Financial Instruments - Fair Value and Notional Principal Amounts of Outstanding or Unsettled Derivative Instruments (Details) - Prepaid Expenses and Other Current Assets - Not Designated as Hedging Instrument - Foreign Exchange-forward Contracts - USD ($)		Jun. 30, 2016	Dec. 31, 2015
Derivatives Fair Value [Line Items]
Fair Value of Derivative, Asset	[1],[2]	$ 1,000,000
Foreign exchange-forward contracts	[1]	$ 34,000,000	$ 25,000,000

[1] Derivative contracts address foreign exchange fluctuations for the Euro versus the U.S. Dollar.

[2] We measure the fair value of our outstanding or unsettled derivatives using Level 2 fair value inputs, as we use a pricing model that takes into account the contract terms as well as current foreign currency exchange rates in active markets.