Consolidated Statements of Earnings - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Oct. 02, 2015	Sep. 26, 2014
Income Statement [Abstract]
Revenues	$ 10,964,157	$ 12,114,832	$ 12,695,157
Costs and Expenses:
Direct costs of contracts	(9,196,326)	(10,146,494)	(10,621,373)
Selling, general and administrative expenses	(1,429,233)	(1,522,811)	(1,545,716)
Operating Profit	338,598	445,527	528,068
Other (Expense) Income:
Interest income	7,848	7,262	9,693
Interest expense	(15,260)	(19,503)	(11,437)
Loss on disposal of business and investments	(41,410)	(2,909)	12,147
Gain on sale of intellectual property, net			12,147
Miscellaneous income (expense), net	(3,053)	(240)	3,695
Total other income (expense), net	(51,875)	(15,390)	14,098
Earnings Before Taxes	286,723	430,137	542,166
Income Tax Expense	(72,208)	(101,255)	(190,054)
Net Earnings of the Group	214,515	328,882	352,112
Net Earnings Attributable to Noncontrolling Interests	(4,052)	(25,911)	(24,004)
Net Earnings Attributable to Jacobs	$ 210,463	$ 302,971	$ 328,108
Net Earnings Per Share:
Basic (in dollars per share)	$ 1.75	$ 2.42	$ 2.51
Diluted (in dollars per share)	$ 1.73	$ 2.40	$ 2.48