Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2025	Sep. 28, 2024	Sep. 27, 2025	Sep. 28, 2024
Segment Reporting Information [Line Items]
Net sales	$ 1,077,824	$ 997,831	$ 3,216,162	$ 2,845,230
Corporate expenses	276,115	206,700	786,545	600,131
Interest expense	(6)	(113)	(48)	(335)
Interest income	10,822	11,145	28,945	42,773
Realized and unrealized gains on short-term investments	(2,277)	164	5,925	529
Pension plan termination expense	4,830	0	4,830	0
Other income, net	627	(122)	(423)	(848)
Income before income taxes	280,451	217,774	816,114	642,250
Piping Systems
Segment Reporting Information [Line Items]
Net sales	709,669	635,183	2,074,222	1,891,732
Industrial Metals
Segment Reporting Information [Line Items]
Net sales	241,857	234,366	755,455	578,389
Climate
Segment Reporting Information [Line Items]
Net sales	126,298	128,282	386,485	375,109
Operating Segments
Segment Reporting Information [Line Items]
Net sales	1,094,008	1,020,380	3,260,299	2,897,767
Manufacturing costs	762,867	755,171	2,328,264	2,135,028
Sales and marketing expense	11,696	11,989	37,533	33,518
Distribution expense	12,015	10,853	37,007	31,978
Other segment items	21,443	13,801	24,102	38,207
Segment operating income	285,987	228,566	833,393	659,036
Operating Segments | Piping Systems
Segment Reporting Information [Line Items]
Net sales	718,404	653,884	2,101,562	1,932,521
Manufacturing costs	473,936	463,926	1,431,571	1,393,226
Sales and marketing expense	6,683	7,390	22,990	20,316
Distribution expense	11,017	9,744	33,541	28,740
Other segment items	10,609	9,223	(11,159)	21,700
Segment operating income	216,159	163,601	624,619	468,539
Operating Segments | Industrial Metals
Segment Reporting Information [Line Items]
Net sales	248,939	238,014	771,450	589,422
Manufacturing costs	208,456	208,227	650,255	498,084
Sales and marketing expense	1,619	1,044	4,179	2,565
Distribution expense	472	564	1,918	1,719
Other segment items	7,464	3,982	23,476	8,893
Segment operating income	30,928	24,197	91,622	78,161
Operating Segments | Climate
Segment Reporting Information [Line Items]
Net sales	126,665	128,482	387,287	375,824
Manufacturing costs	80,475	83,018	246,438	243,718
Sales and marketing expense	3,394	3,555	10,364	10,637
Distribution expense	526	545	1,548	1,519
Other segment items	3,370	596	11,785	7,614
Segment operating income	38,900	40,768	117,152	112,336
Intersegment sales
Segment Reporting Information [Line Items]
Net sales	(16,184)	(22,549)	(44,137)	(52,537)
Intersegment sales | Piping Systems
Segment Reporting Information [Line Items]
Net sales	(8,735)	(18,701)	(27,340)	(40,789)
Intersegment sales | Industrial Metals
Segment Reporting Information [Line Items]
Net sales	(7,082)	(3,648)	(15,995)	(11,033)
Intersegment sales | Climate
Segment Reporting Information [Line Items]
Net sales	(367)	(200)	(802)	(715)
Corporate expenses
Segment Reporting Information [Line Items]
Corporate expenses	(9,872)	(21,866)	(46,848)	(58,905)
Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment
Segment Reporting Information [Line Items]
Interest expense	(6)	(113)	(48)	(335)
Interest income	10,822	11,145	28,945	42,773
Realized and unrealized gains on short-term investments	(2,277)	164	5,925	529
Pension plan termination expense	4,830		4,830
Other income, net	$ 627	$ (122)	$ (423)	$ (848)