrowings, at fair value		(947)	0	0
Proceeds from issuance of senior notes		86,000	0	0
Debt issuance costs paid related to senior notes		(1,326)	0	0
Borrowings under reverse repurchase agreements		9,919,449	5,762,742	9,758,474
Repayments of reverse repurchase agreements		(9,745,437)	(5,854,823)	(10,253,718)
Net cash provided by (used in) financing activities		386,663	(130,328)	(584,477)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS		(76,041)	(60,635)	69,769
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD		123,274	183,909	114,140
CASH AND CASH EQUIVALENTS, END OF PERIOD		47,233	123,274	183,909
Supplemental disclosure of cash flow information:
Interest paid		28,006	15,296	12,112
Share-based long term incentive plan unit awards (non-cash)		385	400	393
Aggregate TBA trade activity (buys sells) (non-cash)		23,917,506	22,923,388	36,357,456
Purchase of investments (non-cash)		(25,318)	(44,914)	0
Proceeds from principal payments of investments (non-cash)		27,307	10,365	0
Proceeds from the disposition of investments (non-cash)		26,800	96,131	0
Payments made to open financial derivatives (non-cash)		0	(4,000)	0
Proceeds from financial derivatives (non-cash)		0	7,486	0
Proceeds from issuance of other secured borrowings (non-cash)		17,175	13,088	0
Principal payments on Other secured borrowings (non-cash)		(65,851)	(29,629)	0
Proceeds received from Other secured borrowings, at fair value (non-cash)		31,958	0	0
Principal payments on Other secured borrowings, at fair value (non-cash)		(13,442)	0	0
Debt issuance costs related to Other secured borrowings, at fair value (non-cash)		(732)	0	0
Borrowings under reverse repurchase agreements (non-cash)		33,329	0	0
Repayments of reverse repurchase agreements (non-cash)		$ (31,607)	$ (48,527)	$ 0

[1] Related to non-qualified mortgage securitization transaction. See Note 6 for further details.