Debt - Mortgages Payable (Details) - Mortgages payable - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Mortgages payable	$ 200,489	$ 213,925
Premium, net of accumulated amortization	120	239
Discount, net of accumulated amortization	(139)	(158)
Debt issuance costs, net of accumulated amortization	(914)	(1,079)
Total debt, net	$ 199,556	$ 212,927
Weighted average interest rate (percent)	4.27%	4.33%
Minimum
Debt Instrument [Line Items]
Fixed interest rate (percent)	3.49%	3.49%
Maximum
Debt Instrument [Line Items]
Fixed interest rate (percent)	5.49%	5.49%

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after accumulated amortization, of debt discount.

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Amount, after accumulated amortization, of debt premium.

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Weighted average interest rate of debt outstanding.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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