Other Non-Current Liabilities Other Current Assets - Components of Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Other Current Assets - Components of Other Current Assets [Line Items]
Unbilled Receivables, Current	$ 21,006	$ 3,538
Other Assets, Miscellaneous, Current	$ 6,632	$ 8,082

Amount received for services rendered and products shipped, but not yet billed, for non-contractual agreements due within one year or the normal operating cycle, if longer.

No definition available.

Name:	us-gaap_UnbilledReceivablesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant