Pension (Plan Asset Allocation, Fair Value) (Details) - U.S. Plans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 318,414	$ 316,184	$ 340,082
Target allocation	100.00%
Short Term Investments
Defined Benefit Plan Disclosure [Line Items]
Target allocation	3.00%
Real Estate
Defined Benefit Plan Disclosure [Line Items]
Target allocation	5.00%
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation	45.00%
Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation	32.00%
Hedge Funds
Defined Benefit Plan Disclosure [Line Items]
Target allocation	15.00%
Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 318,414	316,184
Measured at NAV | Short Term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,766	9,558
Measured at NAV | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,812	17,376
Measured at NAV | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	148,302	138,497
Measured at NAV | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	96,658	101,895
Measured at NAV | Hedge Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 48,876	$ 48,858