Fair Value Measurements - Narratives (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) property	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Fair Value Inputs, Assets
Proceeds from the redemption of investment in shares	$ 3,496	$ 18,750
Equity investments in real estate	276,109		$ 324,004
Unamortized discount	26,344
Unsecured senior notes
Fair Value Inputs, Assets
Unamortized discount	19,300
GCIF | Other assets, net
Fair Value Inputs, Assets
Proceeds from the redemption of investment in shares	3,200
Loss on redemption of shares	300
Equity investments in real estate	8,700		12,200
Level 3 | Fair Value, Measurements, Nonrecurring
Fair Value Inputs, Assets
Recognized impairment costs	66,532	0
Level 3 | Carrying Value | Non-Recourse Debt
Fair Value Inputs, Assets
Unamortized discount	5,600		6,200
Level 3 | Carrying Value | Non recourse mortgage
Fair Value Inputs, Assets
Debt instrument, unamortized discount and debt issuance costs, net	500		600
Level 3 | Land, buildings and improvements and intangibles | Fair Value, Measurements, Nonrecurring
Fair Value Inputs, Assets
Recognized impairment costs	19,420	0
Level 3 | Land, buildings and improvements and intangibles | Fair Value, Measurements, Nonrecurring | Potentially vacant properties
Fair Value Inputs, Assets
Recognized impairment costs	$ 16,000
Number of real estate properties (property) | property	2
Level 3 | Land, buildings and improvements and intangibles | Fair Value, Measurements, Nonrecurring | Impaired property
Fair Value Inputs, Assets
Recognized impairment costs	$ 3,400
Level 3 | Equity investments in the Managed Programs | Fair Value, Measurements, Nonrecurring
Fair Value Inputs, Assets
Recognized impairment costs	47,112	$ 0
Level 2 | Carrying Value | Unsecured senior notes
Fair Value Inputs, Assets
Debt instrument, unamortized discount and debt issuance costs, net	21,600		22,800
Unamortized discount	19,300		20,500
Investment in a Cold Storage Operator | Level 3
Fair Value Inputs, Assets
Fair value of investments	146,200		146,200
CWI 1 | Affiliated Entity
Fair Value Inputs, Assets
Equity investments in real estate	21,899		49,032
CWI 1 | Level 3 | Equity investments in the Managed Programs | Fair Value, Measurements, Nonrecurring | Affiliated Entity
Fair Value Inputs, Assets
Recognized impairment costs	27,800
CWI 2 | Affiliated Entity
Fair Value Inputs, Assets
Equity investments in real estate	15,497		$ 33,669
CWI 2 | Level 3 | Equity investments in the Managed Programs | Fair Value, Measurements, Nonrecurring | Affiliated Entity
Fair Value Inputs, Assets
Recognized impairment costs	$ 19,300