Jacobs Engineering (J) 10-K 21 Nov 17 2017 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Billions	12 Months Ended
	Sep. 29, 2017	Nov. 10, 2017	Mar. 31, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Sep. 29, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	jec
Entity Registrant Name	JACOBS ENGINEERING GROUP INC /DE/
Entity Central Index Key	52,988
Current Fiscal Year End Date	--09-29
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Entity Public Float			$ 6.7
Entity Common Stock, Shares Outstanding		120,466,122

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
Current Assets:
Cash and cash equivalents	$ 774,151	$ 655,716
Receivables	2,102,543	2,115,663
Prepaid expenses and other current assets	119,486	93,091
Total current assets	2,996,180	2,864,470
Property, Equipment, and Improvements, net	349,911	319,673
Other Noncurrent Assets:
Goodwill	3,009,826	3,079,628
Intangibles, net	332,920	336,922
Miscellaneous	692,022	759,329
Total other noncurrent assets	4,034,768	4,175,879
Assets	7,380,859	7,360,022
Current Liabilities:
Notes payable	3,071	2,421
Accounts payable	683,605	522,427
Accrued liabilities	939,687	938,378
Billings in excess of costs	299,864	319,460
Total current liabilities	1,926,227	1,782,686
Long-term Debt	235,000	385,330
Other Deferred Liabilities	732,281	861,824
Commitments and Contingencies
Capital stock:
Preferred stock, $1 par value, authorized—1,000,000 shares; issued and outstanding—none
Common stock, $1 par value, authorized—240,000,000 shares; issued and outstanding—120,385,544 shares and 120,950,899 shares as of September 29, 2017 and September 30, 2016, respectively	120,386	120,951
Additional paid-in capital	1,239,782	1,168,272
Retained earnings	3,721,698	3,586,647
Accumulated other comprehensive loss	(653,514)	(610,594)
Total Jacobs stockholders’ equity	4,428,352	4,265,276
Noncontrolling interests	58,999	64,906
Total Group stockholders’ equity	4,487,351	4,330,182
Liabilities and Stockholders' Equity, Total	$ 7,380,859	$ 7,360,022

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 29, 2017	Sep. 30, 2016
Statement Of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, authorized (in shares)	1,000,000	1,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, authorized (in shares)	240,000,000	240,000,000
Common stock, issued (in shares)	120,385,544	120,950,899
Common stock, outstanding (in shares)	120,385,544	120,950,899

Consolidated Statements of Earn

Consolidated Statements of Earnings - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Income Statement [Abstract]
Revenues	$ 10,022,788	$ 10,964,157	$ 12,114,832
Costs and Expenses:
Direct costs of contracts	(8,250,536)	(9,196,326)	(10,146,494)
Selling, general and administrative expenses	(1,379,983)	(1,429,233)	(1,522,811)
Operating Profit	392,269	338,598	445,527
Other Income (Expense):
Interest income	8,748	7,848	7,262
Interest expense	(12,035)	(15,260)	(19,503)
Gain/(Loss) on disposal of business and investments	10,880	(41,410)	(2,909)
Miscellaneous expense, net	(6,645)	(3,053)	(240)
Total other income (expense), net	948	(51,875)	(15,390)
Earnings Before Taxes	393,217	286,723	430,137
Income Tax Expense	(105,842)	(72,208)	(101,255)
Net Earnings of the Group	287,375	214,515	328,882
Net Loss (Earnings) Attributable to Noncontrolling Interests	6,352	(4,052)	(25,911)
Net Earnings Attributable to Jacobs	$ 293,727	$ 210,463	$ 302,971
Net Earnings Per Share:
Basic (in dollars per share)	$ 2.43	$ 1.75	$ 2.42
Diluted (in dollars per share)	$ 2.42	$ 1.73	$ 2.40

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net Earnings of the Group	$ 287,375	$ 214,515	$ 328,882
Other Comprehensive (Loss) Income:
Foreign currency translation adjustments	(140,527)	(46,515)	(136,168)
Change in pension liability	123,427	(111,488)	33,208
(Losses) Gains on cash flow hedges	(1,350)	(1,403)	2,949
Other Comprehensive Loss Before Income Taxes	(18,450)	(159,406)	(100,011)
Income Tax (Expense) Benefit:
Change in pension liability	(24,380)	13,303	(438)
(Losses) Gains on cash flow hedges	(90)	273	(766)
Income Tax (Expense) Benefit	(24,470)	13,576	(1,204)
Net Other Comprehensive Loss	(42,920)	(145,830)	(101,215)
Net Comprehensive Income of the Group	244,455	68,685	227,667
Net Comprehensive Loss (Income) Attributable to Noncontrolling Interests	6,352	(4,052)	(25,911)
Total Comprehensive Income	$ 250,807	$ 64,633	$ 201,756

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total Jacobs Stockholders' Equity	Non- controlling Interests
Balances at Sep. 26, 2014	$ 4,505,660	$ 131,753	$ 1,173,858	$ 3,527,193	$ (363,549)	$ 4,469,255	$ 36,405
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	328,882			302,971		302,971	25,911
Foreign currency translation adjustments	(136,168)				(136,168)	(136,168)
Pension liability, net of deferred taxes	32,770				32,770	32,770
Gain\(Loss) on derivatives, net of deferred taxes	2,183				2,183	2,183
Noncontrolling interest acquired / consolidated	(82)		0	(9,709)		(9,709)	9,627
Distributions to noncontrolling interests	(7,230)			0		0	(7,230)
Issuances of equity securities, net of deferred taxes	82,391	1,590	80,801			82,391
Repurchases of equity securities	(451,948)	(10,190)	(117,515)	(324,243)		(451,948)
Balances at Oct. 02, 2015	4,356,458	123,153	1,137,144	3,496,212	(464,764)	4,291,745	64,713
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	214,515			210,463		210,463	4,052
Foreign currency translation adjustments	(46,516)				(46,516)	(46,516)
Pension liability, net of deferred taxes	(98,185)				(98,185)	(98,185)
Gain\(Loss) on derivatives, net of deferred taxes	(1,129)				(1,129)	(1,129)
Noncontrolling interest acquired / consolidated	(1,277)		(127)			(127)	(1,150)
Distributions to noncontrolling interests	(5,855)			(3,146)		(3,146)	(2,709)
Issuances of equity securities, net of deferred taxes	73,406	1,351	72,055			73,406
Repurchases of equity securities	(161,235)	(3,553)	(40,800)	(116,882)		(161,235)
Balances at Sep. 30, 2016	4,330,182	120,951	1,168,272	3,586,647	(610,594)	4,265,276	64,906
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	287,375			293,727		293,727	(6,352)
Foreign currency translation adjustments	(140,527)				(140,527)	(140,527)
Pension liability, net of deferred taxes	99,047				99,047	99,047
Gain\(Loss) on derivatives, net of deferred taxes	(1,440)				(1,440)	(1,440)
Noncontrolling interest acquired / consolidated	445						445
Dividends	(72,765)			(72,765)		(72,765)
Distributions to noncontrolling interests	(4,559)			(4,559)		(4,559)
Issuances of equity securities, net of deferred taxes	100,585	1,468	99,117			100,585
Repurchases of equity securities	(110,992)	(2,033)	(27,607)	(81,352)		(110,992)
Balances at Sep. 29, 2017	$ 4,487,351	$ 120,386	$ 1,239,782	$ 3,721,698	$ (653,514)	$ 4,428,352	$ 58,999

Consolidated Statements of Sto7

Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Statement Of Stockholders Equity [Abstract]
Deferred tax benefit (expense), Pension liability	$ (24,380)	$ 13,303	$ (438)
Deferred tax expense (benefit) , Other comprehensive income (loss), Gain\(Loss) on derivatives	90	(274)	766
Deferred tax expense (benefit), Issuances equity securities	$ 1,015	$ 3,382	$ 10,332

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Cash Flows from Operating Activities:
Net earnings attributable to the Group	$ 287,375	$ 214,515	$ 328,882
Depreciation and amortization:
Property, equipment and improvements	76,418	82,363	99,924
Intangible assets	46,095	47,608	49,368
(Gain) Loss on sales of investments	(10,880)	17,049
Loss on sales of business	822	24,361	2,909
Gain on benefit plan change	(9,955)
Stock based compensation	38,764	32,370	41,412
Tax deficiency from stock based compensation	(2,877)	(377)	(1,237)
Equity in losses (earnings) of operating ventures, net	(7,788)	(11,892)	5,483
Change in pension plan obligations	(26,990)	(9,380)	(5,980)
Change in deferred compensation plans	(531)	576	(3,229)
Losses on disposals of assets, net	14,876	10,680	30,985
Deferred income taxes	36,663	(27,407)	(31,177)
Changes in assets and liabilities, excluding the effects of businesses acquired:
Receivables	75,441	397,268	172,958
Prepaid expenses and other current assets	(23,755)	17,906	6,644
Accounts payable	153,961	(44,214)	(28,943)
Accrued liabilities	(56,279)	(71,930)	(120,847)
Billings in excess of costs	(31,976)	33,347	(52,441)
Income taxes payable	4,264	(4,586)	(22,685)
Other deferred liabilities	(6,026)	(28,801)	(15,759)
Deferred gain on synthetic lease transaction			23,343
Other, net	17,259	717	4,962
Net cash provided by operating activities	574,881	680,173	484,572
Cash Flows Used for Investing Activities:
Additions to property and equipment	(118,060)	(67,688)	(88,404)
Disposals of property and equipment	2,387	10,479	369
Purchases of intangibles		(10,027)
Purchases of investments		(3,403)
Sales of investments	31,701		13
Acquisitions of businesses, net of cash acquired	(150,190)	(49,943)	(8,101)
Sales of business	(2,036)	(19,039)
Net cash used for investing activities	(236,198)	(139,621)	(96,123)
Cash Flows Used for Financing Activities:
Proceeds from long-term borrowings	1,694,023	1,649,653	1,768,639
Repayments of long-term borrowings	(1,846,797)	(1,840,789)	(1,907,109)
Proceeds from short-term borrowings	1,347	3,040	362,433
Repayments of short-term borrowings	(702)	(14,042)	(382,190)
Proceeds from issuances of common stock	62,645	43,140	33,222
Common stock repurchases	(97,180)	(152,550)	(422,316)
Excess tax benefits from stock based compensation	2,877	377	1,237
Cash dividends	(54,234)
Dividends paid to noncontrolling interests	(4,559)	(5,855)	(7,230)
Net cash used for financing activities	(242,580)	(317,026)	(553,314)
Effect of Exchange Rate Changes	22,332	(28,669)	(106,923)
Net Increase (Decrease) in Cash and Cash Equivalents	118,435	194,857	(271,788)
Cash and Cash Equivalents at Beginning of Period	655,716	460,859	732,647
Cash and Cash Equivalents at End of Period	$ 774,151	$ 655,716	$ 460,859

Description Of Business And Bas

Description Of Business And Basis Of Presentation	12 Months Ended
	Sep. 29, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business and Basis of Presentation	1. Description of Business and Basis of Presentation Description of Business We provide a broad range of technical, professional, and construction services including engineering, design, and architectural services; construction and construction management services; operations and maintenance services; and process, scientific, and systems consulting services. We provide our services through offices and subsidiaries located primarily in North America, South America, Europe, the Middle East, India, Australia, Africa, and Asia. We provide our services under cost-reimbursable and fixed-price contracts. The percentage of revenues realized from each of these types of contracts for the fiscal years ended September 29, 2017, September 30, 2016 and October 2, 2015 was as follows: For the Year Ended September 29, 2017 September 30, 2016 October 2, 2015 Cost-reimbursable 81% 82 % 83 % Fixed-price 19% 18 % 17 % Basis of Presentation, Definition of Fiscal Year, and Other Matters The accompanying Consolidated Financial Statements have been prepared in accordance with U.S. GAAP and include the accounts of Jacobs Engineering Group Inc. and its subsidiaries and affiliates which it controls. All intercompany accounts and transactions have been eliminated in consolidation. The Company’s fiscal year ends on the Friday closest to September 30 (determined on the basis of the number of workdays) and, accordingly, an additional week of activity is added every five -to- six years. Fiscal 2015 included an extra week of activity. During the second quarter of fiscal 2016, we reorganized our operating and reporting structure around four lines of business (“LOB”). This reorganization is intended to better serve our global clients, leverage our workforce, help streamline operations, and provide enhanced growth opportunities. The four global LOBs are: Petroleum & Chemicals, Buildings & Infrastructure, Aerospace & Technology, and Industrial. Previously, the Company operated its business as a single segment. For a further discussion of our segment information, please refer to Note 15- Segment Information. Please refer to Note 17— Definitions

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Sep. 29, 2017
New Accounting Pronouncements And Changes In Accounting Principles [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies Revenue Accounting for Contracts and Use of Joint Ventures We recognize revenue earned on our technical professional and field services projects under the percentage-of-completion method described in ASC 605-35, Construction-Type and Production-Type Contracts. In general, we recognize revenues at the time we provide services. Pre-contract costs are generally expensed as incurred. Contracts are generally segmented between types of services, such as project services and construction, and accordingly, gross margin related to each activity is recognized as those separate services are rendered. For multiple contracts with a single customer we account for each contract separately. The percentage-of-completion method of accounting is applied by comparing contract costs incurred to date to the total estimated costs at completion. On cost-reimbursable contracts, the cost of materials and subcontracts are generally excluded from the calculation of the measure of progress towards completion to provide a more meaningful allocation of income. Contract losses are provided for in their entirety in the period they become known, without regard to the percentage-of-completion. Unapproved change orders are included in the contract price to the extent it is probable that such change orders will result in additional contract revenue and the amount of such additional revenue can be reliably estimated. Claims meeting these recognition criteria are included in revenues only to the extent of the related costs incurred. Certain cost-reimbursable contracts include incentive-fee arrangements. These incentive fees can be based on a variety of factors but the most common are the achievement of target completion dates, target costs, and/or other performance criteria. Failure to meet these targets can result in unrealized incentive fees. We recognize incentive fees based on expected results using the percentage-of-completion method of accounting. As the contract progresses and more information becomes available, the estimate of the anticipated incentive fee that will be earned is revised as necessary. We bill incentive fees based on the terms and conditions of the individual contracts. In certain situations, we are allowed to bill a portion of the incentive fees over the performance period of the contract. In other situations, we are allowed to bill incentive fees only after the target criterion has been achieved. Incentive fees which have been recognized but not billed are included in receivables in the accompanying Consolidated Balance Sheets. Certain cost-reimbursable contracts with government customers as well as certain commercial clients provide that contract costs are subject to audit and adjustment. In this situation, revenues are recorded at the time services are performed based upon the amounts we expect to realize upon completion of the contracts. Revenues are not recognized for non-recoverable costs. In those situations where an audit indicates that we may have billed a client for costs not allowable under the terms of the contract, we estimate the amount of such nonbillable costs and adjust our revenues accordingly. When we are directly responsible for subcontractor labor or third-party materials and equipment, we reflect the costs of such items in both revenues and costs (and we refer to such costs as “pass-through” costs). On those projects where the client elects to pay for such items directly and we have no associated responsibility for such items, these amounts are not reflected in either revenues or costs. The following table sets forth pass-through costs included in revenues in the accompanying Consolidated Statements of Earnings (in millions): For the Year Ended September 29, 2017 September 30, 2016 October 2, 2015 $ 2,539.3 $ 2,489.9 $ 2,602.6 As is common to the industry, we execute certain contracts jointly with third parties through various forms of joint ventures and consortiums. Although the joint ventures own and hold the contracts with the clients, the services required by the contracts are typically performed by us and our joint venture partners, or by other subcontractors under subcontracting agreements with the joint ventures. The assets of our joint ventures, therefore, consist almost entirely of cash and receivables (representing amounts due from clients), and the liabilities of our joint ventures consist almost entirely of amounts due to the joint venture partners (for services provided by the partners to the joint ventures under their individual subcontracts) and other subcontractors. In general, at any given time, the equity of our joint ventures represents the undistributed profits earned on contracts the joint ventures hold with clients. Very few of our joint ventures have employees. None of our joint ventures have third-party debt or credit facilities. Under U.S. GAAP, our share of profits and losses associated with the contracts held by the joint ventures is reflected in our Consolidated Financial Statements. Certain of our joint ventures meet the definition of a VIE. In evaluating our VIEs for possible consolidation, we perform a qualitative analysis to determine whether or not we have a “controlling financial interest” in the VIE as defined by U.S. GAAP. We consolidate only those VIEs over which we have a controlling financial interest and are the primary beneficiary. For the Company’s unconsolidated joint ventures, we use either the equity method of accounting or proportional consolidation. There were no changes in facts and circumstances during the period that caused the Company to reassess the method of accounting for its VIEs. Fair Value Measurements The net carrying amounts of cash and cash equivalents, trade receivables and payables, and notes payable approximate Fair Value due to the short-term nature of these instruments. Similarly, we believe the carrying value of long-term debt also approximates Fair Value based on the interest rates and scheduled maturities applicable to the outstanding borrowings. Certain other assets and liabilities, such as forward contracts and an interest rate swap agreement we purchased as cash-flow hedges discussed in Note 11 — Commitments and Contingencies and Derivative Financial Instruments The Fair Value of the Company’s reporting units (used for purposes of determining whether there is an indication of possible impairment of the carrying value of goodwill) is determined using both an income approach and a market approach. Both approaches require us to make certain estimates and judgments. Under the income approach, Fair Value is determined by using the discounted cash flows of our reporting units. Under the market approach, the Fair Values of our reporting units are determined by reference to guideline companies that are reasonably comparable to our reporting units; the Fair Values are estimated based on the valuation multiples of the invested capital associated with the guideline companies. In assessing whether there is an indication that the carrying value of goodwill has been impaired, we utilize the results of both valuation techniques and consider the range of Fair Values indicated. The range of values (both ends of the range) for each reporting unit exceeded the respective book values by 27% to 110%. With respect to equity-based compensation (i.e., share-based payments), we estimate the Fair Value of stock options granted to employees and directors using the Black-Scholes option-pricing model. Like all option-pricing models, the Black-Scholes model requires the use of subjective assumptions including (i) the expected volatility of the market price of the underlying stock, and (ii) the expected term of the award, among others. Accordingly, changes in assumptions and any subsequent adjustments to those assumptions can cause different Fair Values to be assigned to our future stock option awards. For restricted stock units containing service, market and performance conditions, compensation expense is based on the Fair Value of such units using a Monte Carlo simulation. The Fair Values of the assets owned by the various pension plans that the Company sponsors are determined based on the type of asset, consistent with U.S. GAAP. Equity securities are valued by using market observable data such as quoted prices. Publicly traded corporate equity securities are valued at the last reported sale price on the last business day of the year. Securities not traded on the last business day are valued at the last reported bid price. Debt securities are valued at the last reported sale price on the last business day applicable. Real estate consists primarily of common or collective trusts, with underlying investments in real estate. These investments are valued using the best information available, including quoted market price, market prices for similar assets when available, internal cash flow estimates discounted at an appropriate interest rate, or independent appraisals, as appropriate. Management values insurance contracts, investments in infrastructure/raw goods, and hedge funds using actuarial assumptions and certain values reported by fund managers. The methodologies described above and elsewhere in these Notes to Consolidated Financial Statements may produce a Fair Value measure that may not be indicative of net realizable value or reflective of future Fair Values. Furthermore, while the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the Fair Value of certain financial instruments could result in a different Fair Value measurement. Cash Equivalents We consider all highly liquid investments with original maturities of less than three months to be cash equivalents. Cash equivalents at September 29, 2017 and September 30, 2016 consisted primarily of money market mutual funds and overnight bank deposits. Receivables and Billings in Excess of Costs Receivables include billed receivables, unbilled receivables, and retentions receivable. Billed receivables represent amounts invoiced to clients in accordance with the terms of our client contracts. They are recorded in our financial statements when they are issued. Unbilled receivables and retentions receivable represent reimbursable costs and amounts earned and reimbursable under contracts in progress as of the respective balance sheet dates. Such amounts become billable according to the contract terms, which usually consider the passage of time, achievement of certain milestones or completion of the project. We anticipate that substantially all of such unbilled amounts will be billed and collected over the next fiscal year. Certain contracts allow us to issue invoices to clients in advance of providing services. Billings in excess of costs represent billings to, and cash collected from, clients in advance of work performed. We anticipate that substantially all such amounts will be earned over the next twelve months. Property, Equipment, and Improvements Property, equipment and improvements are carried at cost, and are shown net of accumulated depreciation and amortization in the accompanying Consolidated Balance Sheets. Depreciation and amortization is computed primarily by using the straight-line method over the estimated useful lives of the assets. The cost of leasehold improvements is amortized using the straight-line method over the lesser of the estimated useful life of the asset or the remaining term of the related lease. Estimated useful lives range from 20 to 40 years for buildings, from 3 to 10 years for equipment and from 4 to 10 years for leasehold improvements. Goodwill and Other Intangible Assets Goodwill represents the excess of the cost of an acquired business over the Fair Value of the net tangible and intangible assets acquired. Goodwill and intangible assets with indefinite lives are not amortized; instead, on an annual basis as of the end of the third quarter of each fiscal year we test goodwill and intangible assets with indefinite lives for possible impairment. Interim testing for impairment is performed if indicators of potential impairment exist. For purposes of impairment testing, goodwill is assigned to the applicable reporting units based on the current reporting structure. During the second quarter of fiscal 2016, we reorganized our operations around four global lines of business, which also serve as our operating segments: Petroleum & Chemicals, Buildings & Infrastructure, Aerospace & Technology, and Industrial. When testing goodwill for impairment quantitatively, the Company first compares the fair value of each reporting unit with its carrying amount. If the carrying amount of a reporting unit exceeds its fair value, a second step is performed to measure the amount of potential impairment. In the second step, the Company compared the implied fair value of the reporting unit goodwill with the carrying amount of the reporting unit's goodwill. If the carrying amount of reporting unit goodwill exceeds the implied fair value of that goodwill, an impairment loss is recognized. During 2017, we completed our annual goodwill impairment test and quantitatively determined that none of the goodwill was impaired. The Company recorded $119.3 million of goodwill during 2017 in conjunction with the acquisitions of Aquenta Consulting Pty Ltd. and Blue Canopy LLC. Goodwill for each of the Company's segments is presented in Note 15. We have determined that the fair value of our reporting units substantially exceeded their respective carrying values for the Consolidated Balance Sheets presented. The following table presents the components of our goodwill by reporting unit appearing in the accompanying Consolidated Balance Sheets at September 29, 2017 (in thousands): September 29, 2017 Aerospace & Technology $ 1,025,780 Buildings & Infrastructure 751,407 Industrial 561,785 Petroleum & Chemicals 670,854 Total Goodwill $ 3,009,826 During the preparation of the Form 10-Q for the first fiscal quarter of 2017, the Company determined that its prior financial statements contained immaterial misstatements related to incorrect translation of the Company’s non-U.S. goodwill balances from local currency to the U.S. Dollar reporting currency. It was determined that the Company had incorrectly used historical translation rates for the U.S. Dollar in place at the time of the Company’s recording of its foreign goodwill balances rather than using current translation rates at each balance sheet date in accordance with U.S. GAAP. The error dated back to the time of our initial reporting of non-US goodwill balances in the late 1990s and affected our historical quarterly and annual reporting periods through the first fiscal quarter of 2017. As a result, goodwill and accumulated other comprehensive income in the Company’s September 30, 2016 consolidated balance sheet (which have not been adjusted) were each overstated by $209.9 million and were corrected in the first fiscal quarter of 2017 foreign currency translation adjustment. Consequently, the correction was a direct component of the overall translation adjustment amount of $140.5 million that was reported for fiscal 2017. These adjustments had no impact on the Company’s Consolidated Statements of Earnings or Cash Flows. Also, other comprehensive income for the year ended September 30, 2016 was overstated by $33.8 million as a result of these misstatements. The following table provides certain information related to the Company’s acquired intangible assets in the accompanying Consolidated Balance Sheets at September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): Customer Relationships, Contracts, and Backlog Developed Technology Trade Names Patents Other Total Balances, September 26, 2014 $ 408,041 $ 17,378 $ 14,148 $ — $ 625 $ 440,192 Acquisitions (4,315 ) — (1,292 ) — 300 (5,307 ) Amortization (39,967 ) (1,533 ) (4,172 ) — (277 ) (45,949 ) Foreign currency translation (34,418 ) — (1,085 ) — (14 ) (35,517 ) Balances, October 2, 2015 329,341 15,845 7,599 — 634 353,419 Acquisitions 7,286 — 859 10,027 — 18,172 Amortization (38,595 ) (1,534 ) (3,819 ) — (454 ) (44,402 ) Foreign currency translation 9,605 — 147 — (19 ) 9,733 Balances, September 30, 2016 307,637 14,311 4,786 10,027 161 336,922 Acquisitions 29,803 1,685 4,417 — — 35,905 Amortization (39,679 ) (1,534 ) (2,549 ) (400 ) (50 ) (44,212 ) Foreign currency translation 3,707 — 45 553 — 4,305 Balances, September 29, 2017 $ 301,468 14,462 6,699 10,180 111 332,920 Weighted Average Amortization Period (years) 7.9 7.7 4.4 24 2.2 8.3 The weighted average amortization period includes the effects of foreign currency translation. The above table excludes the values assigned to those intangible assets embedded in the Company’s equity method investment in AWE Management Ltd. (“AWE”) and Guimar Engenharia LTDA ("Guimar"). Those amounts are included in the carrying value of the Company’s investment in AWE and Guimar. The amount of amortization expense we estimate we will record during each of the next five fiscal years relating to intangible assets existing at September 29, 2017, including those associated with AWE and Guimar, is: fiscal 2018 - $49.7 million; fiscal 2019 - $48.3 million; fiscal 2020 - $46.1 million; fiscal 2021 - $40.9 million; and fiscal 2022 - $39.5 million. Foreign Currencies In preparing our Consolidated Financial Statements, it is necessary to translate the financial statements of our subsidiaries operating outside the U.S., which are denominated in currencies other than the U.S. dollar, into the U.S. dollar. In accordance with U.S. GAAP, revenues and expenses of operations outside the U.S. are translated into U.S. dollars using weighted-average exchange rates for the applicable periods being translated while the assets and liabilities of operations outside the U.S. are generally translated into U.S. dollars using period-end exchange rates. The net effect of foreign currency translation adjustments is included in stockholders’ equity as a component of accumulated other comprehensive income (loss) in the accompanying Consolidated Balance Sheets. Share-Based Payments We measure the value of services received from employees and directors in exchange for an award of an equity instrument based on the grant-date Fair Value of the award. The computed value is recognized as a non-cash cost on a straight-line basis over the period the individual provides services, which is typically the vesting period of the award with the exception of awards containing an internal performance measure which is recognized on a straight-line basis over the vesting period subject to the probability of meeting the performance requirements and adjusted for the number of shares expected to be earned. The cost of these awards is recorded in selling, general and administrative expense in the accompanying Consolidated Statements of Earnings. The following table presents our stock-based compensation expense for the various types of awards made by the Company as included in the Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended Award Type September 29, 2017 September 30, 2016 October 2, 2015 Restricted Stock and Restricted Stock Units (excluding Market and Performance Awards) $ 26,393 $ 21,156 $ 20,779 Stock Options 4,338 7,165 10,683 Market and Performance Awards 8,033 4,049 9,950 Total Expense $ 38,764 $ 32,370 $ 41,412 The Company has two incentive plans whereby eligible employees and directors of Jacobs may be granted stock options, restricted stock, and/or restricted stock units. Stock Options —Substantially all of the stock options granted during the previous years were awarded on the same date for all employees and directors (although the date is different for employees and directors). For fiscal year 2017, there were no stock options granted to either employees or directors. The following table presents the assumptions used in the Black-Scholes option-pricing model for awards made to employees and directors for the years ended September 30, 2016 and October 2, 2015: Awards Made to Employees Awards Made to Directors September 30, 2016 October 2, 2015 September 30, 2016 October 2, 2015 Dividend yield — % — % — % — % Expected volatility 27.77 % 27.00 % 29.21 % 29.28 % Risk-free interest rate 1.82 % 1.67 % 1.44 % 1.63 % Expected term of options (in years) 5.82 5.82 5.82 5.82 Market and Performance Awards — The Company granted restricted stock units containing service, performance, and market conditions (“PSUs”). PSUs are earned over a three-year performance period if the specified performance metrics are met. During fiscal 2015, the Company only granted PSUs based on net earnings growth (“Net Earnings Growth Based PSUs”). For fiscal 2016, half of the PSUs granted were based on relative total stockholder return (“Relative TSR Based PSUs”) and the other half of the PSUs were based on earnings per share (“EPS Based PSUs”). For fiscal 2017, half of the PSUs granted were EPS Based PSUs and the other half were based on return on invested capital (“ROIC Based PSUs”). 2014 and 2015 Awards The number of Net Earnings Growth Based PSUs awarded in fiscal years 2014 and 2015 which may ultimately vest is equal to the sum of the following: (1) an amount, not less than zero, equal to one-third of the target Net Earnings Growth Based PSUs multiplied by the Net Earnings Growth Performance Multiplier (or, "NEGPM", as shown in the table below) determined based upon the growth in the Company's Adjusted Net Earnings (as defined in the applicable award agreements under the Stock Incentive Plan) over the period starting on the first day of the Company's third quarter of fiscal 2014 (in the case of Net Earnings Growth Based PSUs issued in fiscal 2014), or fiscal 2015 (in the case of Net Earnings Growth Based PSUs issued in fiscal 2015) and ending on the last day of the Company's second quarter of fiscal 2015 and fiscal 2016, respectively; plus, (2) an amount, not less than zero, equal to (A) two-thirds of the target Net Earnings Growth Based PSUs multiplied by the NEGPM determined based upon the average growth in the Company's Adjusted Net Earnings over the period starting on the first day of the Company's third quarter of fiscal 2014 (in the case of Net Earnings Growth Based PSUs issued in fiscal 2014), or fiscal 2015 (in the case of Net Earnings Growth Based PSUs issued in fiscal 2015) and ending on the last day of the Company's second quarter of fiscal 2016 and fiscal 2017, respectively, minus (B) the amount determined pursuant to (1) above; plus, (3) an amount, not less than zero, equal to (A) the target Net Earnings Growth Based PSUs multiplied by the NEGPM determined based upon the average growth in the Company's Adjusted Net Earnings over the period starting on the first day of the Company's third quarter of fiscal 2014 If the Company's average growth in Adjusted Net Earnings over the applicable fiscal years during the respective performance periods is between 5% and 10%, 10% and 15%, or 15% and 20%, the Net Earnings Growth Performance Multiplier will be determined using straight line interpolation based on the actual average growth in the Company's Adjusted Net Earnings. The following table presents the basis on which the Net Earnings Growth Based PSUs are determined: Average Adjusted Net Earnings Growth Net Earnings Multiplier Less than 5% 0 % 5% 50 % 10% 100 % 15% 150 % 20% 200 % Unless stated otherwise, the Net Earnings Growth Based PSUs are valued based on the closing price of the Company's common stock as reported in the NYSE Composite Price History on their respective grant dates. 2016 Awards EPS Based PSUs For the EPS Based PSUs issued in fiscal 2016, the number of restricted stock units to be issued on the vesting date of November 19, 2018 is based on the Company’s adjusted EPS growth over fiscal 2016, 2017 and 2018. The number of restricted stock units to be issued equals the sum of: (i) an amount, not less than zero, equal to one-third of the target number of restricted stock units multiplied by an EPS Performance Multiplier (as defined below) for that period determined based upon the growth in the Company’s adjusted EPS (“EPS Growth Rate”) from fiscal 2015 to fiscal 2016; (ii) an amount, not less than zero, equal to two-thirds of the target number of restricted stock units multiplied by an EPS Performance Multiplier determined based upon the Compound Annual EPS Growth Rate (as defined below) for fiscal 2017 as compared to fiscal 2015, minus the amount of shares earned pursuant to clause (i); and (iii) an amount, not less than zero, equal to the target number of restricted stock units multiplied by an EPS Performance Multiplier determined based upon the Compound Annual EPS Growth Rate for fiscal 2018 as compared to fiscal 2015, minus the amount of shares earned pursuant to clauses (i) and (ii). The “Compound Annual EPS Growth Rate” for purposes of clauses (ii) and (iii) above means the growth rate, which when multiplied two times fiscal 2015 adjusted EPS (in the case of clause (ii)) or three times fiscal 2015 adjusted EPS (in the case of clause (iii)) results in a number equal to actual fiscal 2017 adjusted EPS and fiscal 2018 adjusted EPS, respectively. The “EPS Performance Multiplier” is determined by reference to the following table based upon the Company’s EPS Growth Rate or Compound Annual EPS Growth Rate over the relevant fiscal periods. The Human Resource and Compensation Committee of the Board of Directors of the Company set these metrics based on the Company’s plan at the start of the fiscal year. EPS Growth Rate or Compound Annual EPS Growth Rate EPS Performance Multiplier Less than 4% 0 % 4% 50 % 7.5% 100 % 15% 150 % 20% or greater 200 % If the EPS Growth Rate or Compound Annual EPS Growth Rate falls between 4% and 7.5%, 7.5% and 15%, or 15% and 20%, the EPS Performance Multiplier is determined using linear interpolation based on the actual growth in adjusted EPS. Unless stated otherwise, the EPS Based PSUs are valued based on the closing price of the Company's common stock as reported in the NYSE Composite Price History on their respective grant dates. Relative TSR Based PSUs The number of Relative TSR Based PSUs which may ultimately vest is equal to the target Relative TSR Based PSUs multiplied by the TSR Performance Multiplier. The TSR Performance Multiplier is determined by comparing the Company's total stockholder return to the total stockholder return of each of the companies in a specified industry peer group over the three year period immediately following the award date. For purposes of computing total stockholder return, the beginning stock price is the average closing stock price over the 30 calendar day period ending on the award date ("Performance Period"), and the ending stock price is the average closing price over the 30 calendar day period ending on the last day of the Performance Period. Any dividend payments made over the Performance Period are deemed re-invested on the ex-dividend date in additional shares of the applicable company. The following table presents the basis on which the Relative TSR Based PSUs are determined: Company TSR Percentile Rank TSR Multiplier Below 30th percentile 0 % 30th percentile 50 % 50th percentile 100 % 70th percentile or above 150 % If the Company's total stockholder return over the Performance Period falls between any of the brackets described above, the TSR Performance Multiplier will be determined using straight line interpolation based on the actual percentile ranking. Substantially all of the TSR Based PSUs awarded during fiscal year 2016 were awarded on the same date. For fiscal year 2017 and 2015, no TSR Based PSUs were awarded. The following table presents the assumptions used to value the TSR Based PSUs for the years ended September 29, 2017, September 30, 2016 and October 2, 2015: For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Dividend yield — % — % — % Expected volatility — % 25.06 % — % Risk-free interest rate — % 1.21 % — % Expected term (in years) — 3 — 2017 Awards For the EPS Based PSUs issued in fiscal 2017, the number of restricted stock units to be issued on the vesting date of November 16, 2019 is based on the Company’s adjusted EPS growth over fiscal 2017, 2018 and 2019. The number of restricted stock units to be issued equals the sum of: (i) an amount, not less than zero, equal to one-third of the target number of restricted stock units multiplied by an EPS Performance Multiplier (as shown in the table below) for that period determined based upon the growth in the Company’s adjusted EPS (“EPS Growth Rate”) from fiscal 2016 to fiscal 2017; (ii) an amount, not less than zero, equal to two-thirds of the target number of restricted stock units multiplied by an EPS Performance Multiplier determined based upon the average EPS Growth Rate in fiscal years 2017 and 2018 as compared to fiscal 2016, minus the amount of shares earned pursuant to clause (i); and (iii) an amount, not less than zero, equal to the target number of restricted stock units multiplied by an EPS Performance Multiplier determined based upon the average EPS Growth Rate in fiscal years 2017, 2018 and 2019 as compared to fiscal 2016, minus the amount of shares earned pursuant to clauses (i) and (ii). The “EPS Performance Multiplier” is determined by reference to the following table based upon the average growth in the Company’s adjusted EPS over the indicated fiscal periods. The Human Resource and Compensation Committee of the Board of Directors of the Company set these metrics based on the Company’s plan at the start of the fiscal year. Average EPS Growth Rate from fiscal 2016 to fiscal 2017 Average EPS Growth Rate EPS Performance Multiplier Less than 0% 0 2.3% 100 % 4.3% 200 % Average EPS Growth Rate from fiscal 2016 to fiscal 2018 Average EPS Growth Rate EPS Performance Multiplier Less than 2.1% 0 4.1% 100 % 6.1% 200 % Average EPS Growth Rate from fiscal 2016 to fiscal 2019 Average EPS Growth Rate EPS Performance Multiplier Less than 3.6% 0 5.6% 100 % 7.6% 200 % If the average EPS Growth Rate falls between the percentages referenced in the tables above, the EPS Performance Multiplier will be determined using linear interpolation based on the actual average EPS Growth Rate. Unless stated otherwise, the EPS Based PSUs are valued based on the closing price of the Company's common stock as reported in the NYSE Composite Price History on their respective grant dates. For the ROIC Based PSUs issued in fiscal 2017, the number of restricted stock units to be issued on the vesting date of November 16, 2019 is based on the Company’s average annual return on invested capital (“ROIC”) from fiscal 2017 to fiscal 2019. The number of restricted stock units to be issued equals the target number of restricted stock units multiplied by an ROIC Performance Multiplier (as shown in the table below) determined based upon the Company’s average annual ROIC from fiscal 2017 to fiscal 2019. Average ROIC – Fiscal 2017 - 2019 ROIC Performance Multiplier Less than 8.9% 0 % 8.9% 50 % 9.9% 100 % 10.9% 200 % If the average annual ROIC falls between 8.9% and 9.9% and 10.9%, the ROIC Performance Multiplier will be determined using linear interpolation based on the actual average ROIC. Concentrations of Credit Risk Our cash balances and cash equivalents are maintained in accounts held by major banks and financial institutions located in North America, South America, Europe, the Middle East, India, Australia, Africa, and Asia. In the normal course of business, and consistent with industry practices, we grant credit to our clients without requiring collateral. Concentrations of credit risk is the risk that, if we extend a significant amount of credit to clients in a specific geographic area or industry, we may experience disproportionately high levels of default if those clients are adversely affected by factors particular to their geographic area or industry. Concentrations of credit risk relative to trade receivables are limited due to our diverse client base, which includes the U.S. federal government and multi-national corporations operating in a broad range of industries and geographic areas. Additionally, in order to mitigate credit risk, we continually evaluate the credit worthiness of our major commercial clients. Use of Estimates and Assumptions The preparation of financial statements in conformity with U.S. GAAP requires us to employ estimates and make assumptions t

