Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 01, 2016	Jun. 26, 2015	Jul. 01, 2016	Jun. 26, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net Earnings of the Group	$ 70,937	$ 97,308	$ 184,632	$ 291,613
Other Comprehensive Income (Loss):
Foreign currency translation adjustment	(35,840)	17,650	(35,094)	(69,041)
Gain (loss) on cash flow hedges	(459)	3,071	(872)	(1,773)
Change in pension liabilities	42,008	(15,035)	60,426	15,886
Other comprehensive income (loss) before taxes	5,709	5,686	24,460	(54,928)
Income Tax Benefit:
Cash flow hedges	(69)	(839)	(65)	425
Change in pension liabilities	(8,706)	3,090	(12,893)	(2,913)
Income Tax Benefit (Expense):	(8,775)	2,251	(12,958)	(2,488)
Net other comprehensive income (loss)	(3,066)	7,937	11,502	(57,416)
Net Comprehensive Income of the Group	67,871	105,245	196,134	234,197
Net Comprehensive Income Attributable to Noncontrolling Interests	(1,882)	(6,246)	(3,813)	(18,505)
Net Comprehensive Income Attributable to Jacobs	$ 65,989	$ 98,999	$ 192,321	$ 215,692