FAIR VALUE (Assets and Liabilities Not Measured at Fair Value) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Assets:
Cash and Restricted cash	$ 1,188,284	$ 620,135	$ 848,600	$ 724,215
Liabilities:
Variable-rate debt	2,536,978	2,229,958
Allowance for doubtful accounts	15,700	15,600
Allowance for notes receivable	200	200
Level 1 | Carrying Amount
Assets:
Cash and Restricted cash	1,188,284	620,135
Level 1 | Estimated Fair Value
Assets:
Cash and Restricted cash	1,188,284	620,135
Level 3 | Carrying Amount
Assets:
Accounts receivable, net	17,711	12,279
Notes receivable, net	56,511	36,379
Level 3 | Estimated Fair Value
Assets:
Accounts receivable, net	17,711	12,279
Notes receivable, net	56,511	36,379
Level 2 | Carrying Amount
Liabilities:
Fixed-rate debt	1,902,175	1,908,660
Variable-rate debt	2,536,978	2,229,958
Level 2 | Estimated Fair Value
Liabilities:
Fixed-rate debt	1,829,057	1,949,773
Variable-rate debt	$ 2,536,978	$ 2,229,958