Employee Stock Purchase and Sto

Employee Stock Purchase and Stock Option Plans	12 Months Ended
	Sep. 29, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Employee Stock Purchase and Stock Option Plans	3. Employee Stock Purchase and Stock Option Plans Broad-Based, Employee Stock Purchase Plans Under the 1989 ESPP and the GESPP, eligible employees who elect to participate in these plans are granted the right to purchase shares of the common stock of Jacobs at a discount that is limited to 5% of the per-share market value on the day shares are sold to employees. The following table summarizes the stock issuance activity under the 1989 ESPP and the GESPP for the fiscal years ended September 29, 2017, September 30, 2016 and October 2, 2015: For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Aggregate Purchase Price Paid for Shares Sold: Under the 1989 ESPP $ 21,084,657 $ 23,631,241 $ 28,621,800 Under the GESPP 2,105,834 2,660,067 3,535,479 Total $ 23,190,491 $ 26,291,308 $ 32,157,279 Aggregate Number of Shares Sold: Under the 1989 ESPP 403,652 564,461 696,853 Under the GESPP 39,648 63,196 84,361 Total 443,300 627,657 781,214 On January 19, 2017, the Company’s stockholders approved an increase in the number of shares authorized by 4,350,000 shares for the 1989 ESPP and by 150,000 shares for the GESPP. At September 29, 2017, there remains 4,545,854 shares reserved for issuance under the 1989 ESPP and 174,980 shares reserved for issuance under the GESPP. Stock Incentive Plans We also sponsor the 1999 SIP and the 1999 ODSP. The 1999 SIP provides for the issuance of incentive stock options, nonqualified stock options, share appreciation rights ("SARs"), restricted stock, and restricted stock units to employees. The 1999 ODSP provides for awards of shares of common stock, restricted stock, and restricted stock units, and grants of nonqualified stock options to our outside (i.e., nonemployee) directors. The following table sets forth certain information about the 1999 Plans: 1999 SIP 1999 ODSP Total Number of shares authorized 29,850,000 1,100,000 30,950,000 Number of remaining shares reserved for issuance at September 29, 2017 9,641,396 539,787 10,181,183 Number of shares relating to outstanding stock options at September 29, 2017 2,289,450 227,375 2,516,825 Number of shares available for future awards: At September 29, 2017 7,351,946 312,412 7,664,358 At September 30, 2016 7,233,173 319,535 7,552,708 Effective September 28, 2012, all grants of shares under the 1999 SIP are issued on a fungible basis. An award other than an option or SAR are granted on a 1.92-to-1.00 basis (“Fungible”). An award of an option or SAR are granted on a 1-to-1 basis (“Not Fungible”). The following table presents the Fair Value of shares (of restricted stock and restricted stock units) vested for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Restricted Stock and Restricted Stock Units (service condition) $ 34,466 $ 17,481 $ 18,568 Restricted Stock Units (service, market, and performance conditions at target) 4,183 4,336 11,264 Total $ 38,649 $ 21,817 $ 29,832 The following table presents the Company’s total pre-tax compensation cost relating to share-based payments included in the accompanying Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015(in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 $ 38,764 $ 32,370 $ 41,412 At September 29, 2017, the amount of compensation cost relating to nonvested awards not yet recognized in the financial statements is approximately $83.7 million. The majority of the unrecognized compensation costs will be recognized by the first quarter of fiscal 2019. The weighted average remaining contractual term of options currently exercisable is 4.8 years. Stock Options The following table summarizes the stock option activity for the years ended September 29, 2017, September 30, 2016 and October 2, 2015: Number of Stock Options Weighted Average Exercise Price Outstanding at September 26, 2014 4,221,147 $ 53.23 Granted 614,759 $ 43.56 Exercised (34,000 ) $ 31.54 Cancelled or expired (729,199 ) $ 86.15 Outstanding at October 2, 2015 4,072,707 $ 46.06 Granted 460,770 $ 42.17 Exercised (412,416 ) $ 40.88 Cancelled or expired (543,549 ) $ 49.13 Outstanding at September 30, 2016 3,577,512 $ 45.69 Granted — $ — Exercised (906,648 ) $ 43.79 Cancelled or expired (154,039 ) $ 48.79 Outstanding at September 29, 2017 2,516,825 $ 46.19 Stock options outstanding at September 29, 2017 consisted entirely of nonqualified stock options. The following table presents the total intrinsic value of stock options exercised for the fiscal years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 $ 14,713 $ 4,149 $ 442 The total intrinsic value of stock options exercisable at September 29, 2017 was approximately $23.5 million. The following table presents certain other information regarding our 1999 SIP and 1999 OSDP for the fiscal years ended September 29, 2017, September 30, 2016 and October 2, 2015: September 29, September 30, October 2, At fiscal year end: Range of exercise prices for options outstanding $32.51–$80.63 $32.51–$80.63 $32.51–$80.63 Number of options exercisable 1,992,022 2,581,421 2,590,560 For the fiscal year: Range of prices relating to options exercised $37.03–$55.53 $36.88–$55.00 $25.87–$42.74 Estimated weighted average fair values of options granted $ — $ 12.80 $ 13.41 The following table presents certain information regarding stock options outstanding and stock options exercisable at September 29, 2017: September 29, 2017 Options Outstanding Options Exercisable Range of Exercise Prices Number Weighted Average Remaining Contractual Life (years) Weighted Average Price Number Weighted Average Exercise Price $32.51 - $37.03 247,875 4.47 $ 36.99 247,875 $ 36.99 $37.43 - $46.09 1,360,188 5.63 $ 42.69 890,206 $ 42.65 $47.11 - $55.13 836,812 5.30 $ 52.81 788,116 $ 52.80 $60.08 - $80.63 71,950 4.23 $ 66.92 65,825 $ 67.52 2,516,825 5.37 $ 46.19 1,992,022 $ 46.78 The 1999 ODSP and the 1999 SIP allow participants to satisfy the exercise price of stock options by tendering shares of Jacobs common stock that have been owned by the participants for at least six months. Shares so tendered are retired and canceled, and are shown as repurchases of common stock in the accompanying Consolidated Statements of Stockholders’ Equity. Restricted Stock The following table presents the number of shares of restricted stock and restricted stock units issued as common stock under the 1999 SIP for the year ended September 29, 2017, September 30, 2016 and October 2, 2015: For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Restricted stock — 597,091 507,882 Restricted stock units (service condition) 496,951 183,131 126,635 Restricted stock units (service, market and performance conditions) 237,058 372,794 219,965 The amount of restricted stock units issued for awards with performance and market conditions in the above table are issued based on performance against the target amount. The number of shares ultimately issued, which could be greater or less than target, will be based on achieving specific performance conditions described in Note 2 – Significant Accounting Policies The share amounts in the above tables reflect the Non-Fungible share counting of one share for each share of restricted stock and restricted stock unit issued. The following table presents the number of shares of restricted stock and restricted stock units cancelled and withheld for taxes under the 1999 SIP for the years ended September 29, 2017, September 30, 2016 and October 2, 2015: For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Restricted stock 365,481 512,903 326,480 Restricted stock units (service condition) 128,536 177,640 70,296 Restricted stock units (service, market and performance conditions) 86,742 275,933 194,116 The amount of unvested restricted stock units cancelled for awards with service and performance conditions in the above table is based on the service period achieved and performance against the target amount. The share amounts in the above tables reflect the Non-Fungible share counting of one share for each share of restricted stock and restricted stock unit issued. The restrictions attached to restricted stock and restricted stock units generally relate to the recipient’s ability to sell or otherwise transfer the stock or stock units. There are also restrictions that subject the stock and stock units to forfeiture back to the Company until earned by the recipient through continued employment or service. The following table provides the number of shares of restricted stock and restricted stock units outstanding at September 29, 2017 under the 1999 SIP. Shares granted in the table below are granted on a 1.92 -to-1.00 basis (fungible): September 29, 2017 Total Restricted stock 950,593 Restricted stock units (service condition) 766,759 Restricted stock units (service, market and performance conditions) 672,440 The following table presents the number of shares of restricted stock and restricted stock units issued under the 1999 ODSP for the years ended September 29, 2017, September 30, 2016 and October 2, 2015: For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Restricted stock units (service condition) 21,123 23,090 13,500 The following table provides the number of shares of restricted stock and restricted stock units outstanding at September 29, 2017 under the 1999 ODSP: September 29, 2017 Restricted stock 34,000 Restricted stock units (service condition) 90,595 All shares granted under the 1999 ODSP are issued on a 1-to-1 basis. Modification On January 18, 2017, the Company modified time vested outstanding restricted stock units, paid out in stock and cash, specifically to allow participants to be entitled to dividend equivalents during the vesting period on the outstanding RSUs. Dividends will be paid out at the end of the vesting period and are forfeitable before the vesting period concludes. This modification affected 786 employees and resulted in $1.1 million of incremental compensation cost and will be recognized over the remaining vesting period for each grant, since dividends are forfeitable until vesting is achieved.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Sep. 29, 2017
Earnings Per Share Reconciliation [Abstract]
Earnings Per Share	4. Earnings Per Share Basic and Diluted Earnings Per Share Basic and diluted earnings per share are computed using the two-class method, which is an earnings allocation method that determines earnings per share (“EPS”) for common shares and participating securities. The undistributed earnings are allocated between common shares and participating securities as if all earnings had been distributed during the period. Participating securities and common shares have equal rights to undistributed earnings. Net earnings used for the purpose of determining basic and diluted earnings per share is determined by taking net earnings, less earnings available to participating securities. The following table reconciles the denominator used to compute basic EPS to the denominator used to compute diluted EPS for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Numerator for Basic and Diluted EPS: Net income $ 293,727 $ 210,463 $ 302,971 Net income allocated to participating securities (3,077 ) — — Net income allocated to common stock for EPS calculation $ 290,650 $ 210,463 $ 302,971 Denominator for Basic and Diluted EPS: Weighted average basic shares 119,370 120,133 125,007 Effect of dilutive securities: Stock compensation plans 777 680 481 Restricted stock 1,319 670 622 Diluted shares 121,466 121,483 126,110 Shares allocated to participating securities (1,319 ) — — Shares used for calculating diluted EPS attributable to common stock 120,147 121,483 126,110 Basic EPS $ 2.43 $ 1.75 $ 2.42 Diluted EPS $ 2.42 $ 1.73 $ 2.40 Share Repurchases On July 23, 2015, the Board of Directors approved a share repurchase program to repurchase up to $500 million of the Company's common stock over the ensuing three years (the "2015 Share Repurchase Program"). As authorized, share repurchases may be executed through various means including, without limitation, open market transactions and/or privately negotiated transactions. The 2015 Share Repurchase Program does not obligate the Company to purchase any shares, and expires on July 22, 2018. The timing of shares repurchases may depend upon market conditions, other uses of capital, and other factors. The following table summarizes the activity under this program during fiscal 2017 (in thousands, except per-share amounts): Amount Authorized (in Average Price Per Share (1) Shares Retired (In thousands) Shares Repurchased (In thousands) $ 500,000 $ 55.60 1,748 1,748 (1) Includes commissions paid and calculated as the average price per share since the repurchase program authorization date. Dividend Program On December 1, 2016, the Company announced that the Board of Directors has approved the initiation of a cash dividend program. Quarterly dividends of $0.15 per share were paid in each of the second, third and fourth quarters of fiscal 2017. On September 27, 2017, the Board of Directors declared a quarterly cash dividend of $0.15 per share, which was paid on November 10, 2017. Future dividend payments are subject to review and approval by the Company’s Board of Directors.

Restructuring and Other Charges

Restructuring and Other Charges	12 Months Ended
	Sep. 29, 2017
Restructuring And Related Activities [Abstract]
Restructuring and Other Charges	5. During the second fiscal quarter of 2015, the Company began implementing a series of initiatives intended to improve operational efficiency, reduce costs, and better position itself to drive growth of the business in the future. We refer to these initiatives, in the aggregate, as the "2015 Restructuring". These activities evolved and developed over time as management identified and evaluated opportunities for changes in the Company’s operations (and related areas of potential cost savings), as economic conditions changed and as the realignment of the Company’s operations into its four global lines of business was implemented. Actions related to the 2015 Restructuring included involuntary terminations, the abandonment of certain leased offices, combining operational organizations, and the co-location of employees into other existing offices. We did not exit any service types or client end-markets in connection with the 2015 Restructuring. The majority of the costs associated with the 2015 Restructuring are included in SG&A expense in the Consolidated Statements of Earnings. The following table summarizes the impacts of the 2015 Restructuring on the Company's reportable segment income by line of business for the years ended September 29, 2017 and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Aerospace & Technology $ 1,820 $ 5,835 Buildings & Infrastructure 23,675 23,378 Industrial 6,698 29,690 Petroleum & Chemicals 36,664 87,188 Corporate 29,831 41,816 Total Restructuring Charges $ 98,688 $ 187,907 Total 2015 restructuring charges were $157,192 for the year ended October 2, 2015. The activity in the Company’s accrual for the 2015 Restructuring for the year ended September 29, 2017 is as follows (in thousands): Balance at September 30, 2016 $ 152,174 Charges 98,688 Payments (122,407 ) Balance at September 29, 2017 $ 128,455 The following table summarizes the 2015 Restructuring by major type of restructuring costs for the years ended September 29, 2017 and September 30, 2016 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Lease Abandonments $ 55,647 $ 92,643 $ 90,569 Involuntary Terminations 30,716 85,599 55,313 Outside Services 4,236 7,398 12,734 Other restructuring related costs, net 8,089 2,267 (1,424 ) Total $ 98,688 $ 187,907 $ 157,192 Cumulative amounts incurred to date for the 2015 Restructuring by each major type of restructuring costs as of September 29, 2017 is as follows (in thousands): Lease Abandonments $ 238,859 Involuntary Terminations 171,628 Outside Services 24,368 Other restructuring related costs, net 8,932 Total $ 443,787 The 2015 Restructuring was completed in the fourth quarter of fiscal 2017. Also, during the second fiscal quarter of 2017, the Company entered into strategic business restructuring activities associated with realignment of its Europe, U.K. and Middle East regional operations in our Buildings & Infrastructure segment. Pre-tax net charges of $22.6 million were recorded associated mainly with net realizable value write-offs on contract accounts receivable of $16.5 million, with additional charges recorded for statutory redundancy and severance costs of $1.4 million and other liabilities of $4.7 million which are both expected to be paid or settled within fiscal 2018. Additional charges of $1.2 million were recorded under this business exit during third quarter fiscal 2017 associated mainly with contract accounts receivable charges. Further, management has determined that these business restructuring activities do not qualify for discontinued operations treatment in accordance with U.S. GAAP.

Borrowings

Borrowings	12 Months Ended
	Sep. 29, 2017
Debt Disclosure [Abstract]
Borrowings	6. Borrowings Short-Term Credit Arrangements The Company maintains both committed and uncommitted credit arrangements with several banks providing for short-term borrowing capacity and overdraft protection. There were borrowings of $3.1 million outstanding under these short-term credit facilities at a weighted average interest rate of 4.33% at September 29, 2017, and there were borrowings of $2.4 million outstanding under these short-term credit facilities at September 30, 2016. Long-term Debt On February 7, 2014, the Company and certain of its subsidiaries entered into a $1.6 billion long-term unsecured, revolving credit facility (as amended the "Revolving Credit Facility") with a syndicate of large U.S. and international banks and financial institutions. The following table presents certain information regarding the Company’s long-term revolving credit facilities at September 29, 2017 and September 30, 2016 (dollars in thousands): September 29, 2017 September 30, 2016 Principal Balance Outstanding Range of Interest Rates Principal Balance Outstanding Range of Interest Rates $ 235,000 1.0% – 2.23% $ 385,330 1.0% – 1.65% The total amount outstanding under the Revolving Credit Facility in the form of direct borrowings at September 29, 2017 was $235.0 million. The Company issued $2.5 million in letters of credit leaving $1.363 billion of available borrowing capacity under the Revolving Credit Facility at September 29, 2017. In addition, the Company had $259.6 million issued under separate, committed and uncommitted letter-of-credit facilities for total issued letters of credit of $262.1 million at September 29, 2017. The Revolving Credit Facility expires in February 2020 and permits the Company to borrow under two separate tranches in U.S. dollars, certain specified foreign currencies, and any other currency that may be approved in accordance with the terms of the Revolving Credit Facility. Depending on the Company's Consolidated Leverage Ratio, borrowings under the Revolving Credit Facility will bear interest at either a euro rate plus a margin of between 1.0% and 1.5% or a base rate plus a margin of between 0% and 0.5%. The Revolving Credit Facility also provides for a financial letter of credit subfacility of $300.0 million, permits performance letters of credit, and provides for a $50.0 million subfacility for swingline loans. Letters of credit are subject to fees based on the Company's Consolidated Leverage Ratio at the time any such letter of credit is issued. The Revolving Credit Facility also provides an accordion feature that allows the Company and the lenders to increase the facility amount to $2.1 billion. The Company pays a facility fee of between 0.100% and 0.25% per annum depending on the Company's Consolidated Leverage Ratio. Amounts outstanding under the Revolving Credit Facility may be prepaid at the option of the Company without premium or penalty, subject to customary breakage fees in connection with the prepayment of eurocurrency loans. The Revolving Credit Facility contains affirmative, negative, and financial covenants customary for financings of this type including, among other things, limitations on certain other indebtedness, loans and investments, liens, mergers, asset sales and transactions with affiliates. In addition, the Revolving Credit Facility contains customary events of default. We were in compliance with these debt covenants at September 29, 2017. On September 28, 2017, the Company entered into a Second Amendment to the Revolving Credit Facility, which provides for, among other things, an amendment to certain financial definitions used in the Revolving Credit Facility, including “Consolidated EBITDA”. These amendments are effective upon the consummation of the acquisition of CH2M. On September 28, 2017, the Company entered into a $1.5 billion unsecured delayed-draw term loan facility (the “Term Loan Facility”) with a syndicate of financial institutions as lenders and letter of credit issuers and BNP Paribas as administrative agent, TD Bank, N.A. and U.S. Bank National Association as co-documentation agent, BNP Paribas Securities Corp., The Bank of Nova Scotia and Wells Fargo Securities, LLC as joint book runners, and as joint arrangers. Subject to certain terms and conditions set forth therein, loans under the Term Loan Facility may be incurred on the day the CH2M acquisition is consummated in order to pay cash consideration for the acquisition, and to pay fees and expenses related to the acquisition and the Term Loan Facility. The Term Loan Facility has a three year maturity from the date of initial funding and permits the Company to borrow in U.S. dollars at a base rate or a eurocurrency rate. Depending on the Company’s consolidated leverage ratio, borrowings under the Term Loan Facility will bear interest at either a eurocurrency rate plus a margin of between 1.00% and 1.50% or a base rate plus a margin of between 0.00% and 0.50%. In addition, prior to the date the acquisition is consummated, the Company must pay a ticking fee of between 0.10% and 0.25% of unused commitments under the Term Loan Facility. Amounts outstanding under the Term Loan Facility may be prepaid at the option of the Company without premium or penalty, subject to customary breakage fees in connection with the prepayment of eurocurrency loans. The Term Loan Facility contains affirmative, negative and financial covenants customary for financings of this type, including, among other things, limitations on certain other indebtedness, investments, liens, mergers, asset sales and transactions with affiliates. In addition, the Term Loan Facility contains customary events of default. We were in compliance with these covenants at September 29, 2017. The following table presents certain additional information regarding the Company’s long-term debt for the fiscal years shown: 2017 2016 Maximum amount outstanding at any month-end during the fiscal year $ 659,103 $ 958,460 Average amount outstanding during the year $ 639,210 $ 825,641 Weighted average interest rate during the year 1.67 % 1.39 % The following table presents the amount of interest paid by the Company during September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 $ 12,862 $ 13,282 $ 15,506

Pension and Other Postretiremen

Pension and Other Postretirement Benefit Plans	12 Months Ended
	Sep. 29, 2017
Defined Benefit Pension Plans And Defined Benefit Postretirement Plans Disclosure [Abstract]
Pension and Other Postretirement Benefit Plans	7. Pension and Other Postretirement Benefit Plans Company-Only Sponsored Plans We sponsor various defined benefit pension plans covering employees of certain U.S. and international subsidiaries. The pension plans provide pension benefits that are based on the employee’s compensation and years of service. Our funding policy is to fund the actuarially determined accrued benefits where applicable, allowing for projected compensation increases using the projected unit method. The accounting for pension and other post-retirement benefit plans requires the use of assumptions and estimates in order to calculate periodic benefit cost and the value of the plans’ assets and benefit obligations. These assumptions include discount rates, investment returns, and projected salary increases, among others. The discount rates used in valuing the plans' benefit obligations were determined with reference to high quality corporate and government bonds that are appropriately matched to the duration of each plan's obligations. The expected long-term rate of return on plan assets is generally based on using country-specific simulation models which select a single outcome for expected return based on the target asset allocation. The expected long-term-rates of return used in the valuation are the annual average returns generated by these assumptions over a 20-year period for each asset class based on the expected long-term rate of return of the underlying assets. The following table sets forth the changes in the plans’ combined net benefit obligation (segregated between plans existing within and outside the U.S.) for the years ended September 29, 2017 and September 30, 2016 (in thousands): U.S. Pension Plans Non-U.S. Pension Plans September 29, 2017 September 30, 2016 September 29, 2017 September 30, 2016 Net benefit obligation at the beginning of the year $ 185,664 $ 533,665 $ 1,363,782 $ 1,155,592 Service cost 1,000 9,875 7,509 14,378 Interest cost 5,757 16,746 31,205 38,892 Participants’ contributions — 1,847 250 2,255 Actuarial (gains)/losses (9,922 ) 29,129 (142,273 ) 382,691 Benefits paid (14,338 ) (14,143 ) (40,208 ) (32,277 ) Curtailments/settlements — (35,224 ) (1,375 ) (35,375 ) Transfers * — (356,231 ) — — Effect of exchange rate changes and other, net 1,781 — 87,917 (162,374 ) Net benefit obligation at the end of the year $ 169,942 $ 185,664 $ 1,306,807 $ 1,363,782 * Pension plan transferred to a new sponsor for the plan The following table sets forth the changes in the combined Fair Value of the plans’ assets (segregated between plans existing within and outside the U.S.) for the year ended September 29, 2017 and September 30, 2016 (in thousands): U.S. Pension Plans Non-U.S. Pension Plans September 29, 2017 September 30, 2016 September 29, 2017 October 2, 2016 Fair value of plan assets at the beginning of the year $ 142,464 $ 379,907 $ 1,003,911 $ 896,298 Actual return on plan assets 18,662 28,835 16,789 242,927 Employer contributions 1,000 10,213 21,005 23,217 Participants’ contributions — 1,847 250 2,255 Gross benefits paid (14,338 ) (14,143 ) (40,208 ) (32,277 ) Curtailments/settlements — (35,224 ) (228 ) (1,863 ) Transfers* — (228,971 ) — — Effect of exchange rate changes and other, net — — 75,409 (126,646 ) Fair value of plan assets at the end of the year $ 147,788 $ 142,464 $ 1,076,928 $ 1,003,911 * Pension plan transferred to a new sponsor for the plan During fiscal 2017 we curtailed the pension plan in Ireland and in fiscal 2016 we curtailed our U.K. and French pension plans. The following table reconciles the combined funded statuses of the plans recognized in the accompanying Consolidated Balance Sheets at September 29, 2017 and September 30, 2016 (segregated between plans existing within and outside the U.S.) (in thousands): U.S. Pension Plans Non-U.S. Pension Plans September 29, 2017 September 30, 2016 September 29, 2017 September 30, 2016 Net benefit obligation at the end of the year $ 169,942 $ 185,664 $ 1,306,807 $ 1,363,782 Fair value of plan assets at the end of the year 147,788 142,464 1,076,928 1,003,911 Under funded amount recognized at the end of the year $ 22,154 $ 43,200 $ 229,879 $ 359,871 The following table presents the accumulated benefit obligation at September 29, 2017 and September 30, 2016 (segregated between plans existing within and outside the U.S.) (in thousands): U.S. Pension Plans Non-U.S. Pension Plans September 29, 2017 September 30, 2016 September 29, 2017 September 30, 2016 Accumulated benefit obligation at the end of the year $ 169,942 $ 185,664 $ 1,291,600 $ 1,331,884 The following table presents the amounts recognized in the accompanying Consolidated Balance Sheets at September 29, 2017 and September 30, 2016 (segregated between plans existing within and outside the U.S.) (in thousands): U.S. Pension Plans Non-U.S. Pension Plans September 29, 2017 September 30, 2016 September 29, 2017 September 30, 2016 Prepaid benefit cost included in prepaid assets $ — $ — $ 3,035 $ 492 Accrued benefit cost included in current liabilities — — 585 608 Accrued benefit cost included in noncurrent liabilities 22,154 43,200 232,329 359,755 Net amount recognized at the end of the year $ 22,154 $ 43,200 $ 229,879 $ 359,871 In fiscal 2015 and through June 30, 2016, we were responsible for administering a U.S. pension plan for participating employees who were assigned to, and worked exclusively on, a specific operating contract with the U.S. federal government. The costs of this pension plan were fully reimbursed by the U.S. federal government pursuant to applicable cost accounting standards. As of June 30, 2016, we ceased performing on this operating contract, and, as such, we are no longer responsible for administering this pension plan. As a result of no longer administering the plan, we derecognized the plan benefit obligation and plan assets pertaining to the plan resulting in a decrease of plan benefit obligation by $356.2 million and plan assets by $229.0 million. The following table presents the significant actuarial assumptions used in determining the funded statuses and the following year's benefit cost of the Company’s U.S. plans for the years ended September 29, 2017, September 30, 2016 and October 2, 2015: For the Year Ended September 29, 2017 September 30, 2016 October 2, 2015 Weighted average discount rates 3.5 % 3.2 3.9% to 4.0% Rates of compensation increases — % — % 3.0 % Return on Assets 7.5 % 7.4 % 7.4 % The following table presents the significant actuarial assumptions used in determining the funded statuses and the following year's benefit cost of the Company’s non-U.S. pension plans for the years ended September 29, 2017, September 30, 2016 and October 2, 2015: September 29, 2017 September 30, 2016 October 2, 2015 Weighted average discount rates 1.3% to 7.0% 0.7% to 7.0% 1.6% to 7.8% Rates of compensation increases 2.5% to 7.5% 2.5% to 7.5% 2.4% to 7.5% Expected long-term rates of return on assets 3.5% to 8.5% 3.5% to 8.5% 3.5% to 8.5% The following table presents certain amounts relating to our U.S. pension plans recognized in accumulated other comprehensive (gain) loss at September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 Arising during the period: Net actuarial (gain) loss $ (11,372 ) $ 4,337 $ 12,237 Reclassification adjustments: Net actuarial losses (2,431 ) (2,312 ) (2,347 ) Total $ (13,803 ) $ 2,025 $ 9,890 The following table presents certain amounts relating to our non-U.S. pension plans recognized in accumulated other comprehensive (gain) loss at September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 Arising during the period: Net actuarial (gain) loss $ (76,860 ) $ 102,925 $ (27,165 ) Prior service cost (benefit) 119 580 (1,512 ) Total (76,741 ) 103,505 (28,677 ) Reclassification adjustments: Net actuarial losses (8,732 ) (7,508 ) (14,034 ) Prior service cost 229 163 51 Total (8,503 ) (7,345 ) (13,983 ) Total $ (85,244 ) $ 96,160 $ (42,660 ) The following table presents certain amounts relating to our pension plans recorded in accumulated other comprehensive loss that have not yet been recognized as components of net periodic benefit cost at September 29, 2017, and September 30, 2016 (segregated between U.S. and non-U.S. plans) (in thousands): U.S. Pension Plans Non-U.S. Pension Plans September 29, 2017 September 30, 2016 September 29, 2017 September 30, 2016 Net actuarial loss $ 47,681 $ 61,483 $ 218,752 $ 304,345 Prior service cost — — (855 ) (1,203 ) Total $ 47,681 $ 61,483 $ 217,897 $ 303,142 The following table presents the amount of accumulated comprehensive income that will be amortized against earnings as part of our net periodic benefit cost in fiscal 2018 based on 2017 exchange rates (segregated between U.S. and non-U.S. plans) (in thousands): U.S. Pension Plans Non-U.S. Pension Plans Unrecognized net actuarial loss $ 3,325 $ 6,829 Unrecognized prior service cost — (277 ) Accumulated comprehensive loss to be recorded against earnings $ 3,325 $ 6,552 We consider various factors in developing the estimates for the expected, long-term rates of return on plan assets. These factors include the projected, long-term rates of returns on the various types of assets in which the plans invest, as well as historical returns. In general, investment allocations are determined by each plan’s trustees and/or investment committees. The objectives of the plans’ investment policies are to (i) maximize returns while preserving capital; (ii) provide returns sufficient to meet the current and long-term obligations of the plan as the obligations become due; and (iii) maintain a diversified portfolio of assets so as to reduce the risk associated with having a disproportionate amount of the plans’ total assets invested in any one type of asset, issuer or geography. None of our pension plans hold Jacobs common stock directly (although some plans may hold shares indirectly through investments in mutual funds). The plans’ weighted average asset allocations at September 29, 2017 and September 30, 2016 (the measurement dates used in valuing the plans’ assets and liabilities) were as follows: U.S. Pension Plans Non-U.S. Pension Pans September 29, 2017 September 30, 2016 September 29, 2017 September 30, 2016 Equity securities 70 % 71 % 24 % 25 % Debt securities 23 % 20 % 32 % 32 % Real estate investments — % 2 % 5 % 6 % Other 7 % 7 % 39 % 37 % The following table presents the Fair Value of the Company’s Domestic U.S. plan assets at September 29, 2017, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands): September 29, 2017 Fair Value, Determined Using Fair Value Measurement Inputs Level 1 Level 3 Total U.S. Domestic equities $ 103,760 $ — $ 103,760 U.S. Domestic bonds 33,404 — 33,404 Cash and equivalents 4,448 — 4,448 Hedge funds — 6,176 6,176 Total $ 141,612 $ 6,176 $ 147,788 The following table presents the Fair Value of the Company’s non-U.S. pension plan assets at September 29, 2017, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands): September 29, 2017 Fair Value, Determined Using Fair Value Measurement Inputs Level 1 Level 3 Total U.S. Domestic equities $ 30,916 $ — $ 30,916 Overseas equities 229,205 — 229,205 U.S. Domestic bonds 263,145 — 263,145 Overseas bonds 77,682 — 77,682 Cash and equivalents 38,924 — 38,924 Real estate — 58,974 58,974 Insurance contracts — 74,353 74,353 Other — 303,729 303,729 Total $ 639,872 $ 437,056 $ 1,076,928 The following table presents the Fair Value of the Company’s U.S. pension plan assets at September 30, 2016, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands): September 30, 2016 Fair Value, Determined Using Fair Value Measurement Inputs Level 1 Level 3 Total U.S. Domestic equities $ 85,494 $ — $ 85,494 Overseas equities 15,169 — 15,169 U.S. Domestic bonds 28,886 — 28,886 Cash and equivalents 3,723 — 3,723 Real estate — 3,477 3,477 Hedge funds — 5,715 5,715 Total $ 133,272 $ 9,192 $ 142,464 The following table presents the Fair Value of the Company’s non-U.S. pension plan assets at September 30, 2016, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands): September 30, 2016 Fair Value, Determined Using Fair Value Measurement Inputs Level 1 Level 3 Total U.S. Domestic equities $ 31,972 $ — $ 31,972 Overseas equities 220,179 — 220,179 U.S. Domestic bonds 258,949 — 258,949 Overseas bonds 61,974 — 61,974 Cash and equivalents 63,182 — 63,182 Real estate — 55,665 55,665 Insurance contracts — 39,473 39,473 Hedge funds — 272,517 272,517 Total $ 636,256 $ 367,655 $ 1,003,911 At September 29, 2017 and September 30, 2016, the Company holds no assets in the U.S. or non-U.S. pension plans that use Level 2 fair value measurement inputs. The following table summarizes the changes in the Fair Value of the Company’s U.S. Pension Plans’ Level 3 assets for the year ended September 29, 2017 (in thousands): Real Estate Hedge Funds Balance at September 30, 2016 $ 3,477 $ 5,715 Purchases, sales, and settlements (3,477 ) (557 ) Realized and unrealized gains — 1,018 Balance at September 29, 2017 $ — $ 6,176 The following table summarizes the changes in the Fair Value of the Company’s non-U.S. Pension Plans’ Level 3 assets for the year ended September 29, 2017 (in thousands): Real Estate Insurance Contracts Hedge Funds Balance at September 30, 2016 $ 55,665 $ 39,473 $ 272,517 Purchases, sales, and settlements (1,199 ) 422 (9,022 ) Realized and unrealized gains (losses) 2,642 (7,572 ) 19,662 Transfers — 40,031 11,758 Effect of exchange rate changes 1,866 1,999 8,814 Balance at September 29, 2017 $ 58,974 $ 74,353 $ 303,729 The following table summarizes the changes in the Fair Value of the Company’s U.S. Pension Plans’ Level 3 assets for the year ended September 30, 2016 (in thousands): Real Estate Hedge Funds Balance at October 2, 2015 $ 9,914 $ 16,372 Purchases (6,530 ) (10,788 ) Realized and unrealized gains 93 131 Balance at September 30, 2016 $ 3,477 $ 5,715 The following table summarizes the changes in the Fair Value of the Company’s non-U.S. Pension Plans’ Level 3 assets for the year ended September 30, 2016 (in thousands): Real Estate Insurance Contracts Hedge Funds Balance at October 2, 2015 $ 61,996 $ 32,522 $ 260,720 Purchases, sales, and settlements (462 ) (165 ) (1,205 ) Realized and unrealized gains 2,572 6,451 57,656 Effect of exchange rate changes (8,441 ) 665 (44,654 ) Balance at September 30, 2016 $ 55,665 $ 39,473 $ 272,517 The following table presents the amount of cash contributions we anticipate making into the plans during fiscal 2018 (in thousands): U.S. Pension Plans Non-U.S. Pension Pans Anticipated cash contributions $ 1,300 $ 22,574 The following table presents the total benefit payments expected to be paid to pension plan participants during each of the next five fiscal years, and in total for the five years thereafter (in thousands): U.S. Pension Plans Non-U.S. Pension Pans 2018 $ 21,506 $ 31,063 2019 11,372 32,509 2020 11,377 32,923 2021 11,472 36,220 2022 11,485 38,086 For the periods 2023 through 2027 54,747 231,183 The following table presents the components of net periodic benefit cost for the Company’s U.S. pension plans recognized in the accompanying Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 Service cost $ 1,000 $ 9,875 $ 12,045 Interest cost 5,757 16,746 20,629 Expected return on plan assets (9,942 ) (22,368 ) (29,526 ) Actuarial loss 3,985 7,512 3,756 Prior service cost — (176 ) (239 ) Net pension cost, before special items 800 11,589 6,665 Contractual expense/Settlement loss 1,781 8,061 — Total net periodic pension cost recognized $ 2,581 $ 19,650 $ 6,665 The fiscal 2016 settlement loss included in the U.S. pension plan net periodic benefit cost table above related to the previously discussed transfer of a U.S. pension plan to a new service provider. The following table presents the components of net periodic benefit cost for the Company’s Non-U.S. pension plans recognized in the accompanying Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 Service cost $ 7,509 $ 14,378 $ 21,374 Interest cost 31,205 38,892 44,659 Expected return on plan assets (56,269 ) (50,190 ) (53,052 ) Actuarial loss 10,616 9,092 17,398 Prior service cost (329 ) (260 ) (96 ) Net pension cost, before special items (7,268 ) 11,912 30,283 Curtailments and settlements (298 ) (7,512 ) 255 Total net periodic pension cost recognized $ (7,566 ) $ 4,400 $ 30,538 The fiscal 2016 settlement loss included in the Non-U.S. pension plan net periodic benefit cost table above related to the sale of the Company’s French subsidiary. Multiemployer Plans In Canada and the U.S., we contribute to various trusteed pension plans covering hourly construction employees under industry-wide agreements. We also contribute to various trusteed plans in Australia and certain countries in Europe covering both hourly and certain salaried employees. Contributions are based on the hours worked by employees covered under these agreements and are charged to direct costs of contracts on a current basis. The majority of the contributions the Company makes to multiemployer pension plans are outside the U.S. With respect to these multiemployer plans, the Company's liability to fund these plans is generally limited to the contributions we are required to make under collective bargaining agreements. Based on our review of our multiemployer pension plans under the guidance provided in ASU 2011-09— Compensation-Retirement Benefits-Multiemployer Plans The following table presents the Company’s contributions to these multiemployer plans for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 Canada $ 35,182 $ 44,912 $ 42,575 Europe $ 6,212 $ 8,771 $ 10,902 United States $ 4,548 $ 5,058 $ 5,968 Contributions to multiemployer pension plans $ 45,942 $ 58,741 $ 59,445 Other Benefit Plans During the second fiscal quarter of 2017, the Company restructured certain employee welfare trust plans benefitting certain of its employees within its India operations by moving these plans under the legal ownership and operation of the Company’s legal entity structure in the region. Historically, the Company structured these plans as separate, stand-alone entities outside of the Company’s consolidated legal entity framework. As a result of these changes, the Company has recorded a one-time, non-cash benefit of $9.9 million reported in SG&A expense in its Consolidated Statement of Earnings for the year ended September 29, 2017, with corresponding assets in the plans associated with restricted investments of $7.7 million and employee loans receivable of $2.2 million and both recorded in Total other non-current assets in our Consolidated Balance Sheet at September 29, 2017.

