Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Apr. 01, 2016	Mar. 31, 2017	Apr. 01, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net Earnings of the Group	$ 44,165	$ 63,389	$ 105,318	$ 113,695
Other Comprehensive Income (Loss):
Foreign currency translation adjustment	41,441	17,248	(246,083)	746
Gain (loss) on cash flow hedges	5,690	(2,965)	4,748	(413)
Change in pension liabilities	(2,458)	6,975	22,295	18,418
Other comprehensive income (loss) before taxes	44,673	21,258	(219,040)	18,751
Income Tax (Expense) Benefit:
Cash flow hedges	(1,024)	727	(1,106)	4
Change in pension liabilities	253	(1,705)	(4,269)	(4,187)
Income Tax (Expense) Benefit:	(771)	(978)	(5,375)	(4,183)
Net other comprehensive income (loss)	43,902	20,280	(224,415)	14,568
Net Comprehensive Income of the Group	88,067	83,669	(119,097)	128,263
Net Comprehensive Income Attributable to Noncontrolling Interests	5,853	1,861	5,236	(1,931)
Net Comprehensive Income (Loss) Attributable to Jacobs	$ 93,920	$ 85,530	$ (113,861)	$ 126,332