Consolidated Statements of Cash Flows (Parenthetical) $ in Thousands	12 Months Ended
Dec. 31, 2017 USD ($)
Statement of Cash Flows [Abstract]
Tax impact of non-cash reclassification of the 2036 Convertible Notes conversion liability to additional paid in capital	$ 18,025

Adjustments to Additional Paid in Capital, Convertible Debt with Conversion Feature, Tax Impact

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration