Consolidated Statements Of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	$ 281	$ (371)	$ (729)
Derivative financial instruments adjustment, tax (benefit)	(503)	111	727
Net gains or losses and prior service costs, tax (benefit)	(319)	(2,518)	(1,874)
Amortization of prior service costs and net gains or losses, tax	$ 3,028	$ 4,234	$ 4,398