Revision of Previously Issued Consolidated Financial Statements (Statement of Cash Flows)(Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended		12 Months Ended
	Jun. 28, 2025	Mar. 29, 2025	Dec. 28, 2024	Jun. 29, 2024	Mar. 30, 2024	Dec. 30, 2023	Mar. 29, 2025	Mar. 30, 2024	Jun. 28, 2025	Jun. 29, 2024	Sep. 27, 2025	Sep. 28, 2024	Sep. 30, 2023
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net earnings	$ 58,486	$ 54,610	$ 57,526	$ 59,111	$ 54,506	$ 52,635	$ 112,136	$ 107,141	$ 170,622	$ 166,252	$ 235,028	$ 208,786	$ 175,156
Depreciation			22,429			20,695	44,779	41,702	68,252	63,334	94,013	85,878	77,763
Amortization			2,323			2,720	4,629	5,296	6,996	7,677	9,715	10,149	11,541
Deferred income taxes			(4,261)			(3,519)	(12,824)	(18,393)	(19,642)	(26,458)	(6,545)	(29,651)	(34,997)
Equity-based compensation expense			4,325			4,165	8,020	7,212	12,669	11,301	16,708	14,959	10,582
Loss on sale of businesses											0	0	900
Asset Impairment and Inventory Write-Down								6,925	10,988	8,637	13,848	29,176	18,973
Gain on sale of buildings											0	(979)	(10,030)
Pension settlement											0	0	12,542
Other			1,401			(2,478)	2,291	2,207	3,648	5,374	4,432	6,283	6,244
Receivables			(63,037)			71,587	(123,555)	30,169	(105,346)	(5,977)	(87,070)	35,962	(69,275)
Unbilled receivables			(36,140)			(105,723)	(31,216)	(137,181)	(37,642)	(108,731)	(64,588)	(50,474)	(35,423)
Inventories			(48,612)			(47,993)	(54,040)	(80,278)	(65,256)	(108,283)	(51,772)	(131,330)	(127,442)
Accounts payable			(22,973)			(5,752)	1,975	1,847	(4,201)	918	24,711	26,446	28,641
Contract advances and progress billings			(4,043)			105,234	8,501	65,091	9,009	13,582	81,597	(41,717)	39,448
Accrued expenses			(27,301)			(47,662)	(29,523)	(7,672)	(4,796)	26,172	3,743	7,900	(3,185)
Accrued income taxes			(6,652)			12,760	(22,429)	11,202	(20,095)	10,444	(20,214)	14,502	23,644
Net pension and post retirement liabilities			636			2,957	12,067	5,687	14,644	8,783	18,194	11,791	13,940
Other assets and liabilities			(8,531)			2,296	(13,705)	(21,819)	(7,453)	(22,625)	1,286	181	629
Net cash provided (used) by operating activities			(132,910)			61,922	(92,894)	19,136	32,397	50,400	273,086	197,862	139,651
Acquisitions of businesses, net of cash acquired						(5,212)		(5,911)		(5,911)	(41,179)	(5,911)	0
Purchase of property, plant and equipment			(32,778)			(39,050)	(70,382)	(80,510)	(103,041)	(113,823)	(144,731)	(151,995)	(177,309)
Net proceeds from businesses sold			13,487				13,487		13,487	1,627	13,487	1,627	1,892
Net proceeds from buildings sold											0	1,453	19,702
Other investing transactions			169			(479)	(2,062)	(515)	(2,844)	(646)	(2,833)	(766)	(11,455)
Net cash provided (used) by investing activities			(19,122)			(44,741)	(58,957)	(86,936)	(92,398)	(118,753)	(175,256)	(155,592)	(167,170)
Proceeds from revolving lines of credit			426,500			279,500	752,500	509,500	957,500	784,500	1,229,500	1,038,500	1,044,101
Payments on revolving lines of credit			(197,000)			(223,000)	(462,000)	(425,000)	(1,001,500)	(691,000)	(1,410,000)	(1,029,500)	(1,017,420)
Proceeds from long-term debt									250,000		250,000	0	0
Payments on long-term debt											0	0	(916)