Other Comprehensive Income

Other Comprehensive Income	12 Months Ended
	Sep. 29, 2017
Equity [Abstract]
Other Comprehensive Income	8. Other Comprehensive Income The following table presents amounts reclassified from changes in pension liabilities in other comprehensive income to direct cost of contracts and SG&A expenses in the Company's Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 related to the Company's defined benefit pension plans (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 Amortization of Defined Benefit Items: Actuarial losses $ (14,601 ) $ (12,880 ) $ (21,153 ) Prior service cost 328 260 96 Total Before Income Tax (14,273 ) (12,620 ) (21,057 ) Income Tax Benefit 3,339 2,963 4,727 Total reclassifications after-tax $ (10,934 ) $ (9,657 ) $ (16,330 )

Savings and Deferred Compensati

Savings and Deferred Compensation Plans	12 Months Ended
	Sep. 29, 2017
Savings And Deferred Compensation Plans [Abstract]
Savings and Deferred Compensation Plans	9. Savings and Deferred Compensation Plans Savings Plans We sponsor various defined contribution savings plans which allow participants to make voluntary contributions by salary deduction. Such plans cover substantially all of our domestic, nonunion employees in the U.S. and are qualified under Section 401(k) of the U.S. Internal Revenue Code. Similar plans outside the U.S. cover various groups of employees of our international subsidiaries and affiliates. Several of these plans allow the Company to match, on a voluntary basis, a portion of the employee contributions. The following table presents the Company’s contributions to these savings plans for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 $ 82,882 $ 89,966 $ 87,973 Deferred Compensation Plans Our Executive Security Plan and Executive Deferral Plans are nonqualified deferred compensation programs that provide benefits payable to directors, officers, and certain key employees or their designated beneficiaries at specified future dates, upon retirement, or death. Benefit payments under both plans are funded by a combination of contributions from participants and the Company, and most of the participants are covered by life insurance policies with the Company designated as the beneficiary. The following table presents the amount charged to expense for the Company’s deferred compensation plans for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 $ 4,368 $ 5,792 $ 5,536

Income Taxes

Income Taxes	12 Months Ended
	Sep. 29, 2017
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes The following table presents the components of our consolidated income tax expense for years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Current income tax expense: Federal $ 29,297 $ 36,020 $ 72,840 State 8,535 11,336 16,248 Foreign 31,347 52,259 43,344 Total current tax expense 69,179 99,615 132,432 Deferred income tax expense (benefit): Federal 29,390 6,439 13,337 State 3,407 485 2,295 Foreign 3,866 (34,331 ) (46,809 ) Total deferred tax expense (benefit) 36,663 (27,407 ) (31,177 ) Consolidated income tax expense $ 105,842 $ 72,208 $ 101,255 Deferred taxes reflect the tax effects of temporary differences between the amounts recorded as assets and liabilities for financial reporting purposes and the comparable amounts recorded for income tax purposes. Deferred tax assets and liabilities are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The following table presents the components of our net deferred tax assets at September 29, 2017 and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Deferred tax assets: Obligations relating to: Defined benefit pension plans $ 52,299 $ 77,834 Other employee benefit plans 192,299 179,063 Net Operating Losses 136,783 139,125 Self-insurance programs 489 1,722 Contract revenues and costs (18,374 ) (8,177 ) Deferred Rent 25,654 7,955 Restructuring 18,258 47,792 Other 19,389 9,933 Valuation Allowance (58,097 ) (41,684 ) Gross deferred tax assets 368,700 413,563 Deferred tax liabilities: Depreciation and amortization (176,327 ) (154,939 ) Other, net (1,438 ) (1,555 ) Gross deferred tax liabilities (177,765 ) (156,494 ) Net deferred tax assets $ 190,935 $ 257,069 A valuation allowance is recorded to reduce deferred tax assets to the amount that is more likely than not to be realized based on an assessment of positive and negative evidence, including estimates of future taxable income necessary to realize future deductible amounts. The valuation allowance at September 29, 2017 and September 30, 2016 was $58.1 million and $41.7 million, respectively. Net operating loss carry forwards of foreign subsidiaries at September 29, 2017 and September 30, 2016 totaled $490.9 million and $483.4 million, respectively. If unused, foreign net operating losses of $117.1 million will expire between 2018 and 2037. Net operating losses of $373.8 million can be carried forward indefinitely. The following table presents the income tax benefits realized from the exercise of nonqualified stock options and disqualifying dispositions of stock sold under our employee stock purchase plans for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in millions): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 $ 5.20 $ 1.50 $ 0.20 The Company’s consolidated effective income tax rate is generally lower than the US statutory rate of 35% primarily due to the impacts of favorable tax rate differences in our foreign operations. The following table reconciles total income tax expense using the statutory U.S. federal income tax rate to the consolidated income tax expense shown in the accompanying Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (dollars in thousands): For the Years Ended September 29, 2017 % September 30, 2016 % October 2, 2015 % Statutory amount $ 137,626 35.0% $ 100,353 35.0% $ 150,548 35.0% State taxes, net of the federal benefit 8,955 2.3% 7,853 2.7% 12,857 3.0% Exclusion of tax on non-controlling interests 2,223 0.6% (1,418 ) (0.5% ) (9,069 ) (2.1%) Foreign: Difference in tax rates of foreign operations (16,987 ) (4.3% ) (17,184 ) (6.0% ) (19,180 ) (4.5%) Benefit from foreign valuation allowance release (3,085 ) (0.8% ) (11,182 ) (3.9% ) (3,372 ) (0.8%) Tax deductible foreign currency loss — 0.0% — 0.0% (23,100 ) (5.4%) U.K. tax rate change on deferred tax assets — 0.0% 8,853 3.1% — 0.0% Nontaxable income from foreign affiliate (3,280 ) (0.8% ) — 0.0% — 0.0% U.S. tax cost of foreign operations 18,612 4.7% 30,850 10.9% 6,814 1.6% Tax differential on foreign earnings (4,740 ) (1.2% ) 11,337 4.1% (38,838 ) (9.0%) Foreign tax credits (20,454 ) (5.2% ) (44,018 ) (15.4% ) (21,313 ) (5.0%) Uncertain tax positions (5,779 ) (1.5% ) 1,449 0.5% 2,281 0.5% Other items: IRS §179D deduction (3,351 ) (0.8% ) (2,153 ) (0.8% ) — 0.0% IRS §199D deduction (2,113 ) (0.5% ) (2,800 ) (1.0% ) (4,582 ) (1.1%) Foreign partnership income/(loss) (9,861 ) (2.5% ) (2,658 ) (0.9% ) 11,858 2.8% Other items – net 3,336 0.7% 4,263 1.5% (2,487 ) (0.6%) Total other items (11,989 ) (3.1% ) (3,348 ) (1.2% ) 4,789 1.1% Taxes on income $ 105,842 26.9% $ 72,208 25.2% $ 101,255 23.5% The Company’s consolidated effective income tax rate for the year ended September 29, increased to 26.9% from 25.2% for fiscal 2016. Key drivers for this year over year increase include the impacts of credit benefits and lower benefits from valuation allowance releases on foreign deferred tax assets, partly offset by favorable impacts of U.S. tax cost of foreign , the non-recurrence of 2016 tax rate change impacts on deferred income tax assets in the UK and favorable impacts from change in The Company’s consolidated effective income tax rate for the year ended September 30, 2016 increased to 25.2% from 23.5% for fiscal 2015. The primary components of this increase in tax rate were due mainly to other unfavorable items The following table presents income tax payments made during the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in millions): September 29, 2017 September 30, 2016 October 2, 2015 $ 78.39 $ 116.30 $ 156.50 The following table presents the components of our consolidated earnings before taxes for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 United States earnings $ 232,342 $ 206,159 $ 283,504 Foreign earnings 160,875 80,564 146,633 $ 393,217 $ 286,723 $ 430,137 United States income taxes, net of applicable credits, have been provided on the undistributed earnings of the Company’s foreign subsidiaries, except in those instances where the earnings have been permanently reinvested. At September 29, 2017, approximately $26.1 million of such undistributed earnings of certain foreign subsidiaries have been permanently reinvested. Should these earnings be repatriated, approximately $6.0 million of income taxes would be payable. The Company accounts for unrecognized tax benefits in accordance with ASC Topic 740, Income Taxes The following table presents the reconciliation of the beginning and ending amount of unrecognized tax benefits for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Balance, beginning of year $ 44,167 $ 42,666 $ 41,923 Additions based on tax positions related to the current year 5,900 5,670 6,440 Additions for tax positions of prior years 237 367 — Reductions for tax positions of prior years (4,524 ) (2,451 ) (5,697 ) Settlement (7,200 ) (2,085 ) — Balance, end of year $ 38,580 $ 44,167 $ 42,666

Commitments and Contingencies,

Commitments and Contingencies, and Derivative Financial Instruments	12 Months Ended
	Sep. 29, 2017
Commitments And Contingencies And Derivative Financial Instruments [Abstract]
Commitments and Contingencies, and Derivative Financial Instruments	11. Commitments and Contingencies, and Derivative Financial Instruments Commitments Under Operating Leases We lease certain of our facilities and equipment under operating leases with net aggregate future lease payments of approximately $753,102 million at September 29, 2017, payable as follows (in thousands): In fiscal years, 2018 $ 139,967 2019 133,609 2020 118,207 2021 97,062 2022 104,990 Thereafter 174,269 768,104 Amounts representing sublease income (15,002 ) $ 753,102 We recognize rent expense, inclusive of landlord concessions and tenant allowances, over the lease term on a straight-line basis. We also recognize rent expense on a straight-line basis for leases containing fixed escalation clauses and rent holidays. Contingent rentals are included in rent expense as accruable. Operating leases relating to many of our major offices generally contain renewal options, and provide for additional rental based on escalation in operating expenses and real estate taxes. The following table presents rent expense and sublease income offsetting the Company’s rent expense for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Rent expense $ 145,344 $ 151,539 $ 175,067 Sublease income (7,052 ) (7,212 ) (5,275 ) Net rent $ 138,292 $ 144,327 $ 169,792 Guarantee We are party to a synthetic lease agreement involving certain real and personal property located in Houston, Texas that we use in our operations. A synthetic lease is a type of off-balance sheet transaction which provides us with certain tax and other financial benefits. Significant terms of the lease are as follows: End of lease term 2025 End of term purchase option (in thousands) $ 76,950 Residual value guaranty (in thousands) $ 62,412 The Company refinanced the synthetic lease agreement effective July 28, 2015 with a ten-year term. The new lease agreement continues to gives us the right to request an extension of the lease term. We may also assist the owner in selling the property at the end of the lease term, the proceeds from which would be used to reduce our residual value guarantee. The minimum lease payments required by the lease agreement is included in the above lease pay-out schedule. We have determined that the estimated Fair Value of the aforementioned financial guarantee was not significant at September 29, 2017. Derivative Financial Instruments In situations where our operations incur contract costs in currencies other than their functional currency, we attempt to have a portion of the related contract revenues denominated in the same currencies as the costs. In those situations where revenues and costs are transacted in different currencies, we sometimes enter into foreign exchange contracts in order to limit our exposure to fluctuating foreign currencies. The Company does not currently have exchange rate sensitive instruments that would have a material effect on our consolidated financial statements or results of operations. Letters of Credit Letters of credit outstanding at September 29, 2017 totaled $262.1 million. Of this amount, $2.5 million has been issued under the Revolving Credit Facility and $259.6 million are issued under separate, committed and uncommitted letter-of-credit facilities.

Contractual Guarantees, Litigat

Contractual Guarantees, Litigation, Investigations, And Insurance	12 Months Ended
	Sep. 29, 2017
Contractual Guarantees Litigation Investigations And Insurance [Abstract]
Contractual Guarantees, Litigation, Investigations, and Insurance	12. Contractual Guarantees, Litigation, Investigations, and Insurance In the normal course of business, we are subject to certain contractual guarantees and litigation. The guarantees to which we are a party generally relate to project schedules and plant performance. Most of the litigation in which we are involved has us as a defendant in workers’ compensation, personal injury, environmental, employment/labor, professional liability, and other similar lawsuits. We maintain insurance coverage for various aspects of our business and operations. Our insurance programs have varying coverage limits and maximums, and insurance companies may seek to not pay any claims we might make. We have also elected to retain a portion of losses that occur through the use of various deductibles, limits, and retentions under our insurance programs. As a result, we may be subject to future liability for which we are only partially insured or completely uninsured. We intend to mitigate any such future liability by continuing to exercise prudent business judgment in negotiating the terms and conditions of our contracts. Our insurers are also subject to business risk and, as a result, one or more of them may be unable to fulfill their insurance obligations due to insolvency or otherwise. Additionally, as a contractor providing services to the U.S. federal government and several of its agencies, we are subject to many levels of audits, investigations, and claims by, or on behalf of, the U.S. federal government with respect to our contract performance, pricing, costs, cost allocations, and procurement practices. Furthermore, our income, franchise, and similar tax returns and filings are also subject to audit and investigation by the Internal Revenue Service, most states within the U.S., as well as by various government agencies representing jurisdictions outside the U.S. We record in our Consolidated Balance Sheets amounts representing our estimated liability relating to such claims, guarantees, litigation, and audits and investigations. We perform an analysis to determine the level of reserves to establish for insurance-related claims that are known and have been asserted against us, and for insurance-related claims that are believed to have been incurred based on actuarial analysis, but have not yet been reported to our claims administrators as of the respective balance sheet dates. We include any adjustments to such insurance reserves in our consolidated results of operations. Insurance recoveries are recorded as assets if recovery is probable. Estimated liabilities are not reduced by expected insurance recoveries. The Company believes, after consultation with counsel, that such guarantees, litigation, U.S. government contract-related audits, investigations and claims, and income tax audits and investigations should not have any material adverse effect on our consolidated financial statements. On August 9, 2014, the Company received a Notice of Arbitration from Motiva Enterprises LLC (“Motiva”) seeking monetary relief in excess of $8 billion from the Bechtel-Jacobs CEP Port Arthur Joint Venture (“BJJV”), a joint venture between Bechtel Corporation (“Bechtel”) and the Company. On December 30, 2016, the arbitral panel in this matter issued its unanimous decision, which rejected all of Motiva’s claims and assigned no liability to BJJV, the Company or Bechtel. On September 30, 2015, Nui Phao Mining Company Limited (“NPMC”) commenced arbitration proceedings against Jacobs E&C Australia Pty Limited (“Jacobs E&C”). The arbitration is pending in Singapore before the Singapore International Arbitration Centre. In March 2011, Jacobs E&C was engaged by NPMC for the provision of management, design, engineering, and procurement services for the Nui Phao mine/mineral processing project in Vietnam. In the Notice of Arbitration dated February 1, 2016, and in a subsequently filed Statement of Claim and Supplementary Statement of Claim dated February 26, 2016, and an Amended Statement of Claim dated August 17, 2017, NPMC asserts various causes of action and alleges that the quantum of its claim exceeds $167 million. Jacobs has denied liability and is vigorously defending this claim. A hearing on the merits is scheduled to begin on November 27, 2017. The Company does not expect the resolution of this matter to have a material adverse effect on its financial condition, results of operations and/or cash flows. On December 7, 2009, the Judicial Council of California, Administrative Office of the Courts (“AOC”) initiated an action in the San Francisco County Superior Court against Jacobs Facilities Inc. (“JFI”) and Jacobs Project Management (“JPM”) and subsequently added Jacobs as a defendant. The action arises out of a contract between AOC and JFI pursuant to which JFI provided regular maintenance and repairs at certain AOC court facilities. AOC has alleged, among other things, that the Jacobs entities are required under California’s Contractors’ State License Law (“CSLL”) to disgorge certain fees paid by AOC, and the Jacobs entities have, among other things, cross-claimed for unpaid sums for work performed. On May 2, 2012, the jury returned a special verdict in favor of the Jacobs entities finding, among other things, JPM was owed approximately $4.7 million in unpaid fees and that JFI was not required to disgorge the approximate $18.3 million that AOC had paid for work performed. On August 20, 2015, the California Court of Appeal reversed the jury’s verdict, holding that JFI had violated the CSLL. The Court of Appeal remanded to the San Francisco County Superior Court for an evidentiary hearing to determine whether the JFI had “substantially complied” with the CSLL under California Business and Professions Code Section 7031(e). Establishing “substantial compliance” would prevent $18.3 million in disgorgement against Jacobs and permit Jacobs to recover $4.7 million. The evidentiary hearing on substantial compliance was conducted between July 18 and August 5, 2016. On December 29, 2016, the court issued a Statement of Decision in favor of the Company, finding that Jacobs Facilities had substantially complied with the CSLL, and entered a judgment in favor of JPM in the amount of $4.7 million plus prejudgment interest. On January 30, 2017, AOC filed a notice of appeal and has filed its opening brief. The Company’s response is due in January 2018, subject to any extensions. The Company does not expect the resolution of this matter to have a material adverse effect on its financial condition, results of operations and/or cash flows.

Common And Preferred Stock

Common And Preferred Stock	12 Months Ended
	Sep. 29, 2017
Class Of Stock Disclosures [Abstract]
Common and Preferred Stock	13. Common and Preferred Stock Jacobs is authorized to issue two classes of capital stock designated “common stock” and “preferred stock” (each has a par value of $1.00 per share). The preferred stock may be issued in one or more series. The number of shares to be included in a series as well as each series’ designation, relative powers, dividend and other preferences, rights and qualifications, redemption provisions, and restrictions are to be fixed by the Company’s Board of Directors at the time each series is issued. Except as may be provided by the Company’s Board of Directors in a preferred stock designation, or otherwise provided for by statute, the holders of shares of common stock have the exclusive right to vote for the election of directors and on all other matters requiring stockholder action. The holders of shares of common stock are entitled to dividends if and when declared by the Company’s Board of Directors from whatever assets are legally available for that purpose.

Other Financial Information

Other Financial Information	12 Months Ended
	Sep. 29, 2017
Other Financial Information [Abstract]
Other Financial Information	14. Other Financial Information Receivables The following table presents the components of “Receivables” as shown in the accompanying Consolidated Balance Sheets at September 29, 2017 and September 30, 2016 as well as certain other related information (in thousands): September 29, 2017 September 30, 2016 Amounts billed, net $ 949,060 $ 1,110,042 Unbilled receivables and other 1,118,144 937,552 Retentions receivable 35,339 68,069 Total receivables, net $ 2,102,543 $ 2,115,663 Other information about receivables: Amounts due from the United States federal government included above, net of advanced $ 226,236 $ 235,203 Claims receivable $ 4,600 $ 26,061 Billed receivables, net consist of amounts invoiced to clients in accordance with the terms of the client contracts and are shown net of an allowance for doubtful accounts. We anticipate that substantially all of such billed amounts will be collected over the next twelve months. Unbilled receivables and retentions receivable represent reimbursable costs and amounts earned and reimbursable under contracts in progress as of the respective balance sheet dates. Such amounts become billable according to the contract terms, which usually consider the passage of time, achievement of certain milestones or completion of the project. We anticipate that substantially all of such unbilled amounts will be billed and collected over the next twelve months. Claims receivable are included in “Receivables” in the accompanying Consolidated Balance Sheets and represent certain costs incurred on contracts to the extent it is probable that such claims will result in additional contract revenue and the amount of such additional revenue can be reliably estimated. Property, Equipment, and Improvements, Net The following table presents the components of our property, equipment, and improvements, net at September 29, 2017 and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Land $ 17,197 $ 16,680 Buildings 93,313 91,194 Equipment 627,609 531,539 Leasehold improvements 220,295 221,437 Construction in progress 21,300 36,764 979,714 897,614 Accumulated depreciation and amortization (629,803 ) (577,941 ) $ 349,911 $ 319,673 Miscellaneous Noncurrent Assets The following table presents the components of “Miscellaneous noncurrent assets” shown in the accompanying Consolidated Balance Sheets at September 29, 2017 and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Deferred income taxes $ 368,700 $ 413,563 Cash surrender value of life insurance policies 130,411 122,364 Investments 145,069 178,256 Notes receivable 17,839 18,303 Other 30,003 26,843 Total $ 692,022 $ 759,329 Accrued Liabilities The following table presents the components of “Accrued liabilities” shown in the accompanying Consolidated Balance Sheets at September 29, 2017 and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Accrued payroll and related liabilities $ 572,946 $ 561,652 Project-related accruals 71,815 102,400 Non project-related accruals 68,025 87,813 Insurance liabilities 67,546 54,984 Sales and other similar taxes 32,163 37,029 Deferred rent 60,593 69,059 Dividends payable 18,180 — Other 48,419 25,441 Total $ 939,687 $ 938,378 Other Deferred Liabilities The following table presents the components of “Other deferred liabilities” shown in the accompanying Consolidated Balance Sheets at September 29, 2017 and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Liabilities relating to defined benefit pension and early retirement plans $ 254,483 $ 402,955 Liabilities relating to nonqualified deferred compensation Arrangements 114,616 123,926 Deferred income taxes 177,765 156,494 Miscellaneous 185,417 178,449 Total $ 732,281 $ 861,824 Total Accumulated Other Comprehensive Loss The following table presents the components of “Accumulated other comprehensive loss” shown in the accompanying Consolidated Balance Sheets at September 29, 2017, and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Foreign currency translation adjustments $ (386,131 ) $ (245,603 ) Adjustments relating to defined benefit pension plans (265,578 ) (364,625 ) Other (1,805 ) (366 ) Total $ (653,514 ) $ (610,594 ) Supplemental Cash Flow Information During fiscal 2017 and fiscal 2016, the Company acquired businesses for cash of $150.2 million and cash and stock of $49.9 million, respectively. The following table presents the non-cash adjustments relating to these acquisitions made in preparing the accompanying Consolidated Statements of Cash Flows (in thousands): September 29, 2017 September 30, 2016 Working capital $ 9,121 $ 10,023 Property and equipment 912 879 Noncurrent assets 35,976 8,192 Deferred liabilities (273 ) — Goodwill 104,454 30,849

