CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Net sales	$ 634,360	$ 573,366	$ 1,246,684	$ 1,126,918
Cost of sales	346,993	316,441	682,665	619,052
Gross profit	287,367	256,925	564,019	507,866
Selling, general and administrative expenses	137,548	131,792	275,875	262,265
Restructuring expenses	1,988	0	3,630	4,797
Operating income	147,831	125,133	284,514	240,804
Other (income) expense - net	(50)	372	(4,499)	64
Interest expense	11,140	11,304	22,140	22,856
Income before income taxes	136,741	113,457	266,873	217,884
Provision for income taxes	29,615	29,613	60,789	58,141
Net income	$ 107,126	$ 83,844	$ 206,084	$ 159,743
Basic earnings per common share (in dollars per share)	$ 1.40	$ 1.10	$ 2.69	$ 2.09
Diluted earnings per common share (in dollars per share)	$ 1.38	$ 1.08	$ 2.65	$ 2.07
Share data:
Basic weighted average common shares outstanding (in shares)	76,539	76,220	76,479	76,167
Diluted weighted average common shares outstanding (in shares)	77,704	77,320	77,722	77,107