Jacobs Engineering (J) 10-K 22 Nov 13 2013 FY Annual report Financial data

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Sep. 27, 2013	Nov. 14, 2013	Mar. 28, 2013
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	27-Sep-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Trading Symbol	'jec	'	'
Entity Registrant Name	'JACOBS ENGINEERING GROUP INC /DE/	'	'
Entity Central Index Key	'0000052988	'	'
Current Fiscal Year End Date	'--09-27	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	131,713,475	'
Entity Public Float	'	'	$7.40
Entity Current Reporting Status	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 27, 2013	Sep. 28, 2012
In Thousands, unless otherwise specified
Current Assets:	'	'
Cash and cash equivalents	$1,256,405	$1,032,457
Receivables	2,548,990	2,348,892
Deferred income taxes	131,086	142,369
Prepaid expenses and other current assets	103,077	88,359
Total current assets	4,039,558	3,612,077
Property, Equipment, and Improvements, Net	379,296	331,131
Other Noncurrent Assets:	'	'
Goodwill	2,022,831	2,010,340
Miscellaneous	832,459	885,885
Total other noncurrent assets	2,855,290	2,896,225
Assets, Total	7,274,144	6,839,433
Current Liabilities:	'	'
Notes payable	22,783	0
Accounts payable	457,893	376,694
Accrued liabilities	1,029,816	1,061,969
Billings in excess of costs	345,097	263,275
Income taxes payable	32,030	45,114
Total current liabilities	1,887,619	1,747,052
Long-term Debt	415,086	528,260
Other Deferred Liabilities	723,104	796,338
Redeemable Noncontrolling Interest	0	8,894
Commitments and Contingencies	'	'
Capital stock:	'	'
Preferred stock, $1 par value, authorized—1,000,000 shares; issued and outstanding—none	0	0
Common stock, $1 par value, authorized—240,000,000 shares; issued and outstanding—131,639,196 shares and 129,935,881 shares, respectively	131,639	129,936
Additional paid-in capital	1,084,624	953,983
Retained earnings	3,300,961	2,920,441
Accumulated other comprehensive loss	-304,127	-281,887
Total Jacobs stockholders’ equity	4,213,097	3,722,473
Noncontrolling interests	35,238	36,416
Total Group stockholders’ equity	4,248,335	3,758,889
Liabilities and Stockholders' Equity, Total	$7,274,144	$6,839,433

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 27, 2013	Sep. 28, 2012
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)	131,639,196	129,935,881
Common stock, outstanding (in shares)	131,639,196	129,935,881

Consolidated_Statements_Of_Ear

Consolidated Statements Of Earnings (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 27, 2013		Sep. 28, 2012		Sep. 30, 2011
Income Statement [Abstract]	'		'		'
Revenues	$11,818,376		$10,893,778		$10,381,664
Costs and Expenses:	'		'		'
Direct costs of contracts	-9,976,057		-9,166,789		-8,822,171
Selling, general and administrative expenses	-1,173,340		-1,130,916		-1,040,575
Operating Profit	668,979	[1]	596,073	[1]	518,918	[1]
Other (Expense) Income:	'		'		'
Interest income	5,395		6,049		4,917
Interest expense	-12,906		-11,686		-8,799
Gain on sale of intellectual property, net	0		6,292		0
Miscellaneous income (expense), net	80		-3,392		1,625
Total other expense, net	-7,431		-2,737		-2,257
Earnings Before Taxes	661,548		593,336		516,661
Income Tax Expense	-221,366		-202,382		-181,440
Net Earnings of the Group	440,182		390,954		335,221
Net Earnings Attributable to Noncontrolling Interests	-17,089		-12,000		-4,192
Net Earnings Attributable to Jacobs	$423,093		$378,954	[2]	$331,029
Net Earnings Per Share:	'		'		'
Basic (in dollars per share)	$3.27		$2.97	[2]	$2.63
Diluted (in dollars per share)	$3.23		$2.94	[2]	$2.60
[1]	Operating profit represents revenues less (i) direct costs of contracts, and (ii) selling, general and administrative expenses.
[2]	Includes a one-time, after-tax gain of $4.0 million, or $0.03 per diluted share, related to the sale of the Company's intellectual property for iron ore pelletizing and certain other related assets.

