XML 44 R31.htm IDEA: XBRL DOCUMENT v3.10.0.1
Derivative Instruments (Narrative) (Details) - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2018
Dec. 31, 2017
Ineffectiveness on Foreign Currency Fair Value Hedges is Immaterial $ 0  
Senior Unsecured Notes 3.375% due 2024    
Debt instrument, face amount 600,000,000  
Designated as Hedging Instrument | Foreign Exchange Contract    
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months 5,000,000 $ 7,000,000
Designated as Hedging Instrument | Cash Flow Hedging    
Derivative, terminated notional amount 600,000,000  
Designated as Hedging Instrument | Interest rate swap liability    
Derivative, terminated notional amount $ 500,000,000