Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Net Sales	$ 221,962	$ 201,183	$ 434,017	$ 396,092
Operating Earnings, Excluding Indirect Operating Expenses	48,068	40,714	91,503	81,637
Reconciliation from Segment Totals to Consolidated [Abstract]
Combination-related expenses	(4,291)	(4,338)	(9,500)	(13,413)
Indirect Operating Expenses	(19,369)	(16,642)	(35,511)	(32,959)
Amortization	(1,845)	(1,831)	(3,698)	(3,604)
Operating income	22,563	17,903	42,794	31,661
Other income (expense), net	261	(1,571)	(108)	(1,676)
Interest Expense	(1,602)	(780)	(3,294)	(1,436)
Interest Income	571	540	1,060	1,063
Income Before Taxes and Equity in Net Income of Associated Companies	21,793	16,092	40,452	29,612
North America [Member]
Segment Reporting Information [Line Items]
Net Sales	97,392	90,331	189,212	177,672
Operating Earnings, Excluding Indirect Operating Expenses	23,237	19,621	43,602	40,258
North America [Member] | Intersegment Sales Elimination [Member]
Segment Reporting Information [Line Items]
Net Sales	1,800	2,500	4,800	4,600
EMEA [Member]
Segment Reporting Information [Line Items]
Net Sales	60,166	54,507	122,221	108,434
Operating Earnings, Excluding Indirect Operating Expenses	9,096	8,217	19,389	17,463
EMEA [Member] | Intersegment Sales Elimination [Member]
Segment Reporting Information [Line Items]
Net Sales	5,400	5,000	11,000	9,800
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Sales	55,348	47,724	104,125	92,874
Operating Earnings, Excluding Indirect Operating Expenses	14,621	11,812	26,763	22,055
Asia Pacific [Member] | Intersegment Sales Elimination [Member]
Segment Reporting Information [Line Items]
Net Sales	100	100	400	100
South America [Member]
Segment Reporting Information [Line Items]
Net Sales	9,056	8,621	18,459	17,112
Operating Earnings, Excluding Indirect Operating Expenses	1,114	1,064	1,749	1,861
South America [Member] | Intersegment Sales Elimination [Member]
Segment Reporting Information [Line Items]
Net Sales	$ 100	$ 100	$ 100	$ 100