Consolidated_Statements_Of_Com

Consolidated Statements Of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Statement of Comprehensive Income [Abstract]	'	'	'
Net Earnings of the Group	$440,182	$390,954	$335,221
Other Comprehensive (Loss) Income:	'	'	'
Foreign currency translation adjustments	-23,704	30,038	-22,524
Change in pension liability	4,496	-100,385	99,881
Gains (losses) on cash flow hedges	1,467	3,567	137
Other Comprehensive (Loss) Income Before Income Taxes	-17,741	-66,780	77,494
Income Tax Benefit (Expense):	'	'	'
Foreign currency translation adjustments	0	-750	-2,500
Change in pension liability	-3,949	24,443	-26,707
Gains (losses) on cash flow hedges	-550	-1,262	-84
Total Income Tax Benefit (Expense)	-4,499	22,431	-29,291
Net Other Comprehensive Income (Loss)	-22,240	-44,349	48,203
Net Comprehensive Income of the Group	417,942	346,605	383,424
Net Comprehensive Income Attributable to Noncontrolling Interests	-17,089	-12,000	-4,192
Total Comprehensive Income Attributable to Jacobs	$400,853	$334,605	$379,232

Consolidated_Statements_Of_Sto

Consolidated Statements Of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total Jacobs Stockholders' Equity [Member]	Non-controlling Interests [Member]
In Thousands, unless otherwise specified
Balances at Oct. 01, 2010	$2,864,928	$125,909	$767,514	$2,251,366	($285,741)	$2,859,048	$5,880
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net earnings	335,221	'	'	331,029	'	331,029	4,192
Foreign currency translation adjustments	-25,024	'	'	'	-25,024	-25,024	'
Pension liability, net of deferred tax	73,174	'	'	'	73,174	73,174	'
Gain on derivatives, net of deferred tax expense	53	'	'	'	53	53	'
Noncontrolling interest acquired / consolidated	4,942	'	'	'	'	'	4,942
Distributions to noncontrolling interests	-4,617	'	'	'	'	'	-4,617
Issuances of equity securities, net	98,292	2,282	96,010	'	'	98,292	'
Repurchases of equity securities	-23,584	-406	-5,064	-18,114	'	-23,584	'
Balances at Sep. 30, 2011	3,323,385	127,785	858,460	2,564,281	-237,538	3,312,988	10,397
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net earnings	390,954	'	'	378,954	'	378,954	12,000
Foreign currency translation adjustments	29,288	'	'	'	29,288	29,288	'
Pension liability, net of deferred tax	-75,942	'	'	'	-75,942	-75,942	'
Gain on derivatives, net of deferred tax expense	2,305	'	'	'	2,305	2,305	'
Noncontrolling interest acquired / consolidated	11,557	'	'	-3,971	'	-3,971	15,528
Distributions to noncontrolling interests	-5,376	'	'	'	'	'	-5,376
Contributions from noncontrolling interests	3,867	'	'	'	'	'	3,867
Issuances of equity securities, net	109,200	2,706	106,494	'	'	109,200	'
Repurchases of equity securities	-30,349	-555	-10,971	-18,823	'	-30,349	'
Balances at Sep. 28, 2012	3,758,889	129,936	953,983	2,920,441	-281,887	3,722,473	36,416
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net earnings	440,182	'	'	423,093	'	423,093	17,089
Foreign currency translation adjustments	-23,704	'	'	'	-23,704	-23,704	'
Pension liability, net of deferred tax	547	'	'	'	547	547	'
Gain on derivatives, net of deferred tax expense	917	'	'	'	917	917	'
Noncontrolling interest acquired / consolidated	794	'	11,087	'	'	11,087	-10,293
Distributions to noncontrolling interests	-7,974	'	'	'	'	'	-7,974
Issuances of equity securities, net	140,456	2,864	137,592	'	'	140,456	'
Repurchases of equity securities	-61,772	-1,161	-18,038	-42,573	'	-61,772	'
Balances at Sep. 27, 2013	$4,248,335	$131,639	$1,084,624	$3,300,961	($304,127)	$4,213,097	$35,238

