FAIR VALUE (Assets and Liabilities Measured on a Nonrecurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Assets:
Cash and restricted cash	$ 612,548	$ 964,300	$ 962,215	$ 915,139
Liabilities:
Variable-rate debt:	1,644,791	1,350,914
Allowance for doubtful accounts	9,800	9,300
Allowance for notes receivable	100	100
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Carrying Amount
Assets:
Cash and restricted cash	612,548	914,165
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Estimated Fair Value
Assets:
Cash and restricted cash	612,548	914,165
Recurring | Significant Other Observable Inputs (Level 2) | Carrying Amount
Liabilities:
Fixed-rate debt:	1,651,695	1,526,875
Variable-rate debt:	1,644,791	1,350,914
Recurring | Significant Other Observable Inputs (Level 2) | Estimated Fair Value
Liabilities:
Fixed-rate debt:	1,644,391	1,554,766
Variable-rate debt:	1,644,791	1,350,914
Recurring | Significant Unobservable Inputs (Level 3) | Carrying Amount
Assets:
Accounts receivable, net	15,437	13,041
Notes receivable, net	40,220	5,864
Recurring | Significant Unobservable Inputs (Level 3) | Estimated Fair Value
Assets:
Accounts receivable, net	15,437	13,041
Notes receivable, net	$ 40,220	$ 5,864