Segment Information

Segment Information	12 Months Ended
	Sep. 29, 2017
Segment Reporting [Abstract]
Segment Information	15. Segment Information During the second fiscal quarter of 2016, we reorganized our operations around four global lines of business (“LOB”), which also serve as our operating segments: Petroleum & Chemicals, Buildings & Infrastructure, Aerospace & Technology, and Industrial. We determined that this new organization would better support the needs of managing each unique set of customers that fall within each segment. As a result of the new organization, we subsequently realigned our internal reporting structures to enable our Chief Executive Officer, who is also our Chief Operating Decision Maker (“CODM”), to evaluate the performance of each of these segments and make appropriate resource allocations among each of the segments. For purposes of our goodwill impairment testing, we have determined that our operating segments are also our reporting units based on management’s conclusion that the components comprising each of our operating segments share similar economic characteristics and meet the aggregation criteria in accordance with ASC 350. Under the current organization, each LOB has a president that reports directly to the Company's Chairman and CEO or CODM. In addition, the sales function, which had been managed centrally for many years, is now managed on an LOB basis, and accordingly, the associated cost is now embedded in the new segments and reported to the respective LOB presidents. In addition, a portion of the costs of other support functions (e.g., finance, legal, human resources, and information technology) is allocated to each LOB using methodologies which, we believe, effectively attribute the cost of these support functions to the revenue generating activities of the Company on a rational basis. The cost of the Company’s cash incentive plan, the Management Incentive Plan (“MIP”) and the expense associated with the Jacobs Engineering Group Inc. 1999 Stock Incentive Plan (“1999 SIP”) have likewise been charged to the LOBs except for those amounts determined to relate to the business as a whole (which amounts remain in corporate’s results of operations). Financial information for each LOB is reviewed by the CODM to assess performance and make decisions regarding the allocation of resources. The Company generally does not track assets by LOB, nor does it provide such information to the CODM. The CODM evaluates the operating performance of our LOBs using operating profit, which is defined as margin less “corporate charges” (e.g., the allocated amounts described above). The Company incurs certain SG&A costs which relate to its business as a whole which are not allocated to the LOBs. The following tables present total revenues and operating profit for each reportable segment (in thousands) and includes a reconciliation of segment operating profit to total U.S. GAAP operating profit by including certain corporate-level expenses and expenses relating to the Restructuring and other charges and CH2M professional fees and integration costs (in thousands). For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Revenues from External Customers: Aerospace & Technology $ 2,360,613 $ 2,657,433 $ 2,924,753 Buildings & Infrastructure 2,452,321 2,253,512 2,458,379 Industrial 2,743,662 2,793,713 2,517,571 Petroleum & Chemicals 2,466,192 3,259,499 4,214,129 Total $ 10,022,788 $ 10,964,157 $ 12,114,832 For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Operating Profit: Aerospace & Technology $ 202,595 $ 203,808 $ 205,368 Buildings & Infrastructure (1) 193,455 174,648 145,299 Industrial 115,262 81,268 126,531 Petroleum & Chemicals 113,858 126,604 138,351 Total Segment Operating Profit 625,170 586,328 615,549 Other Corporate Items (81,595 ) ( 60,100 ) (15,739 ) Restructuring and Other Charges ( 134,206 ) ( 187,630 ) ( 154,283 ) CH2M Professional Fees and Integration Costs (17,100 ) — — Total U.S. GAAP Operating Profit 392,269 338,598 445,527 Gain (Loss) on disposal of business and investments 10,880 ( 41,410 ) (2,909 ) Total Other Expense (2) ( 9,932 ) ( 10,465 ) (12,481 ) Earnings Before Taxes $ 393,217 $ 286,723 $ 430,137 (1) Excludes $ 23,844 in restructuring and other charges for the fiscal year ended September 29, 2017. (2) Years ending September 29, 2017 and September 30, 2016 include Restructuring and other charges of $1,233 and $277, respectively. Included in “other corporate items” in the above table are costs and expenses which relate to general corporate activities as well as corporate-managed benefit and insurance programs. Such costs and expenses include: (i) those elements of SG&A expenses relating to the business as a whole; (ii) those elements of the Management Incentive Plan and the 1999 SIP relating to corporate personnel whose other compensation costs are not allocated to the LOBs; (iii) the amortization of intangible assets acquired as part of purchased business combinations; (iv) the quarterly variances between the Company’s actual costs of certain of its self-insured integrated risk and employee benefit programs and amounts charged to the LOBs; and (v) certain adjustments relating to costs associated with the Company’s international defined benefit pension plans. In addition, “other corporate items” includes adjustments to contract margins (both positive and negative) associated with projects where it has been determined, in the opinion of management, that such adjustments are not indicative of the performance of the related LOB and therefore should not be attributed to the LOB. Included in gain on disposal of business and investments for the year ended September 29, 2017 was a gain on the sale of the Company’s ownership interest in the Neste Jacobs joint venture. Included in loss on disposal of business and investments for the year ended September 30, 2016 was the losses associated with the sale of the Company’s French subsidiary and a non-cash write-off on an equity investment. We provide a broad range of technical, professional, and construction services including engineering, design, and architectural services; construction and construction management services; operations and maintenance services; and process, scientific, and systems consulting services. We provide our services through offices and subsidiaries located primarily in North America, South America, Europe, the Middle East, India, Australia, Africa, and Asia. We provide our services under cost-reimbursable and fixed-price contracts. The following tables present total services revenues for each reportable segment for the three years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Year Ended September 29, 2017 Aerospace & Technology Buildings & Infrastructure Industrial Petroleum & Chemicals Total Technical Professional Services Revenues Project Services $ 960,374 $ 2,185,220 $ 196,171 $ 1,464,098 $ 4,805,863 Process, Scientific and Systems Consulting 774,063 — — 31,081 805,144 Total Technical Professional Services Revenues 1,734,437 2,185,220 196,171 1,495,179 5,611,007 Field Services Revenues Construction 250,956 254,118 1,901,299 967,888 3,374,261 Operations and Maintenance ("O&M") 375,220 12,983 646,192 3,125 1,037,520 Total Field Services Revenues 626,176 267,101 2,547,491 971,013 4,411,781 Total Revenues $ 2,360,613 $ 2,452,321 $ 2,743,662 $ 2,466,192 $ 10,022,788 For the Year Ended September 30, 2016 Aerospace & Technology Buildings & Infrastructure Industrial Petroleum & Chemicals Total Technical Professional Services Revenues Project Services $ 910,290 $ 2,094,282 $ 891,018 $ 1,843,250 $ 5,738,840 Process, Scientific and Systems Consulting 803,654 — — 48,675 852,329 Total Technical Professional Services Revenues 1,713,944 2,094,282 891,018 1,891,925 6,591,169 Field Services Revenues Construction 171,614 119,463 1,601,562 1,366,251 3,258,890 Operations and Maintenance ("O&M") 771,875 39,767 301,133 1,323 1,114,098 Total Field Services Revenues 943,489 159,230 1,902,695 1,367,574 4,372,988 Total Revenues $ 2,657,433 $ 2,253,512 $ 2,793,713 $ 3,259,499 $ 10,964,157 The following table presents certain financial information by geographic area (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Revenues: United States $ 5,822,843 $ 6,247,448 $ 7,154,433 Europe 2,262,092 2,346,224 2,074,837 Canada 590,604 927,942 1,065,651 Asia 253,167 299,952 304,393 India 165,295 187,929 163,871 Australia and New Zealand 628,945 436,670 611,271 South America and Mexico 73,456 125,610 143,014 Middle East and Africa 226,386 392,382 597,362 Total $ 10,022,788 $ 10,964,157 $ 12,114,832 Property, equipment and improvements, net: United States $ 220,416 $ 195,392 $ 208,155 Europe 46,108 37,163 55,713 Canada 18,435 21,464 36,647 Asia 2,793 3,069 3,859 India 19,191 13,350 16,264 Australia and New Zealand 18,692 18,888 24,460 South America and Mexico 4,619 5,621 9,127 Middle East and Africa 19,657 24,726 27,013 Total $ 349,911 $ 319,673 $ 381,238 Revenues were earned from unaffiliated clients located primarily within the various and respective geographic areas shown. The following table presents the revenues earned directly or indirectly from the U.S. federal government and its agencies, expressed as a percentage of total revenues: For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 19.2% 21.4% 21.7%

Selected Quarterly Information

Selected Quarterly Information - Unaudited	12 Months Ended
	Sep. 29, 2017
Selected Quarterly Financial Information [Abstract]
Selected Quarterly Information - Unaudited	16. Selected Quarterly Information — Unaudited The following table presents selected quarterly financial information. (in thousands, except for per share amounts): First Quarter Second Quarter Third Quarter Fourth Quarter Fiscal Year September 29, 2017 Revenues $ 2,551,604 $ 2,302,567 (f) $ 2,514,751 (f) $ 2,653,866 $ 10,022,788 Operating profit (a) 88,628 68,173 (f) 128,475 (f) 106,993 392,269 Earnings before taxes 85,880 60,491 127,396 119,450 393,217 Net earnings of the Group 61,153 44,165 88,629 93,428 287,375 Net earnings attributable to Jacobs 60,536 (f) 50,018 (f) 89,032 (f) 94,141 (f)(g) 293,727 Earnings per share: Basic 0.50 (f) 0.41 (f) 0.74 (f) 0.78 (f)(g) 2.43 Diluted 0.50 (f) 0.41 (f) 0.74 (f) 0.78 (f)(g) 2.42 September 30, 2016 Revenues $ 2,847,934 $ 2,781,763 $ 2,693,873 $ 2,640,587 $ 10,964,157 Operating profit (a) 59,450 86,781 109,556 82,811 338,598 Earnings before taxes 57,787 90,456 102,807 35,673 286,723 Net earnings of the Group 50,306 63,389 70,937 29,883 214,515 Net earnings attributable to Jacobs 46,514 (b) 65,250 (b) 69,055 (b) 29,644 (b) 210,463 Earnings per share: Basic 0.38 (b) 0.54 (b) 0.58 (b) 0.25 (b) 1.75 Diluted 0.38 (b) 0.54 (b) 0.57 (b) 0.24 (b) 1.73 October 2, 2015 Revenues $ 3,187,005 $ 2,903,332 $ 2,907,541 $ 3,116,954 $ 12,114,832 Operating profit (a) 158,223 133,045 100,434 53,825 445,527 Earnings before taxes 154,695 128,962 97,188 49,292 430,137 Net earnings of the Group 106,195 88,110 97,308 37,269 328,882 Net earnings attributable to Jacobs 100,079 81,967 (c) 91,062 (c) 29,863 (c) 302,971 Earnings per share: Basic 0.78 0.65 (c) 0.74 (c) 0.25 (c) 2.42 Diluted 0.77 0.64 (c) 0.73 (c) 0.24 (c) 2.40 (a) Operating profit represents revenues less (i) direct costs of contracts, and (ii) selling, general and administrative expenses. (b) Includes costs of $48.1 million, or $0.39 per diluted share, in the first quarter of fiscal 2016, $25.7 million or $0.21 per diluted share in the second quarter of fiscal 2016, $25.8 million, or $0.21 per diluted share, in the third quarter, and $36.0 million or $0.3 per diluted share in the fourth quarter of fiscal 2016, in each case, related to the 2015 Restructuring. Also included in the fourth quarter of fiscal 2016 were $17.1 million, or $0.14 per diluted share related to the loss on sale of our French subsidiary; and $10.4 million, or $0.09 per diluted share related to the non-cash write-off on an equity investment. (c) Includes costs of $9.6 million, or $0.08 per diluted share, in the second quarter of fiscal 2015, $30.1 million or $0.24 per diluted share in the third quarter of fiscal 2015, and $68.2 million, or $0.56 per diluted share, in the fourth quarter of fiscal 2015, in each case, related to the 2015 Restructuring. (d) Includes costs of $47.0 million, or $0.35 per diluted share, in the third quarter of fiscal 2014, and $30.4 million, or $0.23 per diluted share, in the fourth quarter of fiscal 2014, in each case, related to the 2014 Restructuring. (e) Includes $6.4 million, or $0.05 per diluted share, increase to net earnings related to a gain on the sale of certain intellectual property in the second quarter of fiscal 2014. (f) Includes costs of $31.7 million, or $0.18 per diluted share, in the first quarter of fiscal 2017; includes $16.5 million in revenue, $72.2 million in operating profit, $45.2 million in net earnings attributable to Jacobs, or $0.37 per diluted share, in the second quarter of fiscal 2017; includes $1 million in revenue, $10.7 million in operating profit and $6.3 million in net earnings attributable to Jacobs, or $0.05 per diluted share, in the third quarter of fiscal 2017; includes $19.5 million in operating profit, $13.6 million in net earnings attributable to Jacobs, or $0.11 per diluted share, in the fourth quarter of fiscal 2017, in each case, related to restructuring and other charges. ( g ) Includes costs of $10.6 million, or $0.09 per diluted share, in the fourth quarter of fiscal 2017 related to professional fees and integration costs for the CH2M acquisition.

Definitions

Definitions	12 Months Ended
	Sep. 29, 2017
Definitions [Abstract]
Definitions	17. The following terms used in the accompanying Consolidated Financial Statements and these Notes to Consolidated Financial Statements have the meanings set forth below: “1989 ESPP” means the Jacobs Engineering Group Inc. 1989 Employee Stock Purchase Plan, as amended and restated. The 1989 ESPP is a shareholder-approved, broad-based, employee stock purchase plan qualified under Section 423 of the U.S. Internal Revenue Code. “1999 ODSP" means the Jacobs Engineering Group Inc. 1999 Outside Director Stock Plan, as amended and restated. The 1999 ODSP is a shareholder-approved, equity-based compensation plan covering Jacobs' non-management directors. “1999 SIP” means the Jacobs Engineering Group Inc. 1999 Stock Incentive Plan, as amended and restated. The 1999 SIP is a shareholder-approved, equity-based compensation plan covering the Company's officers and key employees. The "2015 Restructuring" refers to a series of initiatives intended to improve operational efficiency, reduce costs, and better position the Company to drive growth of the business in the future. Actions included involuntary terminations, the abandonment of certain leased offices, and the co-location of employees. Included in the Company's consolidated results of operations for fiscal 2017, fiscal 2016 and fiscal 2015 are pre-tax costs of $98.7 million, $187.9 million and $157.2 million, respectively, relating to the 2015 Restructuring. These costs are primarily included in SG&A in the accompanying Consolidated Statements of Earnings. The "2014 Restructuring" refers to a series of initiatives intended to improve operational efficiency, reduce costs, accelerate the integration of SKM, and better position the Company to drive growth of the business in the future. Actions included involuntary terminations, the abandonment of certain leased offices, and the co-location of employees. Included in the Company's consolidated results of operations for fiscal 2014 are pre-tax costs of $93.3 million relating to the 2014 Restructuring. These costs are included in SG&A in the accompanying Consolidated Statements of Earnings. “ASC” refers to the Accounting Standards Codification as maintained by the FASB. The ASC is the primary source of U.S. GAAP to be applied by the Company and all other nongovernmental entities. The ASC organizes and presents hundreds of previously separate pieces of authoritative accounting guidance into a single on-line research database. The accounting principles promulgated by the ASC are organized therein by broad topics, and are updated by the FASB through the issuances of ASUs. “ASU” means Accounting Standards Updates, the primary means by which the ASC is updated by the FASB. “Company” (including “we”, “us” or “our”) means Jacobs Engineering Group Inc. and its consolidated subsidiaries and affiliates. “Consolidated EBITDA" generally means consolidated net earnings attributable to Jacobs, plus consolidated (i) interest expense, (ii) tax expense, and (iii) depreciation and amortization expense (including amortization expense relating to intangible assets). "Consolidated Funded Indebtedness" generally means the sum of (i) the balances outstanding under all loan, credit, and similar agreements for borrowed money (including purchase money indebtedness), (ii) all amounts representing direct obligations arising under letters of credit, (iii) indebtedness in respect of capital leases and similar financing arrangements, and (iv) the value of all guarantees issued with respect to the types of indebtedness described in (i) through (iii). "Consolidated Leverage Ratio" means, as of any date of determination, the ratio of (i) the Company's Consolidated Funded Indebtedness as of such date to (ii) the Company's Consolidated EBITDA for the immediately preceding four consecutive fiscal quarters. “EPS” means earnings-per-share. “Basic EPS” is computed by dividing the consolidated net earnings attributable to Jacobs by the weighted average number of shares of common stock outstanding during the period. “Diluted EPS” is computed in a manner similar to the computation of Basic EPS, but gives effect to all dilutive securities that were outstanding during the period. Our dilutive securities consist of nonqualified stock options and restricted stock (including restricted stock units) “Fair Value” means the price that would be received from selling an asset, or paid to transfer a liability, in an orderly transaction between market participants as of the date fair value is determined (i.e., the “measurement date”). When determining fair value, U.S. GAAP requires that we consider the principal or most advantageous market in which we would transact any sale or purchase. U.S. GAAP also requires that the inputs (factors) we use (consider) to determine fair value be considered in the following order of priority: • Level 1 inputs are quoted prices in active markets for identical assets or liabilities; • Level 2 inputs are observable inputs (other than quoted prices in active markets included in Level 1) such as (i) quoted prices for similar assets or liabilities, (ii) quoted prices in markets that have insufficient volume or infrequent transactions (i.e., less active markets), and (iii) model-driven valuations in which all significant inputs are observable or can be derived principally from, or corroborated with, observable market data for substantially the full term of the asset or liability; and • Level 3 inputs are unobservable inputs to the valuation methodology that are significant to the fair value measurement. “FASB” means the Financial Accounting Standards Board. The FASB is the designated organization within the U.S. for establishing standards of financial accounting that govern the preparation of financial reports by nongovernmental entities. “GESPP” means the Jacobs Engineering Group Inc. Global Employee Stock Purchase Plan, as amended. The GESPP is a shareholder-approved, broad-based, employee stock purchase plan covering employees of certain of Jacobs' non-U.S. subsidiaries. “Group” refers to the combined economic interests and activities of Jacobs and the persons and entities holding noncontrolling interests in the subsidiaries and affiliates that are consolidated into the accompanying Consolidated Financial Statements. “Jacobs” means Jacobs Engineering Group Inc. “U.S. GAAP” means those accounting principles and practices generally accepted in the United States. “U.S. IRC” means the U.S. Internal Revenue Code of 1986, as amended. “VIE” means a “Variable Interest Entity” as defined in U.S. GAAP. A VIE is a legal entity in which equity investors do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support or, as a group, the holders of the equity investment at risk lack any one of the following three characteristics: (i) the power, through voting rights or similar rights, to direct the activities of a legal entity that most significantly impact the entity's economic performance; (ii) the obligation to absorb the expected losses of the legal entity; or (iii) the right to receive the expected residual returns of the legal entity. Accordingly, entities issuing consolidated financial statements (i.e., a “reporting entity”) shall consolidate a VIE if the reporting entity has a “controlling financial interest” in the VIE, as demonstrated by the reporting entity having both (i) the power to direct the activities of a VIE that most significantly impact the VIE's economic performance; and (ii) the right to receive benefits from the VIE that could potentially be significant to the VIE or the obligation to absorb losses of the VIE that could potentially be significant to the VIE.

Significant Accounting Polici26

Significant Accounting Policies (Policies)	12 Months Ended
	Sep. 29, 2017
Accounting Policies [Abstract]
Revenue Accounting for Contracts and Use of Joint Ventures Policy	Revenue Accounting for Contracts and Use of Joint Ventures We recognize revenue earned on our technical professional and field services projects under the percentage-of-completion method described in ASC 605-35, Construction-Type and Production-Type Contracts. In general, we recognize revenues at the time we provide services. Pre-contract costs are generally expensed as incurred. Contracts are generally segmented between types of services, such as project services and construction, and accordingly, gross margin related to each activity is recognized as those separate services are rendered. For multiple contracts with a single customer we account for each contract separately. The percentage-of-completion method of accounting is applied by comparing contract costs incurred to date to the total estimated costs at completion. On cost-reimbursable contracts, the cost of materials and subcontracts are generally excluded from the calculation of the measure of progress towards completion to provide a more meaningful allocation of income. Contract losses are provided for in their entirety in the period they become known, without regard to the percentage-of-completion. Unapproved change orders are included in the contract price to the extent it is probable that such change orders will result in additional contract revenue and the amount of such additional revenue can be reliably estimated. Claims meeting these recognition criteria are included in revenues only to the extent of the related costs incurred. Certain cost-reimbursable contracts include incentive-fee arrangements. These incentive fees can be based on a variety of factors but the most common are the achievement of target completion dates, target costs, and/or other performance criteria. Failure to meet these targets can result in unrealized incentive fees. We recognize incentive fees based on expected results using the percentage-of-completion method of accounting. As the contract progresses and more information becomes available, the estimate of the anticipated incentive fee that will be earned is revised as necessary. We bill incentive fees based on the terms and conditions of the individual contracts. In certain situations, we are allowed to bill a portion of the incentive fees over the performance period of the contract. In other situations, we are allowed to bill incentive fees only after the target criterion has been achieved. Incentive fees which have been recognized but not billed are included in receivables in the accompanying Consolidated Balance Sheets. Certain cost-reimbursable contracts with government customers as well as certain commercial clients provide that contract costs are subject to audit and adjustment. In this situation, revenues are recorded at the time services are performed based upon the amounts we expect to realize upon completion of the contracts. Revenues are not recognized for non-recoverable costs. In those situations where an audit indicates that we may have billed a client for costs not allowable under the terms of the contract, we estimate the amount of such nonbillable costs and adjust our revenues accordingly. When we are directly responsible for subcontractor labor or third-party materials and equipment, we reflect the costs of such items in both revenues and costs (and we refer to such costs as “pass-through” costs). On those projects where the client elects to pay for such items directly and we have no associated responsibility for such items, these amounts are not reflected in either revenues or costs. The following table sets forth pass-through costs included in revenues in the accompanying Consolidated Statements of Earnings (in millions): For the Year Ended September 29, 2017 September 30, 2016 October 2, 2015 $ 2,539.3 $ 2,489.9 $ 2,602.6 As is common to the industry, we execute certain contracts jointly with third parties through various forms of joint ventures and consortiums. Although the joint ventures own and hold the contracts with the clients, the services required by the contracts are typically performed by us and our joint venture partners, or by other subcontractors under subcontracting agreements with the joint ventures. The assets of our joint ventures, therefore, consist almost entirely of cash and receivables (representing amounts due from clients), and the liabilities of our joint ventures consist almost entirely of amounts due to the joint venture partners (for services provided by the partners to the joint ventures under their individual subcontracts) and other subcontractors. In general, at any given time, the equity of our joint ventures represents the undistributed profits earned on contracts the joint ventures hold with clients. Very few of our joint ventures have employees. None of our joint ventures have third-party debt or credit facilities. Under U.S. GAAP, our share of profits and losses associated with the contracts held by the joint ventures is reflected in our Consolidated Financial Statements. Certain of our joint ventures meet the definition of a VIE. In evaluating our VIEs for possible consolidation, we perform a qualitative analysis to determine whether or not we have a “controlling financial interest” in the VIE as defined by U.S. GAAP. We consolidate only those VIEs over which we have a controlling financial interest and are the primary beneficiary. For the Company’s unconsolidated joint ventures, we use either the equity method of accounting or proportional consolidation. There were no changes in facts and circumstances during the period that caused the Company to reassess the method of accounting for its VIEs.
Fair Value Measurements	Fair Value Measurements The net carrying amounts of cash and cash equivalents, trade receivables and payables, and notes payable approximate Fair Value due to the short-term nature of these instruments. Similarly, we believe the carrying value of long-term debt also approximates Fair Value based on the interest rates and scheduled maturities applicable to the outstanding borrowings. Certain other assets and liabilities, such as forward contracts and an interest rate swap agreement we purchased as cash-flow hedges discussed in Note 11 — Commitments and Contingencies and Derivative Financial Instruments The Fair Value of the Company’s reporting units (used for purposes of determining whether there is an indication of possible impairment of the carrying value of goodwill) is determined using both an income approach and a market approach. Both approaches require us to make certain estimates and judgments. Under the income approach, Fair Value is determined by using the discounted cash flows of our reporting units. Under the market approach, the Fair Values of our reporting units are determined by reference to guideline companies that are reasonably comparable to our reporting units; the Fair Values are estimated based on the valuation multiples of the invested capital associated with the guideline companies. In assessing whether there is an indication that the carrying value of goodwill has been impaired, we utilize the results of both valuation techniques and consider the range of Fair Values indicated. The range of values (both ends of the range) for each reporting unit exceeded the respective book values by 27% to 110%. With respect to equity-based compensation (i.e., share-based payments), we estimate the Fair Value of stock options granted to employees and directors using the Black-Scholes option-pricing model. Like all option-pricing models, the Black-Scholes model requires the use of subjective assumptions including (i) the expected volatility of the market price of the underlying stock, and (ii) the expected term of the award, among others. Accordingly, changes in assumptions and any subsequent adjustments to those assumptions can cause different Fair Values to be assigned to our future stock option awards. For restricted stock units containing service, market and performance conditions, compensation expense is based on the Fair Value of such units using a Monte Carlo simulation. The Fair Values of the assets owned by the various pension plans that the Company sponsors are determined based on the type of asset, consistent with U.S. GAAP. Equity securities are valued by using market observable data such as quoted prices. Publicly traded corporate equity securities are valued at the last reported sale price on the last business day of the year. Securities not traded on the last business day are valued at the last reported bid price. Debt securities are valued at the last reported sale price on the last business day applicable. Real estate consists primarily of common or collective trusts, with underlying investments in real estate. These investments are valued using the best information available, including quoted market price, market prices for similar assets when available, internal cash flow estimates discounted at an appropriate interest rate, or independent appraisals, as appropriate. Management values insurance contracts, investments in infrastructure/raw goods, and hedge funds using actuarial assumptions and certain values reported by fund managers. The methodologies described above and elsewhere in these Notes to Consolidated Financial Statements may produce a Fair Value measure that may not be indicative of net realizable value or reflective of future Fair Values. Furthermore, while the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the Fair Value of certain financial instruments could result in a different Fair Value measurement.
Cash Equivalents	Cash Equivalents We consider all highly liquid investments with original maturities of less than three months to be cash equivalents. Cash equivalents at September 29, 2017 and September 30, 2016 consisted primarily of money market mutual funds and overnight bank deposits.
Receivables and Billings in Excess of Costs	Receivables and Billings in Excess of Costs Receivables include billed receivables, unbilled receivables, and retentions receivable. Billed receivables represent amounts invoiced to clients in accordance with the terms of our client contracts. They are recorded in our financial statements when they are issued. Unbilled receivables and retentions receivable represent reimbursable costs and amounts earned and reimbursable under contracts in progress as of the respective balance sheet dates. Such amounts become billable according to the contract terms, which usually consider the passage of time, achievement of certain milestones or completion of the project. We anticipate that substantially all of such unbilled amounts will be billed and collected over the next fiscal year. Certain contracts allow us to issue invoices to clients in advance of providing services. Billings in excess of costs represent billings to, and cash collected from, clients in advance of work performed. We anticipate that substantially all such amounts will be earned over the next twelve months.
Property, Equipment and Improvements	Property, Equipment, and Improvements Property, equipment and improvements are carried at cost, and are shown net of accumulated depreciation and amortization in the accompanying Consolidated Balance Sheets. Depreciation and amortization is computed primarily by using the straight-line method over the estimated useful lives of the assets. The cost of leasehold improvements is amortized using the straight-line method over the lesser of the estimated useful life of the asset or the remaining term of the related lease. Estimated useful lives range from 20 to 40 years for buildings, from 3 to 10 years for equipment and from 4 to 10 years for leasehold improvements.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill represents the excess of the cost of an acquired business over the Fair Value of the net tangible and intangible assets acquired. Goodwill and intangible assets with indefinite lives are not amortized; instead, on an annual basis as of the end of the third quarter of each fiscal year we test goodwill and intangible assets with indefinite lives for possible impairment. Interim testing for impairment is performed if indicators of potential impairment exist. For purposes of impairment testing, goodwill is assigned to the applicable reporting units based on the current reporting structure. During the second quarter of fiscal 2016, we reorganized our operations around four global lines of business, which also serve as our operating segments: Petroleum & Chemicals, Buildings & Infrastructure, Aerospace & Technology, and Industrial. When testing goodwill for impairment quantitatively, the Company first compares the fair value of each reporting unit with its carrying amount. If the carrying amount of a reporting unit exceeds its fair value, a second step is performed to measure the amount of potential impairment. In the second step, the Company compared the implied fair value of the reporting unit goodwill with the carrying amount of the reporting unit's goodwill. If the carrying amount of reporting unit goodwill exceeds the implied fair value of that goodwill, an impairment loss is recognized. During 2017, we completed our annual goodwill impairment test and quantitatively determined that none of the goodwill was impaired. The Company recorded $119.3 million of goodwill during 2017 in conjunction with the acquisitions of Aquenta Consulting Pty Ltd. and Blue Canopy LLC. Goodwill for each of the Company's segments is presented in Note 15. We have determined that the fair value of our reporting units substantially exceeded their respective carrying values for the Consolidated Balance Sheets presented.
Foreign Currencies	Foreign Currencies In preparing our Consolidated Financial Statements, it is necessary to translate the financial statements of our subsidiaries operating outside the U.S., which are denominated in currencies other than the U.S. dollar, into the U.S. dollar. In accordance with U.S. GAAP, revenues and expenses of operations outside the U.S. are translated into U.S. dollars using weighted-average exchange rates for the applicable periods being translated while the assets and liabilities of operations outside the U.S. are generally translated into U.S. dollars using period-end exchange rates. The net effect of foreign currency translation adjustments is included in stockholders’ equity as a component of accumulated other comprehensive income (loss) in the accompanying Consolidated Balance Sheets.
Share-based Payments	Share-Based Payments We measure the value of services received from employees and directors in exchange for an award of an equity instrument based on the grant-date Fair Value of the award. The computed value is recognized as a non-cash cost on a straight-line basis over the period the individual provides services, which is typically the vesting period of the award with the exception of awards containing an internal performance measure which is recognized on a straight-line basis over the vesting period subject to the probability of meeting the performance requirements and adjusted for the number of shares expected to be earned. The cost of these awards is recorded in selling, general and administrative expense in the accompanying Consolidated Statements of Earnings.
Concentrations of Credit Risk	Concentrations of Credit Risk Our cash balances and cash equivalents are maintained in accounts held by major banks and financial institutions located in North America, South America, Europe, the Middle East, India, Australia, Africa, and Asia. In the normal course of business, and consistent with industry practices, we grant credit to our clients without requiring collateral. Concentrations of credit risk is the risk that, if we extend a significant amount of credit to clients in a specific geographic area or industry, we may experience disproportionately high levels of default if those clients are adversely affected by factors particular to their geographic area or industry. Concentrations of credit risk relative to trade receivables are limited due to our diverse client base, which includes the U.S. federal government and multi-national corporations operating in a broad range of industries and geographic areas. Additionally, in order to mitigate credit risk, we continually evaluate the credit worthiness of our major commercial clients.
Use of Estimates and Assumptions	Use of Estimates and Assumptions The preparation of financial statements in conformity with U.S. GAAP requires us to employ estimates and make assumptions that affect the reported amounts of certain assets and liabilities; the revenues and expenses reported for the periods covered by the financial statements; and certain amounts disclosed in these Notes to the Consolidated Financial Statements. Although such estimates and assumptions are based on management’s most recent assessment of the underlying facts and circumstances utilizing the most current information available and past experience, actual results could differ significantly from those estimates and assumptions. Our estimates, judgments, and assumptions are evaluated periodically and adjusted accordingly. Earlier in these Notes to Consolidated Financial Statements we discussed three significant accounting policies that rely on the application of estimates and assumptions: revenue recognition for long-term construction contracts; the process for testing goodwill for possible impairment; and the accounting for share-based payments to employees and directors. The following is a discussion of certain other significant accounting policies that rely on the use of estimates: Accounting for Pensions — We use certain assumptions and estimates in order to calculate periodic pension cost and the value of the assets and liabilities of our pension plans. These assumptions involve discount rates, investment returns, and projected salary increases, among others. Changes in the actuarial assumptions may have a material effect on the plans’ liabilities and the projected pension expense. Accounting for Income Taxes — We determine our consolidated income tax expense using the asset and liability method prescribed by U.S. GAAP. Under this method, deferred tax assets and liabilities are recognized for the temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and income tax purposes. Such deferred tax assets and liabilities are adjusted, as appropriate, to reflect changes in tax rates expected to be in effect when the temporary differences reverse. If and when we determine that a deferred tax asset will not be realized for its full amount, we will recognize and record a valuation allowance with a corresponding charge to earnings. Judgment is required in determining our worldwide provision for income taxes. In the normal course of business, we may engage in numerous transactions every day for which the ultimate tax outcome (including the period in which the transaction will ultimately be included in taxable income or deducted as an expense) is uncertain. Additionally, we file income, franchise, gross receipts and similar tax returns in many jurisdictions. Our tax returns are subject to audit and investigation by the Internal Revenue Service, most states in the U.S., and by various government agencies representing many jurisdictions outside the U.S. Contractual Guarantees, Litigation, Investigations, and Insurance — In the normal course of business we are subject to certain contractual guarantees and litigation. We record in the Consolidated Balance Sheets amounts representing our estimated liability relating to such guarantees, litigation, and insurance claims. We perform an analysis to determine the level of reserves to establish for both insurance-related claims that are known and have been asserted against us as well as for insurance-related claims that are believed to have been incurred based on actuarial analysis, but have not yet been reported to our claims administrators as of the respective balance sheet dates. We include any adjustments to such insurance reserves in our Consolidated Statements of Earnings. In addition, as a contractor providing services to various agencies of the U.S. federal government, we are subject to many levels of audits, investigations, and claims by, or on behalf of, the U.S. federal government with respect to contract performance, pricing, costs, cost allocations, and procurement practices. We adjust revenues based upon the amounts we expect to realize considering the effects of any client audits or governmental investigations. Accounting for Business Combinations — U.S. GAAP requires that the purchase price paid for business combinations accounted for using the acquisition method be allocated to the assets and liabilities acquired based on their respective Fair Values. Determining the Fair Value of contract assets and liabilities acquired often requires estimates and judgments regarding, among other things, the estimated cost to complete such contracts. The Company must also make certain estimates and judgments relating to other assets and liabilities acquired as well as any identifiable intangible assets acquired. During the fourth fiscal quarter of 2017, the Company acquired Blue Canopy LLC. During the second fiscal quarter of 2017, the Company acquired Aquenta Consulting Pty Ltd. During the first fiscal quarter of 2016, the Company acquired J.L. Patterson & Associates. These acquisitions were not material to the Company’s consolidated results for fiscal 2017 or 2016. On May 19, 2017, the Company entered into an agreement with Saudi Aramco to form a 50/50 Saudi Arabia-based joint venture company to provide professional program and construction management (“PMCM”) services for social infrastructure projects throughout Saudi Arabia and across the Middle East and North Africa. The venture commenced start-up operations in fourth quarter fiscal 2017. Initial funding commitments from each of the partners include $6.5 million in capital contributions and $7.0 million in partner loans which are expected to be executed during fiscal 2018. The partners have also committed up to an additional $7.0 million each for future loans to the joint venture.
New Accounting Pronouncements	New Accounting Pronouncements Revenue Recognition From time to time, the Financial Accounting Standards Board (“FASB”) issues accounting standards updates (each being an “ASU”) to its Accounting Standards Codification (“ASC”), which constitutes the primary source of U.S. GAAP. The Company regularly monitors ASUs as they are issued and considers their applicability to its business. All ASUs applicable to the Company are adopted by the due date and in the manner prescribed by the FASB. In May 2014, the FASB issued ASU No. 2014-09— Revenue from Contracts with Customers. The new guidance provided by ASU 2014-09 is intended to remove inconsistencies and perceived weaknesses in the existing revenue requirements, provide a more robust framework for addressing revenue issues, improve comparability, provide more useful information and simplify the preparation of financial statements. ASU 2014-09 was initially effective for annual and interim reporting periods beginning after December 15, 2016. On July 9, 2015, the FASB approved a one-year deferral of the effective date of this standard. The revised effective date for the standard is for annual reporting periods beginning after December 15, 2017 and interim periods therein. The FASB also approved changes allowing for early adoption of the standard as of the original effective date. The Company’s adoption activities will be performed over three phases: (i) assessment, (ii) design, and (iii) implementation. Our assessment phase is predominantly complete. The following are the potential significant differences identified during the assessment phase: Performance Obligations Under current U.S. GAAP the Company typically considers engineering and construction services as separate performance obligations. Under ASU 2014-09, the Company has determined that, in most instances, it is likely that engineering and construction services will be required to be combined into a single performance obligation. In these instances, this will likely change the timing and pattern of revenue recognition. Contract Modifications In many instances, the Company enters into contracts for construction services subsequent to entering in to engineering services contracts. Under ASU 2014-09, the construction services contract may be deemed to modify the engineering contract, or may be required to be combined with the engineering contract. This modification or combination of contracts may result in a cumulative catch-up adjustment, which will have an immediate impact on the Company’s results of operations in the period the contract combination or modification occurs. In addition, it will change the timing and pattern of revenue recognition after the period the contracts have been combined or modified. The Company currently intends to adopt the new standard using the Modified Retrospective application. This standard could have a significant impact on the Company’s Consolidated Financial Statements and an administrative impact on its operations and will depend on the magnitude of the items discussed above. The Company will continue to evaluate the impact through the design and implementation phases. Lease Accounting In February 2016, the FASB issued ASU 2016-02—Leases. ASU 2016-02 requires lessees to recognize assets and liabilities for most leases. ASU 2016-02 is effective for public entity financial statements for annual periods beginning after December 15, 2018, and interim periods within those annual periods. Early adoption is permitted, including adoption in an interim period. The guidance must be adopted using a modified retrospective approach for leases that exist or are entered into after the beginning of the earliest comparative period in the financial statements. The Company is evaluating the impact of the new guidance on its consolidated financial statements. This standard could have a significant administrative impact on its operations, and the Company will further assess the impact through its implementation program. Employee Share-Based Payment Accounting In March 2016, the FASB issued ASU 2016-09—Improvements to Employee Share-Based Payment Accounting. ASU 2016-09 simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. The Company is evaluating the impact of the new guidance on its consolidated financial statements and plans to adopt in fiscal 2018.