Payments on finance lease obligations			(2,119)			(1,183)	(4,469)	(2,508)	(7,128)	(4,106)	(10,159)	(6,037)	(4,313)
Payment of dividends			(8,961)			(8,619)	(18,106)	(17,572)	(27,247)	(26,521)	(36,430)	(35,476)	(34,074)
Proceeds from sale of treasury stock						581	7,825	7,579	10,970	7,579	19,568	15,685	19,785
Purchase of outstanding shares for treasury			(55,692)			(8,711)	(126,425)	(20,238)	(127,808)	(21,832)	(142,707)	(36,738)	(29,306)
Proceeds from sale of stock held by SECT			9,665			5,001	19,289	15,788	20,287	16,670	32,664	28,202	15,713
Purchase of stock held by SECT			(8,087)			(4,561)	(14,808)	(9,407)	(18,505)	(14,296)	(28,985)	(22,837)	(14,251)
Other financing transactions			(439)				(1,457)		(1,600)		(1,742)	0	(2,027)
Net cash provided (used) by financing activities			163,867			39,008	152,349	58,142	54,969	50,994	(98,291)	(48,201)	(22,708)
Effect of exchange rate changes on cash			(2,564)			1,495	(2,309)	245	(491)	(267)	(1,863)	1,324	2,043
Increase (decrease) in cash, cash equivalents and restricted cash			9,271			57,684	(1,811)	(9,413)	(5,523)	(17,626)	(2,324)	(4,607)	(48,184)
Cash, cash equivalents and restricted cash at beginning of year(1)	62,726	73,808	64,537	59,731	126,828	69,144	64,537	69,144	64,537	69,144	64,537	69,144	117,328
Cash, cash equivalents and restricted cash at end of year (1)	59,014	62,726	73,808	51,518	59,731	126,828	62,726	59,731	59,014	51,518	62,213	64,537	69,144
Interest paid											70,977	65,382	59,453
Income taxes paid, net of refunds											100,347	78,482	69,253
Treasury shares issued as compensation			3,186			2,574	6,288	5,325	6,288	5,323	6,289	5,323	4,174
Assets acquired through lease financing			17,172			8,133	23,999	19,716	35,657	28,910	47,014	39,383	64,034
(1) Cash related to assets held for sale included in ending cash flow cash balance Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents												2,720
Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net earnings	59,707	55,754	53,113	56,360	60,003	47,812	108,867	107,815	168,574	164,175		207,220	170,998
Depreciation			23,478			20,927	45,822	42,276	69,292	64,302		82,957	78,692
Amortization			2,323			2,720	4,629	5,296	6,996	7,677		10,149	11,541
Deferred income taxes			(3,577)			(4,547)	(12,252)	(17,805)	(18,645)	(26,483)		(31,735)	(35,531)
Equity-based compensation expense			4,325			4,165	8,020	7,212	12,669	11,301		14,959	10,582
Loss on sale of businesses													900
Asset Impairment and Inventory Write-Down								6,925	10,988	8,637		29,176	18,973
Gain on sale of buildings												(979)	(10,030)
Pension settlement													12,542
Other			2,708			(2,478)	2,997	2,207	4,399	5,374		6,512	6,244
Receivables			(63,037)			58,887	(123,555)	17,469	(105,346)	(18,677)		23,262	(56,575)
Unbilled receivables			(31,073)			(51,015)	(26,967)	(86,197)	(35,174)	(57,723)		2,856	(87,915)
Inventories			(48,711)			(46,852)	(54,209)	(77,396)	(64,095)	(105,629)		(126,978)	(130,378)
Accounts payable			(22,973)			(5,752)	1,975	1,847	(3,301)	918		26,446	28,641
Contract advances and progress billings			(1,314)			64,171	9,964	24,512	8,798	(26,882)		(84,296)	79,983
Accrued expenses			(29,372)			(31,814)	(30,966)	903	(6,645)	36,928		26,493	(1,692)