Consolidated_Statements_Of_Sto1

Consolidated Statements Of Stockholders' Equity (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Statement of Stockholders' Equity [Abstract]	'	'	'
Deferred tax expense, Foreign currency translation adjustments	$0	($750)	($2,500)
Deferred tax benefit (expense), pension liability	-3,949	24,443	-26,707
Deferred tax expense, gain (loss) on derivatives	-550	-1,262	-84
Stock Issued During Period, Deferred Income Tax Expense (Benefit)	($3,111)	$4,074	$6,961

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Cash Flows from Operating Activities:	'	'	'
Net earnings attributable to the Group	$440,182	$390,954	$335,221
Depreciation and amortization:	'	'	'
Property, equipment and improvements	69,889	58,890	57,620
Intangible assets	28,985	41,934	37,750
Purchase accounting gain	0	0	-3,716
Gain on sale of intellectual property	0	-6,292	0
Stock based compensation	39,518	32,442	29,084
Tax deficiency (benefit) from stock based compensation	3,213	-3,957	-6,837
Equity in earnings of investees	-59,300	-63,690	-55,528
Dividends received from earnings of investees	45,160	54,710	46,799
Change in pension plan obligations	-8,714	-28,351	-27,150
Change in deferred compensation plans	-8,915	-5,474	0
(Gains) Losses on sales of assets, net	519	811	-481
Changes in assets and liabilities, excluding the effects of businesses acquired:	'	'	'
Receivables	-234,864	-227,123	-234,024
Prepaid expenses and other current assets	-15,898	-19,265	-14,604
Accounts payable	82,389	10,673	-15,997
Accrued liabilities	-18,214	80,806	41,529
Billings in excess of costs	84,043	-15,626	13,304
Income taxes payable	-5,676	10,015	26,387
Deferred income taxes	-4,358	-1,036	15,853
Other deferred liabilities	-2,199	-4,764	-1,218
Change in long-term receivables	15,815	0	0
Other, net	-3,059	-5,852	-7,502
Net cash provided by operating activities	448,516	299,805	236,490
Cash Flows from Investing Activities:	'	'	'
Additions to property and equipment	-127,270	-102,574	-98,749
Disposals of property and equipment	4,276	319	3,860
Change in cash related to consolidation of joint ventures	5,344	0	0
Purchases of investments	-15	-38	-193
Sales of investments	11	15	4,667
Sale of intellectual property	0	12,726	0
Acquisitions of businesses, net of cash acquired	-39,429	-91,575	-711,421
Net cash used for investing activities	-157,083	-181,127	-801,836
Cash Flows from Financing Activities:	'	'	'
Proceeds from long-term borrowings	0	528,673	825,681
Repayments of long-term borrowings	-118,293	-98	-239,189
Proceeds from short-term borrowings	59,094	2,586	77,055
Repayments of short-term borrowings	-35,400	-579,901	-159,394
Proceeds from issuances of common stock	46,079	43,568	45,943
Tax (deficiency) benefit from stock based compensation	-3,213	3,956	6,837
Distributions to noncontrolling interests	-7,974	-5,376	0
Contributions from noncontrolling interests	0	3,868	0
Net cash (used for) provided by financing activities	-59,707	-2,724	556,933
Effect of Exchange Rate Changes	-7,778	10,870	-24,796
Increase (Decrease) in Cash and Cash Equivalents	223,948	126,824	-33,209
Cash and Cash Equivalents at Beginning of Period	1,032,457	905,633	938,842
Cash and Cash Equivalents at End of Period	$1,256,405	$1,032,457	$905,633

Description_Of_Business_And_Ba

Description Of Business And Basis Of Presentation	12 Months Ended
	Sep. 27, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Description Of Business And Basis Of Presentation	'
	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 each of the last three fiscal years was as follows:
		2013		2012		2011
	Cost-reimbursable	85	%	85	%	84	%
	Fixed-price	15	%	15	%	16	%
	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 significant 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.
	Please refer to Note 16—Definitions for the definitions of certain terms used in the accompanying Consolidated Financial Statements and these Notes to Consolidated Financial Statements.

