Indebtedness - Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Maturity and Other
2020	$ 2,857,060
2021	1,541,478
2022	2,872,980
2023	1,868,669
2024	2,896,466
Thereafter	12,208,803
Total principal maturities	24,245,456
Net unamortized debt premium	6,775
Net unamortized debt discount	(54,976)
Debt issuance costs, net	(101,280)	$ (96,175)
Other Debt Obligations	67,255	67,255
Total mortgages and unsecured indebtedness	$ 24,163,230	$ 23,305,535

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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