Description Of Business And B27

Description Of Business And Basis Of Presentation (Tables)	12 Months Ended
	Sep. 29, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Revenues Realized from Each of These Types of Contracts	The percentage of revenues realized from each of these types of contracts for the fiscal years ended September 29, 2017, September 30, 2016 and October 2, 2015 was as follows: For the Year Ended September 29, 2017 September 30, 2016 October 2, 2015 Cost-reimbursable 81% 82 % 83 % Fixed-price 19% 18 % 17 %

Significant Accounting Polici28

Significant Accounting Policies (Tables)	12 Months Ended
	Sep. 29, 2017
Significant Accounting Policies [Line Items]
Pass-Through Costs Included in Revenues	The following table sets forth pass-through costs included in revenues in the accompanying Consolidated Statements of Earnings (in millions): For the Year Ended September 29, 2017 September 30, 2016 October 2, 2015 $ 2,539.3 $ 2,489.9 $ 2,602.6
Components of Goodwill by Reporting Units	The following table presents the components of our goodwill by reporting unit appearing in the accompanying Consolidated Balance Sheets at September 29, 2017 (in thousands): September 29, 2017 Aerospace & Technology $ 1,025,780 Buildings & Infrastructure 751,407 Industrial 561,785 Petroleum & Chemicals 670,854 Total Goodwill $ 3,009,826
Schedule of Acquired Intangible Assets	The following table provides certain information related to the Company’s acquired intangible assets in the accompanying Consolidated Balance Sheets at September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): Customer Relationships, Contracts, and Backlog Developed Technology Trade Names Patents Other Total Balances, September 26, 2014 $ 408,041 $ 17,378 $ 14,148 $ — $ 625 $ 440,192 Acquisitions (4,315 ) — (1,292 ) — 300 (5,307 ) Amortization (39,967 ) (1,533 ) (4,172 ) — (277 ) (45,949 ) Foreign currency translation (34,418 ) — (1,085 ) — (14 ) (35,517 ) Balances, October 2, 2015 329,341 15,845 7,599 — 634 353,419 Acquisitions 7,286 — 859 10,027 — 18,172 Amortization (38,595 ) (1,534 ) (3,819 ) — (454 ) (44,402 ) Foreign currency translation 9,605 — 147 — (19 ) 9,733 Balances, September 30, 2016 307,637 14,311 4,786 10,027 161 336,922 Acquisitions 29,803 1,685 4,417 — — 35,905 Amortization (39,679 ) (1,534 ) (2,549 ) (400 ) (50 ) (44,212 ) Foreign currency translation 3,707 — 45 553 — 4,305 Balances, September 29, 2017 $ 301,468 14,462 6,699 10,180 111 332,920 Weighted Average Amortization Period (years) 7.9 7.7 4.4 24 2.2 8.3
Stock-based Compensation Expense by Type of Award	The following table presents our stock-based compensation expense for the various types of awards made by the Company as included in the Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended Award Type September 29, 2017 September 30, 2016 October 2, 2015 Restricted Stock and Restricted Stock Units (excluding Market and Performance Awards) $ 26,393 $ 21,156 $ 20,779 Stock Options 4,338 7,165 10,683 Market and Performance Awards 8,033 4,049 9,950 Total Expense $ 38,764 $ 32,370 $ 41,412
Fair Value of Option Grant Date Award	The following table presents the assumptions used in the Black-Scholes option-pricing model for awards made to employees and directors for the years ended September 30, 2016 and October 2, 2015: Awards Made to Employees Awards Made to Directors September 30, 2016 October 2, 2015 September 30, 2016 October 2, 2015 Dividend yield — % — % — % — % Expected volatility 27.77 % 27.00 % 29.21 % 29.28 % Risk-free interest rate 1.82 % 1.67 % 1.44 % 1.63 % Expected term of options (in years) 5.82 5.82 5.82 5.82
Unit Basis for Earned Net Earnings Growth Based PSUs	The following table presents the basis on which the Net Earnings Growth Based PSUs are determined: Average Adjusted Net Earnings Growth Net Earnings Multiplier Less than 5% 0 % 5% 50 % 10% 100 % 15% 150 % 20% 200 %
Basis to Determine EPS Performance Multiplier	The “EPS Performance Multiplier” is determined by reference to the following table based upon the Company’s EPS Growth Rate or Compound Annual EPS Growth Rate over the relevant fiscal periods. The Human Resource and Compensation Committee of the Board of Directors of the Company set these metrics based on the Company’s plan at the start of the fiscal year. EPS Growth Rate or Compound Annual EPS Growth Rate EPS Performance Multiplier Less than 4% 0 % 4% 50 % 7.5% 100 % 15% 150 % 20% or greater 200 %
Unit Basis for Earned Relative TSR Restricted Stock	The following table presents the basis on which the Relative TSR Based PSUs are determined: Company TSR Percentile Rank TSR Multiplier Below 30th percentile 0 % 30th percentile 50 % 50th percentile 100 % 70th percentile or above 150 %
Schedule of Fair Value Assumptions for Earned Relative TSR Restricted Stock Units	The following table presents the assumptions used to value the TSR Based PSUs for the years ended September 29, 2017, September 30, 2016 and October 2, 2015: For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Dividend yield — % — % — % Expected volatility — % 25.06 % — % Risk-free interest rate — % 1.21 % — % Expected term (in years) — 3 —
Basis to Determine Return on Invested Capital Based PSUs	The number of restricted stock units to be issued equals the target number of restricted stock units multiplied by an ROIC Performance Multiplier (as shown in the table below) determined based upon the Company’s average annual ROIC from fiscal 2017 to fiscal 2019. Average ROIC – Fiscal 2017 - 2019 ROIC Performance Multiplier Less than 8.9% 0 % 8.9% 50 % 9.9% 100 % 10.9% 200 %
EPS Growth Rate Restricted Stock Units 2017 Awards
Significant Accounting Policies [Line Items]
Basis to Determine EPS Performance Multiplier	The “EPS Performance Multiplier” is determined by reference to the following table based upon the average growth in the Company’s adjusted EPS over the indicated fiscal periods. The Human Resource and Compensation Committee of the Board of Directors of the Company set these metrics based on the Company’s plan at the start of the fiscal year. Average EPS Growth Rate from fiscal 2016 to fiscal 2017 Average EPS Growth Rate EPS Performance Multiplier Less than 0% 0 2.3% 100 % 4.3% 200 % Average EPS Growth Rate from fiscal 2016 to fiscal 2018 Average EPS Growth Rate EPS Performance Multiplier Less than 2.1% 0 4.1% 100 % 6.1% 200 % Average EPS Growth Rate from fiscal 2016 to fiscal 2019 Average EPS Growth Rate EPS Performance Multiplier Less than 3.6% 0 5.6% 100 % 7.6% 200 %

Employee Stock Purchase and S29

Employee Stock Purchase and Stock Option Plans (Tables)	12 Months Ended
	Sep. 29, 2017
Stock Issuance Activity Under the 1989 ESPP and the GESPP	The following table summarizes the stock issuance activity under the 1989 ESPP and the GESPP for the fiscal years ended September 29, 2017, September 30, 2016 and October 2, 2015: For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Aggregate Purchase Price Paid for Shares Sold: Under the 1989 ESPP $ 21,084,657 $ 23,631,241 $ 28,621,800 Under the GESPP 2,105,834 2,660,067 3,535,479 Total $ 23,190,491 $ 26,291,308 $ 32,157,279 Aggregate Number of Shares Sold: Under the 1989 ESPP 403,652 564,461 696,853 Under the GESPP 39,648 63,196 84,361 Total 443,300 627,657 781,214
Stock-based Compensation Expense by Type of Award	The following table presents our stock-based compensation expense for the various types of awards made by the Company as included in the Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended Award Type September 29, 2017 September 30, 2016 October 2, 2015 Restricted Stock and Restricted Stock Units (excluding Market and Performance Awards) $ 26,393 $ 21,156 $ 20,779 Stock Options 4,338 7,165 10,683 Market and Performance Awards 8,033 4,049 9,950 Total Expense $ 38,764 $ 32,370 $ 41,412
Fair Value of Shares Vested	The following table presents the Fair Value of shares (of restricted stock and restricted stock units) vested for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Restricted Stock and Restricted Stock Units (service condition) $ 34,466 $ 17,481 $ 18,568 Restricted Stock Units (service, market, and performance conditions at target) 4,183 4,336 11,264 Total $ 38,649 $ 21,817 $ 29,832
Stock Options Activity	The following table summarizes the stock option activity for the years ended September 29, 2017, September 30, 2016 and October 2, 2015: Number of Stock Options Weighted Average Exercise Price Outstanding at September 26, 2014 4,221,147 $ 53.23 Granted 614,759 $ 43.56 Exercised (34,000 ) $ 31.54 Cancelled or expired (729,199 ) $ 86.15 Outstanding at October 2, 2015 4,072,707 $ 46.06 Granted 460,770 $ 42.17 Exercised (412,416 ) $ 40.88 Cancelled or expired (543,549 ) $ 49.13 Outstanding at September 30, 2016 3,577,512 $ 45.69 Granted — $ — Exercised (906,648 ) $ 43.79 Cancelled or expired (154,039 ) $ 48.79 Outstanding at September 29, 2017 2,516,825 $ 46.19
Total Intrinsic Value of Options Exercised	The following table presents the total intrinsic value of stock options exercised for the fiscal years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 $ 14,713 $ 4,149 $ 442
Information Regarding our Stock Option Plans	The following table presents certain other information regarding our 1999 SIP and 1999 OSDP for the fiscal years ended September 29, 2017, September 30, 2016 and October 2, 2015: September 29, September 30, October 2, At fiscal year end: Range of exercise prices for options outstanding $32.51–$80.63 $32.51–$80.63 $32.51–$80.63 Number of options exercisable 1,992,022 2,581,421 2,590,560 For the fiscal year: Range of prices relating to options exercised $37.03–$55.53 $36.88–$55.00 $25.87–$42.74 Estimated weighted average fair values of options granted $ — $ 12.80 $ 13.41
Information Regarding Options Outstanding, and Options Exercisable	The following table presents certain information regarding stock options outstanding and stock options exercisable at September 29, 2017: September 29, 2017 Options Outstanding Options Exercisable Range of Exercise Prices Number Weighted Average Remaining Contractual Life (years) Weighted Average Price Number Weighted Average Exercise Price $32.51 - $37.03 247,875 4.47 $ 36.99 247,875 $ 36.99 $37.43 - $46.09 1,360,188 5.63 $ 42.69 890,206 $ 42.65 $47.11 - $55.13 836,812 5.30 $ 52.81 788,116 $ 52.80 $60.08 - $80.63 71,950 4.23 $ 66.92 65,825 $ 67.52 2,516,825 5.37 $ 46.19 1,992,022 $ 46.78
Restricted Stock and Restricted Stock Units Activity	Restricted Stock The following table presents the number of shares of restricted stock and restricted stock units issued as common stock under the 1999 SIP for the year ended September 29, 2017, September 30, 2016 and October 2, 2015: For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Restricted stock — 597,091 507,882 Restricted stock units (service condition) 496,951 183,131 126,635 Restricted stock units (service, market and performance conditions) 237,058 372,794 219,965 The amount of restricted stock units issued for awards with performance and market conditions in the above table are issued based on performance against the target amount The share amounts in the above tables reflect the Non-Fungible share counting of one share for each share of restricted stock and restricted stock unit issued. The following table presents the number of shares of restricted stock and restricted stock units cancelled and withheld for taxes under the 1999 SIP for the years ended September 29, 2017, September 30, 2016 and October 2, 2015: For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Restricted stock 365,481 512,903 326,480 Restricted stock units (service condition) 128,536 177,640 70,296 Restricted stock units (service, market and performance conditions) 86,742 275,933 194,116 The amount of unvested restricted stock units cancelled for awards with service and performance conditions in the above table is based on the service period achieved and performance against the target amount. The share amounts in the above tables reflect the Non-Fungible share counting of one share for each share of restricted stock and restricted stock unit issued. The following table provides the number of shares of restricted stock and restricted stock units outstanding at September 29, 2017 under the 1999 SIP. Shares granted in the table below are granted on a 1.92 -to-1.00 basis (fungible): September 29, 2017 Total Restricted stock 950,593 Restricted stock units (service condition) 766,759 Restricted stock units (service, market and performance conditions) 672,440 The following table presents the number of shares of restricted stock and restricted stock units issued under the 1999 ODSP for the years ended September 29, 2017, September 30, 2016 and October 2, 2015: For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Restricted stock units (service condition) 21,123 23,090 13,500 The following table provides the number of shares of restricted stock and restricted stock units outstanding at September 29, 2017 under the 1999 ODSP: September 29, 2017 Restricted stock 34,000 Restricted stock units (service condition) 90,595
Total Pre-Tax Compensation Cost Relating to Share-Based Payments Included in the Accompanying Consolidated Statements of Earnings	The following table presents the Company’s total pre-tax compensation cost relating to share-based payments included in the accompanying Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015(in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 $ 38,764 $ 32,370 $ 41,412
Stock Incentive Plans
Stock-based Compensation Expense by Type of Award	The following table sets forth certain information about the 1999 Plans: 1999 SIP 1999 ODSP Total Number of shares authorized 29,850,000 1,100,000 30,950,000 Number of remaining shares reserved for issuance at September 29, 2017 9,641,396 539,787 10,181,183 Number of shares relating to outstanding stock options at September 29, 2017 2,289,450 227,375 2,516,825 Number of shares available for future awards: At September 29, 2017 7,351,946 312,412 7,664,358 At September 30, 2016 7,233,173 319,535 7,552,708

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Sep. 29, 2017
Earnings Per Share Reconciliation [Abstract]
Earnings Per Share	The following table reconciles the denominator used to compute basic EPS to the denominator used to compute diluted EPS for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Numerator for Basic and Diluted EPS: Net income $ 293,727 $ 210,463 $ 302,971 Net income allocated to participating securities (3,077 ) — — Net income allocated to common stock for EPS calculation $ 290,650 $ 210,463 $ 302,971 Denominator for Basic and Diluted EPS: Weighted average basic shares 119,370 120,133 125,007 Effect of dilutive securities: Stock compensation plans 777 680 481 Restricted stock 1,319 670 622 Diluted shares 121,466 121,483 126,110 Shares allocated to participating securities (1,319 ) — — Shares used for calculating diluted EPS attributable to common stock 120,147 121,483 126,110 Basic EPS $ 2.43 $ 1.75 $ 2.42 Diluted EPS $ 2.42 $ 1.73 $ 2.40
Share Repurchases	The following table summarizes the activity under this program during fiscal 2017 (in thousands, except per-share amounts): Amount Authorized (in Average Price Per Share (1) Shares Retired (In thousands) Shares Repurchased (In thousands) $ 500,000 $ 55.60 1,748 1,748 (1) Includes commissions paid and calculated as the average price per share since the repurchase program authorization date.

Restructuring and Other Charg31

Restructuring and Other Charges (Tables)	12 Months Ended
	Sep. 29, 2017
Restructuring And Related Activities [Abstract]
Summary of 2015 Restructuring Impacts on Reportable Segment Income by Line of Business	The following table summarizes the impacts of the 2015 Restructuring on the Company's reportable segment income by line of business for the years ended September 29, 2017 and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Aerospace & Technology $ 1,820 $ 5,835 Buildings & Infrastructure 23,675 23,378 Industrial 6,698 29,690 Petroleum & Chemicals 36,664 87,188 Corporate 29,831 41,816 Total Restructuring Charges $ 98,688 $ 187,907
Schedule of 2015 Restructuring Activity	The activity in the Company’s accrual for the 2015 Restructuring for the year ended September 29, 2017 is as follows (in thousands): Balance at September 30, 2016 $ 152,174 Charges 98,688 Payments (122,407 ) Balance at September 29, 2017 $ 128,455
Summary of Restructuring by Major Type of Restructuring Costs	The following table summarizes the 2015 Restructuring by major type of restructuring costs for the years ended September 29, 2017 and September 30, 2016 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Lease Abandonments $ 55,647 $ 92,643 $ 90,569 Involuntary Terminations 30,716 85,599 55,313 Outside Services 4,236 7,398 12,734 Other restructuring related costs, net 8,089 2,267 (1,424 ) Total $ 98,688 $ 187,907 $ 157,192
Summary of Cumulative Amounts Incurred for 2015 Restructuring Costs	Cumulative amounts incurred to date for the 2015 Restructuring by each major type of restructuring costs as of September 29, 2017 is as follows (in thousands): Lease Abandonments $ 238,859 Involuntary Terminations 171,628 Outside Services 24,368 Other restructuring related costs, net 8,932 Total $ 443,787

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Sep. 29, 2017
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	The following table presents certain information regarding the Company’s long-term revolving credit facilities at September 29, 2017 and September 30, 2016 (dollars in thousands): September 29, 2017 September 30, 2016 Principal Balance Outstanding Range of Interest Rates Principal Balance Outstanding Range of Interest Rates $ 235,000 1.0% – 2.23% $ 385,330 1.0% – 1.65%
Schedule of Other Loan Agreements	The following table presents certain additional information regarding the Company’s long-term debt for the fiscal years shown: 2017 2016 Maximum amount outstanding at any month-end during the fiscal year $ 659,103 $ 958,460 Average amount outstanding during the year $ 639,210 $ 825,641 Weighted average interest rate during the year 1.67 % 1.39 %
Schedule of Interest Expense	The following table presents the amount of interest paid by the Company during September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 $ 12,862 $ 13,282 $ 15,506

Pension and Other Postretirem33

Pension and Other Postretirement Pension Plans (Tables)	12 Months Ended
	Sep. 29, 2017
Schedule of Change in Plans' Combined Net Benefit Obligation	The following table sets forth the changes in the plans’ combined net benefit obligation (segregated between plans existing within and outside the U.S.) for the years ended September 29, 2017 and September 30, 2016 (in thousands): U.S. Pension Plans Non-U.S. Pension Plans September 29, 2017 September 30, 2016 September 29, 2017 September 30, 2016 Net benefit obligation at the beginning of the year $ 185,664 $ 533,665 $ 1,363,782 $ 1,155,592 Service cost 1,000 9,875 7,509 14,378 Interest cost 5,757 16,746 31,205 38,892 Participants’ contributions — 1,847 250 2,255 Actuarial (gains)/losses (9,922 ) 29,129 (142,273 ) 382,691 Benefits paid (14,338 ) (14,143 ) (40,208 ) (32,277 ) Curtailments/settlements — (35,224 ) (1,375 ) (35,375 ) Transfers * — (356,231 ) — — Effect of exchange rate changes and other, net 1,781 — 87,917 (162,374 ) Net benefit obligation at the end of the year $ 169,942 $ 185,664 $ 1,306,807 $ 1,363,782 * Pension plan transferred to a new sponsor for the plan
Schedule of Change in Combined Fair Value of the Plans' Assets	The following table sets forth the changes in the combined Fair Value of the plans’ assets (segregated between plans existing within and outside the U.S.) for the year ended September 29, 2017 and September 30, 2016 (in thousands): U.S. Pension Plans Non-U.S. Pension Plans September 29, 2017 September 30, 2016 September 29, 2017 October 2, 2016 Fair value of plan assets at the beginning of the year $ 142,464 $ 379,907 $ 1,003,911 $ 896,298 Actual return on plan assets 18,662 28,835 16,789 242,927 Employer contributions 1,000 10,213 21,005 23,217 Participants’ contributions — 1,847 250 2,255 Gross benefits paid (14,338 ) (14,143 ) (40,208 ) (32,277 ) Curtailments/settlements — (35,224 ) (228 ) (1,863 ) Transfers* — (228,971 ) — — Effect of exchange rate changes and other, net — — 75,409 (126,646 ) Fair value of plan assets at the end of the year $ 147,788 $ 142,464 $ 1,076,928 $ 1,003,911 * Pension plan transferred to a new sponsor for the plan
Reconciliation of Combined Funded Status of Plans and Recognized in Consolidated Balance Sheet	The following table reconciles the combined funded statuses of the plans recognized in the accompanying Consolidated Balance Sheets at September 29, 2017 and September 30, 2016 (segregated between plans existing within and outside the U.S.) (in thousands): U.S. Pension Plans Non-U.S. Pension Plans September 29, 2017 September 30, 2016 September 29, 2017 September 30, 2016 Net benefit obligation at the end of the year $ 169,942 $ 185,664 $ 1,306,807 $ 1,363,782 Fair value of plan assets at the end of the year 147,788 142,464 1,076,928 1,003,911 Under funded amount recognized at the end of the year $ 22,154 $ 43,200 $ 229,879 $ 359,871
Schedule of Accumulated and Projected Benefit Obligations	The following table presents the accumulated benefit obligation at September 29, 2017 and September 30, 2016 (segregated between plans existing within and outside the U.S.) (in thousands): U.S. Pension Plans Non-U.S. Pension Plans September 29, 2017 September 30, 2016 September 29, 2017 September 30, 2016 Accumulated benefit obligation at the end of the year $ 169,942 $ 185,664 $ 1,291,600 $ 1,331,884
Schedule of Amount Recognized in Accompanying Balance Sheets	The following table presents the amounts recognized in the accompanying Consolidated Balance Sheets at September 29, 2017 and September 30, 2016 (segregated between plans existing within and outside the U.S.) (in thousands): U.S. Pension Plans Non-U.S. Pension Plans September 29, 2017 September 30, 2016 September 29, 2017 September 30, 2016 Prepaid benefit cost included in prepaid assets $ — $ — $ 3,035 $ 492 Accrued benefit cost included in current liabilities — — 585 608 Accrued benefit cost included in noncurrent liabilities 22,154 43,200 232,329 359,755 Net amount recognized at the end of the year $ 22,154 $ 43,200 $ 229,879 $ 359,871
Schedule of Pension Plans Recorded in Accumulated Other Comprehensive Loss Not Yet Recognized as Component of Net Periodic Pension Cost	The following table presents certain amounts relating to our pension plans recorded in accumulated other comprehensive loss that have not yet been recognized as components of net periodic benefit cost at September 29, 2017, and September 30, 2016 (segregated between U.S. and non-U.S. plans) (in thousands): U.S. Pension Plans Non-U.S. Pension Plans September 29, 2017 September 30, 2016 September 29, 2017 September 30, 2016 Net actuarial loss $ 47,681 $ 61,483 $ 218,752 $ 304,345 Prior service cost — — (855 ) (1,203 ) Total $ 47,681 $ 61,483 $ 217,897 $ 303,142
Schedule of Accumulated Comprehensive Income Amortized Against Earnings in the Next Year	The following table presents the amount of accumulated comprehensive income that will be amortized against earnings as part of our net periodic benefit cost in fiscal 2018 based on 2017 exchange rates (segregated between U.S. and non-U.S. plans) (in thousands): U.S. Pension Plans Non-U.S. Pension Plans Unrecognized net actuarial loss $ 3,325 $ 6,829 Unrecognized prior service cost — (277 ) Accumulated comprehensive loss to be recorded against earnings $ 3,325 $ 6,552
Schedule of Weighted Average Measurement of Assets and Liabilities	The plans’ weighted average asset allocations at September 29, 2017 and September 30, 2016 (the measurement dates used in valuing the plans’ assets and liabilities) were as follows: U.S. Pension Plans Non-U.S. Pension Pans September 29, 2017 September 30, 2016 September 29, 2017 September 30, 2016 Equity securities 70 % 71 % 24 % 25 % Debt securities 23 % 20 % 32 % 32 % Real estate investments — % 2 % 5 % 6 % Other 7 % 7 % 39 % 37 %
Anticipated Cash Contributions	The following table presents the amount of cash contributions we anticipate making into the plans during fiscal 2018 (in thousands): U.S. Pension Plans Non-U.S. Pension Pans Anticipated cash contributions $ 1,300 $ 22,574
Schedule of Expected Payments to Participants in Pension Plan	The following table presents the total benefit payments expected to be paid to pension plan participants during each of the next five fiscal years, and in total for the five years thereafter (in thousands): U.S. Pension Plans Non-U.S. Pension Pans 2018 $ 21,506 $ 31,063 2019 11,372 32,509 2020 11,377 32,923 2021 11,472 36,220 2022 11,485 38,086 For the periods 2023 through 2027 54,747 231,183
Schedule of Contribution to Multiemployer Pension Plans	The following table presents the Company’s contributions to these multiemployer plans for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 Canada $ 35,182 $ 44,912 $ 42,575 Europe $ 6,212 $ 8,771 $ 10,902 United States $ 4,548 $ 5,058 $ 5,968 Contributions to multiemployer pension plans $ 45,942 $ 58,741 $ 59,445
U.S. Pension Plans
Schedule of Significant Actuarial Assumptions in Determining the Funded Status Plans	The following table presents the significant actuarial assumptions used in determining the funded statuses and the following year's benefit cost of the Company’s U.S. plans for the years ended September 29, 2017, September 30, 2016 and October 2, 2015: For the Year Ended September 29, 2017 September 30, 2016 October 2, 2015 Weighted average discount rates 3.5 % 3.2 3.9% to 4.0% Rates of compensation increases — % — % 3.0 % Return on Assets 7.5 % 7.4 % 7.4 %
Schedule of Pension Plans Recognized in Accumulated Other Comprehensive Loss	The following table presents certain amounts relating to our U.S. pension plans recognized in accumulated other comprehensive (gain) loss at September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 Arising during the period: Net actuarial (gain) loss $ (11,372 ) $ 4,337 $ 12,237 Reclassification adjustments: Net actuarial losses (2,431 ) (2,312 ) (2,347 ) Total $ (13,803 ) $ 2,025 $ 9,890
Schedule of Fair Value of Pension Plan Assets	The following table presents the Fair Value of the Company’s Domestic U.S. plan assets at September 29, 2017, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands): September 29, 2017 Fair Value, Determined Using Fair Value Measurement Inputs Level 1 Level 3 Total U.S. Domestic equities $ 103,760 $ — $ 103,760 U.S. Domestic bonds 33,404 — 33,404 Cash and equivalents 4,448 — 4,448 Hedge funds — 6,176 6,176 Total $ 141,612 $ 6,176 $ 147,788 The following table presents the Fair Value of the Company’s U.S. pension plan assets at September 30, 2016, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands): September 30, 2016 Fair Value, Determined Using Fair Value Measurement Inputs Level 1 Level 3 Total U.S. Domestic equities $ 85,494 $ — $ 85,494 Overseas equities 15,169 — 15,169 U.S. Domestic bonds 28,886 — 28,886 Cash and equivalents 3,723 — 3,723 Real estate — 3,477 3,477 Hedge funds — 5,715 5,715 Total $ 133,272 $ 9,192 $ 142,464
Summary of Changes in the Fair Value of the Plans' Level 3 Assets	The following table summarizes the changes in the Fair Value of the Company’s U.S. Pension Plans’ Level 3 assets for the year ended September 29, 2017 (in thousands): Real Estate Hedge Funds Balance at September 30, 2016 $ 3,477 $ 5,715 Purchases, sales, and settlements (3,477 ) (557 ) Realized and unrealized gains — 1,018 Balance at September 29, 2017 $ — $ 6,176 The following table summarizes the changes in the Fair Value of the Company’s U.S. Pension Plans’ Level 3 assets for the year ended September 30, 2016 (in thousands): Real Estate Hedge Funds Balance at October 2, 2015 $ 9,914 $ 16,372 Purchases (6,530 ) (10,788 ) Realized and unrealized gains 93 131 Balance at September 30, 2016 $ 3,477 $ 5,715
Schedule of Components of Net Periodic Pension Cost Recognized	The following table presents the components of net periodic benefit cost for the Company’s U.S. pension plans recognized in the accompanying Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 Service cost $ 1,000 $ 9,875 $ 12,045 Interest cost 5,757 16,746 20,629 Expected return on plan assets (9,942 ) (22,368 ) (29,526 ) Actuarial loss 3,985 7,512 3,756 Prior service cost — (176 ) (239 ) Net pension cost, before special items 800 11,589 6,665 Contractual expense/Settlement loss 1,781 8,061 — Total net periodic pension cost recognized $ 2,581 $ 19,650 $ 6,665
Non-U.S. Pension Plans
Schedule of Significant Actuarial Assumptions in Determining the Funded Status Plans	The following table presents the significant actuarial assumptions used in determining the funded statuses and the following year's benefit cost of the Company’s non-U.S. pension plans for the years ended September 29, 2017, September 30, 2016 and October 2, 2015: September 29, 2017 September 30, 2016 October 2, 2015 Weighted average discount rates 1.3% to 7.0% 0.7% to 7.0% 1.6% to 7.8% Rates of compensation increases 2.5% to 7.5% 2.5% to 7.5% 2.4% to 7.5% Expected long-term rates of return on assets 3.5% to 8.5% 3.5% to 8.5% 3.5% to 8.5%
Schedule of Pension Plans Recognized in Accumulated Other Comprehensive Loss	The following table presents certain amounts relating to our non-U.S. pension plans recognized in accumulated other comprehensive (gain) loss at September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 Arising during the period: Net actuarial (gain) loss $ (76,860 ) $ 102,925 $ (27,165 ) Prior service cost (benefit) 119 580 (1,512 ) Total (76,741 ) 103,505 (28,677 ) Reclassification adjustments: Net actuarial losses (8,732 ) (7,508 ) (14,034 ) Prior service cost 229 163 51 Total (8,503 ) (7,345 ) (13,983 ) Total $ (85,244 ) $ 96,160 $ (42,660 )
Schedule of Fair Value of Pension Plan Assets	The following table presents the Fair Value of the Company’s non-U.S. pension plan assets at September 29, 2017, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands): September 29, 2017 Fair Value, Determined Using Fair Value Measurement Inputs Level 1 Level 3 Total U.S. Domestic equities $ 30,916 $ — $ 30,916 Overseas equities 229,205 — 229,205 U.S. Domestic bonds 263,145 — 263,145 Overseas bonds 77,682 — 77,682 Cash and equivalents 38,924 — 38,924 Real estate — 58,974 58,974 Insurance contracts — 74,353 74,353 Other — 303,729 303,729 Total $ 639,872 $ 437,056 $ 1,076,928 The following table presents the Fair Value of the Company’s non-U.S. pension plan assets at September 30, 2016, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands): September 30, 2016 Fair Value, Determined Using Fair Value Measurement Inputs Level 1 Level 3 Total U.S. Domestic equities $ 31,972 $ — $ 31,972 Overseas equities 220,179 — 220,179 U.S. Domestic bonds 258,949 — 258,949 Overseas bonds 61,974 — 61,974 Cash and equivalents 63,182 — 63,182 Real estate — 55,665 55,665 Insurance contracts — 39,473 39,473 Hedge funds — 272,517 272,517 Total $ 636,256 $ 367,655 $ 1,003,911
Summary of Changes in the Fair Value of the Plans' Level 3 Assets	The following table summarizes the changes in the Fair Value of the Company’s non-U.S. Pension Plans’ Level 3 assets for the year ended September 29, 2017 (in thousands): Real Estate Insurance Contracts Hedge Funds Balance at September 30, 2016 $ 55,665 $ 39,473 $ 272,517 Purchases, sales, and settlements (1,199 ) 422 (9,022 ) Realized and unrealized gains (losses) 2,642 (7,572 ) 19,662 Transfers — 40,031 11,758 Effect of exchange rate changes 1,866 1,999 8,814 Balance at September 29, 2017 $ 58,974 $ 74,353 $ 303,729 The following table summarizes the changes in the Fair Value of the Company’s non-U.S. Pension Plans’ Level 3 assets for the year ended September 30, 2016 (in thousands): Real Estate Insurance Contracts Hedge Funds Balance at October 2, 2015 $ 61,996 $ 32,522 $ 260,720 Purchases, sales, and settlements (462 ) (165 ) (1,205 ) Realized and unrealized gains 2,572 6,451 57,656 Effect of exchange rate changes (8,441 ) 665 (44,654 ) Balance at September 30, 2016 $ 55,665 $ 39,473 $ 272,517
Schedule of Components of Net Periodic Pension Cost Recognized	The following table presents the components of net periodic benefit cost for the Company’s Non-U.S. pension plans recognized in the accompanying Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 Service cost $ 7,509 $ 14,378 $ 21,374 Interest cost 31,205 38,892 44,659 Expected return on plan assets (56,269 ) (50,190 ) (53,052 ) Actuarial loss 10,616 9,092 17,398 Prior service cost (329 ) (260 ) (96 ) Net pension cost, before special items (7,268 ) 11,912 30,283 Curtailments and settlements (298 ) (7,512 ) 255 Total net periodic pension cost recognized $ (7,566 ) $ 4,400 $ 30,538

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	12 Months Ended
	Sep. 29, 2017
Equity [Abstract]
Reclassification out of Accumulated Other Comprehensive Income	The following table presents amounts reclassified from changes in pension liabilities in other comprehensive income to direct cost of contracts and SG&A expenses in the Company's Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 related to the Company's defined benefit pension plans (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 Amortization of Defined Benefit Items: Actuarial losses $ (14,601 ) $ (12,880 ) $ (21,153 ) Prior service cost 328 260 96 Total Before Income Tax (14,273 ) (12,620 ) (21,057 ) Income Tax Benefit 3,339 2,963 4,727 Total reclassifications after-tax $ (10,934 ) $ (9,657 ) $ (16,330 )

