Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 48,214	$ 48,901	$ 101,727	$ 114,034
Other comprehensive income, net of tax:
Foreign currency translation	(44,584)	46,791	(29,073)	66,706
Net unrealized (loss) gain on cash flow hedges, net of tax of $(78), $(120), $154 and $235, respectively	(235)	(196)	251	383
Net unrealized (loss) gain on investment securities, net of tax of $(447), $758, $(1,813) and $1,102, respectively	(1,305)	1,291	(5,296)	1,876
Adjustments to pension and postretirement plans, net of tax of $(304)	0	0	0	(1,482)
Amortization of pension and postretirement costs, net of tax benefits of $2,564, $3,442, $5,368 and $6,956, respectively	7,868	6,624	16,040	13,335
Other comprehensive (loss) income, net of tax	(38,256)	54,510	(18,078)	80,818
Comprehensive income	$ 9,958	$ 103,411	$ 83,649	$ 194,852