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Net Intangible Assets Transferred to Assets Held for Sale

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Net Intangible Liabilities Transferred to Liabilities Related to Assets Held for Sale

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Significant Accounting Policies - Investments in Commercial Real Estate Properties (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Investment in Commercial Real Estate Properties
Rental revenue decrease from amortization of acquired leases	$ 200,000	$ 300,000	$ 100,000	$ 4,000,000
Identified intangible assets (included in other assets):
Gross amount	403,552,000		403,552,000		$ 199,722,000
Accumulated amortization	(179,211,000)		(179,211,000)		(182,643,000)
Net	224,341,000		224,341,000		17,079,000
Identified intangible liabilities (included in deferred revenue):
Gross amount	361,338,000		361,338,000		212,767,000
Accumulated amortization	(203,064,000)		(203,064,000)		(210,262,000)
Net	158,274,000		158,274,000		2,505,000
Net intangible assets reclassified to assets held for sale	0		0		1,800,000
Net intangible liabilities reclassified to liabilities relates to assets held for sale	$ 0		$ 0		$ 0
Minimum \| Above-market leases
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)			1 year
Minimum \| Below-market leases
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)			1 year
Minimum \| In-place leases
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)			1 year
Maximum \| Above-market leases
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)			15 years
Maximum \| Below-market leases
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)			15 years
Maximum \| In-place leases
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)			15 years
Building \| Minimum
Investment in Commercial Real Estate Properties
Estimated useful life (in years)			3 years
Building \| Maximum
Investment in Commercial Real Estate Properties
Estimated useful life (in years)			40 years