XML 94 R76.htm IDEA: XBRL DOCUMENT v3.8.0.1
Derivative Instruments Derivative Instruments - Additional Details (Details)
12 Months Ended
Dec. 31, 2017
Not Designated as Hedging Instrument [Member]  
Derivative [Line Items]  
Maturities of forward of contracts 45 days
Designated as Hedging Instrument [Member]  
Derivative [Line Items]  
Maturities of foreign currency forward contracts 18 months