Consolidated Statements Of Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated Statements Of Shareholders' Equity
Unrealized gain on interest rate swap and foreign currency forward contracts, deferred income tax expense	$ 7,050	$ 12,228	$ 3,742
Foreign currency translation adjustments, deferred income tax (benefit)	$ (1,226)	$ (2,548)	$ (1,565)