Savings and Deferred Compensa35

Savings and Deferred Compensation Plans (Tables)	12 Months Ended
	Sep. 29, 2017
Savings And Deferred Compensation Plans [Abstract]
Schedule of Savings Plans Contributions	The following table presents the Company’s contributions to these savings plans for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 $ 82,882 $ 89,966 $ 87,973
Schedule of Deferred Compensation Plans Expense	The following table presents the amount charged to expense for the Company’s deferred compensation plans for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): September 29, 2017 September 30, 2016 October 2, 2015 $ 4,368 $ 5,792 $ 5,536

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Sep. 29, 2017
Income Tax Disclosure [Abstract]
Components of Consolidated Income Tax Expense	The following table presents the components of our consolidated income tax expense for years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Current income tax expense: Federal $ 29,297 $ 36,020 $ 72,840 State 8,535 11,336 16,248 Foreign 31,347 52,259 43,344 Total current tax expense 69,179 99,615 132,432 Deferred income tax expense (benefit): Federal 29,390 6,439 13,337 State 3,407 485 2,295 Foreign 3,866 (34,331 ) (46,809 ) Total deferred tax expense (benefit) 36,663 (27,407 ) (31,177 ) Consolidated income tax expense $ 105,842 $ 72,208 $ 101,255
Components of Deferred Tax Assets	The following table presents the components of our net deferred tax assets at September 29, 2017 and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Deferred tax assets: Obligations relating to: Defined benefit pension plans $ 52,299 $ 77,834 Other employee benefit plans 192,299 179,063 Net Operating Losses 136,783 139,125 Self-insurance programs 489 1,722 Contract revenues and costs (18,374 ) (8,177 ) Deferred Rent 25,654 7,955 Restructuring 18,258 47,792 Other 19,389 9,933 Valuation Allowance (58,097 ) (41,684 ) Gross deferred tax assets 368,700 413,563 Deferred tax liabilities: Depreciation and amortization (176,327 ) (154,939 ) Other, net (1,438 ) (1,555 ) Gross deferred tax liabilities (177,765 ) (156,494 ) Net deferred tax assets $ 190,935 $ 257,069
Income Tax Benefits Realized from the Exercise of Nonqualified Stock Options, and Disqualifying Dispositions of Stock Sold Under our Employee Stock Purchase Plans	The following table presents the income tax benefits realized from the exercise of nonqualified stock options and disqualifying dispositions of stock sold under our employee stock purchase plans for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in millions): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 $ 5.20 $ 1.50 $ 0.20
Income Tax Expense in Consolidated Statements of Earnings	The following table reconciles total income tax expense using the statutory U.S. federal income tax rate to the consolidated income tax expense shown in the accompanying Consolidated Statements of Earnings for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (dollars in thousands): For the Years Ended September 29, 2017 % September 30, 2016 % October 2, 2015 % Statutory amount $ 137,626 35.0% $ 100,353 35.0% $ 150,548 35.0% State taxes, net of the federal benefit 8,955 2.3% 7,853 2.7% 12,857 3.0% Exclusion of tax on non-controlling interests 2,223 0.6% (1,418 ) (0.5% ) (9,069 ) (2.1%) Foreign: Difference in tax rates of foreign operations (16,987 ) (4.3% ) (17,184 ) (6.0% ) (19,180 ) (4.5%) Benefit from foreign valuation allowance release (3,085 ) (0.8% ) (11,182 ) (3.9% ) (3,372 ) (0.8%) Tax deductible foreign currency loss — 0.0% — 0.0% (23,100 ) (5.4%) U.K. tax rate change on deferred tax assets — 0.0% 8,853 3.1% — 0.0% Nontaxable income from foreign affiliate (3,280 ) (0.8% ) — 0.0% — 0.0% U.S. tax cost of foreign operations 18,612 4.7% 30,850 10.9% 6,814 1.6% Tax differential on foreign earnings (4,740 ) (1.2% ) 11,337 4.1% (38,838 ) (9.0%) Foreign tax credits (20,454 ) (5.2% ) (44,018 ) (15.4% ) (21,313 ) (5.0%) Uncertain tax positions (5,779 ) (1.5% ) 1,449 0.5% 2,281 0.5% Other items: IRS §179D deduction (3,351 ) (0.8% ) (2,153 ) (0.8% ) — 0.0% IRS §199D deduction (2,113 ) (0.5% ) (2,800 ) (1.0% ) (4,582 ) (1.1%) Foreign partnership income/(loss) (9,861 ) (2.5% ) (2,658 ) (0.9% ) 11,858 2.8% Other items – net 3,336 0.7% 4,263 1.5% (2,487 ) (0.6%) Total other items (11,989 ) (3.1% ) (3,348 ) (1.2% ) 4,789 1.1% Taxes on income $ 105,842 26.9% $ 72,208 25.2% $ 101,255 23.5%
Income Tax Payments	The following table presents income tax payments made during the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in millions): September 29, 2017 September 30, 2016 October 2, 2015 $ 78.39 $ 116.30 $ 156.50
Components of our Consolidated Earnings Before Taxes	The following table presents the components of our consolidated earnings before taxes for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 United States earnings $ 232,342 $ 206,159 $ 283,504 Foreign earnings 160,875 80,564 146,633 $ 393,217 $ 286,723 $ 430,137
Schedule of Unrecognized Tax Benefits Roll Forward	The following table presents the reconciliation of the beginning and ending amount of unrecognized tax benefits for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Balance, beginning of year $ 44,167 $ 42,666 $ 41,923 Additions based on tax positions related to the current year 5,900 5,670 6,440 Additions for tax positions of prior years 237 367 — Reductions for tax positions of prior years (4,524 ) (2,451 ) (5,697 ) Settlement (7,200 ) (2,085 ) — Balance, end of year $ 38,580 $ 44,167 $ 42,666

Commitments and Contingencies37

Commitments and Contingencies, and Derivative Financial Instruments (Tables)	12 Months Ended
	Sep. 29, 2017
Commitments And Contingencies And Derivative Financial Instruments [Abstract]
Commitment Under Operating Leases	We lease certain of our facilities and equipment under operating leases with net aggregate future lease payments of approximately $753,102 million at September 29, 2017, payable as follows (in thousands): In fiscal years, 2018 $ 139,967 2019 133,609 2020 118,207 2021 97,062 2022 104,990 Thereafter 174,269 768,104 Amounts representing sublease income (15,002 ) $ 753,102
Rent Expense and Sublease Income	The following table presents rent expense and sublease income offsetting the Company’s rent expense for the years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Rent expense $ 145,344 $ 151,539 $ 175,067 Sublease income (7,052 ) (7,212 ) (5,275 ) Net rent $ 138,292 $ 144,327 $ 169,792
Significant Terms of the Lease	Significant terms of the lease are as follows: End of lease term 2025 End of term purchase option (in thousands) $ 76,950 Residual value guaranty (in thousands) $ 62,412

Other Financial Information (Ta

Other Financial Information (Tables)	12 Months Ended
	Sep. 29, 2017
Other Financial Information [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	The following table presents the components of “Receivables” as shown in the accompanying Consolidated Balance Sheets at September 29, 2017 and September 30, 2016 as well as certain other related information (in thousands): September 29, 2017 September 30, 2016 Amounts billed, net $ 949,060 $ 1,110,042 Unbilled receivables and other 1,118,144 937,552 Retentions receivable 35,339 68,069 Total receivables, net $ 2,102,543 $ 2,115,663 Other information about receivables: Amounts due from the United States federal government included above, net of advanced $ 226,236 $ 235,203 Claims receivable $ 4,600 $ 26,061
Property, Plant and Equipment	The following table presents the components of our property, equipment, and improvements, net at September 29, 2017 and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Land $ 17,197 $ 16,680 Buildings 93,313 91,194 Equipment 627,609 531,539 Leasehold improvements 220,295 221,437 Construction in progress 21,300 36,764 979,714 897,614 Accumulated depreciation and amortization (629,803 ) (577,941 ) $ 349,911 $ 319,673
Miscellaneous Noncurrent Assets	The following table presents the components of “Miscellaneous noncurrent assets” shown in the accompanying Consolidated Balance Sheets at September 29, 2017 and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Deferred income taxes $ 368,700 $ 413,563 Cash surrender value of life insurance policies 130,411 122,364 Investments 145,069 178,256 Notes receivable 17,839 18,303 Other 30,003 26,843 Total $ 692,022 $ 759,329
Components of Accrued Liabilities	The following table presents the components of “Accrued liabilities” shown in the accompanying Consolidated Balance Sheets at September 29, 2017 and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Accrued payroll and related liabilities $ 572,946 $ 561,652 Project-related accruals 71,815 102,400 Non project-related accruals 68,025 87,813 Insurance liabilities 67,546 54,984 Sales and other similar taxes 32,163 37,029 Deferred rent 60,593 69,059 Dividends payable 18,180 — Other 48,419 25,441 Total $ 939,687 $ 938,378
Components of Other Deferred Liabilities	The following table presents the components of “Other deferred liabilities” shown in the accompanying Consolidated Balance Sheets at September 29, 2017 and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Liabilities relating to defined benefit pension and early retirement plans $ 254,483 $ 402,955 Liabilities relating to nonqualified deferred compensation Arrangements 114,616 123,926 Deferred income taxes 177,765 156,494 Miscellaneous 185,417 178,449 Total $ 732,281 $ 861,824
Components of Total Accumulated Other Comprehensive Loss	The following table presents the components of “Accumulated other comprehensive loss” shown in the accompanying Consolidated Balance Sheets at September 29, 2017, and September 30, 2016 (in thousands): September 29, 2017 September 30, 2016 Foreign currency translation adjustments $ (386,131 ) $ (245,603 ) Adjustments relating to defined benefit pension plans (265,578 ) (364,625 ) Other (1,805 ) (366 ) Total $ (653,514 ) $ (610,594 )
Supplemental Cash Flow Information	The following table presents the non-cash adjustments relating to these acquisitions made in preparing the accompanying Consolidated Statements of Cash Flows (in thousands): September 29, 2017 September 30, 2016 Working capital $ 9,121 $ 10,023 Property and equipment 912 879 Noncurrent assets 35,976 8,192 Deferred liabilities (273 ) — Goodwill 104,454 30,849

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Sep. 29, 2017
Segment Reporting [Abstract]
Schedule of Total Revenues, Operating Profit and Total Asset for Reporting Segment	The following tables present total revenues and operating profit for each reportable segment (in thousands) and includes a reconciliation of segment operating profit to total U.S. GAAP operating profit by including certain corporate-level expenses and expenses relating to the Restructuring and other charges and CH2M professional fees and integration costs (in thousands). For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Revenues from External Customers: Aerospace & Technology $ 2,360,613 $ 2,657,433 $ 2,924,753 Buildings & Infrastructure 2,452,321 2,253,512 2,458,379 Industrial 2,743,662 2,793,713 2,517,571 Petroleum & Chemicals 2,466,192 3,259,499 4,214,129 Total $ 10,022,788 $ 10,964,157 $ 12,114,832 For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Operating Profit: Aerospace & Technology $ 202,595 $ 203,808 $ 205,368 Buildings & Infrastructure (1) 193,455 174,648 145,299 Industrial 115,262 81,268 126,531 Petroleum & Chemicals 113,858 126,604 138,351 Total Segment Operating Profit 625,170 586,328 615,549 Other Corporate Items (81,595 ) ( 60,100 ) (15,739 ) Restructuring and Other Charges ( 134,206 ) ( 187,630 ) ( 154,283 ) CH2M Professional Fees and Integration Costs (17,100 ) — — Total U.S. GAAP Operating Profit 392,269 338,598 445,527 Gain (Loss) on disposal of business and investments 10,880 ( 41,410 ) (2,909 ) Total Other Expense (2) ( 9,932 ) ( 10,465 ) (12,481 ) Earnings Before Taxes $ 393,217 $ 286,723 $ 430,137 (1) Excludes $ 23,844 in restructuring and other charges for the fiscal year ended September 29, 2017. (2) Years ending September 29, 2017 and September 30, 2016 include Restructuring and other charges of $1,233 and $277, respectively.
Schedule of Services Revenues for Reportable Segment	The following tables present total services revenues for each reportable segment for the three years ended September 29, 2017, September 30, 2016 and October 2, 2015 (in thousands): For the Year Ended September 29, 2017 Aerospace & Technology Buildings & Infrastructure Industrial Petroleum & Chemicals Total Technical Professional Services Revenues Project Services $ 960,374 $ 2,185,220 $ 196,171 $ 1,464,098 $ 4,805,863 Process, Scientific and Systems Consulting 774,063 — — 31,081 805,144 Total Technical Professional Services Revenues 1,734,437 2,185,220 196,171 1,495,179 5,611,007 Field Services Revenues Construction 250,956 254,118 1,901,299 967,888 3,374,261 Operations and Maintenance ("O&M") 375,220 12,983 646,192 3,125 1,037,520 Total Field Services Revenues 626,176 267,101 2,547,491 971,013 4,411,781 Total Revenues $ 2,360,613 $ 2,452,321 $ 2,743,662 $ 2,466,192 $ 10,022,788 For the Year Ended September 30, 2016 Aerospace & Technology Buildings & Infrastructure Industrial Petroleum & Chemicals Total Technical Professional Services Revenues Project Services $ 910,290 $ 2,094,282 $ 891,018 $ 1,843,250 $ 5,738,840 Process, Scientific and Systems Consulting 803,654 — — 48,675 852,329 Total Technical Professional Services Revenues 1,713,944 2,094,282 891,018 1,891,925 6,591,169 Field Services Revenues Construction 171,614 119,463 1,601,562 1,366,251 3,258,890 Operations and Maintenance ("O&M") 771,875 39,767 301,133 1,323 1,114,098 Total Field Services Revenues 943,489 159,230 1,902,695 1,367,574 4,372,988 Total Revenues $ 2,657,433 $ 2,253,512 $ 2,793,713 $ 3,259,499 $ 10,964,157
Financial Information by Geographic Area	The following table presents certain financial information by geographic area (in thousands): For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 Revenues: United States $ 5,822,843 $ 6,247,448 $ 7,154,433 Europe 2,262,092 2,346,224 2,074,837 Canada 590,604 927,942 1,065,651 Asia 253,167 299,952 304,393 India 165,295 187,929 163,871 Australia and New Zealand 628,945 436,670 611,271 South America and Mexico 73,456 125,610 143,014 Middle East and Africa 226,386 392,382 597,362 Total $ 10,022,788 $ 10,964,157 $ 12,114,832 Property, equipment and improvements, net: United States $ 220,416 $ 195,392 $ 208,155 Europe 46,108 37,163 55,713 Canada 18,435 21,464 36,647 Asia 2,793 3,069 3,859 India 19,191 13,350 16,264 Australia and New Zealand 18,692 18,888 24,460 South America and Mexico 4,619 5,621 9,127 Middle East and Africa 19,657 24,726 27,013 Total $ 349,911 $ 319,673 $ 381,238
Revenues Earned Directly or Indirectly from the U.S. Federal Government and its Agencies	The following table presents the revenues earned directly or indirectly from the U.S. federal government and its agencies, expressed as a percentage of total revenues: For the Years Ended September 29, 2017 September 30, 2016 October 2, 2015 19.2% 21.4% 21.7%

Selected Quarterly Informatio40

Selected Quarterly Information - Unaudited (Tables)	12 Months Ended
	Sep. 29, 2017
Selected Quarterly Financial Information [Abstract]
Schedule of Quarterly Financial Information	The following table presents selected quarterly financial information. (in thousands, except for per share amounts): First Quarter Second Quarter Third Quarter Fourth Quarter Fiscal Year September 29, 2017 Revenues $ 2,551,604 $ 2,302,567 (f) $ 2,514,751 (f) $ 2,653,866 $ 10,022,788 Operating profit (a) 88,628 68,173 (f) 128,475 (f) 106,993 392,269 Earnings before taxes 85,880 60,491 127,396 119,450 393,217 Net earnings of the Group 61,153 44,165 88,629 93,428 287,375 Net earnings attributable to Jacobs 60,536 (f) 50,018 (f) 89,032 (f) 94,141 (f)(g) 293,727 Earnings per share: Basic 0.50 (f) 0.41 (f) 0.74 (f) 0.78 (f)(g) 2.43 Diluted 0.50 (f) 0.41 (f) 0.74 (f) 0.78 (f)(g) 2.42 September 30, 2016 Revenues $ 2,847,934 $ 2,781,763 $ 2,693,873 $ 2,640,587 $ 10,964,157 Operating profit (a) 59,450 86,781 109,556 82,811 338,598 Earnings before taxes 57,787 90,456 102,807 35,673 286,723 Net earnings of the Group 50,306 63,389 70,937 29,883 214,515 Net earnings attributable to Jacobs 46,514 (b) 65,250 (b) 69,055 (b) 29,644 (b) 210,463 Earnings per share: Basic 0.38 (b) 0.54 (b) 0.58 (b) 0.25 (b) 1.75 Diluted 0.38 (b) 0.54 (b) 0.57 (b) 0.24 (b) 1.73 October 2, 2015 Revenues $ 3,187,005 $ 2,903,332 $ 2,907,541 $ 3,116,954 $ 12,114,832 Operating profit (a) 158,223 133,045 100,434 53,825 445,527 Earnings before taxes 154,695 128,962 97,188 49,292 430,137 Net earnings of the Group 106,195 88,110 97,308 37,269 328,882 Net earnings attributable to Jacobs 100,079 81,967 (c) 91,062 (c) 29,863 (c) 302,971 Earnings per share: Basic 0.78 0.65 (c) 0.74 (c) 0.25 (c) 2.42 Diluted 0.77 0.64 (c) 0.73 (c) 0.24 (c) 2.40 (a) Operating profit represents revenues less (i) direct costs of contracts, and (ii) selling, general and administrative expenses. (b) Includes costs of $48.1 million, or $0.39 per diluted share, in the first quarter of fiscal 2016, $25.7 million or $0.21 per diluted share in the second quarter of fiscal 2016, $25.8 million, or $0.21 per diluted share, in the third quarter, and $36.0 million or $0.3 per diluted share in the fourth quarter of fiscal 2016, in each case, related to the 2015 Restructuring. Also included in the fourth quarter of fiscal 2016 were $17.1 million, or $0.14 per diluted share related to the loss on sale of our French subsidiary; and $10.4 million, or $0.09 per diluted share related to the non-cash write-off on an equity investment. (c) Includes costs of $9.6 million, or $0.08 per diluted share, in the second quarter of fiscal 2015, $30.1 million or $0.24 per diluted share in the third quarter of fiscal 2015, and $68.2 million, or $0.56 per diluted share, in the fourth quarter of fiscal 2015, in each case, related to the 2015 Restructuring. (d) Includes costs of $47.0 million, or $0.35 per diluted share, in the third quarter of fiscal 2014, and $30.4 million, or $0.23 per diluted share, in the fourth quarter of fiscal 2014, in each case, related to the 2014 Restructuring. (e) Includes $6.4 million, or $0.05 per diluted share, increase to net earnings related to a gain on the sale of certain intellectual property in the second quarter of fiscal 2014. (f) Includes costs of $31.7 million, or $0.18 per diluted share, in the first quarter of fiscal 2017; includes $16.5 million in revenue, $72.2 million in operating profit, $45.2 million in net earnings attributable to Jacobs, or $0.37 per diluted share, in the second quarter of fiscal 2017; includes $1 million in revenue, $10.7 million in operating profit and $6.3 million in net earnings attributable to Jacobs, or $0.05 per diluted share, in the third quarter of fiscal 2017; includes $19.5 million in operating profit, $13.6 million in net earnings attributable to Jacobs, or $0.11 per diluted share, in the fourth quarter of fiscal 2017, in each case, related to restructuring and other charges. ( g ) Includes costs of $10.6 million, or $0.09 per diluted share, in the fourth quarter of fiscal 2017 related to professional fees and integration costs for the CH2M acquisition.

Description of Business and B41

Description of Business and Basis of Presentation (Revenues Realized from Each of These Types of Contracts) (Details) - Business	3 Months Ended	12 Months Ended
	Apr. 01, 2016	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Basis of Presentation [Line Items]
Cost-reimbursable		81.00%	82.00%	83.00%
Fixed-price		19.00%	18.00%	17.00%
Number of operating and reporting structure of business	4
Minimum
Basis of Presentation [Line Items]
Frequency of fiscal year with an additional week of activity (in years)		5 years
Maximum
Basis of Presentation [Line Items]
Frequency of fiscal year with an additional week of activity (in years)		6 years

Significant Accounting Polici42

Significant Accounting Policies (Pass-Through Costs Included in Revenues) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Accounting Policies [Abstract]
Pass-through costs included in revenues	$ 2,539.3	$ 2,489.9	$ 2,602.6

Significant Accounting Polici43

Significant Accounting Policies (Narrative) (Details)	3 Months Ended		12 Months Ended
	Dec. 30, 2016USD ($)	Apr. 01, 2016Business	Sep. 29, 2017USD ($)Planshares	Sep. 30, 2016USD ($)	Oct. 02, 2015USD ($)shares	May 19, 2017USD ($)
Significant Accounting Policies [Line Items]
Number of operating and reporting structure of business | Business		4
Goodwill, impairment during period			$ 0
Goodwill			3,009,826,000	$ 3,079,628,000
Overall foreign currency translation adjustment			140,527,000	$ 46,515,000	$ 136,168,000
Amortization of intangible assets year one			49,700,000
Amortization of intangible assets year two			48,300,000
Amortization of intangible assets year three			46,100,000
Amortization of intangible assets year four			40,900,000
Amortization of intangible assets year five			$ 39,500,000
Number of incentive plans | Plan			2
Number of stock options granted | shares			0
EPS Based Awards, maturity date			Nov. 19, 2018
EPS Based Awards, vesting date			Nov. 16, 2019
Saudi Arabia-based Joint Venture
Significant Accounting Policies [Line Items]
Date of joint venture agreement			May 19, 2017
Percentage of ownership interest in joint venture						50.00%
Initial capital contributions to joint venture						$ 6,500,000
Loan commitment to joint venture						7,000,000
Additional future loans commitments to joint venture						$ 7,000,000
Performance Shares
Significant Accounting Policies [Line Items]
Performance period for meeting certain performance targets			3 years
Earned Net Earnings Growth Based PSUs | Fiscal 2015
Significant Accounting Policies [Line Items]
Restricted Stock, unit basis rule, percent of target RSU			33.30%
Earned Net Earnings Growth Based PSUs | Fiscal 2016
Significant Accounting Policies [Line Items]
Restricted Stock, unit basis rule, percent of target RSU			66.70%
EPS Growth Rate | Fiscal 2016
Significant Accounting Policies [Line Items]
Restricted Stock, unit basis rule, percent of target RSU			33.30%
EPS Growth Rate | Fiscal 2017
Significant Accounting Policies [Line Items]
Restricted Stock, unit basis rule, percent of target RSU			66.70%
Earned Relative TSR Based PSUs
Significant Accounting Policies [Line Items]
Determination period			3 years
Total stockholder return, beginning stock price, number of calendar days average closing common stock price ending on award date			30 days
Total stockholder return, ending stock price, number of calendar days average closing price ending on last day of performance period			30 days
Number of stock units awarded | shares			0		0
EPS Growth Rate Restricted Stock Units 2017 Awards | Fiscal 2017
Significant Accounting Policies [Line Items]
Restricted Stock, unit basis rule, percent of target RSU			33.30%
EPS Growth Rate Restricted Stock Units 2017 Awards | Fiscal 2018
Significant Accounting Policies [Line Items]
Restricted Stock, unit basis rule, percent of target RSU			66.70%
ROIC Based PSUs | Between 8.9%
Significant Accounting Policies [Line Items]
EPS Growth rate, unit basis rule, ROIC threshold percent for multiplier to be determined using straight line Interpolation			8.90%
ROIC Based PSUs | Between 9.9%
Significant Accounting Policies [Line Items]
EPS Growth rate, unit basis rule, ROIC threshold percent for multiplier to be determined using straight line Interpolation			9.90%
ROIC Based PSUs | Between 10.9%
Significant Accounting Policies [Line Items]
EPS Growth rate, unit basis rule, ROIC threshold percent for multiplier to be determined using straight line Interpolation			10.90%
Goodwill Adjustment
Significant Accounting Policies [Line Items]
Overstatement adjustment of financial statements line item	$ 209,900,000
Accumulated Other Comprehensive Income Adjustment
Significant Accounting Policies [Line Items]
Overstatement adjustment of financial statements line item	$ 209,900,000
Other Comprehensive Income Adjustment
Significant Accounting Policies [Line Items]
Overstatement adjustment of financial statements line item			$ 33,800,000
Aquenta Consulting Pty Ltd. And Blue Canopy LLC [Member]
Significant Accounting Policies [Line Items]
Goodwill			$ 119,300,000
Minimum
Significant Accounting Policies [Line Items]
Percentage of fair value of each reporting unit in excess of book value			27.00%
Minimum | Earned Net Earnings Growth Based PSUs | Between 5% and 10%
Significant Accounting Policies [Line Items]
Earned Adjusted Net Earnings Growth Restricted Stock, unit basis rule, net earnings average growth threshold percent for multiplier to be determined using straight line Interpolation			5.00%
Minimum | Earned Net Earnings Growth Based PSUs | Between 10% and 15%
Significant Accounting Policies [Line Items]
Earned Adjusted Net Earnings Growth Restricted Stock, unit basis rule, net earnings average growth threshold percent for multiplier to be determined using straight line Interpolation			10.00%
Minimum | Earned Net Earnings Growth Based PSUs | Between 15% and 20%
Significant Accounting Policies [Line Items]
Earned Adjusted Net Earnings Growth Restricted Stock, unit basis rule, net earnings average growth threshold percent for multiplier to be determined using straight line Interpolation			15.00%
Minimum | EPS Growth Rate | Between 15% and 20%
Significant Accounting Policies [Line Items]
EPS Growth rate, unit basis rule, EPS threshold percent for multiplier to be determined using straight line Interpolation			15.00%
Minimum | EPS Growth Rate | Between 4% and 7.5%
Significant Accounting Policies [Line Items]
EPS Growth rate, unit basis rule, EPS threshold percent for multiplier to be determined using straight line Interpolation			4.00%
Minimum | EPS Growth Rate | Between 7.5% and 15%
Significant Accounting Policies [Line Items]
EPS Growth rate, unit basis rule, EPS threshold percent for multiplier to be determined using straight line Interpolation			7.50%
Minimum | Building
Significant Accounting Policies [Line Items]
Estimated useful life of assets			20 years
Minimum | Equipment
Significant Accounting Policies [Line Items]
Estimated useful life of assets			3 years
Minimum | Leasehold Improvements
Significant Accounting Policies [Line Items]
Estimated useful life of assets			4 years
Maximum
Significant Accounting Policies [Line Items]
Percentage of fair value of each reporting unit in excess of book value			110.00%
Maximum | Earned Net Earnings Growth Based PSUs | Between 5% and 10%
Significant Accounting Policies [Line Items]
Earned Adjusted Net Earnings Growth Restricted Stock, unit basis rule, net earnings average growth threshold percent for multiplier to be determined using straight line Interpolation			10.00%
Maximum | Earned Net Earnings Growth Based PSUs | Between 10% and 15%
Significant Accounting Policies [Line Items]
Earned Adjusted Net Earnings Growth Restricted Stock, unit basis rule, net earnings average growth threshold percent for multiplier to be determined using straight line Interpolation			15.00%
Maximum | Earned Net Earnings Growth Based PSUs | Between 15% and 20%
Significant Accounting Policies [Line Items]
Earned Adjusted Net Earnings Growth Restricted Stock, unit basis rule, net earnings average growth threshold percent for multiplier to be determined using straight line Interpolation			20.00%
Maximum | EPS Growth Rate | Between 15% and 20%
Significant Accounting Policies [Line Items]
EPS Growth rate, unit basis rule, EPS threshold percent for multiplier to be determined using straight line Interpolation			20.00%
Maximum | EPS Growth Rate | Between 4% and 7.5%
Significant Accounting Policies [Line Items]
EPS Growth rate, unit basis rule, EPS threshold percent for multiplier to be determined using straight line Interpolation			7.50%
Maximum | EPS Growth Rate | Between 7.5% and 15%
Significant Accounting Policies [Line Items]
EPS Growth rate, unit basis rule, EPS threshold percent for multiplier to be determined using straight line Interpolation			15.00%
Maximum | Building
Significant Accounting Policies [Line Items]
Estimated useful life of assets			40 years
Maximum | Equipment
Significant Accounting Policies [Line Items]
Estimated useful life of assets			10 years
Maximum | Leasehold Improvements
Significant Accounting Policies [Line Items]
Estimated useful life of assets			10 years

Significant Accounting Polici44

Significant Accounting Policies (Components of Goodwill by Reporting Units) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
Goodwill [Line Items]
Goodwill	$ 3,009,826	$ 3,079,628
Aerospace & Technology
Goodwill [Line Items]
Goodwill	1,025,780
Buildings & Infrastructure
Goodwill [Line Items]
Goodwill	751,407
Industrial
Goodwill [Line Items]
Goodwill	561,785
Petroleum & Chemicals
Goodwill [Line Items]
Goodwill	$ 670,854

Significant Accounting Polici45

Significant Accounting Policies (Schedule of Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets beginning balance	$ 336,922	$ 353,419	$ 440,192
Acquisitions	35,905	18,172	(5,307)
Amortization	(46,095)	(47,608)	(49,368)
Foreign currency translation	4,305	9,733	(35,517)
Acquired intangible assets ending balance	$ 332,920	336,922	353,419
Weighted Average Amortization Period (years)	8 years 3 months 19 days
Excluding Investment in AWE Management Ltd
Acquired Finite Lived Intangible Assets [Line Items]
Amortization	$ (44,212)	(44,402)	(45,949)
Customer Relationships, Contracts, and Backlog
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets beginning balance	307,637	329,341	408,041
Acquisitions	29,803	7,286	(4,315)
Foreign currency translation	3,707	9,605	(34,418)
Acquired intangible assets ending balance	$ 301,468	307,637	329,341
Weighted Average Amortization Period (years)	7 years 10 months 24 days
Customer Relationships, Contracts, and Backlog | Excluding Investment in AWE Management Ltd
Acquired Finite Lived Intangible Assets [Line Items]
Amortization	$ (39,679)	(38,595)	(39,967)
Developed Technology
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets beginning balance	14,311	15,845	17,378
Acquisitions	1,685
Acquired intangible assets ending balance	$ 14,462	14,311	15,845
Weighted Average Amortization Period (years)	7 years 8 months 12 days
Developed Technology | Excluding Investment in AWE Management Ltd
Acquired Finite Lived Intangible Assets [Line Items]
Amortization	$ (1,534)	(1,534)	(1,533)
Trade Names
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets beginning balance	4,786	7,599	14,148
Acquisitions	4,417	859	(1,292)
Foreign currency translation	45	147	(1,085)
Acquired intangible assets ending balance	$ 6,699	4,786	7,599
Weighted Average Amortization Period (years)	4 years 4 months 24 days
Trade Names | Excluding Investment in AWE Management Ltd
Acquired Finite Lived Intangible Assets [Line Items]
Amortization	$ (2,549)	(3,819)	(4,172)
Patents
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets beginning balance	10,027
Acquisitions		10,027
Foreign currency translation	553
Acquired intangible assets ending balance	$ 10,180	10,027
Weighted Average Amortization Period (years)	24 years
Patents | Excluding Investment in AWE Management Ltd
Acquired Finite Lived Intangible Assets [Line Items]
Amortization	$ (400)
Other
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets beginning balance	161	634	625
Acquisitions			300
Foreign currency translation		(19)	(14)
Acquired intangible assets ending balance	$ 111	161	634
Weighted Average Amortization Period (years)	2 years 2 months 13 days
Other | Excluding Investment in AWE Management Ltd
Acquired Finite Lived Intangible Assets [Line Items]
Amortization	$ (50)	$ (454)	$ (277)

Significant Accounting Polici46

Significant Accounting Policies (Stock-based Compensation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 38,764	$ 32,370	$ 41,412
Restricted Stock and Restricted Stock Units (excluding Market and Performance Awards)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	26,393	21,156	20,779
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	4,338	7,165	10,683
Market and Performance Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 8,033	$ 4,049	$ 9,950

Significant Accounting Polici47

Significant Accounting Policies (Fair Value Assumptions of Option Grant Date Award) (Details)	12 Months Ended
	Sep. 30, 2016	Oct. 02, 2015
Awards Made to Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	27.77%	27.00%
Risk-free interest rate	1.82%	1.67%
Expected term of options (in years)	5 years 9 months 26 days	5 years 9 months 26 days
Awards Made to Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	29.21%	29.28%
Risk-free interest rate	1.44%	1.63%
Expected term of options (in years)	5 years 9 months 26 days	5 years 9 months 26 days

Significant Accounting Polici48

Significant Accounting Policies (Basis to Determine Earned Net Earnings Growth Based PSUs) (Details) - Net Earnings Growth Based PSUs	12 Months Ended
	Sep. 29, 2017
Less than 5%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Earnings Growth Performance Multiplier	0.00%
5%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Earnings Growth Performance Multiplier	50.00%
10%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Earnings Growth Performance Multiplier	100.00%
15%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Earnings Growth Performance Multiplier	150.00%
20%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Earnings Growth Performance Multiplier	200.00%

