FAIR VALUE OF FINANCIAL INSTRUMENTS - Level 3 and Unobservable Inputs (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Liabilities:
Allowance, notes receivable	$ 700	$ 200
Nonrecurring | Reported Value Measurement
Assets:
Cash and cash equivalents	736,816	445,283
Notes receivable, net	25,076	1,664
Liabilities:
Fixed-rate debt	1,113,866	1,141,381
Variable-rate debt	1,441,551	1,314,973
Nonrecurring | Estimate of Fair Value Measurement
Assets:
Cash and cash equivalents	736,816	445,283
Notes receivable, net	25,076	1,664
Liabilities:
Fixed-rate debt	1,110,712	1,137,166
Variable-rate debt	$ 1,441,551	$ 1,314,973