Components of Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance		$ (63,800)		$ (45,900)	$ (34,700)
Other comprehensive income before reclassifications		15,400		(20,200)	(23,200)
Amounts reclassified to consolidated statement of income	[1]	14,500	[2]	(100)	2,200
Tax benefit (expense)		(2,500)		2,400	9,800
Other comprehensive (loss) income		27,400		(17,900)	(11,200)
Ending balance		(36,400)		(63,800)	(45,900)
Foreign Currency Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance		(50,000)		(38,500)	(16,400)
Other comprehensive income before reclassifications		20,000		(12,100)	(35,800)
Amounts reclassified to consolidated statement of income	[1]	0	[2]	0	0
Tax benefit (expense)		(1,600)		600	13,700
Other comprehensive (loss) income		18,400		(11,500)	(22,100)
Ending balance		(31,600)		(50,000)	(38,500)
Defined Benefit Plans
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance		(13,200)		(11,500)	(17,700)
Other comprehensive income before reclassifications		3,300		(2,200)	3,000
Amounts reclassified to consolidated statement of income	[1]	11,900	[2]	0	5,200
Tax benefit (expense)		(2,600)		500	(2,000)
Other comprehensive (loss) income		12,600		(1,700)	6,200
Ending balance		(600)		(13,200)	(11,500)
Derivative Agreements
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance		(600)		4,100	(600)
Other comprehensive income before reclassifications		(7,900)		(5,900)	9,600
Amounts reclassified to consolidated statement of income	[1]	2,600	[2]	(100)	(3,000)
Tax benefit (expense)		1,700		1,300	(1,900)
Other comprehensive (loss) income		(3,600)		(4,700)	4,700
Ending balance		$ (4,200)		$ (600)	$ 4,100

[1] Amounts reclassified to cost of sales or selling, general and administrative expenses.

[2] In connection with the termination of international defined benefit pension plans, $11.9 was reclassified to SG&A.  All other amounts were reclassified to Cost of Sales