Combined Consolidated Statements of Income - USD ($) $ in Thousands					3 Months Ended								11 Months Ended	12 Months Ended
	Dec. 10, 2015	Sep. 10, 2015	Jun. 15, 2015	Apr. 06, 2015	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax														$ 500	$ 5,800	$ 0
Net interest income
Interest income					$ 62,903	$ 63,013	$ 59,239	$ 56,384	$ 56,931	$ 48,459	$ 45,112	$ 36,822		241,539	187,325	121,578
Interest expense														113,303	77,574	48,745
Net interest income														128,236	109,751	72,833
Provision for loan losses														600	600	600
Net interest income after provision for loan losses					33,297	33,328	31,602	29,409	30,728	28,381	28,211	21,831		127,636	109,151	72,233
Other income
Operating lease income														80,465	56,649	37,395
Tenant recoveries														9,907	9,183	3,271
Sale of loans, net														71,066	145,275	146,708
Realized gain (loss) on securities														24,007	26,977	4,231
Unrealized gain (loss) on Agency interest-only securities														(1,249)	2,144	(2,665)
Realized gain on sale of real estate, net														40,386	29,760	13,565
Fee and other income														15,205	11,704	7,922
Net result from derivative transactions														(38,937)	(94,798)	28,075
Earnings (loss) from investment in unconsolidated joint ventures														371	1,990	3,203
Gain on assignment of mortgage loan financing														0	432	0
Loss on extinguishment of debt														0	(150)	0
Total other income					72,183	7,549	86,452	35,037	31,906	61,337	55,489	40,434		201,221	189,166	241,705
Costs and expenses
Salaries and employee benefits														61,612	82,144	61,038
Operating expenses														25,103	25,398	14,937
Real estate operating expenses														35,886	32,670	17,404
Real estate acquisition costs														1,983	2,404	3,626
Fee expense														4,521	3,023	2,955
Depreciation and amortization														39,061	28,447	21,515
Total costs and expenses					38,347	42,260	44,180	43,379	48,045	42,207	45,258	38,575		168,166	174,086	121,475
Income (loss) before taxes					67,133	(1,383)	73,874	21,067	14,589	47,511	38,442	23,690		160,691	124,231	192,463
Income tax expense (benefit)					10,457	(4,181)	5,177	3,104	2,783	10,335	8,199	5,289		14,557	26,605	3,730
Net income					56,676	2,798	68,697	17,963	11,806	37,176	30,243	18,401		146,134	97,626	188,733
Net (income) loss attributable to noncontrolling interest in consolidated joint ventures					(2,146)	85	684	(191)	(83)	306	(46)	192		(1,568)	370	1,098
Pre-IPO net loss attributable to predecessor unitholders									0	0	0	12,628		0	12,628	189,831
Net (income) loss attributable to noncontrolling interest in operating partnership					(27,407)	430	(35,171)	(8,597)	(7,350)	(22,827)	(17,691)	(18,568)		(70,745)	(66,437)	189,831
Net income attributable to Class A common shareholders					$ 27,123	$ 3,313	$ 34,210	$ 9,175	$ 4,374	$ 14,656	$ 12,505	$ 12,652		$ 73,821	$ 44,187
Earnings per share:
Basic (in dollars per share)					$ 0.51	$ 0.06	$ 0.68	$ 0.18	$ 0.09	$ 0.30	$ 0.26	$ 0.26		$ 1.43	$ 0.90
Diluted (in dollars per share)					0.50	0.06	0.67	0.15	$ 0.09	$ 0.28	$ 0.22	$ 0.24		$ 1.42	$ 0.86
Weighted average shares outstanding:
Basic (in shares)													49,296,417	51,702,188	49,296,417
Diluted (in shares)													97,583,310	51,870,808	97,583,310
Dividends per share of common stock (in dollars per share)					$ 1.45	$ 0.275	$ 0.25	$ 0.25
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax														$ (500)	$ (5,800)	$ 0
Class A Common Stock
Costs and expenses
Net income attributable to Class A common shareholders													$ 44,187	$ 73,821	$ 44,187
Earnings per share:
Basic (in dollars per share)													$ 0.90	$ 1.43
Diluted (in dollars per share)													$ 0.86	$ 1.42
Weighted average shares outstanding:
Basic (in shares)													49,296,417	51,702,188
Diluted (in shares)													97,583,310	51,870,808
Dividends per share of common stock (in dollars per share)	$ 1.45	$ 0.275	$ 0.25	$ 0.25										$ 2.225	$ 0