CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	Common Stock Class A Common Shares	Common Stock Class B Common Shares	Common Stock	Additional Paid In Capital	Retained Earnings Class A Common Shares	Retained Earnings Class B Common Shares	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Class A Common Shares	Class B Common Shares	Total
Balance at beginning of period at Dec. 31, 2023			$ 4,553	$ 142,124			$ 786,487	$ (20,408)			$ 912,756
Balance (in shares) at Dec. 31, 2023	17,203	2,155
Increase (Decrease) in Stockholders' Equity
Net income							82,355				82,355
Net change in AOCI								6,175			6,175
Dividends declared on Common Stock:
Dividends declared on Common Stock					$ (20,989)	$ (2,388)			$ (20,989)	$ (2,388)
Stock options exercised, net of shares withheld			32	1,784			(2,510)				(694)
Stock options exercised, net of shares withheld (in shares)	65
Conversion of Class B to Class A Common Shares (in shares)	5	(5)
Net change in notes receivable on Class A Common Stock				106							106
Deferred director compensation expense - Class A Common Stock				620							620
Deferred designed key employee compensation expense - Class A Common Stock				560							560
Deferred designed key employee compensation expense - Class A Common Stock (In shares)	11
Employee stock purchase plan - Class A Common Stock			3	573							576
Employee stock purchase plan - Class A Common Stock (in shares)	10
Stock-based awards, Performance stock units				108							108
Stock-based awards, Restricted stock, net of shares withheld			(3)	507			(440)				64
Stock-based awards, Restricted stock, net of shares withheld (in shares)	(1)
Stock-based awards, Stock options				456							456
Balance at end of period at Sep. 30, 2024			4,585	146,838			842,515	(14,233)			979,705
Balance (in shares) at Sep. 30, 2024	17,293	2,150
Balance at beginning of period at Jun. 30, 2024			4,581	144,139			825,496	(18,793)			955,423
Balance (in shares) at Jun. 30, 2024	17,275	2,150
Increase (Decrease) in Stockholders' Equity
Net income							26,543				26,543
Net change in AOCI								4,560			4,560
Dividends declared on Common Stock:
Dividends declared on Common Stock					(7,007)	(796)			(7,007)	(796)
Stock options exercised, net of shares withheld			4	1,767			(1,601)				170
Stock options exercised, net of shares withheld (in shares)	17
Net change in notes receivable on Class A Common Stock				60							60
Deferred director compensation expense - Class A Common Stock				109							109
Deferred designed key employee compensation expense - Class A Common Stock				164							164
Employee stock purchase plan - Class A Common Stock			1	177							178
Employee stock purchase plan - Class A Common Stock (in shares)	3
Stock-based awards, Performance stock units				36							36
Stock-based awards, Restricted stock, net of shares withheld			(1)	262			(120)				141
Stock-based awards, Restricted stock, net of shares withheld (in shares)	(2)
Stock-based awards, Stock options				124							124
Balance at end of period at Sep. 30, 2024			4,585	146,838			842,515	(14,233)			979,705
Balance (in shares) at Sep. 30, 2024	17,293	2,150
Balance at beginning of period at Dec. 31, 2024			4,587	148,053			853,627	(14,238)			992,029
Balance (in shares) at Dec. 31, 2024	17,298	2,150
Increase (Decrease) in Stockholders' Equity
Net income							108,496				108,496
Net change in AOCI								7,138			7,138
Dividends declared on Common Stock:
Dividends declared on Common Stock					(23,404)	(2,644)			(23,404)	(2,644)
Stock options exercised, net of shares withheld			12	3,974			(3,578)				408
Stock options exercised, net of shares withheld (in shares)	53
Conversion of Class B to Class A Common Shares (in shares)	1	(1)
Repurchase of Class A Common Stock				(8)			(64)				(72)
Repurchase of Class A Common Stock (in shares)	(1)
Net change in notes receivable on Class A Common Stock				(65)							(65)
Deferred director compensation expense - Class A Common Stock				437							437
Deferred designed key employee compensation expense - Class A Common Stock			(1)	405			(179)				225
Deferred designed key employee compensation expense - Class A Common Stock (In shares)	18
Employee stock purchase plan - Class A Common Stock			2	529							531
Employee stock purchase plan - Class A Common Stock (in shares)	8
Stock-based awards, Performance stock units				108							108
Stock-based awards, Restricted stock, net of shares withheld				1,078			(212)				866
Stock-based awards, Restricted stock, net of shares withheld (in shares)	10
Stock-based awards, Stock options				467							467
Balance at end of period at Sep. 30, 2025			4,600	154,978			932,042	(7,100)			1,084,520
Balance (in shares) at Sep. 30, 2025	17,387	2,149
Balance at beginning of period at Jun. 30, 2025			4,597	153,733			911,337	(9,561)			1,060,106
Balance (in shares) at Jun. 30, 2025	17,378	2,149
Increase (Decrease) in Stockholders' Equity
Net income							29,744				29,744
Net change in AOCI								2,461			2,461
Dividends declared on Common Stock:
Dividends declared on Common Stock					$ (7,802)	$ (881)			$ (7,802)	$ (881)
Stock options exercised, net of shares withheld			2	366			(325)				43
Stock options exercised, net of shares withheld (in shares)	7
Net change in notes receivable on Class A Common Stock				(17)							(17)
Deferred director compensation expense - Class A Common Stock				135							135
Deferred designed key employee compensation expense - Class A Common Stock				147							147
Employee stock purchase plan - Class A Common Stock			1	162							163
Employee stock purchase plan - Class A Common Stock (in shares)	2
Stock-based awards, Performance stock units				36							36
Stock-based awards, Restricted stock, net of shares withheld				264			(31)				233
Stock-based awards, Stock options				152							152
Balance at end of period at Sep. 30, 2025			$ 4,600	$ 154,978			$ 932,042	$ (7,100)			$ 1,084,520
Balance (in shares) at Sep. 30, 2025	17,387	2,149