Derivative Instruments - Narrative (Details) - Foreign exchange forward contracts - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Not designated as hedging instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative notional amount	$ 130,000,000
Designated as hedging instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cash flow hedge gain (loss) be be reclassified within 12 months	2,000,000
Gain (loss) on cash flow hedge ineffectiveness	0
Designated as hedging instrument | Cash flow hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative notional amount	307,000,000	$ 65,000,000
Selling and general expenses
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain on derivatives not designated as hedging instruments	$ 3,000,000