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. 30, 2022	$ 6,104,392	$ 6,060,056	$ 127,393	$ 2,682,009	$ 4,225,784	$ (975,130)	$ 44,336
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	366,994	352,160			352,160		14,834
Foreign currency translation adjustments, net of deferred taxes	181,644	181,644				181,644
Pension liability, net of deferred taxes	(22,918)	(22,918)				(22,918)
Change in cash flow hedges, net of deferred taxes	(21,638)	(21,638)				(21,638)
Dividends	(33,438)	(33,438)			(33,438)
Redeemable Noncontrolling interests redemption value adjustment	(44,494)	(44,494)			(44,494)
Repurchase and issuance of redeemable noncontrolling interests	11,337	11,337			11,337
Noncontrolling interests - distributions and other	(10,783)						(10,783)
Stock based compensation	35,285	35,285		35,285
Issuances of equity securities including shares withheld for taxes	2,165	2,165	650	6,286	(4,771)
Repurchases of equity securities	(140,522)	(140,522)	(1,238)	(26,057)	(113,227)
Ending balance at Mar. 31, 2023	6,428,024	6,379,637	126,805	2,697,523	4,393,351	(838,042)	48,387
Beginning balance at Dec. 30, 2022	6,233,598	6,184,104	126,669	2,672,421	4,230,866	(845,852)	49,494
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	224,315	216,512			216,512		7,803
Foreign currency translation adjustments, net of deferred taxes	22,919	22,919				22,919
Pension liability, net of deferred taxes	(345)	(345)				(345)
Change in cash flow hedges, net of deferred taxes	(14,764)	(14,764)				(14,764)
Dividends	(32,564)	(32,564)			(32,564)
Redeemable Noncontrolling interests redemption value adjustment	(21,177)	(21,177)			(21,177)
Noncontrolling interests - distributions and other	(8,910)						(8,910)
Stock based compensation	15,054	15,054		15,054
Issuances of equity securities including shares withheld for taxes	9,898	9,898	136	10,048	(286)
Ending balance at Mar. 31, 2023	6,428,024	6,379,637	126,805	2,697,523	4,393,351	(838,042)	48,387
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	348,289	333,722			333,722		14,567
Foreign currency translation adjustments, net of deferred taxes	73,177	73,177				73,177
Pension 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	169,452	162,112			162,112		7,340
Foreign currency translation adjustments, net of deferred taxes	(34,872)	(34,872)				(34,872)
Pension 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