Fair Value Measurements and Derivative Instruments (Narrative) (Details) - USD ($)	Sep. 30, 2016	Jan. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Investment securities at a loss position for more than 12 months, aggregate unrealized holding losses (less than)	$ 1,000,000		$ 2,000,000
Investment securities at a loss position for more than 12 months, estimated fair value	14,000,000		36,000,000
Investment securities at a loss position for less than 12 months, aggregate unrealized holding losses (less than)	1,000,000		2,000,000
Investment securities at a loss position for less than 12 months, estimated fair value	81,000,000		146,000,000
Foreign exchange contracts
Derivative [Line Items]
Derivative notional amount	14,000,000		$ 13,000,000
Term Loan | Notes due December 2020
Derivative [Line Items]
Loan amount	300,000,000	$ 300,000,000
Cash Flow Hedge | Interest rate swaps
Derivative [Line Items]
Derivative notional amount	$ 300,000,000
Fixed interest rate	0.8826%