Significant_Accounting_Policie

Significant Accounting Policies	12 Months Ended
	Sep. 27, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Significant Accounting Policies	'
	Significant Accounting Policies
	Revenue Accounting for Contracts and Use of Joint Ventures
	In general, we recognize revenues at the time we provide services. Depending on the commercial terms of the contract, we recognize revenues either when costs are incurred, or using the percentage-of-completion method of accounting by relating contract costs incurred to date to the total estimated costs at completion. Contract losses are provided for in their entirety in the period they become known, without regard to the percentage-of-completion. For multiple contracts with a single customer we account for each contract separately. We also recognize as revenues costs associated with claims and unapproved change orders to the extent it is probable that such claims and change orders will result in additional contract revenue, and the amount of such additional revenue can be reliably estimated.
	Certain cost-reimbursable contracts include incentive-fee arrangements. The incentive fees in such contracts 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 for each of the last three fiscal years (in millions):
	2013				2012				2011
	$	2,624.80			$	2,328.40			$	2,118.50
	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. Our joint ventures, therefore, are simply mechanisms used to deliver engineering and construction services to clients. Rarely do they, in and of themselves, present any risk of loss to us or to our partners separate from those that we would carry if we were performing the contract on our own. Under U.S. GAAP, our share of losses associated with the contracts held by the joint ventures, if and when they occur, has always been 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.
	For the Company’s unconsolidated joint ventures, we use either the equity method of accounting or proportional consolidation. The Company does not currently participate in any significant VIEs in which it has a controlling financial interest that it does not consolidate.
	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 10 —Commitments and Contingencies, and Derivative Financial Instruments are required to be carried in our Consolidated Financial Statements at Fair Value.
	The Fair Value of the Company’s reporting units (needed for purposes of determining whether there is an indication of possible impairment of the carrying value of goodwill) was determined in fiscal year 2011 using a market approach that multiplies the after-tax earnings of each reporting unit for the trailing twelve months by the Company’s overall average market earnings multiple. For fiscal years 2012 and 2013, we used both an income approach and a market approach to test our goodwill for possible impairment. Such approaches require us to make 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 value (both end of the range) for each reporting unit, exceeded the respective book values by more than 60%.
	With respect to 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 highly 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 drastically different Fair Values to be assigned to our stock option awards. For restricted stock units containing service and market conditions, compensation expense is based on the Fair Value of such units using a Monte Carlo simulation. Due to the uncertainties inherent in the use of assumptions and the results of applying Monte Carlo simulations, the amount of expense recorded in the accompanying consolidated financial statements may not be representative of the effects on our future consolidated financial statements because equity awards tend to vest over several years and additional equity awards may be made in the future.
	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 of the plans. 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. They are valued using the best information available, including quoted market prices or market prices for similar assets when available or internal cash flow estimates discounted at an appropriate interest rate or independent appraisals, as appropriate. Insurance contracts, investments in infrastructure/raw goods, and hedge funds are valued using actuarial assumptions and values reported by the 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 27, 2013 and September 28, 2012 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 the cost of intangible assets with indefinite lives are not amortized; instead, we test goodwill for possible impairment. We conduct such tests annually (or more frequently if events occur or circumstances change that would more likely than not reduce the Fair Values of our reporting units below their respective carrying values). The first step in the test is to compare the implied Fair Value of each of the Company’s reporting units to their respective carrying amounts, including goodwill. In the event that the carrying value of a reporting unit exceeds its Fair Value, a second test is performed to measure the amount of the impairment loss, if any. In performing the annual impairment test, the Company evaluates goodwill at the reporting unit level. We have determined that our operating segment is comprised of two reporting units based on geography. Based on the results of these tests, we have determined that the Fair Value of our reporting units substantially exceeded their respective carrying values for fiscal years 2013, 2012, and 2011.
