Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenues	$ 1,875,425	$ 1,805,909	$ 1,808,376
Cost of Goods and Services Sold	1,325,388	1,260,318	1,260,855
Gross profit	550,037	545,591	547,521
Selling, general and administrative expenses	444,904	432,067	443,704
Impairment of Intangible Assets, Finite-lived	10,039	0	0
Restructuring costs (Note 3)	8,008	2,661	1,032
Gain (Loss) on Disposition of Business	5,722	0	0
Net (gain) loss on sale of assets	(1,700)	(256)	11
Operating income	83,064	111,119	102,774
Interest expense, net	20,097	20,581	15,747
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	(12,127)	(3,056)	(3,149)
Other (income) expense, net	(143)	(784)	472
Earnings before income taxes	75,237	94,378	89,704
Income tax expense	21,068	44,552	30,850
Net earnings	$ 54,169	$ 49,826	$ 58,854
Earnings per share:
Earnings Per Share, Basic (in dollars per share)	$ 1.94	$ 1.80	$ 2.17
Diluted earnings per share (in dollars per share)	$ 1.92	$ 1.75	$ 2.10
Weighted average shares outstanding:
Basic (in shares)	27,945	27,611	27,107
Diluted (in shares)	28,223	28,418	28,072