Accrued income taxes			(9,698)			12,324	(24,986)	10,833	(22,669)	9,832		16,219	22,869
Net pension and post retirement liabilities			1,555			2,957	12,986	5,687	15,563	8,783		11,791	13,940
Other assets and liabilities			(10,031)			(11,114)	(15,187)	(35,195)	(8,941)	(35,978)		(11,708)	2,151
Net cash provided (used) by operating activities			(132,284)			60,391	(92,862)	16,389	32,463	46,555		202,344	135,935
Acquisitions of businesses, net of cash acquired						(5,212)		(5,911)		(5,911)		(5,911)
Purchase of property, plant and equipment			(32,778)			(37,416)	(70,382)	(77,530)	(103,041)	(109,616)		(156,018)	(173,286)
Net proceeds from businesses sold			13,487				13,487		13,487	1,627		1,627	1,892
Net proceeds from buildings sold												1,453	19,702
Other investing transactions			169			(479)	(2,062)	(515)	(2,844)	(646)		(766)	(11,455)
Net cash provided (used) by investing activities			(19,122)			(43,107)	(58,957)	(83,956)	(92,398)	(114,546)		(159,615)	(163,147)
Proceeds from revolving lines of credit			426,500			279,500	752,500	509,500	957,500	784,500		1,038,500	1,044,101
Payments on revolving lines of credit			(197,000)			(223,000)	(462,000)	(425,000)	(1,001,500)	(691,000)		(1,029,500)	(1,017,420)
Proceeds from long-term debt									250,000
Payments on long-term debt													(916)
Payments on finance lease obligations			(2,745)			(1,286)	(4,501)	(2,741)	(7,194)	(4,468)		(6,496)	(4,620)
Payment of dividends			(8,961)			(8,619)	(18,106)	(17,572)	(27,247)	(26,521)		(35,476)	(34,074)
Proceeds from sale of treasury stock						581	7,825	7,579	10,970	7,579		15,685	19,785
Purchase of outstanding shares for treasury			(55,692)			(8,711)	(126,425)	(20,238)	(127,808)	(21,832)		(36,738)	(29,306)
Proceeds from sale of stock held by SECT			9,665			5,001	19,289	15,788	20,287	16,670		28,202	15,713
Purchase of stock held by SECT			(8,087)			(4,561)	(14,808)	(9,407)	(18,505)	(14,296)		(22,837)	(14,251)
Other financing transactions			(439)				(1,457)		(1,600)				(2,027)
Net cash provided (used) by financing activities			163,241			38,905	152,317	57,909	54,903	50,632		(48,660)	(23,015)
Effect of exchange rate changes on cash			(2,564)			1,495	(2,309)	245	(491)	(267)		1,324	2,043
Increase (decrease) in cash, cash equivalents and restricted cash			9,271			57,684	(1,811)	(9,413)	(5,523)	(17,626)		(4,607)	(48,184)
Cash, cash equivalents and restricted cash at beginning of year(1)	62,726	73,808	64,537	59,731	126,828	69,144	64,537	69,144	64,537	69,144	64,537	69,144	117,328
Cash, cash equivalents and restricted cash at end of year (1)	59,014	62,726	73,808	51,518	59,731	126,828	62,726	59,731	59,014	51,518		64,537	69,144
Interest paid												61,164	63,193
Income taxes paid, net of refunds												78,482	69,253
Treasury shares issued as compensation			3,186			2,574	6,288	5,325	6,288	5,323		5,323	4,174
Assets acquired through lease financing			18,862			7,845	25,094	18,160	36,787	27,034		45,086	61,805
(1) Cash related to assets held for sale included in ending cash flow cash balance Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents												2,720
