Consolidated Statements of Earnings - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 02, 2021	Jun. 26, 2020	Jul. 02, 2021	Jun. 26, 2020
Income Statement [Abstract]
Revenues	$ 3,576,436	$ 3,260,057	$ 10,506,144	$ 10,047,286
Direct cost of contracts	(2,759,501)	(2,631,031)	(8,290,137)	(8,125,554)
Gross profit	816,935	629,026	2,216,007	1,921,732
Selling, general and administrative expenses	(553,189)	(434,650)	(1,779,435)	(1,408,232)
Operating Profit	263,746	194,376	436,572	513,500
Other Income (Expense):
Interest income	1,001	1,249	2,733	3,180
Interest expense	(20,011)	(18,193)	(52,788)	(48,163)
Miscellaneous income (expense), net	38,658	126,249	138,705	(87,470)
Total other income (expense), net	19,648	109,305	88,650	(132,453)
Earnings from Continuing Operations Before Taxes	283,394	303,681	525,222	381,047
Income Tax Expense from Continuing Operations	(109,186)	(67,674)	(175,437)	(75,041)
Net Earnings of the Group from Continuing Operations	174,208	236,007	349,785	306,006
Net Earnings of the Group from Discontinued Operations	384	18,043	11,690	125,511
Net Earnings of the Group	174,592	254,050	361,475	431,517
Net Earnings Attributable to Noncontrolling Interests from Continuing Operations	(9,182)	(9,121)	(29,366)	(21,662)
Net Loss Attributable to Redeemable Noncontrolling interests	384	0	101,776	0
Net Earnings Attributable to Jacobs from Continuing Operations	165,410	226,886	422,195	284,344
Net Earnings Attributable to Jacobs	$ 165,794	$ 244,929	$ 433,885	$ 409,855
Net Earnings Per Share:
Basic Net Earnings from Continuing Operations Per Share (in dollars per share)	$ 0.83	$ 1.74	$ 2.80	$ 2.15
Basic Net Earnings from Discontinued Operations Per Share (in dollars per share)	0	0.14	0.09	0.95
Basic Earnings Per Share (in dollars per share)	0.83	1.88	2.89	3.11
Diluted Net Earnings from Continuing Operations Per Share (in dollars per share)	0.82	1.73	2.78	2.13
Diluted Net Earnings from Discontinued Operations Per Share (in dollars per share)	0	0.14	0.09	0.94
Diluted Earnings Per Share (in dollars per share)	$ 0.83	$ 1.87	$ 2.87	$ 3.08