CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Total Jacobs Stockholders’ Equity	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Beginning balance at Sep. 29, 2023	$ 6,600,082	$ 6,546,220	$ 125,977	$ 2,735,325	$ 4,542,872	$ (857,954)	$ 53,862
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	348,289	333,722			333,722		14,567
Foreign currency translation adjustments	73,177	73,177				73,177
Pension plan liability, net of deferred taxes	(7,394)	(7,394)				(7,394)
Change in cash flow hedges, net of deferred taxes	(19,072)	(19,072)				(19,072)
Dividends	(37,077)	(37,077)			(37,077)
Redeemable Noncontrolling interests redemption value adjustment	(96,562)	(96,562)			(96,562)
Repurchase and issuance of redeemable noncontrolling interests	1,898	1,898			1,898
Noncontrolling interests - distributions and other	(14,081)						(14,081)
Stock based compensation	35,176	35,176		35,176
Issuances of equity securities including shares withheld for taxes	(10,512)	(10,512)	667	(5,722)	(5,457)
Repurchases of equity securities	(195,462)	(195,462)	(1,428)	(31,021)	(163,013)
Ending balance at Mar. 29, 2024	6,678,462	6,624,114	125,216	2,733,758	4,576,383	(811,243)	54,348
Beginning balance at Dec. 29, 2023	6,734,850	6,678,274	125,599	2,729,416	4,604,850	(781,591)	56,576
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	169,452	162,112			162,112		7,340
Foreign currency translation adjustments	(34,872)	(34,872)				(34,872)
Pension plan liability, net of deferred taxes	3,821	3,821				3,821
Change in cash flow hedges, net of deferred taxes	1,399	1,399				1,399
Dividends	(36,715)	(36,715)			(36,715)
Redeemable Noncontrolling interests redemption value adjustment	(70,845)	(70,845)			(70,845)
Noncontrolling interests - distributions and other	(9,568)						(9,568)
Stock based compensation	15,866	15,866		15,866
Issuances of equity securities including shares withheld for taxes	520	520	257	2,371	(2,108)
Repurchases of equity securities	(95,446)	(95,446)	(640)	(13,895)	(80,911)
Ending balance at Mar. 29, 2024	6,678,462	6,624,114	125,216	2,733,758	4,576,383	(811,243)	54,348
Beginning balance at Sep. 27, 2024	4,567,303	4,549,467	124,084	2,758,064	2,366,769	(699,450)	17,836
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	(18,168)	(12,517)			(12,517)		(5,651)
Foreign currency translation adjustments	(96,108)	(96,108)				(96,108)
Pension plan liability, net of deferred taxes	15,672	15,672				15,672
Change in cash flow hedges, net of deferred taxes	(157)	(157)				(157)
Dividends	(39,894)	(39,894)			(39,894)
Redeemable Noncontrolling interests redemption value adjustment	(8,491)	(8,491)			(8,491)
Repurchase and issuance of redeemable noncontrolling interests	1,079	1,079			1,079
Noncontrolling interests - distributions and other	(3,469)						(3,469)
Distribution adjustments relating to SpinCo Business	(22,645)	(22,645)			(22,645)
Stock based compensation	34,342	34,342		34,342
Issuances of equity securities including shares withheld for taxes	(3,902)	(3,902)	475	269	(4,646)
Repurchases of equity securities	(552,402)	(552,402)	(4,180)	(92,985)	(455,237)
Ending balance at Mar. 28, 2025	3,873,160	3,864,444	120,379	2,699,690	1,824,418	(780,043)	8,716
Beginning balance at Dec. 27, 2024	4,226,966	4,205,359	122,912	2,735,155	2,179,509	(832,217)	21,607
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	(6,119)	5,612			5,612		(11,731)
Foreign currency translation adjustments	64,040	64,040				64,040
Pension plan liability, net of deferred taxes	(7,372)	(7,372)				(7,372)
Change in cash flow hedges, net of deferred taxes	(4,494)	(4,494)				(4,494)
Dividends	(39,634)	(39,634)			(39,634)
Redeemable Noncontrolling interests redemption value adjustment	(8,545)	(8,545)			(8,545)
Repurchase and issuance of redeemable noncontrolling interests	97	97			97
Noncontrolling interests - distributions and other	(1,160)						(1,160)
Distribution adjustments relating to SpinCo Business	(23,645)	(23,645)			(23,645)
Stock based compensation	21,283	21,283		21,283
Issuances of equity securities including shares withheld for taxes	2,519	2,519	191	3,878	(1,550)
Repurchases of equity securities	(350,776)	(350,776)	(2,724)	(60,626)	(287,426)
Ending balance at Mar. 28, 2025	$ 3,873,160	$ 3,864,444	$ 120,379	$ 2,699,690	$ 1,824,418	$ (780,043)	$ 8,716