Accounting for Derivative Instruments and Hedging Activities (Policies)	6 Months Ended
Jun. 30, 2017
Accounting for Derivative Instruments and Hedging Activities [Abstract]
Derivatives Policy	The Company uses derivative instruments to manage interest rate risk on variable debt and foreign exchange risk on the Sterling Notes, and does not hold or issue derivative instruments for speculative trading purposes.

Accounting for Derivative Instruments and Hedging Activities (Policies)

6 Months Ended

Jun. 30, 2017

Accounting for Derivative Instruments and Hedging Activities [Abstract]

The Company uses derivative instruments to manage interest rate risk on variable debt and foreign exchange risk on the Sterling Notes, and does not hold or issue derivative instruments for speculative trading purposes.