CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Net sales	$ 260,378	$ 217,513	$ 746,858	$ 506,913
Cost of goods sold	112,375	95,336	322,320	225,537
Gross profit	148,003	122,177	424,538	281,376
Expenses:
Selling, general and administrative	116,156	100,097	338,315	270,281
Other expense (income), net	2	(2,401)	(40)	(34,298)
Total expenses	116,158	97,696	338,275	235,983
Income before interest and income taxes	31,845	24,481	86,263	45,393
Interest income, net	58	51	173	64
Income before income taxes	31,903	24,532	86,436	45,457
Income tax expense	7,670	6,271	19,939	11,737
Net income	24,233	18,261	66,497	33,720
Other comprehensive income
Adjustments related to retirement plans; net of tax expense of $16 and $48 in 2021 and $10 and $30 in 2020	50	30	148	90
Comprehensive income	$ 24,283	$ 18,291	$ 66,645	$ 33,810
Common Stock [Member]
Other comprehensive income
Basic earnings per share (in dollars per share)	$ 1.35	$ 0.98	$ 3.67	$ 1.80
Diluted earnings per share (in dollars per share)	1.31	0.97	3.55	1.77
Cash dividends per share (in dollars per share)	0.25	0.20	0.72	0.55
Class A Common Stock [Member]
Other comprehensive income
Basic earnings per share (in dollars per share)	1.28	0.94	3.45	1.71
Diluted earnings per share (in dollars per share)	1.25	0.93	3.38	1.70
Cash dividends per share (in dollars per share)	$ 0.23	$ 0.19	$ 0.65	$ 0.52