Consolidated Statements of Earnings - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Jan. 01, 2021
Income Statement [Abstract]
Revenues	$ 3,380,625	$ 3,381,836
Direct cost of contracts	(2,584,151)	(2,749,776)
Gross profit	796,474	632,060
Selling, general and administrative expenses	(619,141)	(418,120)
Operating Profit	177,333	213,940
Other Income (Expense):
Interest income	1,501	1,124
Interest expense	(19,426)	(17,313)
Miscellaneous income, net	9,682	156,360
Total other (expense) income, net	(8,243)	140,171
Earnings from Continuing Operations Before Taxes	169,090	354,111
Income Tax Expense from Continuing Operations	(15,889)	(87,023)
Net Earnings of the Group from Continuing Operations	153,201	267,088
Net Earnings of the Group from Discontinued Operations	(232)	(14)
Net Earnings of the Group	152,969	267,074
Net Earnings Attributable to Noncontrolling Interests from Continuing Operations	(9,252)	(10,026)
Net Earnings Attributable to Redeemable Noncontrolling interests	(9,683)	0
Net Earnings Attributable to Jacobs from Continuing Operations	134,266	257,062
Net Earnings Attributable to Jacobs	$ 134,034	$ 257,048
Net Earnings Per Share:
Basic Net Earnings from Continuing Operations Per Share (in dollars per share)	$ 1.04	$ 1.98
Basic Net Earnings from Discontinued Operations Per Share (in dollars per share)	0	0
Basic Earnings Per Share (in dollars per share)	1.04	1.98
Diluted Net Earnings from Continuing Operations Per Share (in dollars per share)	1.03	1.96
Diluted Net Earnings from Discontinued Operations Per Share (in dollars per share)	0	0
Diluted Earnings Per Share (in dollars per share)	$ 1.03	$ 1.96