Revenue Impact of ASC 606 in Current Period Balance Sheet (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Prepaid expenses and other current assets	$ 25,980	$ 41,286
Increase (Decrease) in Prepaid Expenses, Other	(6,507)
Accrued liabilities	128,820	132,064
Increase (Decrease) in Other Accrued Liabilities	(22,588)
DEFERRED INCOME TAXES	38,654	$ 24,775
Increase (Decrease) in Deferred Income Taxes	(1,999)
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Prepaid expenses and other current assets	32,487
Accrued liabilities	151,408
DEFERRED INCOME TAXES	$ 40,653

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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