FAIR VALUE (Assets and Liabilities Measured on a Nonrecurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Liabilities:
Allowance, Accounts receivable	$ 9,300	$ 7,900
Allowance, Notes receivable	100	100
Recurring
Assets:
Cash	50,135	18
Recurring \| Reported Value Measurement
Assets:
Notes receivable, net	5,864	155
Recurring \| Estimate of Fair Value Measurement
Assets:
Notes receivable, net	5,864	155
Recurring \| Level 1
Assets:
Cash	50,135	18
Recurring \| Level 1 \| Reported Value Measurement
Assets:
Cash	810,924	665,492
Recurring \| Level 1 \| Estimate of Fair Value Measurement
Assets:
Cash	810,924	665,492
Recurring \| Level 2 \| Reported Value Measurement
Liabilities:
Fixed-rate debt	1,526,875	1,184,141
Variable-rate debt	1,350,914	1,524,319
Recurring \| Level 2 \| Estimate of Fair Value Measurement
Liabilities:
Fixed-rate debt	1,554,766	1,224,573
Variable-rate debt	1,350,914	1,524,319
Recurring \| Level 3 \| Reported Value Measurement
Assets:
Accounts receivable, net	13,041	9,883
Recurring \| Level 3 \| Estimate of Fair Value Measurement
Assets:
Accounts receivable, net	$ 13,041	$ 9,883

Fair value portion of amount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible.

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