DEBT OBLIGATIONS, NET - Schedule of Maturities (Details) $ in Thousands	Jun. 30, 2018 USD ($)
Long-term Debt, Fiscal Year Maturity [Abstract]
2018 (Last 6 months)	$ 680,637
2019	1,056,619
2020	506,998
2021	546,801
2022	656,759
Thereafter	1,266,758
Subtotal	4,714,572
Premiums included in mortgage loan financing	(6,060)
Debt obligations	4,702,449
Senior Unsecured Notes
Long-term Debt, Fiscal Year Maturity [Abstract]
Debt issuance costs	(12,658)
CLO debt
Long-term Debt, Fiscal Year Maturity [Abstract]
Debt issuance costs	(4,526)
Mortgage Loan Financing
Long-term Debt, Fiscal Year Maturity [Abstract]
Debt issuance costs	$ (999)

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Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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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 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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