CONSOLIDATED STATEMENTS OF CASH FLOWS - Entity [Domain] - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015		Jun. 30, 2014
Cash flows from operating activities:
Net income (loss)	$ 423,572		$ (538,863)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Amortization of Investment Securities premiums and discounts, net	378,814		268,629
Amortization of commercial real estate investment premiums and discounts, net	(581)		391
Amortization of intangibles	3,586		228
Amortization of deferred financing costs	4,561		5,460
Amortization of net origination fees and costs, net	(2,350)		(2,090)
Amortization of contingent beneficial conversion feature and equity component of Convertible Senior Notes	12,246		14,241
Depreciation expense	5,687		736
Net gain on sale of commercial real estate			(2,748)
Net loss on sale of commercial real estate debt held for investment	100
Net (gains) losses on sales of Investment Securities	(66,289)		(86,621)
Stock compensation expense	1,024		998
Impairment of goodwill	22,966
Unrealized (gains) losses on interest rate swaps	(234,590)		173,880
Net unrealized (gains) losses on financial instruments measured at fair value through earnings	15,965		18,708
Net (gains) losses on trading assets	121,136		192,717
Proceeds from repurchase agreements of RCap	895,400,000		531,215,774
Payments on repurchase agreements of RCap	(900,650,000)		(524,667,907)
Proceeds from reverse repurchase agreements	26,925,000		55,923,453
Payments on reverse repurchase agreements	(26,825,000)		(55,823,453)
Proceeds from securities borrowed			23,888,955
Payments on securities borrowed			(21,306,062)
Proceeds from securities loaned			41,939,298
Payments on securities loaned			(44,466,959)
Proceeds from U.S. Treasury securities			3,159,253
Payments on U.S. Treasury securities			(3,920,425)
Net payments on derivatives	(116,122)		(92,716)
Net change in:
Due to / from brokers			8,596
Other assets	(15,686)		(9,444)
Accrued interest and dividends receivable	45,897		(25,419)
Receivable for investment advisory income	(187)		459
Accrued interest payable	(48,857)		12,170
Accounts payable and other liabilities	13,952		(3,925)
Net cash provided by (used in) operating activities	(4,585,156)		5,877,314
Cash flows from investing activities:
Payments on purchases of Investment Securities	(8,638,138)		(21,722,521)
Proceeds from sales of Investment Securities	18,278,224		11,375,718
Principal payments on Agency mortgage-backed securities	5,342,053		3,570,508
Payments on purchases of corporate debt	(187,035)		(69,748)
Principal payments on corporate debt	42,352		36,429
Purchases of commercial real estate debt investments	(276,918)
Sales of commercial real estate debt investments	41,016
Purchase of securitized loans at fair value	(2,574,353)
Origination of commercial real estate investments, net	(180,531)		(172,120)
Proceeds from sale of commercial real estate investments	46,806
Principal payments on commercial real estate debt investments	1,616
Proceeds from sales of commercial real estate held for sale			26,019
Principal payments on commercial real estate investments	321,050		171,190
Purchase of investments in real estate	(121)		(36,743)
Investment in unconsolidated joint venture	(12,410)
Purchase of equity securities	(8,130)		(200)
Net cash provided by (used in) investing activities	12,195,481		(6,821,468)
Cash flows from financing activities:
Proceeds from repurchase agreements	105,819,378		98,482,785
Principal payments on repurchase agreements	(114,471,752)		(96,439,435)
Payments on maturity of convertible senior notes	(857,541)
Proceeds from other secured financing	203,200		5,000
Proceeds from issuance of securitized debt	2,382,810		260,700
Principal repayments on securitized debt	(37,915)
Principal repayments on securitized loans	50
Payment of deferred financing cost	(641)		(4,288)
Net proceeds from direct purchases and dividend reinvestments	1,144		1,208
Proceeds from mortgages payable			11,025
Principal payments on participation sold	(147)		(139)
Principal payments on mortgages payable	(165)		(11)
Distributions to noncontrolling interests	(245)
Dividends paid	(604,587)		(604,461)
Net cash provided by (used in) financing activities	(7,566,411)		1,712,384
Net (decrease) increase in cash and cash equivalents	43,914		768,230
Cash and cash equivalents, beginning of period	1,741,244	[1]	552,436
Cash and cash equivalents, end of period	1,785,158		1,320,666
Supplemental disclosure of cash flow information:
Interest received	1,541,718		1,617,804
Dividends received	8,366		17,093
Investment advisory income received	20,881		12,691
Interest paid (excluding interest paid on interest rate swaps)	218,272		267,103
Net interest paid on interest rate swaps	305,327		479,006
Taxes paid	1,901		5,061
Noncash investing activities:
Receivable for investments sold	247,361		856,983
Payable for investments purchased	673,933		781,227
Net change in unrealized gains (losses) on available-for-sale securities, net of reclassification adjustment	(559,848)		2,176,677
Noncash financing activities:
Dividends declared, not yet paid	$ 284,331		284,261
Convertible Senior Notes 5.00 Percent Due 2015
Noncash financing activities:
Contingent beneficial conversion feature on 4% Convertible Senior Notes			$ 8,336

[1] Derived from the audited consolidated financial statements at December 31, 2014.