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Land, Buildings and Improvements and Assets Held for Sale - Narratives (Details) $ in Thousands	1 Months Ended	3 Months Ended			12 Months Ended
	Jan. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($) property $ / €	Mar. 31, 2019 USD ($) property	Dec. 31, 2019 USD ($) property $ / €	Mar. 30, 2020 property
Real Estate Properties
Decrease in value of balance sheet item due to foreign currency translation			$ 52,200	$ 173
Direct financing lease, net investments reclassified			(844,945)		$ (896,549)
Investments in real estate
Purchases of real estate			197,626	164,929
Capitalized construction cost			$ 91,500
Number of construction projects \| property			4		3
Unfunded commitment			$ 201,300		$ 227,800
Interest income from direct financing leases			20,100	26,600
Assets held for sale, net			$ 0		$ 104,010
Real Estate
Real Estate Properties
Number of real estate properties (property) \| property			1,215
Investments in real estate
Gross contract revenue			$ 5,967	15,996
Real Estate \| Lease revenue
Investments in real estate
Gross contract revenue			4,400	13,200
Real Estate \| Food, bevarge and other
Investments in real estate
Gross contract revenue			$ 1,600	$ 2,800
Properties disposed of by sale
Investments in real estate
Number of properties sold \| property			4	1
Asset held for sale, not in discontinued operations
Real Estate Properties
Number of real estate properties (property) \| property					1
Investments in real estate
Assets held for sale, net					$ 104,000
In-place lease
Investments in real estate
Purchases of real estate			$ 26,500
Finite lived intangible assets useful life			18 years 3 months 18 days
Above-market rent
Investments in real estate
Purchases of real estate			$ 1,500
Finite lived intangible assets useful life			13 years 6 months
Net investments in direct financing lease
Investments in real estate
Number of properties sold \| property			1
Land
Investments in real estate
Purchases of real estate			$ 30,700
Building
Investments in real estate
Purchases of real estate			145,900
Net Lease Intangible
Investments in real estate
Purchases of real estate			28,000
Construction in progress \| Facility in Westborough, MA
Investments in real estate
Construction in progress placed into service	$ 53,100
Construction in progress \| Facility in Azambuja, Portugal
Investments in real estate
Funding commitment			26,200
Land, buildings and improvements
Investments in real estate
Assets held for sale, net			$ 0		$ 105,573
Land, buildings and improvements \| Properties disposed of by sale
Investments in real estate
Number of properties sold \| property			3
Decrease in carrying value of real estate			$ 2,100
Operating Lease
Real Estate Properties
Decrease in value of balance sheet item due to foreign currency translation			107,100
Depreciation			65,900	$ 55,100
Investments in real estate
Purchases of real estate			204,578
Acquisition related costs			8,600
Operating Properties
Real Estate Properties
Depreciation			$ 700	$ 2,800
Hotel \| Real Estate
Real Estate Properties
Number of real estate properties (property) \| property			1	2		2
Self-storage \| Operating Properties
Real Estate Properties
Number of real estate properties (property) \| property			10	37	10
Hotel \| Operating Properties
Real Estate Properties
Number of real estate properties (property) \| property			1		1
Reclassification
Real Estate Properties
Direct financing lease, net investments reclassified			$ 17,500
Reclassification \| Net investments in direct financing lease
Real Estate Properties
Number of real estate properties (property) \| property			36
Forecast \| Operating Lease \| Warehouse And Distribution Facility In Knoxville, TN
Investments in real estate
Purchases of real estate		$ 68,000
EUR
Real Estate Properties
Decrease in exchange rate			2.50%
Foreign currency exchange rate \| $ / €			1.0956		1.1234