Properties (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($) property	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) property	Sep. 30, 2016 USD ($) property	Dec. 31, 2016 USD ($)
Properties
Number of properties sold | property				0
Gain on sale of investments and other assets, net	$ 11,877	$ 10	$ 17,004	$ 165
Summary of properties
Properties, cost	2,609,578		2,609,578		$ 1,986,285
Less: accumulated depreciation	(88,236)		(88,236)		(41,565)
Properties, net	$ 2,521,342		$ 2,521,342		1,944,720
Operating properties | Disposed of by sale
Properties
Number of properties sold | property	2		5
Proceeds from sale of operating properties	$ 26,000		$ 44,600
Gain on sale of investments and other assets, net	11,200		16,400
Operating properties | Disposed of by sale | Non-Controlling Interests
Properties
Gain on sale of investments and other assets, net	2,400		2,400
Property Segment
Summary of properties
Land and land improvements	526,591		526,591		385,860
Buildings	1,755,511		1,755,511		1,291,531
Furniture & fixtures	26,038		$ 26,038		23,035
Property Segment | Minimum
Summary of properties
Land improvements, useful life			0 years
Building and building improvements, useful life			5 years
Furniture & fixtures, useful life			3 years
Property Segment | Maximum
Summary of properties
Land improvements, useful life			15 years
Building and building improvements, useful life			45 years
Furniture & fixtures, useful life			7 years
Investment and Servicing Segment
Summary of properties
Land and land improvements	90,263		$ 90,263		89,425
Buildings	210,183		210,183		195,178
Furniture & fixtures	$ 992		$ 992		$ 1,256
Investment and Servicing Segment | Minimum
Summary of properties
Land improvements, useful life			0 years
Building and building improvements, useful life			3 years
Furniture & fixtures, useful life			2 years
Investment and Servicing Segment | Maximum
Summary of properties
Land improvements, useful life			15 years
Building and building improvements, useful life			40 years
Furniture & fixtures, useful life			5 years