Accounting Changes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues	$ 761,608	$ 735,994	$ 724,944
Cost of Goods and Services Sold	520,803	508,677	490,915
Gross Profit	240,805	227,317	234,029
Selling, general and administrative expenses	177,187	172,271	169,683
Impairment of Intangible Assets, Finite-lived	0	10,039	0
Restructuring costs (Note 5)	1,558	7,353	2,661
Gain (Loss) on Disposition of Business	3,739	5,722	0
Net loss (gain) on sale of assets	237	(1,031)	(31)
Operating income	53,411	32,963	61,716
Interest expense, net	17,202	20,046	20,578
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	(396)	(12,127)	(3,056)
Other income, net	(309)	(92)	(728)
Earnings before income taxes	40,587	25,136	44,922
Income tax (benefit) expense	(15,859)	9,259	25,214
Net earnings	$ 56,446	15,877	$ 19,708
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues		(59,683)
Cost of Goods and Services Sold		(42,036)
Gross Profit		(17,647)
Selling, general and administrative expenses		(2,281)
Impairment of Intangible Assets, Finite-lived		0
Restructuring costs (Note 5)		0
Gain (Loss) on Disposition of Business		539
Net loss (gain) on sale of assets		0
Operating income		(15,905)
Interest expense, net		0
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component		0
Other income, net		0
Earnings before income taxes		(15,905)
Income tax (benefit) expense		(2,486)
Net earnings		(13,419)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues		676,311
Cost of Goods and Services Sold		466,641
Gross Profit		209,670
Selling, general and administrative expenses		169,990
Impairment of Intangible Assets, Finite-lived		10,039
Restructuring costs (Note 5)		7,353
Gain (Loss) on Disposition of Business		6,261
Net loss (gain) on sale of assets		(1,031)
Operating income		17,058
Interest expense, net		20,046
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component		(12,127)
Other income, net		(92)
Earnings before income taxes		9,231
Income tax (benefit) expense		6,773
Net earnings		$ 2,458