Revision of Prior Period, Error Correction, Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net earnings	(1,221)	(1,144)	4,413	2,751	(5,497)	4,823	3,269	(674)	2,048	2,077		1,566	4,158
Depreciation			(1,049)			(232)	(1,043)	(574)	(1,040)	(968)		2,921	(929)
Amortization			0			0	0	0	0	0		0	0
Deferred income taxes			(684)			1,028	(572)	(588)	(997)	25		2,084	534
Equity-based compensation expense			0			0	0	0	0	0		0	0
Loss on sale of businesses													0
Asset Impairment and Inventory Write-Down								0	0	0		0	0
Gain on sale of buildings												0	0
Pension settlement													0
Other			(1,307)			0	(706)	0	(751)	0		(229)	0
Receivables			0			12,700	0	12,700	0	12,700		12,700	(12,700)
Unbilled receivables			(5,067)			(54,708)	(4,249)	(50,984)	(2,468)	(51,008)		(53,330)	52,492
Inventories			99			(1,141)	169	(2,882)	(1,161)	(2,654)		(4,352)	2,936
Accounts payable			0			0	0	0	(900)	0		0	0
Contract advances and progress billings			(2,729)			41,063	(1,463)	40,579	211	40,464		42,579	(40,535)
Accrued expenses			2,071			(15,848)	1,443	(8,575)	1,849	(10,756)		(18,593)	(1,493)
Accrued income taxes			3,046			436	2,557	369	2,574	612		(1,717)	775
Net pension and post retirement liabilities			(919)			0	(919)	0	(919)	0		0	0
Other assets and liabilities			1,500			13,410	1,482	13,376	1,488	13,353		11,889	(1,522)
Net cash provided (used) by operating activities			(626)			1,531	(32)	2,747	(66)	3,845		(4,482)	3,716
Acquisitions of businesses, net of cash acquired						0		0		0		0
Purchase of property, plant and equipment			0			(1,634)	0	(2,980)	0	(4,207)		4,023	(4,023)
Net proceeds from businesses sold			0				0		0	0		0	0
Net proceeds from buildings sold												0	0
Other investing transactions			0			0	0	0	0	0		0	0
Net cash provided (used) by investing activities			0			(1,634)	0	(2,980)	0	(4,207)		4,023	(4,023)
Proceeds from revolving lines of credit			0			0	0	0	0	0		0	0
Payments on revolving lines of credit			0			0	0	0	0	0		0	0
Proceeds from long-term debt									0
Payments on long-term debt													0
Payments on finance lease obligations			626			103	32	233	66	362		459	307
Payment of dividends			0			0	0	0	0	0		0	0
Proceeds from sale of treasury stock						0	0	0	0	0		0	0
Purchase of outstanding shares for treasury			0			0	0	0	0	0		0	0
Proceeds from sale of stock held by SECT			0			0	0	0	0	0		0	0
Purchase of stock held by SECT			0			0	0	0	0	0		0	0
Other financing transactions			0				0		0				0
Net cash provided (used) by financing activities			626			103	32	233	66	362		459	307
Effect of exchange rate changes on cash			0			0	0	0	0	0		0	0
Increase (decrease) in cash, cash equivalents and restricted cash			0			0	0	0	0	0		0	0
Cash, cash equivalents and restricted cash at beginning of year(1)	0	0	0	0	0	0	0	0	0	0	$ 0	0	0
Cash, cash equivalents and restricted cash at end of year (1)	$ 0	$ 0	0	$ 0	$ 0	0	0	0	0	0		0	0
Interest paid												4,218	(3,740)
Income taxes paid, net of refunds												0	0
Treasury shares issued as compensation			0			0	0	0	0	0		0	0
Assets acquired through lease financing			$ (1,690)			$ 288	$ (1,095)	$ 1,556	$ (1,130)	$ 1,876		(5,703)	$ 2,229
(1) Cash related to assets held for sale included in ending cash flow cash balance Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents												$ 0