Reclassifications Out of Accumulated Other Comprehensive Income (Loss) to Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2025	Jun. 30, 2024	Jun. 29, 2025	Jun. 30, 2024
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income (expense)	$ (15)	$ 13	$ (89)	$ (92)
Unrealized (losses) gains, net	(232)	0	350	1,780
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income (expense)	(15)	13	(89)	(92)
Reclassifications, net of tax			(89)	(92)
Amortization of Prior Service Credit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax	2	2	3	3
Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax	$ (245)	$ 15	$ 264	$ 1,691