Real Estate - Schedule of Real Estate Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	May 31, 2019	Dec. 31, 2018
Real Estate Properties [Line Items]
Land, at cost	$ 307,428		$ 470,339
Buildings and improvements, at cost	1,333,388		1,605,994
Less: accumulated depreciation	(219,214)		(305,314)
Real estate, net	1,421,602		1,771,019
Real estate available and held for sale	12,770		22,551
Total real estate	1,434,372		1,793,570
Net investment in leases	421,842	$ 424,100	0
Real estate assets derecognized at inception of sales-type lease		$ 193,400
Net Lease
Real Estate Properties [Line Items]
Land, at cost	201,658		336,740
Buildings and improvements, at cost	1,255,681		1,487,270
Less: accumulated depreciation	(207,515)		(287,516)
Real estate, net	1,249,824		1,536,494
Real estate available and held for sale	0		1,055
Total real estate	1,249,824		1,537,549
Operating Properties
Real Estate Properties [Line Items]
Land, at cost	105,770		133,599
Buildings and improvements, at cost	77,707		118,724
Less: accumulated depreciation	(11,699)		(17,798)
Real estate, net	171,778		234,525
Real estate available and held for sale	12,770		21,496
Total real estate	184,548		256,021
Residential Condominiums
Real Estate Properties [Line Items]
Real estate available and held for sale	$ 11,800		$ 20,600

Derecognized Real Estate Assets, Inception Of Sales Type Lease

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Carrying amount as of the balance sheet date of investments in land and buildings held for sale, including real estate considered to be inventory of the entity.

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Real Estate Investment Property, Held for Use, Net

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Aggregate of the carrying amounts as of the balance sheet date of investments in building and building improvements.

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Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

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The cumulative amount of depreciation for real estate property held for investment purposes.

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Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of net investment in sales-type lease.

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