Pension (Plan Asset Allocation, Fair Value) (Details) - Pension Plan - U.S. Plans - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
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	2.00%
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation	40.00%
Debt securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation	45.00%
Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Target allocation	10.00%
Measured at NAV as a practical expedient
Defined Benefit Plan Disclosure [Line Items]
Measured at NAV as a practical expedient	$ 304,084	$ 343,219
Measured at NAV as a practical expedient | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Measured at NAV as a practical expedient	9,796	8,061
Measured at NAV as a practical expedient | Real estate
Defined Benefit Plan Disclosure [Line Items]
Measured at NAV as a practical expedient	6,198	16,390
Measured at NAV as a practical expedient | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Measured at NAV as a practical expedient	108,952	156,434
Measured at NAV as a practical expedient | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Measured at NAV as a practical expedient	146,080	125,671
Measured at NAV as a practical expedient | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Measured at NAV as a practical expedient	$ 33,058	$ 36,663