Amount of debt as of the reporting date.

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Amount of total gross properties and lease intangibles acquired at the acquisition date.

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The number of equity interests in unconsolidated commercial real estate properties.

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The number of retail properties.

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Area of a real estate property.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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The net gain (loss) resulting from sales and other disposals of real estate owned for investment purposes.

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Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Properties - Narrative (Details) ft² in Millions, $ in Millions	1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended			13 Months Ended	24 Months Ended
	Dec. 31, 2017 Item	Sep. 30, 2017 ft² property	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) Item property	Jun. 30, 2020 USD ($)	Dec. 31, 2018 Item	Dec. 31, 2016 ft² Item	Dec. 31, 2015 Item	Dec. 31, 2018 Item	Dec. 31, 2016 ft² Item
Real Estate Properties [Line Items]
Proceeds from sale of operating properties				$ 24.1		$ 24.1
Operating properties
Real Estate Properties [Line Items]
Proceeds from sale of operating properties			$ 30.9		$ 30.9
Gain on sale of property			9.7	7.4	9.7	7.4
Operating properties \| Commercial and Residential Lending Segment \| Montgomery Alabama
Real Estate Properties [Line Items]
Proceeds from sale of operating properties					30.6
Gain on sale of property					$ 17.7
Woodstar Portfolio
Real Estate Properties [Line Items]
Number of properties in portfolio investment \| Item					32						32
Number of units acquired \| Item					8,948
Number of acquired properties closed \| Item								14	18
Total gross properties and lease intangibles			638.1		$ 638.1
Debt			573.1		$ 573.1
Woodstar II Portfolio
Real Estate Properties [Line Items]
Number of properties in portfolio investment \| Item					27
Number of acquired properties closed \| Item	8						19			27
Total gross properties and lease intangibles			611.3		$ 611.3
Debt			512.7		$ 512.7
Number of units in portfolio investment \| Item					6,109
Medical Office Portfolio
Real Estate Properties [Line Items]
Number of acquired properties closed \| Item								34
Total gross properties and lease intangibles			761.4		$ 761.4
Debt			593.4		593.4
Area of property \| ft²								1.9			1.9
Master Lease Portfolio
Real Estate Properties [Line Items]
Total gross properties and lease intangibles			343.8		343.8
Debt			192.9		192.9
Number of retail properties acquired \| property		16
Number of square feet of properties \| ft²		1.9
Term of master lease agreements		24 years 7 months 6 days
Master Lease Portfolio \| Minimum \| Retail Properties \| Geographic Concentration Risk \| Utah, Florida, Texas and Minnesota
Real Estate Properties [Line Items]
Concentration risk (as a percent)		50.00%
REIS Equity Portfolio
Real Estate Properties [Line Items]
Total gross properties and lease intangibles			249.6		249.6
Debt			176.8		$ 176.8
Number of retail properties acquired \| property					14
Number of equity interests in unconsolidated commercial real estate properties \| property					1
REIS Equity Portfolio \| Operating properties
Real Estate Properties [Line Items]
Proceeds from sale of operating properties			30.9	24.1	$ 30.9	24.1
Gain on sale of property			$ 9.7	$ 7.4	$ 9.7	$ 7.4