Consolidated Statements of Earnings - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019	Mar. 27, 2020	Mar. 29, 2019
Income Statement [Abstract]
Revenues	$ 3,427,180	$ 3,091,596	$ 6,787,229	$ 6,175,384
Direct cost of contracts	(2,779,045)	(2,474,755)	(5,494,522)	(4,990,023)
Gross profit	648,135	616,841	1,292,707	1,185,361
Selling, general and administrative expenses	(480,357)	(514,160)	(973,582)	(969,551)
Operating Profit	167,778	102,681	319,125	215,810
Other (Expense) Income:
Interest income	985	1,670	1,931	3,774
Interest expense	(15,154)	(29,423)	(29,971)	(54,749)
Miscellaneous (expense) income, net	(330,414)	36,904	(213,719)	39,186
Total other (expense) income, net	(344,583)	9,151	(241,759)	(11,789)
(Loss) Earnings from Continuing Operations Before Taxes	(176,805)	111,832	77,366	204,021
Income Tax Benefit (Expense) for Continuing Operations	61,122	7,947	(7,368)	(14,811)
Net (Loss) Earnings of the Group from Continuing Operations	(115,683)	119,779	69,998	189,210
Net Earnings (Loss) of the Group from Discontinued Operations	29,880	(57,006)	107,468	3,153
Net (Loss) Earnings of the Group	(85,803)	62,773	177,466	192,363
Net Earnings Attributable to Noncontrolling Interests from Continuing Operations	(6,284)	(5,024)	(12,540)	(9,562)
Net (Loss) Earnings Attributable to Jacobs from Continuing Operations	(121,967)	114,755	57,458	179,648
Net Earnings Attributable to Noncontrolling Interests from Discontinued Operations	0	(832)	0	(1,588)
Net Earnings (Loss) Attributable to Jacobs from Discontinued Operations	29,880	(57,838)	107,468	1,565
Net (Loss) Earnings Attributable to Jacobs	$ (92,087)	$ 56,917	$ 164,926	$ 181,213
Net (Loss) Earnings Per Share:
Basic Net (Loss) Earnings from Continuing Operations Per Share (in dollars per share)	$ (0.92)	$ 0.83	$ 0.43	$ 1.28
Basic Net Earnings (Loss) from Discontinued Operations Per Share (in dollars per share)	0.23	(0.42)	0.81	0.01
Basic (Loss) Earnings Per Share (in dollars per share)	(0.69)	0.41	1.24	1.29
Diluted Net (Loss) Earnings from Continuing Operations Per Share (in dollars per share)	(0.92)	0.82	0.43	1.27
Diluted Net Earnings (Loss) from Discontinued Operations Per Share (in dollars per share)	0.23	(0.41)	0.80	0.01
Diluted (Loss) Earnings Per Share (in dollars per share)	$ (0.69)	$ 0.41	$ 1.23	$ 1.28