Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Cash flows from operating activities:
Net income (loss)	$ 125,879		$ 113,720		$ 146,134
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
(Gain) loss on extinguishment of debt	73		(5,382)		0
Depreciation and amortization	40,332		39,447		39,061
Unrealized (gain) loss on derivative instruments	3,432		(4,224)		(10,182)
Unrealized (gain) loss on Agency interest-only securities	(1,405)		56		1,249
Unrealized (gain) loss on investment in mutual fund	(300)		14		0
Provision for loan losses	0		300		600
Amortization of equity based compensation	18,965		17,640		13,788
Amortization of deferred financing costs included in interest expense	7,856		7,459		5,757
Amortization of premium on mortgage loan financing	(1,025)		(894)		(902)
Amortization of above- and below-market lease intangibles	(786)		(108)		(249)
Amortization of premium/(accretion) of discount and other fees on loans	(11,180)		(8,941)		(12,241)
Amortization of premium/(accretion) of discount and other fees on securities	5,241		6,422		8,774
Realized (gain) loss on sale of mortgage loan receivables held for sale	(54,046)		(26,009)		(71,066)
Realized gain on disposition of loan	0		0		(820)
Realized (gain) loss on real estate securities	(17,209)		(7,724)		(24,007)
Realized gain on sale of real estate, net	(11,423)		(20,636)		(40,386)
Realized gain on sale of derivative instruments	199		24		0
Origination of mortgage loan receivables held for sale	(1,465,635)		(1,128,651)		(2,594,141)
Purchases of mortgage loan receivables held for sale	0		(73,421)		0
Repayment of mortgage loan receivables held for sale	2,083		1,768		2,308
Proceeds from sales of mortgage loan receivables held for sale	1,375,733	[1]	1,440,195		2,509,090
(Income) loss from investments in unconsolidated joint ventures in excess of distributions received	(89)		(426)		(371)
Distributions from operations of investment in unconsolidated joint ventures	0		1,017		294
Deferred tax asset (liability)	5,591		1,868		2,900
Payments pursuant to tax receivable agreement	(1,013)		0		0
Changes in operating assets and liabilities:
Accrued interest receivable	(1,437)		(1,662)		621
Other assets	(3,275)		(4,340)		(1,533)
Accrued expenses and other liabilities	(4,576)		(9,085)		(12,985)
Net cash provided by (used in) operating activities	11,985		338,427		(38,307)
Cash flows from investing activities:
Purchase of derivative instruments	(300)		(73)		0
Sale of derivative instruments	0		39		0
Purchases of real estate securities	(210,903)		(977,062)		(725,888)
Repayment of real estate securities	138,413		684,143		186,902
Proceeds from sales of real estate securities	1,025,710		539,295		845,648
Purchase of FHLB stock	0		0		(7,984)
Sale of FHLB stock	0		0		2,409
Origination of mortgage loan receivables held for investment	(1,407,669)		(919,023)		(963,023)
Purchases of mortgage loan receivables held for investment	(94,079)		0		0
Repayment of mortgage loan receivables held for investment	404,584		649,914		752,452
Basis recovery of Agency interest-only securities	51,989		70,053		79,131
Capital contributions to investment in unconsolidated joint ventures	0		0		(31,085)
Distributions received from investments in unconsolidated joint ventures in excess of income	0		48		3,747
Capitalization of interest on investment in unconsolidated joint ventures	(1,327)		(867)		(341)
Capital contributions to investment in mutual fund	0		(10,001)		0
Purchases of real estate	(236,932)		(62,495)		(197,501)
Capital improvements of real estate	(5,640)		(10,640)		(8,375)
Proceeds from sale of real estate	29,519		72,953	[2]	98,558
Net cash provided by (used in) investing activities	(306,635)		36,284		34,650
Cash flows from financing activities:
Deferred financing costs paid	(26,330)		(5,927)		(2,330)
Proceeds from borrowings under debt obligations	10,080,341		12,359,830		16,280,023
Repayment of borrowings under debt obligations	(9,510,272)		(12,689,064)		(16,137,339)
Cash dividends paid to Class A common shareholders	(100,076)		(67,166)		(39,934)
Payment of liability assumed in exchange for shares for the minimum withholding taxes on vesting restricted stock	(18,125)		(786)		(4,897)
Purchase of treasury stock	(2,588)		(4,652)		(994)
Net cash provided by (used in) financing activities	387,905		(448,077)		22,000
Net increase (decrease) in cash, cash equivalents and restricted cash	93,255		(73,366)		18,343
Cash, cash equivalents and restricted cash at beginning of period	89,428		162,794		144,451
Cash, cash equivalents and restricted cash at end of period	182,683		89,428		162,794
Supplemental information:
Cash paid for interest, net of amounts capitalized	130,795		115,246		107,362
Cash paid (received) for income taxes	(214)		8,775		7,306
Non-cash investing and financing activities:
Origination of mortgage loans receivable held for investment	0		50,378		0
Repayment of mortgage loans receivable held for investment	0		(70,678)		0
Proceeds from sales of mortgage loan receivables held for sale	115,359		0		0
Settlement of mortgage loan receivable held for investment by real estate	0		0		4,620
Transfer from mortgage loans receivable held for sale to mortgage loans receivable held for investment, at amortized cost	0
Like-kind exchange of real estate:
Acquisitions	0		0		15,249
Dispositions	0		0		(62,093)
Receivable from qualified intermediary - other assets	0		0		6,483
Real estate acquired in settlement of mortgage loan receivable held for investment	0		0		6,700
Net settlement of sale of real estate, subject to debt - real estate	0		0		(11,310)
Net settlement of sale of real estate, subject to debt - debt obligations	0		0		51,060
Repayment of borrowings under debt obligations	(115,359)		0		0
Exchange of noncontrolling interest for common stock	284,783		145,841		53,659
Change in deferred tax asset related to exchanges of noncontrolling interest for common stock	2,203		980		(320)
Increase in amount payable pursuant to tax receivable agreement	149		610		1,048
Rebalancing of ownership percentage between Company and Operating Partnership	3,524		(8,096)		544
Dividends declared, not paid	30,528		23,364		17,456
Stock dividends	17,319		64,100		0
Operating Partnership
Cash flows from financing activities:
Capital contributed by noncontrolling interests	0		250		0
Capital distributed to noncontrolling interests	(42,218)		(39,805)		(68,673)
Consolidated Joint Venture
Cash flows from financing activities:
Capital contributed by noncontrolling interests	7,479		0		74
Capital distributed to noncontrolling interests	(306)		(757)		(3,930)
Mortgage loans held by consolidated subsidiaries
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Realized (gain) loss on sale of mortgage loan receivables held for sale	0		0		0
Non-cash investing and financing activities:
Origination of mortgage loans receivable held for investment			50,400
Repayment of mortgage loans receivable held for investment			(70,700)
Transfer from mortgage loans receivable held for sale to mortgage loans receivable held for investment, at amortized cost	$ 153,722		$ 0		$ 0

[1] Includes cash proceeds received in the current year that relate to prior year sales of loans of $20.3 million.

[2] Includes cash proceeds received in the current year that relate to prior year sales of real estate of $6.5 million.