CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 337,257	$ 271,109	$ 282,807
Other comprehensive income (loss):
Reclassification adjustments for derivatives, net of tax	4,210	4,361	4,531
Pension and other postretirement adjustments, net of tax	(1,302)	3,049	9,415
Cumulative translation adjustment	110,421	(76,822)	(63,441)
Tax effect of reversal of indefinite assertion on certain intercompany loans	(3,932)	0	0
Reclassification of foreign currency translation to earnings upon sale of businesses	2,749	14,257	(4,725)
Other comprehensive income (loss)	112,146	(55,155)	(54,220)
Comprehensive income	$ 449,403	$ 215,954	$ 228,587