CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Revenue	$ 713,672	$ 501,003	$ 301,563
Cost of sales	176,814	121,104	73,751
Gross profit	536,858	379,899	227,812
Selling, general, and administrative	445,819	310,836	188,180
Income from operations	91,039	69,063	39,632
Other income (expense)
Interest income, net	1,295	1,306	558
Other income (expense)	29	179	136
Other income (expense)	1,324	1,485	694
Income from operations before income taxes	92,363	70,548	40,326
Provision for income taxes	14,447	14,759	12,605
Net income	$ 77,916	$ 55,789	$ 27,721
Basic earnings per share
Earnings per share, basic	$ 6.62	$ 4.67	$ 2.32
Diluted earnings per share
Earnings per share, diluted	$ 6.43	$ 4.62	$ 2.29
Weighted average shares outstanding -
Basic	11,771	11,947	11,924
Diluted	12,117	12,079	12,088
Cash dividends declared per share	$ 3.38	$ 2.19	$ 1.44