Significant Accounting Polici49

Significant Accounting Policies (Basis to Determine EPS Performance Multiplier) (Details)	12 Months Ended
	Sep. 29, 2017
EPS Growth Rate | Less than 4%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	0.00%
EPS Growth Rate | 4%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	50.00%
EPS Growth Rate | 7.5%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	100.00%
EPS Growth Rate | 15%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	150.00%
EPS Growth Rate | 20% or Greater
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	200.00%
EPS Growth Rate Restricted Stock Units 2017 Awards from Fiscal 2016 to Fiscal 2017 | Less than 0%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	0.00%
EPS Growth Rate Restricted Stock Units 2017 Awards from Fiscal 2016 to Fiscal 2017 | 2.3%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	100.00%
EPS Growth Rate Restricted Stock Units 2017 Awards from Fiscal 2016 to Fiscal 2017 | 4.3%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	200.00%
EPS Growth Rate Restricted Stock Units 2017 Awards from Fiscal 2016 to Fiscal 2018 | Less than 2.1%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	0.00%
EPS Growth Rate Restricted Stock Units 2017 Awards from Fiscal 2016 to Fiscal 2018 | 2.3%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	100.00%
EPS Growth Rate Restricted Stock Units 2017 Awards from Fiscal 2016 to Fiscal 2018 | 4.3%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	200.00%
EPS Growth Rate Restricted Stock Units 2017 Awards from Fiscal 2016 to Fiscal 2019 | Less than 3.6%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	0.00%
EPS Growth Rate Restricted Stock Units 2017 Awards from Fiscal 2016 to Fiscal 2019 | 5.6%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	100.00%
EPS Growth Rate Restricted Stock Units 2017 Awards from Fiscal 2016 to Fiscal 2019 | 7.6%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
EPS Performance Multiplier	200.00%

Significant Accounting Polici50

Significant Accounting Policies (Basis to Determine Earned Relative TSR Based on PSU) (Details) - Earned Relative TSR Based PSUs	12 Months Ended
	Sep. 29, 2017
Below 30th percentile
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
TSR Performance Multiplier	0.00%
30th percentile
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
TSR Performance Multiplier	50.00%
50th percentile
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
TSR Performance Multiplier	100.00%
70th percentile or above
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
TSR Performance Multiplier	150.00%

Significant Accounting Polici51

Significant Accounting Policies (Fair Value Assumptions of Earned Relative TSR Based PSU) (Details) - Earned Relative TSR Based PSUs	12 Months Ended
	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	25.06%
Risk-free interest rate	1.21%
Expected term (in years)	3 years

Significant Accounting Polici52

Significant Accounting Policies (Basis to Determine Return on Invested Capital Based PSUs) (Details) - ROIC Based PSUs	12 Months Ended
	Sep. 29, 2017
Less than 8.9%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ROIC Performance Multiplier	0.00%
8.9%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ROIC Performance Multiplier	50.00%
9.9%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ROIC Performance Multiplier	100.00%
10.9%
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ROIC Performance Multiplier	200.00%

Employee Stock Purchase and S53

Employee Stock Purchase and Stock Option Plans (Stock Issuance Activity Under the 1989 ESPP and the GESPP) (Details) - USD ($)	Jan. 19, 2017	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Discount (percent) available to employees on the purchase of common stock		5.00%
Aggregate Purchase Price Paid for Shares Sold		$ 23,190,491	$ 26,291,308	$ 32,157,279
Aggregate Number of Shares Sold		443,300	627,657	781,214
Shares reserved for future Issuance (in shares)		10,181,183
Under the 1989 ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate Purchase Price Paid for Shares Sold		$ 21,084,657	$ 23,631,241	$ 28,621,800
Aggregate Number of Shares Sold		403,652	564,461	696,853
Increase in number of shares authorized	4,350,000
Shares reserved for future Issuance (in shares)		4,545,854
Under the GESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate Purchase Price Paid for Shares Sold		$ 2,105,834	$ 2,660,067	$ 3,535,479
Aggregate Number of Shares Sold		39,648	63,196	84,361
Increase in number of shares authorized	150,000
Shares reserved for future Issuance (in shares)		174,980

Employee Stock Purchase and S54

Employee Stock Purchase and Stock Option Plans (Stock Purchase and Stock Option Plans Information on the 1999 Plans) (Details) - shares	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	30,950,000
Number of remaining shares reserved for issuance at September 29, 2017	10,181,183
Number of shares relating to outstanding stock options at September 29, 2017	2,516,825
Number of shares available for future awards (in shares)	7,664,358	7,552,708
1999 SIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	29,850,000
Number of remaining shares reserved for issuance at September 29, 2017	9,641,396
Number of shares relating to outstanding stock options at September 29, 2017	2,289,450
Number of shares available for future awards (in shares)	7,351,946	7,233,173
1999 SIP | Stock Appreciation Rights (SARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award number of shares, non-fungible share basis (in shares)	1
1999 SIP | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award number of shares, non-fungible share basis (in shares)	1
1999 SIP | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award number of shares, fungible share basis (in shares)	1.92
Award number of shares, non-fungible share basis (in shares)	1
1999 SIP | Other than Option Stock Appreciation Rights (SARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award number of shares, fungible share basis (in shares)	1.92
1999 ODSP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	1,100,000
Number of remaining shares reserved for issuance at September 29, 2017	539,787
Number of shares relating to outstanding stock options at September 29, 2017	227,375
Number of shares available for future awards (in shares)	312,412	319,535
Award number of shares, non-fungible share basis (in shares)	1

Employee Stock Purchase and S55

Employee Stock Purchase and Stock Option Plans (Fair Value of Shares Vested) (Details) - Restricted Stock Units (RSUs) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of shares vested	$ 38,649	$ 21,817	$ 29,832
Service Condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of shares vested	34,466	17,481	18,568
Service, Market, And Performance Conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of shares vested	$ 4,183	$ 4,336	$ 11,264

Employee Stock Purchase and S56

Employee Stock Purchase and Stock Option Plans (Total Pre-Tax Compensation Cost Relating to Share-Based Payments Included in the Accompanying Consolidated Statements of Earnings) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-based compensation expense (pre-tax)	$ 38,764	$ 32,370	$ 41,412

Employee Stock Purchase and S57

Employee Stock Purchase and Stock Option Plans (Information Regarding Options Outstanding, and Options Exercisable) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015	Sep. 26, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Nonvested not yet recognized	$ 83.7
Options exercisable, weighted average remaining contractual term (in years)	4 years 9 months 19 days
Range of exercise prices, minimum (in dollars per share)	$ 32.51	$ 32.51	$ 32.51
Range of exercise prices, maximum (in dollars per share)	$ 80.63	$ 80.63	$ 80.63
Options outstanding number (in shares)	2,516,825	3,577,512	4,072,707	4,221,147
Options outstanding weighted average remaining contractual life (in years)	5 years 4 months 13 days
Options outstanding weighted average price (in dollars per share)	$ 46.19	$ 45.69	$ 46.06	$ 53.23
Options exercisable (in shares)	1,992,022
Options exercisable weighted average exercise price (in dollars per share)	$ 46.78
$32.51 - $37.03
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, minimum (in dollars per share)	32.51
Range of exercise prices, maximum (in dollars per share)	$ 37.03
Options outstanding number (in shares)	247,875
Options outstanding weighted average remaining contractual life (in years)	4 years 5 months 20 days
Options outstanding weighted average price (in dollars per share)	$ 36.99
Options exercisable (in shares)	247,875
Options exercisable weighted average exercise price (in dollars per share)	$ 36.99
$37.43 - $46.09
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, minimum (in dollars per share)	37.43
Range of exercise prices, maximum (in dollars per share)	$ 46.09
Options outstanding number (in shares)	1,360,188
Options outstanding weighted average remaining contractual life (in years)	5 years 7 months 17 days
Options outstanding weighted average price (in dollars per share)	$ 42.69
Options exercisable (in shares)	890,206
Options exercisable weighted average exercise price (in dollars per share)	$ 42.65
$47.11 - $55.13
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, minimum (in dollars per share)	47.11
Range of exercise prices, maximum (in dollars per share)	$ 55.13
Options outstanding number (in shares)	836,812
Options outstanding weighted average remaining contractual life (in years)	5 years 3 months 18 days
Options outstanding weighted average price (in dollars per share)	$ 52.81
Options exercisable (in shares)	788,116
Options exercisable weighted average exercise price (in dollars per share)	$ 52.80
$60.08 - $80.63
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, minimum (in dollars per share)	60.08
Range of exercise prices, maximum (in dollars per share)	$ 80.63
Options outstanding number (in shares)	71,950
Options outstanding weighted average remaining contractual life (in years)	4 years 2 months 23 days
Options outstanding weighted average price (in dollars per share)	$ 66.92
Options exercisable (in shares)	65,825
Options exercisable weighted average exercise price (in dollars per share)	$ 67.52

Employee Stock Purchase and S58

Employee Stock Purchase and Stock Option Plans (Stock Option Activity Under the 1999 Plans and the 1981 Plan) (Details) - $ / shares	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of stock options outstanding, beginning balance (in shares)	3,577,512	4,072,707	4,221,147
Number of stock options granted (in shares)		460,770	614,759
Number of stock options exercised (in shares)	(906,648)	(412,416)	(34,000)
Number of stock options cancelled or expired (in shares)	(154,039)	(543,549)	(729,199)
Number of stock options outstanding, ending balance (in shares)	2,516,825	3,577,512	4,072,707
Options outstanding weighted average price (in dollars per share)	$ 45.69	$ 46.06	$ 53.23
Weighted average exercise price options granted (in dollars per share)		42.17	43.56
Weighted average exercise price options exercised (in dollars per share)	43.79	40.88	31.54
Weighted average exercise price options cancelled or expired (in dollars per share)	48.79	49.13	86.15
Options outstanding weighted average price (in dollars per share)	$ 46.19	$ 45.69	$ 46.06

Employee Stock Purchase and S59

Employee Stock Purchase and Stock Option Plans (Total Intrinsic Value of Options Exercised) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Intrinsic value of stock options exercised	$ 14,713	$ 4,149	$ 442
Intrinsic value of options exercisable	$ 23,500

Employee Stock Purchase and S60

Employee Stock Purchase and Stock Option Plans (Information Regarding Stock Option Plans) (Details) - $ / shares	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
At fiscal year end:
Range of exercise prices for options outstanding, minimum (in dollars per share)	$ 32.51	$ 32.51	$ 32.51
Range of exercise prices for options outstanding, maximum (in dollars per share)	$ 80.63	$ 80.63	$ 80.63
Number of options exercisable	1,992,022	2,581,421	2,590,560
For the fiscal year:
Range of prices relating to options exercised, minimum (in dollars per share)	$ 37.03	$ 36.88	$ 25.87
Range of prices relating to options exercised, maximum (in dollars per share)	$ 55.53	55	42.74
Estimated weighted average fair values of options granted		$ 12.80	$ 13.41

Employee Stock Purchase and S61

Employee Stock Purchase and Stock Option Plans (Number of Shares of Restricted Stock and Restricted Stock Units Issued Under the 1999 Plans) (Details) - shares	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Stock Option Plans 1999 SIP | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units issued		597,091	507,882
Award number of shares, non-fungible share basis (in shares)	1
Restricted stock and restricted stock units cancelled	365,481	512,903	326,480
Award number of shares, fungible share basis (in shares)	1.92
Stock Option Plans 1999 SIP | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award number of shares, non-fungible share basis (in shares)	1
Award number of shares, fungible share basis (in shares)	1.92
Stock Option Plans 1999 SIP | Restricted stock, fungible
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units outstanding	950,593
Stock Option Plans 1999 SIP | Service Condition | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units issued	496,951	183,131	126,635
Restricted stock and restricted stock units cancelled	128,536	177,640	70,296
Stock Option Plans 1999 SIP | Service Condition | Restricted stock units, fungible
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units outstanding	766,759
Stock Option Plans 1999 SIP | Service, Market, And Performance Conditions | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units issued	237,058	372,794	219,965
Restricted stock and restricted stock units cancelled	86,742	275,933	194,116
Stock Option Plans 1999 SIP | Service, Market, And Performance Conditions | Restricted stock units, fungible
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units outstanding	672,440
Stock Option Plans 1999 ODSP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award number of shares, non-fungible share basis (in shares)	1
Stock Option Plans 1999 ODSP | Restricted stock, non fungible
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units outstanding	34,000
Stock Option Plans 1999 ODSP | Service Condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units issued	21,123	23,090	13,500
Stock Option Plans 1999 ODSP | Service Condition | Restricted stock units, non fungible
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units outstanding	90,595

Employee Stock Purchase and S62

Employee Stock Purchase and Stock Option Plans (Narrative) (Details) - Restricted Stock Units (RSUs) $ in Millions	Jan. 18, 2017USD ($)Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of employees affected due to modification | Employee	786
Incremental compensation cost due to modification | $	$ 1.1

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands	1 Months Ended	3 Months Ended												12 Months Ended
	Jul. 23, 2015	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Jan. 01, 2016	Oct. 02, 2015	Jun. 26, 2015	Mar. 27, 2015	Dec. 26, 2014	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Numerator for Basic and Diluted EPS:
Net income		$ 94,141,000	$ 89,032,000	$ 50,018,000	$ 60,536,000	$ 29,644,000	$ 69,055,000	$ 65,250,000	$ 46,514,000	$ 29,863,000	$ 91,062,000	$ 81,967,000	$ 100,079,000	$ 293,727,000	$ 210,463,000	$ 302,971,000
Net income allocated to participating securities														(3,077,000)
Net income allocated to common stock for EPS calculation														$ 290,650,000	$ 210,463,000	$ 302,971,000
Denominator for Basic and Diluted EPS:
Weighted average basic shares														119,370	120,133	125,007
Effect of dilutive securities:
Stock compensation plans														777	680	481
Restricted stock														1,319	670	622
Diluted shares														121,466	121,483	126,110
Shares allocated to participating securities														(1,319)
Shares used for calculating diluted EPS attributable to common stock														120,147	121,483	126,110
Basic EPS		$ 0.78	$ 0.74	$ 0.41	$ 0.50	$ 0.25	$ 0.58	$ 0.54	$ 0.38	$ 0.25	$ 0.74	$ 0.65	$ 0.78	$ 2.43	$ 1.75	$ 2.42
Diluted EPS		$ 0.78	$ 0.74	$ 0.41	$ 0.50	$ 0.24	$ 0.57	$ 0.54	$ 0.38	$ 0.24	$ 0.73	$ 0.64	$ 0.77	$ 2.42	$ 1.73	$ 2.40
Share Repurchases
Amount authorized to be repurchased	$ 500,000,000
Average cost per share repurchased ($ per share)	$ 55.60
Number of shares repurchased (in shares)	1,748

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) - USD ($)	Sep. 27, 2017	Jun. 30, 2017	Mar. 31, 2017	Jul. 23, 2015
Earnings Per Share Reconciliation [Abstract]
Amount authorized to be repurchased				$ 500,000,000
Quarterly dividend per share	$ 0.15	$ 0.15	$ 0.15
Dividends payment date	Nov. 10, 2017

Restructuring and Other Charg65

Restructuring and Other Charges - Summary of 2015 Restructuring Impacts on Reportable Segment Income by Line of Business (Details) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Jan. 01, 2016	Oct. 02, 2015	Jun. 26, 2015	Mar. 27, 2015	Sep. 26, 2014	Jun. 27, 2014	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015	Sep. 26, 2014
Restructuring Charges [Line Items]
Restructuring Charges	$ 36,000	$ 25,800	$ 25,700	$ 48,100	$ 68,200	$ 30,100	$ 9,600	$ 30,400	$ 47,000	$ 98,688	$ 187,907	$ 157,192	$ 93,300
Operating Segments | Aerospace & Technology
Restructuring Charges [Line Items]
Restructuring Charges										1,820	5,835
Operating Segments | Buildings & Infrastructure
Restructuring Charges [Line Items]
Restructuring Charges										23,675	23,378
Operating Segments | Industrial
Restructuring Charges [Line Items]
Restructuring Charges										6,698	29,690
Operating Segments | Petroleum & Chemicals
Restructuring Charges [Line Items]
Restructuring Charges										36,664	87,188
Corporate Non-Segment
Restructuring Charges [Line Items]
Restructuring Charges										$ 29,831	$ 41,816

Restructuring and Other Charg66

Restructuring and Other Charges (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended											12 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Jan. 01, 2016	Oct. 02, 2015	Jun. 26, 2015	Mar. 27, 2015	Sep. 26, 2014	Jun. 27, 2014	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015	Sep. 26, 2014
Restructuring And Related Activities [Abstract]
Restructuring Charges			$ 36,000	$ 25,800	$ 25,700	$ 48,100	$ 68,200	$ 30,100	$ 9,600	$ 30,400	$ 47,000	$ 98,688	$ 187,907	$ 157,192	$ 93,300
Restructuring pre-tax net charges		$ 22,600
Net realizable value write-offs on contract accounts receivables		16,500
Statutory redundancy and severance costs		1,400
Other liabilities		$ 4,700
Additional charges recorded under business exit	$ 1,200

Restructuring and Other Charg67

Restructuring and Other Charges - Schedule of 2015 Restructuring Activity (Details) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Jan. 01, 2016	Oct. 02, 2015	Jun. 26, 2015	Mar. 27, 2015	Sep. 26, 2014	Jun. 27, 2014	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015	Sep. 26, 2014
Restructuring And Related Activities [Abstract]
Balance at September 30, 2016										$ 152,174
Charges	$ 36,000	$ 25,800	$ 25,700	$ 48,100	$ 68,200	$ 30,100	$ 9,600	$ 30,400	$ 47,000	98,688	$ 187,907	$ 157,192	$ 93,300
Payments										(122,407)
Balance at September 29, 2017	$ 152,174									$ 128,455	$ 152,174

Restructuring and Other Charg68

Restructuring and Other Charges - Summary of Restructuring by Major Type of Restructuring Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Restructuring Charges [Line Items]
Restructuring costs	$ 98,688	$ 187,907	$ 157,192
Lease Abandonments
Restructuring Charges [Line Items]
Restructuring costs	55,647	92,643	90,569
Involuntary Terminations
Restructuring Charges [Line Items]
Restructuring costs	30,716	85,599	55,313
Outside Services
Restructuring Charges [Line Items]
Restructuring costs	4,236	7,398	12,734
Other Restructuring Related Costs, Net
Restructuring Charges [Line Items]
Restructuring costs	$ 8,089	$ 2,267	$ (1,424)

Restructuring and Other Charg69

Restructuring and Other Charges - Summary of Cumulative Amounts Incurred for 2015 Restructuring Costs (Details) $ in Thousands	Sep. 29, 2017USD ($)
Restructuring Charges [Line Items]
Cumulative Amount Incurred to Date	$ 443,787
Lease Abandonments
Restructuring Charges [Line Items]
Cumulative Amount Incurred to Date	238,859
Involuntary Terminations
Restructuring Charges [Line Items]
Cumulative Amount Incurred to Date	171,628
Outside Services
Restructuring Charges [Line Items]
Cumulative Amount Incurred to Date	24,368
Other Restructuring Related Costs, Net
Restructuring Charges [Line Items]
Cumulative Amount Incurred to Date	$ 8,932

Borrowings (Narrative) (Details

Borrowings (Narrative) (Details)	12 Months Ended
	Sep. 29, 2017USD ($)tranche	Sep. 28, 2017USD ($)	Sep. 30, 2016USD ($)	Feb. 07, 2014USD ($)
Line of Credit Facility [Line Items]
Total issued letters of credit	$ 262,100,000
Number of tranches in revolving credit facility (in tranches) | tranche	2
Minimum
Line of Credit Facility [Line Items]
Facility fee percentage	0.10%
Maximum
Line of Credit Facility [Line Items]
Facility fee percentage	0.25%
Revolving Credit Facility
Line of Credit Facility [Line Items]
Direct borrowings on credit facility	$ 235,000,000
Available borrowing capacity	1,363,000,000
Credit facility, maximum borrowing capacity	2,100,000,000
Letter of Credit
Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity	300,000,000
Direct borrowings on credit facility	$ 2,500,000
Eurocurrency Interest Rate | Minimum
Line of Credit Facility [Line Items]
Margin added to variable rate interest rate (percentage)	1.00%
Eurocurrency Interest Rate | Maximum
Line of Credit Facility [Line Items]
Margin added to variable rate interest rate (percentage)	1.50%
Base Interest Rate | Minimum
Line of Credit Facility [Line Items]
Margin added to variable rate interest rate (percentage)	0.00%
Base Interest Rate | Maximum
Line of Credit Facility [Line Items]
Margin added to variable rate interest rate (percentage)	0.50%
Sub Facility Of Swing Line Loans
Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity	$ 50,000,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity				$ 1,600,000,000
Revolving Credit Facility | Letter of Credit
Line of Credit Facility [Line Items]
Direct borrowings on credit facility	2,500,000
Committed And Uncommitted Letter Of Credit Facility | Letter of Credit
Line of Credit Facility [Line Items]
Direct borrowings on credit facility	$ 259,600,000
Term Loan Facility
Line of Credit Facility [Line Items]
Direct borrowings on credit facility		$ 1,500,000,000
Line of credit facility, expiration period	3 years
Term Loan Facility | Minimum
Line of Credit Facility [Line Items]
Percentage of unused commitments, ticking fee payment	0.10%
Term Loan Facility | Maximum
Line of Credit Facility [Line Items]
Percentage of unused commitments, ticking fee payment	0.25%
Term Loan Facility | Eurocurrency Interest Rate | Minimum
Line of Credit Facility [Line Items]
Margin added to variable rate interest rate (percentage)	1.00%
Term Loan Facility | Eurocurrency Interest Rate | Maximum
Line of Credit Facility [Line Items]
Margin added to variable rate interest rate (percentage)	1.50%
Term Loan Facility | Base Interest Rate | Minimum
Line of Credit Facility [Line Items]
Margin added to variable rate interest rate (percentage)	0.00%
Term Loan Facility | Base Interest Rate | Maximum
Line of Credit Facility [Line Items]
Margin added to variable rate interest rate (percentage)	0.50%
Other Loan Agreements
Line of Credit Facility [Line Items]
Overdrafts outstanding	$ 3,100,000
Short-term Debt			$ 2,400,000
Bank Overdrafts
Line of Credit Facility [Line Items]
Short-term debt interest rate (percent)	4.33%

Borrowings (Schedule of Long-Te

Borrowings (Schedule of Long-Term Revolving Credit Facility) (Details) - Revolving Credit Facility - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	$ 235,000
2012 Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	$ 235,000	$ 385,330
2012 Facility | Line of Credit | Minimum
Debt Instrument [Line Items]
Range of interest rates	1.00%	1.00%
2012 Facility | Line of Credit | Maximum
Debt Instrument [Line Items]
Range of interest rates	2.23%	1.65%

Borrowings (Schedule of Additio

Borrowings (Schedule of Additional Informational 2014 Facility) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016
Debt Disclosure [Abstract]
Maximum amount outstanding at any month-end during the fiscal year	$ 659,103	$ 958,460
Average amount outstanding during the year	$ 639,210	$ 825,641
Weighted average interest rate during the year	1.67%	1.39%

Borrowings (Schedule of Interes

Borrowings (Schedule of Interest Paid) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Debt Disclosure [Abstract]
Interest paid	$ 12,862	$ 13,282	$ 15,506

Pension and Other Postretirem74

Pension and Other Postretirement Pension Plans (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Sep. 29, 2017
Defined Benefit Plan Disclosure [Line Items]
Decrease of plan benefit obligation	$ 356.2
Decrease of plan assets	$ 229
Total Other Non-current Assets
Defined Benefit Plan Disclosure [Line Items]
Restricted investments		$ 7.7
Employee loans receivable		2.2
SG&A Expense
Defined Benefit Plan Disclosure [Line Items]
One-time, non-cash benefit		$ 9.9
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Period of annual average returns used in return on plan assets simulation model (in years)		20 years

Pension and Other Postretirem75

Pension and Other Postretirement Pension Plans (Schedule of Change in Plans' Combined Net Benefit Obligation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
U.S. Pension Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Net benefit obligation at the beginning of the year	$ 185,664	$ 533,665
Service cost	1,000	9,875	$ 12,045
Interest cost	5,757	16,746	20,629
Participants’ contributions		1,847
Actuarial (gains)/losses	(9,922)	29,129
Benefits paid	(14,338)	(14,143)
Curtailments/settlements		(35,224)
Transfers		(356,231)
Effect of exchange rate changes and other, net	1,781
Net benefit obligation at the end of the year	169,942	185,664	533,665
Non-U.S. Pension Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Net benefit obligation at the beginning of the year	1,363,782	1,155,592
Service cost	7,509	14,378	21,374
Interest cost	31,205	38,892	44,659
Participants’ contributions	250	2,255
Actuarial (gains)/losses	(142,273)	382,691
Benefits paid	(40,208)	(32,277)
Curtailments/settlements	(1,375)	(35,375)
Effect of exchange rate changes and other, net	87,917	(162,374)
Net benefit obligation at the end of the year	$ 1,306,807	$ 1,363,782	$ 1,155,592

Pension and Other Postretirem76

Pension and Other Postretirement Pension Plans (Schedule of Change in Combined Fair Value of the Plans' Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Oct. 02, 2016	Sep. 30, 2016
U.S. Pension Plans
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at the beginning of the year	$ 142,464	$ 379,907	$ 379,907
Actual return on plan assets	18,662		28,835
Employer contributions	1,000		10,213
Participants’ contributions			1,847
Gross benefits paid	(14,338)		(14,143)
Curtailments/settlements			(35,224)
Transfers			(228,971)
Fair value of plan assets at the end of the year	147,788		142,464
Non-U.S. Pension Plans
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at the beginning of the year	1,003,911	896,298	896,298
Actual return on plan assets	16,789	242,927
Employer contributions	21,005	23,217
Participants’ contributions	250	2,255
Gross benefits paid	(40,208)	(32,277)
Curtailments/settlements	(228)	(1,863)
Effect of exchange rate changes and other, net	75,409	(126,646)
Fair value of plan assets at the end of the year	$ 1,076,928	$ 1,003,911	$ 1,003,911

Pension and Other Postretirem77

Pension and Other Postretirement Pension Plans (Reconciliation of Combined Funded Status of Plans and Recognized in Consolidated Balance Sheet) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Oct. 02, 2016	Sep. 30, 2016
U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net benefit obligation at the end of the year	$ 169,942		$ 185,664
Fair value of plan assets at the end of the year	147,788		142,464
Under funded amount recognized at the end of the year	22,154		43,200
Non-U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net benefit obligation at the end of the year	1,306,807		1,363,782
Fair value of plan assets at the end of the year	1,076,928	$ 1,003,911	1,003,911
Under funded amount recognized at the end of the year	$ 229,879		$ 359,871

Pension and Other Postretirem78

Pension and Other Postretirement Pension Plans (Accumulated Benefit Obligation) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation at the end of the year	$ 169,942	$ 185,664
Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation at the end of the year	$ 1,291,600	$ 1,331,884

Pension and Other Postretirem79

Pension and Other Postretirement Pension Plans (Schedule of Amount Recognized in Accompanying Balance Sheets) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Prepaid benefit cost included in prepaid assets	$ 0	$ 0
Accrued benefit cost included in current liabilities	0	0
Accrued benefit cost included in noncurrent liabilities	22,154	43,200
Net amount recognized at the end of the year	22,154	43,200
Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Prepaid benefit cost included in prepaid assets	3,035	492
Accrued benefit cost included in current liabilities	585	608
Accrued benefit cost included in noncurrent liabilities	232,329	359,755
Net amount recognized at the end of the year	$ 229,879	$ 359,871

Pension and Other Postretirem80

Pension and Other Postretirement Pension Plans (Schedule of Significant Actuarial Assumptions in Determining the Funded Status and Benefit Cost) (Details)	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rates	3.50%	3.20%
Rates of compensation increases			3.00%
Expected long-term rates of return on assets	7.50%	7.40%	7.40%
U.S. Pension Plans | Minimum
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rates			3.90%
U.S. Pension Plans | Maximum
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rates			4.00%
Non-U.S. Pension Plans | Minimum
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rates	1.30%	0.70%	1.60%
Rates of compensation increases	2.50%	2.50%	2.40%
Expected long-term rates of return on assets	3.50%	3.50%	3.50%
Non-U.S. Pension Plans | Maximum
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rates	7.00%	7.00%	7.80%
Rates of compensation increases	7.50%	7.50%	7.50%
Expected long-term rates of return on assets	8.50%	8.50%	8.50%

Pension and Other Postretirem81

Pension and Other Postretirement Pension Plans (Schedule of Pension Plans Recognized in Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Reclassification adjustments:
Total	$ (99,047)	$ 98,185	$ (32,770)
U.S. Pension Plans
Arising during the period:
Net actuarial (gain) loss	(11,372)	4,337	12,237
Reclassification adjustments:
Net actuarial losses	(2,431)	(2,312)	(2,347)
Total	(13,803)	2,025	9,890
Non-U.S. Pension Plans
Arising during the period:
Net actuarial (gain) loss	(76,860)	102,925	(27,165)
Prior service cost (benefit)	119	580	(1,512)
Total	(76,741)	103,505	(28,677)
Reclassification adjustments:
Net actuarial losses	(8,732)	(7,508)	(14,034)
Prior service benefit	229	163	51
Total	(8,503)	(7,345)	(13,983)
Total	$ (85,244)	$ 96,160	$ (42,660)

Pension and Other Postretirem82

Pension and Other Postretirement Pension Plans (Schedule of Pension Plans Recorded in Accumulated Other Comprehensive Loss Not Yet Recognized as Component of Net Periodic Pension Cost) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial loss	$ 47,681	$ 61,483
Total	47,681	61,483
Non-U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial loss	218,752	304,345
Prior service cost	(855)	(1,203)
Total	$ 217,897	$ 303,142

Pension and Other Postretirem83

Pension and Other Postretirement Pension Plans (Schedule of Accumulated Comprehensive Income Amortized Against Earnings in the Next Year) (Details) $ in Thousands	Sep. 29, 2017USD ($)
U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Unrecognized net actuarial loss	$ 3,325
Accumulated comprehensive loss to be recorded against earnings	3,325
Non-U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Unrecognized net actuarial loss	6,829
Unrecognized prior service cost	(277)
Accumulated comprehensive loss to be recorded against earnings	$ 6,552

Pension and Other Postretirem84

Pension and Other Postretirement Pension Plans (Schedule of Weighted Average Measurement of Assets and Liabilities) (Details)	Sep. 29, 2017	Sep. 30, 2016
Equity securities | U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension plan asset allocations	70.00%	71.00%
Equity securities | Non-U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension plan asset allocations	24.00%	25.00%
Debt securities | U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension plan asset allocations	23.00%	20.00%
Debt securities | Non-U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension plan asset allocations	32.00%	32.00%
Real estate investments | U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension plan asset allocations		2.00%
Real estate investments | Non-U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension plan asset allocations	5.00%	6.00%
Other | U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension plan asset allocations	7.00%	7.00%
Other | Non-U.S. Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension plan asset allocations	39.00%	37.00%

Pension and Other Postretirem85

Pension and Other Postretirement Pension Plans (Schedule of Fair Value of Pension Plan Assets) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Oct. 02, 2016	Sep. 30, 2016	Oct. 02, 2015
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 147,788		$ 142,464	$ 379,907
U.S. Pension Plans | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	141,612		133,272
U.S. Pension Plans | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,176		9,192
U.S. Pension Plans | Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	103,760		85,494
U.S. Pension Plans | Domestic equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	103,760		85,494
U.S. Pension Plans | Overseas equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			15,169
U.S. Pension Plans | Overseas equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			15,169
U.S. Pension Plans | Domestic bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	33,404		28,886
U.S. Pension Plans | Domestic bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	33,404		28,886
U.S. Pension Plans | Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,448		3,723
U.S. Pension Plans | Cash and equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,448		3,723
U.S. Pension Plans | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			3,477
U.S. Pension Plans | Real estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			3,477	9,914
U.S. Pension Plans | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,176		5,715
U.S. Pension Plans | Hedge funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,176		5,715	16,372
Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,076,928	$ 1,003,911	1,003,911	896,298
Non-U.S. Pension Plans | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	639,872		636,256
Non-U.S. Pension Plans | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	437,056		367,655
Non-U.S. Pension Plans | Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	30,916		31,972
Non-U.S. Pension Plans | Domestic equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	30,916		31,972
Non-U.S. Pension Plans | Overseas equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	229,205		220,179
Non-U.S. Pension Plans | Overseas equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	229,205		220,179
Non-U.S. Pension Plans | Domestic bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	263,145		258,949
Non-U.S. Pension Plans | Domestic bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	263,145		258,949
Non-U.S. Pension Plans | Overseas bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	77,682		61,974
Non-U.S. Pension Plans | Overseas bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	77,682		61,974
Non-U.S. Pension Plans | Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	38,924		63,182
Non-U.S. Pension Plans | Cash and equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	38,924		63,182
Non-U.S. Pension Plans | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	58,974		55,665
Non-U.S. Pension Plans | Real estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	58,974		55,665	61,996
Non-U.S. Pension Plans | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	74,353		39,473
Non-U.S. Pension Plans | Insurance contracts | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	74,353		39,473	32,522
Non-U.S. Pension Plans | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			272,517
Non-U.S. Pension Plans | Hedge funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	303,729		$ 272,517	$ 260,720
Non-U.S. Pension Plans | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	303,729
Non-U.S. Pension Plans | Other | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 303,729

