CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Revenue	$ 165,876	$ 98,596
Cost of sales	40,729	23,788
Gross profit	125,147	74,808
Selling, general, and administrative	100,432	60,125
Income from operations	24,715	14,683
Other income (expense)
Interest income, net	312	249
Other income (expense)	(6)	(1)
Other income (expense)	306	248
Income from operations before income taxes	25,021	14,931
Provision for income taxes	4,271	2,709
Net income	$ 20,750	$ 12,222
Basic earnings per share
Earnings per share, basic	$ 1.75	$ 1.02
Diluted earnings per share
Earnings per share, diluted	$ 1.70	$ 1.01
Weighted average shares outstanding -
Basic	11,880	12,030
Diluted	12,240	12,139
Cash dividends declared per share	$ 0.75	$ 0.48