Debt - Scheduled Principal Repayments (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Debt Disclosure [Abstract]
2017	$ 395,999
2018	69,753
2019	205,295
2020	321,559
2021	253,927
Thereafter	259,138
Long-term debt and convertible notes payable	1,505,671
Unamortized fair market value of assumed debt	1,336	$ 1,364
Net unamortized debt issuance costs	(18,289)	(11,720)
Total indebtedness	$ 1,488,718	$ 1,358,606

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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, after accumulated amortization, of debt premium.

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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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