Indebtedness - Scheduled Principal Repayments and Term-loan Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Principal repayments and maturities
2019	$ 14,926
2020	51,742
2021	228,565
2022	201,912
2023	58,508
Thereafter	145,069
Total	700,722	$ 523,412
Monthly Principal Amortization
Principal repayments and maturities
2019	5,593
2020	6,626
2021	5,821
2022	4,803
2023	11,264
Thereafter	71,475
Total	105,582
Balloon Payments At Loan Maturity
Principal repayments and maturities
2019	9,333
2020	45,116
2021	222,744
2022	197,109
2023	47,244
Thereafter	73,594
Total	$ 595,140

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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