Properties (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) property	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Properties
Gain on sale of investments and other assets, net		$ 1,942	$ 22,664	$ 12,886
Summary of properties
Properties, cost		1,986,285	928,060
Less: accumulated depreciation		(41,565)	(8,835)
Properties, net		1,944,720	919,225
Future rental payments due from tenants under existing non-cancellable operating leases
2017		133,062
2018		91,625
2019		82,485
2020		75,717
2021		69,860
Thereafter		418,144
Total		870,893
Property Segment
Summary of properties
Land and land improvements		385,860	247,589
Buildings and building improvements		1,291,531	516,117
Furniture & fixtures		$ 23,035	$ 11,980
Property Segment | Minimum
Summary of properties
Land improvements, useful life		0 years	0 years
Building and building improvements, useful life		5 years	5 years
Furniture & fixtures, useful life		3 years	3 years
Property Segment | Maximum
Summary of properties
Land improvements, useful life		12 years	12 years
Building and building improvements, useful life		40 years	40 years
Furniture & fixtures, useful life		7 years	7 years
Investment and Servicing Segment
Properties
Gain on sale of investments and other assets, net	$ 17,800
Summary of properties
Land and land improvements		$ 89,425	$ 39,103
Buildings and building improvements		195,178	112,524
Furniture & fixtures		$ 1,256	$ 747
Number of properties sold | property		0
Investment and Servicing Segment | Minimum
Summary of properties
Land improvements, useful life		0 years	0 years
Building and building improvements, useful life		3 years	3 years
Furniture & fixtures, useful life		3 years	3 years
Investment and Servicing Segment | Maximum
Summary of properties
Land improvements, useful life		15 years	15 years
Building and building improvements, useful life		40 years	40 years
Furniture & fixtures, useful life		5 years	5 years