Real Estate (Schedule of Tenant Concentrations) (Details) $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($) properties	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Number of Properties \| properties	228
Property, Plant and Equipment, Gross	$ 3,266,255		$ 3,265,070
Loans and Leases Receivable, Net Amount	301,318		$ 292,427
Operating Leases, Income Statement, Lease Revenue	74,749	$ 76,527
Revenues	80,885	83,076
Real Estate Investment Property, at Cost	3,263,713
Loans and Leases Receivable, Gross	306,174
Nonportfolio Assets, Original Cost	2,500
Escrow Funds Received From Tenants [Member]
Operating Leases, Income Statement, Lease Revenue	$ 2,161	$ 1,553
Percentage of Continuing Revenue	2.00%	2.00%
Senior Living Communities [Member]
Number of Properties \| properties	10
Property, Plant and Equipment, Gross	$ 573,631
Loans and Leases Receivable, Net Amount	44,189
Operating Leases, Income Statement, Lease Revenue	$ 12,723	$ 12,717
Percentage of Continuing Revenue	16.00%	15.00%
Bickford Senior Living [Member]
Number of Properties \| properties	48
Property, Plant and Equipment, Gross	$ 534,376
Loans and Leases Receivable, Net Amount	35,079
Operating Leases, Income Statement, Lease Revenue	$ 10,207	$ 13,603
Percentage of Continuing Revenue	13.00%	16.00%
Holiday Acquisition Holdings [Member]
Number of Properties \| properties	26
Property, Plant and Equipment, Gross	$ 532,672
Operating Leases, Income Statement, Lease Revenue	$ 10,185	$ 10,176
Percentage of Continuing Revenue	13.00%	12.00%
National Healthcare Corporation [Member]
Number of Properties \| properties	42
Property, Plant and Equipment, Gross	$ 171,235
Operating Leases, Income Statement, Lease Revenue	$ 9,452	$ 9,448
Percentage of Continuing Revenue	12.00%	11.00%
Less than 10% Operators [Member]
Property, Plant and Equipment, Gross	$ 1,451,799
Loans and Leases Receivable, Net Amount	226,906
Operating Leases, Income Statement, Lease Revenue	$ 36,157	$ 35,579
Percentage of Continuing Revenue	44.00%	42.00%

This item represents the original cost of corporate assets that are not part of the investment portfolio.

No definition available.

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- Definition

This element represents the percentage of income recognized from a lease tenant.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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The number of real estate properties owned as of the balance sheet date.

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The total amount of revenue recognized for the period from operating leases, including minimum lease revenue, contingent revenue, percentage revenue and sublease revenue.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount of real estate investment property 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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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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