Net Income per Share - Computation of Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 25, 2022	Jun. 26, 2021	Jun. 25, 2022	Jun. 26, 2021
Schedule Of Earnings Per Share Basic And Diluted By Common Class [Line Items]
Earnings to Common Shareholders, As reported - basic	$ 53,349	$ 59,195	$ 51,394	$ 124,760
Weighted-average number of common shares — basic	12,319	12,283	12,309	12,277
EPS, As reported - basic	$ 4.33	$ 4.82	$ 4.18	$ 10.16
Add: effect of dilutive common shares Share-based awards	52	160	63	161
Earnings to Common Shareholders, Net effect of unvested participating shares	$ 132	$ 217	$ 129	$ 513
Common Shares, Net effect of unvested participating shares		66		73
Net Income Available to Common Stockholders, Diluted, Total	$ 53,349	$ 59,195	$ 51,394	$ 124,760
Weighted Average Number of Shares Outstanding, Diluted, Total	12,341	12,465	12,341	12,461
EPS, Net income per common share - diluted	$ 4.31	$ 4.75	$ 4.15	$ 10.01
Common Class A
Schedule Of Earnings Per Share Basic And Diluted By Common Class [Line Items]
Earnings to Common Shareholders, As reported - basic	$ 44,261	$ 48,710	$ 42,631	$ 102,354
Weighted-average number of common shares — basic	10,221	10,108	10,210	10,072
EPS, As reported - basic	$ 4.33	$ 4.82	$ 4.18	$ 10.16
Common Class B
Schedule Of Earnings Per Share Basic And Diluted By Common Class [Line Items]
Earnings to Common Shareholders, As reported - basic	$ 8,956	$ 10,268	$ 8,634	$ 21,893
Weighted-average number of common shares — basic	2,068	2,131	2,068	2,155
EPS, As reported - basic	$ 4.33	$ 4.82	$ 4.18	$ 10.16
Earnings to Common Shareholders, Class B Common Stock	$ 8,956	$ 10,268	$ 8,634	$ 21,893
Class B Common Stock	2,068	2,131	2,068	2,155