CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Revenues	$ 331,549	$ 358,899	$ 612,709	$ 654,848
Cost of sales	151,616	169,520	298,614	327,854
Gross profit	179,933	189,379	314,095	326,994
Selling, general and administrative expenses	123,338	141,548	236,688	246,585
Income from operations	56,595	47,831	77,407	80,409
Foreign currency losses, net	(687)	(261)	(918)	(1,478)
Interest income	49	131	146	326
Interest expense	(2,170)	(2,421)	(4,091)	(4,238)
Other income (expense), net	907	(604)	928	(14)
Income before income taxes	54,694	44,676	73,472	75,005
Income tax expense (benefit)	(1,857)	5,478	5,830	11,097
Net income	$ 56,551	$ 39,198	$ 67,642	$ 63,908
Net income per common share:
Basic (in dollars per share)	$ 0.84	$ 0.55	$ 1.00	$ 0.89
Diluted (in dollars per share)	$ 0.83	$ 0.55	$ 0.99	$ 0.87
Weighted average common shares outstanding:
Basic (in shares)	67,416	70,936	67,674	71,967
Diluted (in shares)	68,038	71,915	68,664	73,369