Pension and Other Postretirem86

Pension and Other Postretirement Pension Plans (Summary of Changes in the Fair Value of the Plans' Level 3 Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Oct. 02, 2016	Sep. 30, 2016
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	$ 142,464	$ 379,907	$ 379,907
Transfers			(228,971)
Fair value of plan assets at the end of the year	147,788		142,464
U.S. Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	9,192
Fair value of plan assets at the end of the year	6,176		9,192
U.S. Pension Plans | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	3,477
Fair value of plan assets at the end of the year			3,477
U.S. Pension Plans | Real estate | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	3,477	9,914	9,914
Purchases, sales, and settlements	(3,477)		(6,530)
Realized and unrealized gains (losses)			93
Fair value of plan assets at the end of the year			3,477
Purchases	(3,477)		(6,530)
U.S. Pension Plans | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	5,715
Fair value of plan assets at the end of the year	6,176		5,715
U.S. Pension Plans | Hedge funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	5,715	16,372	16,372
Purchases, sales, and settlements	(557)		(10,788)
Realized and unrealized gains (losses)	1,018		131
Fair value of plan assets at the end of the year	6,176		5,715
Purchases	(557)		(10,788)
Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	1,003,911	896,298	896,298
Effect of exchange rate changes	75,409	(126,646)
Fair value of plan assets at the end of the year	1,076,928	1,003,911	1,003,911
Non-U.S. Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	367,655
Fair value of plan assets at the end of the year	437,056		367,655
Non-U.S. Pension Plans | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	55,665
Fair value of plan assets at the end of the year	58,974		55,665
Non-U.S. Pension Plans | Real estate | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	55,665	61,996	61,996
Purchases, sales, and settlements	(1,199)		(462)
Realized and unrealized gains (losses)	2,642		2,572
Effect of exchange rate changes	1,866		(8,441)
Fair value of plan assets at the end of the year	58,974		55,665
Purchases	(1,199)		(462)
Non-U.S. Pension Plans | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	272,517
Fair value of plan assets at the end of the year			272,517
Non-U.S. Pension Plans | Hedge funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	272,517	260,720	260,720
Purchases, sales, and settlements	(9,022)		(1,205)
Realized and unrealized gains (losses)	19,662		57,656
Transfers	11,758
Effect of exchange rate changes	8,814		(44,654)
Fair value of plan assets at the end of the year	303,729		272,517
Purchases	(9,022)		(1,205)
Non-U.S. Pension Plans | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	39,473
Fair value of plan assets at the end of the year	74,353		39,473
Non-U.S. Pension Plans | Insurance contracts | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at the beginning of the year	39,473	$ 32,522	32,522
Purchases, sales, and settlements	422		(165)
Realized and unrealized gains (losses)	(7,572)		6,451
Transfers	40,031
Effect of exchange rate changes	1,999		665
Fair value of plan assets at the end of the year	74,353		39,473
Purchases	$ 422		$ (165)

Pension and Other Postretirem87

Pension and Other Postretirement Pension Plans (Anticipated Cash Contributions) (Details) $ in Thousands	12 Months Ended
	Sep. 29, 2017USD ($)
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Anticipated cash contributions	$ 1,300
Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Anticipated cash contributions	$ 22,574

Pension and Other Postretirem88

Pension and Other Postretirement Pension Plans (Schedule of Expected Payments to Participants in Pension Plan) (Details) $ in Thousands	Sep. 29, 2017USD ($)
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
2,018	$ 21,506
2,019	11,372
2,020	11,377
2,021	11,472
2,022	11,485
For the periods 2023 through 2027	54,747
Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
2,018	31,063
2,019	32,509
2,020	32,923
2,021	36,220
2,022	38,086
For the periods 2023 through 2027	$ 231,183

Pension and Other Postretirem89

Pension and Other Postretirement Pension Plans (Schedule of Components of Net Periodic Pension Cost Recognized) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Defined Benefit Plan Disclosure [Line Items]
Gain on benefit plan change	$ (9,955)
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,000	$ 9,875	$ 12,045
Interest cost	5,757	16,746	20,629
Expected return on plan assets	(9,942)	(22,368)	(29,526)
Gain on benefit plan change	3,985	7,512	3,756
Prior service cost		(176)	(239)
Net pension cost, before special items	800	11,589	6,665
Contractual expense/Settlement loss	1,781	8,061
Total net periodic pension cost recognized	2,581	19,650	6,665
Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	7,509	14,378	21,374
Interest cost	31,205	38,892	44,659
Expected return on plan assets	(56,269)	(50,190)	(53,052)
Gain on benefit plan change	10,616	9,092	17,398
Prior service cost	(329)	(260)	(96)
Net pension cost, before special items	(7,268)	11,912	30,283
Curtailments and settlements	(298)	(7,512)	255
Total net periodic pension cost recognized	$ (7,566)	$ 4,400	$ 30,538

Pension and Other Postretirem90

Pension and Other Postretirement Pension Plans (Schedule of Contribution to Multiemployer Pension Plans) (Details) - Multiemployer Plans, Pension - Multiemployer Plan, Individually Insignificant Multiemployer Plans - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Multiemployer Plans [Line Items]
Contributions to multiemployer pension plans	$ 45,942	$ 58,741	$ 59,445
Canada
Multiemployer Plans [Line Items]
Contributions to multiemployer pension plans	35,182	44,912	42,575
Europe and Australia
Multiemployer Plans [Line Items]
Contributions to multiemployer pension plans	6,212	8,771	10,902
United States
Multiemployer Plans [Line Items]
Contributions to multiemployer pension plans	$ 4,548	$ 5,058	$ 5,968

Other Comprehensive Income (Det

Other Comprehensive Income (Details) - Reclassification out of Accumulated Other Comprehensive Income - Accumulated Defined Benefit Plans Adjustment - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Amortization of Defined Benefit Items:
Actuarial losses	$ (14,601)	$ (12,880)	$ (21,153)
Prior service cost	328	260	96
Total Before Income Tax	(14,273)	(12,620)	(21,057)
Income Tax Benefit	3,339	2,963	4,727
Total reclassifications after-tax	$ (10,934)	$ (9,657)	$ (16,330)

Savings and Deferred Compensa92

Savings and Deferred Compensation Plans (Savings Plans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Savings And Deferred Compensation Plans [Abstract]
Savings plans contributions	$ 82,882	$ 89,966	$ 87,973

Savings and Deferred Compensa93

Savings and Deferred Compensation Plans (Deferred Compensation Plans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Savings And Deferred Compensation Plans [Abstract]
Deferred compensation plans expense	$ 4,368	$ 5,792	$ 5,536

Income Taxes (Consolidated Inco

Income Taxes (Consolidated Income Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Current income tax expense:
Federal	$ 29,297	$ 36,020	$ 72,840
State	8,535	11,336	16,248
Foreign	31,347	52,259	43,344
Total current tax expense	69,179	99,615	132,432
Deferred income tax expense (benefit):
Federal	29,390	6,439	13,337
State	3,407	485	2,295
Foreign	3,866	(34,331)	(46,809)
Total deferred tax expense (benefit)	36,663	(27,407)	(31,177)
Consolidated income tax expense	$ 105,842	$ 72,208	$ 101,255

Income Taxes (Components of Net

Income Taxes (Components of Net Deferred Tax Assets) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
Obligations relating to:
Defined benefit pension plans	$ 52,299	$ 77,834
Other employee benefit plans	192,299	179,063
Net Operating Losses	136,783	139,125
Self-insurance programs	489	1,722
Contract revenues and costs	(18,374)	(8,177)
Deferred Rent	25,654	7,955
Restructuring	18,258	47,792
Other	19,389	9,933
Valuation Allowance	(58,097)	(41,684)
Gross deferred tax assets	368,700	413,563
Deferred tax liabilities:
Depreciation and amortization	(176,327)	(154,939)
Other, net	(1,438)	(1,555)
Gross deferred tax liabilities	(177,765)	(156,494)
Net deferred tax assets	$ 190,935	$ 257,069

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015	Sep. 26, 2014
Income Tax Contingency [Line Items]
Valuation Allowance	$ 58,097	$ 41,684
Effective income tax rate reconciliation US Statutory rate	35.00%	35.00%	35.00%
Effective income tax rate (percent)	26.90%	25.20%	23.50%
Undistributed earnings of the Company's foreign subsidiaries expected to be reinvested	$ 26,100
Income tax payable upon repatriation of earnings	6,000
Gross unrecognized tax benefits	38,580	$ 44,167	$ 42,666	$ 41,923
Accrued interest and penalties	$ 36,600	36,400
Estimated period of unrecognized tax benefits (in months)	12 months
Earliest Tax Year
Income Tax Contingency [Line Items]
Income tax return years subject to examination	2,015
Foreign Country
Income Tax Contingency [Line Items]
Loss carry forwards of foreign subsidiaries	$ 490,900	$ 483,400
Gross unrecognized tax benefits	6,500
Foreign Country | Expiring Between 2018 and 2037
Income Tax Contingency [Line Items]
Loss carry forwards of foreign subsidiaries	117,100
Foreign Country | No Expiration Date
Income Tax Contingency [Line Items]
Loss carry forwards of foreign subsidiaries	$ 373,800

Income Taxes (Income Tax Benefi

Income Taxes (Income Tax Benefits Realized from the Exercise of Nonqualified Stock Options, and Disqualifying Dispositions of Stock Sold Under our Employee Stock Purchase Plans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Income Tax Disclosure [Abstract]
Income tax benefits realized under stock plans	$ 5,200	$ 1,500	$ 200

Income Taxes (Income Tax Expens

Income Taxes (Income Tax Expense In Consolidated Statements Of Earnings) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Income Tax Disclosure [Abstract]
Statutory amount	$ 137,626	$ 100,353	$ 150,548
State taxes, net of the federal benefit	8,955	7,853	12,857
Exclusion of tax on non-controlling interests	2,223	(1,418)	(9,069)
Foreign:
Difference in tax rates of foreign operations	(16,987)	(17,184)	(19,180)
Benefit from foreign valuation allowance release	(3,085)	(11,182)	(3,372)
Tax deductible foreign currency loss			(23,100)
U.K. tax rate change on deferred tax assets		8,853
Nontaxable income from foreign affiliate	(3,280)
U.S. tax cost of foreign operations	18,612	30,850	6,814
Tax differential on foreign earnings	(4,740)	11,337	(38,838)
Foreign tax credits	(20,454)	(44,018)	(21,313)
Uncertain tax positions	(5,779)	1,449	2,281
Other items:
IRS §179D deduction	(3,351)	(2,153)
IRS §199D deduction	(2,113)	(2,800)	(4,582)
Foreign partnership income/(loss)	(9,861)	(2,658)	11,858
Other items – net	3,336	4,263	(2,487)
Total other items	(11,989)	(3,348)	4,789
Consolidated income tax expense	$ 105,842	$ 72,208	$ 101,255
Statutory amount	35.00%	35.00%	35.00%
State taxes, net of the federal benefit	2.30%	2.70%	3.00%
Exclusion of tax on non-controlling interests	0.60%	(0.50%)	(2.10%)
Foreign:
Difference in tax rates of foreign operations	(4.30%)	(6.00%)	(4.50%)
Benefit from foreign valuation allowance release	(0.80%)	(3.90%)	(0.80%)
Tax deductible foreign currency loss	0.00%	0.00%	(5.40%)
U.K. tax rate change on deferred tax assets	0.00%	3.10%	0.00%
Nontaxable income from foreign affiliate	(0.80%)	0.00%	0.00%
U.S. tax cost of foreign operations	4.70%	10.90%	1.60%
Tax differential on foreign earnings	(1.20%)	4.10%	(9.00%)
Foreign tax credits	(5.20%)	(15.40%)	(5.00%)
Uncertain tax positions	(1.50%)	0.50%	0.50%
Other items:
IRS §179D deduction	(0.80%)	(0.80%)	0.00%
IRS §199D deduction	(0.50%)	(1.00%)	(1.10%)
Foreign partnership income/(loss)	(2.50%)	(0.90%)	2.80%
Other items – net	0.70%	1.50%	(0.60%)
Total other items	(3.10%)	(1.20%)	1.10%
Taxes on income	26.90%	25.20%	23.50%

Income Taxes (Income Tax Paymen

Income Taxes (Income Tax Payments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Income Tax Disclosure [Abstract]
Income tax payments	$ 78,390	$ 116,300	$ 156,500

Income Taxes (Components of our

Income Taxes (Components of our Consolidated Earnings Before Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Jan. 01, 2016	Oct. 02, 2015	Jun. 26, 2015	Mar. 27, 2015	Dec. 26, 2014	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Income Tax Examination [Line Items]
Results of operations, income before income taxes	$ 119,450	$ 127,396	$ 60,491	$ 85,880	$ 35,673	$ 102,807	$ 90,456	$ 57,787	$ 49,292	$ 97,188	$ 128,962	$ 154,695	$ 393,217	$ 286,723	$ 430,137
United States earnings
Income Tax Examination [Line Items]
Results of operations, income before income taxes													232,342	206,159	283,504
Foreign earnings
Income Tax Examination [Line Items]
Results of operations, income before income taxes													$ 160,875	$ 80,564	$ 146,633

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Balance, beginning of year	$ 44,167	$ 42,666	$ 41,923
Additions based on tax positions related to the current year	5,900	5,670	6,440
Additions for tax positions of prior years	237	367
Reductions for tax positions of prior years	(4,524)	(2,451)	(5,697)
Settlement	(7,200)	(2,085)
Balance, end of year	$ 38,580	$ 44,167	$ 42,666

Commitments And Contingencie102

Commitments And Contingencies, And Derivative Financial Instruments (Narrative) (Details) - USD ($) $ in Millions	Jul. 28, 2015	Sep. 29, 2017
Loss Contingencies [Line Items]
Net aggregate future lease payments		$ 753,102
Lease Term	10 years
Letters of credit outstanding		262.1
Standby Letters of Credit
Loss Contingencies [Line Items]
Letters of credit outstanding		262.1
Separate, Committed and Uncommitted Letter-of-Credit Facilities
Loss Contingencies [Line Items]
Line of credit facility, amount outstanding		259.6
Letter of Credit
Loss Contingencies [Line Items]
Line of credit facility, amount outstanding		2.5
Revolving Credit Facility, One Billion Six Hundred Million | Letter of Credit
Loss Contingencies [Line Items]
Line of credit facility, amount outstanding		$ 2.5

Commitments And Contingencie103

Commitments And Contingencies, And Derivative Financial Instruments (Commitments Under Operating Leases) (Details) $ in Thousands	Sep. 29, 2017USD ($)
Commitments And Contingencies And Derivative Financial Instruments [Abstract]
2,018	$ 139,967
2,019	133,609
2,020	118,207
2,021	97,062
2,022	104,990
Thereafter	174,269
Future minimum payments due	768,104
Amounts representing sublease income	(15,002)
Total, net aggregate future lease payments	$ 753,102

Commitments And Contingencie104

Commitments And Contingencies, And Derivative Financial Instruments (Rent Expense And Sublease Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Commitments And Contingencies And Derivative Financial Instruments [Abstract]
Rent expense	$ 145,344	$ 151,539	$ 175,067
Sublease income	(7,052)	(7,212)	(5,275)
Net rent	$ 138,292	$ 144,327	$ 169,792

Commitments And Contingencie105

Commitments And Contingencies, And Derivative Financial Instruments (Significant Terms Of The Lease) (Details) $ in Thousands	12 Months Ended
	Sep. 29, 2017USD ($)
Commitments And Contingencies And Derivative Financial Instruments [Abstract]
End of lease term	2,025
End of term purchase option (in thousands)	$ 76,950
Residual value guaranty (in thousands)	$ 62,412

Contractual Guarantees, Liti106

Contractual Guarantees, Litigation, Investigations, and Insurance (Narrative) (Details) $ in Millions	Dec. 29, 2016USD ($)	Sep. 30, 2015USD ($)	Aug. 20, 2015USD ($)	Aug. 09, 2014USD ($)	May 02, 2012USD ($)	Sep. 29, 2017insurer
Loss Contingencies [Line Items]
Minimum number of insurers with possible inability to fulfill insurance obligations | insurer						1
Litigation amount	$ 4.7
Motiva Enterprises LLC v. Bechtel-Jacobs CEP Port Arthur Joint Venture | Pending Litigation
Loss Contingencies [Line Items]
Damages sought				$ 8,000
Nui Phao Mining Company
Loss Contingencies [Line Items]
Damages sought		$ 167
Judicial Council Of California - Unpaid Fees
Loss Contingencies [Line Items]
Litigation amount					$ 4.7
Litigation contract amount			$ 4.7
Judicial Council Of California, Disgorged Fees
Loss Contingencies [Line Items]
Litigation amount					$ 18.3
Litigation contract amount			$ 18.3

Common and Preferred Stock (Det

Common and Preferred Stock (Details)	12 Months Ended
	Sep. 29, 2017class$ / shares	Sep. 30, 2016$ / shares
Class Of Stock Disclosures [Abstract]
Number of capital stock classes | class	2
Common stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, par value (in dollars per share)	$ 1	$ 1

Other Financial Information (Co

Other Financial Information (Components of Receivables) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
Components of receivables:
Amounts billed, net	$ 949,060	$ 1,110,042
Unbilled receivables and other	1,118,144	937,552
Retentions receivable	35,339	68,069
Total receivables, net	2,102,543	2,115,663
Other information about receivables:
Amounts due from the United States federal government included above, net of advanced billings	226,236	235,203
Claims receivable	$ 4,600	$ 26,061

Other Financial Information (Na

Other Financial Information (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016
Other Financial Information [Abstract]
Duration which unbilled amounts will be billed and collected over (duration)	12 months
Billed receivables collection period (in months)	12 months
Acquisition of business	$ 150.2	$ 49.9

Other Financial Information (Pr

Other Financial Information (Property, Equipment and Improvements, Net) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Property, Plant and Equipment [Line Items]
Property, equipment and improvements, gross	$ 979,714	$ 897,614
Accumulated depreciation and amortization	(629,803)	(577,941)
Property, equipment and improvements, net	349,911	319,673	$ 381,238
Land
Property, Plant and Equipment [Line Items]
Property, equipment and improvements, gross	17,197	16,680
Buildings
Property, Plant and Equipment [Line Items]
Property, equipment and improvements, gross	93,313	91,194
Equipment
Property, Plant and Equipment [Line Items]
Property, equipment and improvements, gross	627,609	531,539
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property, equipment and improvements, gross	220,295	221,437
Construction in progress
Property, Plant and Equipment [Line Items]
Property, equipment and improvements, gross	$ 21,300	$ 36,764

Other Financial Information (Mi

Other Financial Information (Miscellaneous Noncurrent Assets) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
Other Financial Information [Abstract]
Deferred income taxes	$ 368,700	$ 413,563
Cash surrender value of life insurance policies	130,411	122,364
Investments	145,069	178,256
Notes receivable	17,839	18,303
Other	30,003	26,843
Total	$ 692,022	$ 759,329

Other Financial Information 112

Other Financial Information (Components of Accrued Liabilities) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
Other Financial Information [Abstract]
Accrued payroll and related liabilities	$ 572,946	$ 561,652
Project-related accruals	71,815	102,400
Non project-related accruals	68,025	87,813
Insurance liabilities	67,546	54,984
Sales and other similar taxes	32,163	37,029
Deferred rent	60,593	69,059
Dividends payable	18,180
Other	48,419	25,441
Total	$ 939,687	$ 938,378

Other Financial Information 113

Other Financial Information (Components of Other Deferred Liabilities) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
Other Financial Information [Abstract]
Liabilities relating to defined benefit pension and early retirement plans	$ 254,483	$ 402,955
Liabilities relating to nonqualified deferred compensation Arrangements	114,616	123,926
Deferred income taxes	177,765	156,494
Miscellaneous	185,417	178,449
Total	$ 732,281	$ 861,824

Other Financial Information 114

Other Financial Information (Components of Total Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
Other Financial Information [Abstract]
Foreign currency translation adjustments	$ (386,131)	$ (245,603)
Adjustments relating to defined benefit pension plans	(265,578)	(364,625)
Other	(1,805)	(366)
Total	$ (653,514)	$ (610,594)

Other Financial Information (Su

Other Financial Information (Supplemental Cash Flow Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016
Other Financial Information [Abstract]
Working capital	$ 9,121	$ 10,023
Property and equipment	912	879
Noncurrent assets	35,976	8,192
Deferred liabilities	(273)
Goodwill	$ 104,454	$ 30,849

Segment Information (Narrative)

Segment Information (Narrative) (Details)	3 Months Ended
	Apr. 01, 2016Business
Segment Reporting [Abstract]
Number of operating and reporting structure of business	4

Segment Information - Schedule

Segment Information - Schedule of Total Revenues, Operating Profit and Total Asset for Reporting Segment (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Jan. 01, 2016	Oct. 02, 2015	Jun. 26, 2015	Mar. 27, 2015	Dec. 26, 2014	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Segment Reporting Information [Line Items]
Revenues from External Customers	$ 2,653,866	$ 2,514,751	$ 2,302,567	$ 2,551,604	$ 2,640,587	$ 2,693,873	$ 2,781,763	$ 2,847,934	$ 3,116,954	$ 2,907,541	$ 2,903,332	$ 3,187,005	$ 10,022,788	$ 10,964,157	$ 12,114,832
Total Operating Profit	106,993	$ 128,475	$ 68,173	88,628	$ 82,811	$ 109,556	$ 86,781	$ 59,450	$ 53,825	$ 100,434	$ 133,045	$ 158,223	392,269	338,598	445,527
Restructuring and Other Charges				$ (31,700)									(134,206)	(187,630)	(154,283)
Gain (Loss) on disposal of business and investments													10,880	(41,410)	(2,909)
Total Other Expense													(9,932)	(10,465)	(12,481)
Earnings Before Taxes													393,217	286,723	430,137
CH2M HILL Companies, Ltd.
Segment Reporting Information [Line Items]
CH2M Professional Fees and Integration Costs	$ (10,600)
Operating Segments
Segment Reporting Information [Line Items]
Total Operating Profit													625,170	586,328	615,549
Corporate Non-Segment
Segment Reporting Information [Line Items]
Other Corporate Items													(81,595)	(60,100)	(15,739)
Segment Reconciling Items | CH2M HILL Companies, Ltd.
Segment Reporting Information [Line Items]
CH2M Professional Fees and Integration Costs													(17,100)
Petroleum & Chemicals
Segment Reporting Information [Line Items]
Revenues from External Customers													2,466,192	3,259,499	4,214,129
Petroleum & Chemicals | Operating Segments
Segment Reporting Information [Line Items]
Total Operating Profit													113,858	126,604	138,351
Aerospace & Technology
Segment Reporting Information [Line Items]
Revenues from External Customers													2,360,613	2,657,433	2,924,753
Aerospace & Technology | Operating Segments
Segment Reporting Information [Line Items]
Total Operating Profit													202,595	203,808	205,368
Buildings & Infrastructure
Segment Reporting Information [Line Items]
Revenues from External Customers													2,452,321	2,253,512	2,458,379
Restructuring and Other Charges													(23,844)
Buildings & Infrastructure | Operating Segments
Segment Reporting Information [Line Items]
Total Operating Profit													193,455	174,648	145,299
Industrial
Segment Reporting Information [Line Items]
Revenues from External Customers													2,743,662	2,793,713	2,517,571
Industrial | Operating Segments
Segment Reporting Information [Line Items]
Total Operating Profit													$ 115,262	$ 81,268	$ 126,531

Segment Information - Schedu118

Segment Information - Schedule of Total Revenues, Operating Profit and Total Asset for Reporting Segment (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Segment Reporting Information [Line Items]
Restructuring and other charges	$ 31,700	$ 134,206	$ 187,630	$ 154,283
Other Expense
Segment Reporting Information [Line Items]
Restructuring and other charges		1,233	$ 277
Buildings & Infrastructure
Segment Reporting Information [Line Items]
Restructuring and other charges		$ 23,844

Segment Information - Schedu119

Segment Information - Schedule of Total Services Revenues for Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Jan. 01, 2016	Oct. 02, 2015	Jun. 26, 2015	Mar. 27, 2015	Dec. 26, 2014	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Segment Reporting Information [Line Items]
Revenues	$ 2,653,866	$ 2,514,751	$ 2,302,567	$ 2,551,604	$ 2,640,587	$ 2,693,873	$ 2,781,763	$ 2,847,934	$ 3,116,954	$ 2,907,541	$ 2,903,332	$ 3,187,005	$ 10,022,788	$ 10,964,157	$ 12,114,832
Aerospace & Technology
Segment Reporting Information [Line Items]
Revenues													2,360,613	2,657,433	2,924,753
Buildings & Infrastructure
Segment Reporting Information [Line Items]
Revenues													2,452,321	2,253,512	2,458,379
Industrial
Segment Reporting Information [Line Items]
Revenues													2,743,662	2,793,713	2,517,571
Petroleum & Chemicals
Segment Reporting Information [Line Items]
Revenues													2,466,192	3,259,499	$ 4,214,129
Project Services
Segment Reporting Information [Line Items]
Revenues													4,805,863	5,738,840
Project Services | Aerospace & Technology
Segment Reporting Information [Line Items]
Revenues													960,374	910,290
Project Services | Buildings & Infrastructure
Segment Reporting Information [Line Items]
Revenues													2,185,220	2,094,282
Project Services | Industrial
Segment Reporting Information [Line Items]
Revenues													196,171	891,018
Project Services | Petroleum & Chemicals
Segment Reporting Information [Line Items]
Revenues													1,464,098	1,843,250
Process, Scientific, and Systems Consulting
Segment Reporting Information [Line Items]
Revenues													805,144	852,329
Process, Scientific, and Systems Consulting | Aerospace & Technology
Segment Reporting Information [Line Items]
Revenues													774,063	803,654
Process, Scientific, and Systems Consulting | Petroleum & Chemicals
Segment Reporting Information [Line Items]
Revenues													31,081	48,675
Technical Professional Services
Segment Reporting Information [Line Items]
Revenues													5,611,007	6,591,169
Technical Professional Services | Aerospace & Technology
Segment Reporting Information [Line Items]
Revenues													1,734,437	1,713,944
Technical Professional Services | Buildings & Infrastructure
Segment Reporting Information [Line Items]
Revenues													2,185,220	2,094,282
Technical Professional Services | Industrial
Segment Reporting Information [Line Items]
Revenues													196,171	891,018
Technical Professional Services | Petroleum & Chemicals
Segment Reporting Information [Line Items]
Revenues													1,495,179	1,891,925
Construction
Segment Reporting Information [Line Items]
Revenues													3,374,261	3,258,890
Construction | Aerospace & Technology
Segment Reporting Information [Line Items]
Revenues													250,956	171,614
Construction | Buildings & Infrastructure
Segment Reporting Information [Line Items]
Revenues													254,118	119,463
Construction | Industrial
Segment Reporting Information [Line Items]
Revenues													1,901,299	1,601,562
Construction | Petroleum & Chemicals
Segment Reporting Information [Line Items]
Revenues													967,888	1,366,251
Operations and Maintenance ("O&M")
Segment Reporting Information [Line Items]
Revenues													1,037,520	1,114,098
Operations and Maintenance ("O&M") | Aerospace & Technology
Segment Reporting Information [Line Items]
Revenues													375,220	771,875
Operations and Maintenance ("O&M") | Buildings & Infrastructure
Segment Reporting Information [Line Items]
Revenues													12,983	39,767
Operations and Maintenance ("O&M") | Industrial
Segment Reporting Information [Line Items]
Revenues													646,192	301,133
Operations and Maintenance ("O&M") | Petroleum & Chemicals
Segment Reporting Information [Line Items]
Revenues													3,125	1,323
Field Services
Segment Reporting Information [Line Items]
Revenues													4,411,781	4,372,988
Field Services | Aerospace & Technology
Segment Reporting Information [Line Items]
Revenues													626,176	943,489
Field Services | Buildings & Infrastructure
Segment Reporting Information [Line Items]
Revenues													267,101	159,230
Field Services | Industrial
Segment Reporting Information [Line Items]
Revenues													2,547,491	1,902,695
Field Services | Petroleum & Chemicals
Segment Reporting Information [Line Items]
Revenues													$ 971,013	$ 1,367,574

Segment Information - Financial

Segment Information - Financial Information by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Jan. 01, 2016	Oct. 02, 2015	Jun. 26, 2015	Mar. 27, 2015	Dec. 26, 2014	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 2,653,866	$ 2,514,751	$ 2,302,567	$ 2,551,604	$ 2,640,587	$ 2,693,873	$ 2,781,763	$ 2,847,934	$ 3,116,954	$ 2,907,541	$ 2,903,332	$ 3,187,005	$ 10,022,788	$ 10,964,157	$ 12,114,832
Property, equipment and improvements, net	349,911				319,673				381,238				349,911	319,673	381,238
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues													5,822,843	6,247,448	7,154,433
Property, equipment and improvements, net	220,416				195,392				208,155				220,416	195,392	208,155
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues													2,262,092	2,346,224	2,074,837
Property, equipment and improvements, net	46,108				37,163				55,713				46,108	37,163	55,713
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues													590,604	927,942	1,065,651
Property, equipment and improvements, net	18,435				21,464				36,647				18,435	21,464	36,647
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues													253,167	299,952	304,393
Property, equipment and improvements, net	2,793				3,069				3,859				2,793	3,069	3,859
India
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues													165,295	187,929	163,871
Property, equipment and improvements, net	19,191				13,350				16,264				19,191	13,350	16,264
Australia and New Zealand
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues													628,945	436,670	611,271
Property, equipment and improvements, net	18,692				18,888				24,460				18,692	18,888	24,460
South America and Mexico
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues													73,456	125,610	143,014
Property, equipment and improvements, net	4,619				5,621				9,127				4,619	5,621	9,127
Middle East and Africa
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues													226,386	392,382	597,362
Property, equipment and improvements, net	$ 19,657				$ 24,726				$ 27,013				$ 19,657	$ 24,726	$ 27,013

Segment Information - Revenues

Segment Information - Revenues Earned Directly or Indirectly from the U.S. Federal Government and its Agencies (Details)	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Segment Reporting [Abstract]
Percentage of revenue earned from the U.S. federal government and its agencies	19.20%	21.40%	21.70%

Selected Quarterly Informati122

Selected Quarterly Information - Unaudited (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended															12 Months Ended
	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Jan. 01, 2016	Oct. 02, 2015	Jun. 26, 2015	Mar. 27, 2015	Dec. 26, 2014	Sep. 26, 2014	Jun. 27, 2014	Mar. 28, 2014	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015	Sep. 26, 2014
Selected Quarterly Financial Information [Line Items]
Revenues	$ 2,653,866	$ 2,514,751	$ 2,302,567	$ 2,551,604	$ 2,640,587	$ 2,693,873	$ 2,781,763	$ 2,847,934	$ 3,116,954	$ 2,907,541	$ 2,903,332	$ 3,187,005				$ 10,022,788	$ 10,964,157	$ 12,114,832
Operating profit	106,993	128,475	68,173	88,628	82,811	109,556	86,781	59,450	53,825	100,434	133,045	158,223				392,269	338,598	445,527
Earnings before taxes	119,450	127,396	60,491	85,880	35,673	102,807	90,456	57,787	49,292	97,188	128,962	154,695				393,217	286,723	430,137
Net Earnings of the Group	93,428	88,629	44,165	61,153	29,883	70,937	63,389	50,306	37,269	97,308	88,110	106,195				287,375	214,515	328,882
Net earnings attributable to Jacobs	$ 94,141	$ 89,032	$ 50,018	$ 60,536	$ 29,644	$ 69,055	$ 65,250	$ 46,514	$ 29,863	$ 91,062	$ 81,967	$ 100,079				$ 293,727	$ 210,463	$ 302,971
Earnings per share:
Basic (in dollars per share)	$ 0.78	$ 0.74	$ 0.41	$ 0.50	$ 0.25	$ 0.58	$ 0.54	$ 0.38	$ 0.25	$ 0.74	$ 0.65	$ 0.78				$ 2.43	$ 1.75	$ 2.42
Diluted (in dollars per share)	0.78	0.74	0.41	$ 0.50	$ 0.24	$ 0.57	$ 0.54	$ 0.38	$ 0.24	$ 0.73	$ 0.64	$ 0.77				$ 2.42	$ 1.73	$ 2.40
Restructuring Charges					$ 36,000	$ 25,800	$ 25,700	$ 48,100	$ 68,200	$ 30,100	$ 9,600		$ 30,400	$ 47,000		$ 98,688	$ 187,907	$ 157,192	$ 93,300
Effect of restructuring charge on earnings per diluted share (in dollars per share)					$ (0.3)	$ (0.21)	$ (0.21)	$ (0.39)	$ (0.56)	$ (0.24)	$ (0.08)		$ (0.23)	$ (0.35)
Restructuring and other charges				$ 31,700												$ 134,206	$ 187,630	$ 154,283
Effect of restructuring and other charges on earnings per diluted share (in dollars per share)	$ 0.11	$ 0.05	$ 0.37	$ 0.18
CH2M Acquisition
Earnings per share:
Professional fees and integration costs	$ 10,600
Effect of professional fees and integration costs on earnings per diluted share (in dollars per share)	$ 0.09
Intellectual Property
Earnings per share:
Gain after tax on sale of intellectual property per diluted share (in dollars per share)															$ 0.05
Gain on sale of intellectual property															$ 6,400
Loss on Sale of Subsidiary [Member]
Earnings per share:
Restructuring Charges					$ 17,100
Effect of restructuring charge on earnings per diluted share (in dollars per share)					$ 0.14
Revenue
Earnings per share:
Restructuring and other charges			$ 1,000	$ 16,500
Operating Profit
Earnings per share:
Restructuring and other charges		$ 19,500	10,700	72,200
Net Earnings Attributable to Jacobs
Earnings per share:
Restructuring and other charges		$ 13,600	$ 6,300	$ 45,200
Non-Cash Write-Off on Equity Investment [Member]
Earnings per share:
Restructuring Charges					$ 10,400
Effect of restructuring charge on earnings per diluted share (in dollars per share)					$ 0.09

Definitions (Details)

Definitions (Details) $ in Thousands	3 Months Ended									12 Months Ended
	Sep. 30, 2016USD ($)	Jul. 01, 2016USD ($)	Apr. 01, 2016USD ($)	Jan. 01, 2016USD ($)	Oct. 02, 2015USD ($)	Jun. 26, 2015USD ($)	Mar. 27, 2015USD ($)	Sep. 26, 2014USD ($)	Jun. 27, 2014USD ($)	Sep. 29, 2017USD ($)quarter	Sep. 30, 2016USD ($)	Oct. 02, 2015USD ($)	Sep. 26, 2014USD ($)
Definitions [Abstract]
Restructuring Charges | $	$ 36,000	$ 25,800	$ 25,700	$ 48,100	$ 68,200	$ 30,100	$ 9,600	$ 30,400	$ 47,000	$ 98,688	$ 187,907	$ 157,192	$ 93,300
Number of consecutive fiscal quarters included In consolidated leverage ratio calculation | quarter										4