Debt - Aggregate Principal Repayments on Mortgage Notes (Details) - Mortgages [Member] - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
July 1, 2019 - December 31, 2019 (1)	$ 38,035
2020	264,823
2021	352,381
2022	290,854
2023	125,667
Thereafter	670,647
Total	$ 1,742,407	$ 1,917,132

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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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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