Debt Obligations, net - Future Scheduled Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Maturities of Long-term Debt [Abstract]
2019 (remaining nine months)	$ 116
2020	400,000
2021	436,213
2022	1,111,198
2023	645,125
Thereafter	524,668
Total principal maturities	3,117,320	$ 3,661,617
Unamortized discounts and deferred financing costs, net	(47,024)	(52,531)
Total debt obligations, net	3,070,296	3,609,086
Unsecured Debt
Maturities of Long-term Debt [Abstract]
2019 (remaining nine months)	0
2020	400,000
2021	275,000
2022	1,062,500
2023	0
Thereafter	100,000
Total principal maturities	1,837,500
Unamortized discounts and deferred financing costs, net	(37,818)
Total debt obligations, net	1,799,682
Secured Debt
Maturities of Long-term Debt [Abstract]
2019 (remaining nine months)	116
2020	0
2021	161,213
2022	48,698
2023	645,125
Thereafter	424,668
Total principal maturities	1,279,820	$ 1,449,117
Unamortized discounts and deferred financing costs, net	(9,206)
Total debt obligations, net	$ 1,270,614

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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