	The following table provides certain information related to the Company’s acquired intangible assets for each of the fiscal years presented (in thousands):
			Customer				Developed				Trade			Other				Total
			Relationships,				Technology				Names
			Contracts, and
			Backlog
	Balances, October 1, 2010		$	95,478			$	—			$	2,052		$	2,515			$	100,045
	Acquisitions		155,512				23,000				2,744			2,542				183,798
	Amortization		(21,239		)		(1,023		)		(1,214		)	(1,225		)		(24,701		)
	Foreign currency translation		(13		)		—				(109		)	(14		)		(136		)
	Balances, September 30, 2011		229,738				21,977				3,473			3,818				259,006
	Acquisitions		13,010				—				1,200			410				14,620
	Amortization		(24,406		)		(1,533		)		(1,430		)	(1,597		)		(28,966		)
	Foreign currency translation		(613		)		—				(161		)	(124		)		(898		)
	Balances, September 28, 2012		217,729				20,444				3,082			2,507				243,762
	Amortization		(20,731		)		(1,533		)		(614		)	(1,130		)		(24,008		)
	Foreign currency translation		(1,471		)		—				(289		)	(90		)		(1,850		)
	Balances, September 27, 2013		$	195,527			$	18,911			$	2,179		$	1,287			$	217,904
	Weighted average amortization period		10.2				13				13.4			7.2				10.5
	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 investment in AWE Management Ltd. (“AWE”). Those amounts are included in the carrying value of the Company’s investment in AWE. 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 27, 2013, including those associated with AWE, is: fiscal 2014 - $24.4 million; fiscal 2015 - $23.9 million; fiscal 2016 - $23.8 million; fiscal 2017 - $23.7 million; and fiscal 2018 - $23.7 million. The amounts reported for future amortization include the effect of exchange rate changes.
	The change in goodwill during the period relates primarily to businesses acquired during fiscal 2013.
	Business Combinations
	The Company did not enter into any material business combinations during fiscal years 2012 and 2013,
	On September 8, 2013, the Company, entered into a Merger Implementation Deed with Sinclair Knight Merz (“SKM”), a 6,500-person professional services firm headquartered in Australia. In accordance with the terms of the Merger Implementation Deed, SKM would enter into a Sale Agreement immediately prior to implementation of the Acquisition. Pursuant to the Agreements, the Company would acquire 100% of SKM for approximately AUS$1.3 billion in cash (approximately US$1.2 billion as of September 27, 2013). The purchase price reflects an enterprise value of AUS$1.2 billion (US$1.1 billion as of September 27, 2013) plus adjustments for cash, debt and other items.
	SKM is an employee-owned company that provides engineering, design, procurement, construction and project management, as well as consulting, planning and scientific services in the mining and metals, building and infrastructure, water and environment and power and energy industries. SKM has significant operations in Australia, Asia, South America and the U.K.
	Additional detail regarding the SKM transaction can be found in the Company's Form 8-K dated September 8, 2013.
	During the second quarter of fiscal 2011, we acquired certain operations within the process and construction business of Aker Solutions ASA, and in April 2011 we completed the acquisition of Aker Projects (Shanghai) Company Limited (together, the "Aker Entities"). The acquisition of the Aker Entities is described in more detail on pages 6 and F-16 of our 2011 Form 10-K. Consistent with most other business combinations we have completed, we began integrating the Aker Entities into our existing operations shortly after the businesses were acquired. Accordingly, it is not practicable to provide complete financial information for the Aker Entities on a stand-alone basis.
	The purchase price consisted of $675.0 million plus approximately $234.6 million representing the value of certain transactions specified in the share purchase agreement (“SPA”) and a preliminary estimate of net cash and working capital acquired. Prior to the acquisition of the Aker Entities, the seller completed certain transactions that could have affected the amounts of net cash and net working capital of the operations acquired. The parties therefore negotiated into the SPA a "net cash and working capital adjustment" by which the net cash and working capital of the acquired operations were compared to target amounts specified in the SPA and which, after considering bands within which no settlement would be required, may cause one party to pay cash to the other. The final adjustment amount was determined in accordance with the terms of the SPA in the fourth quarter of fiscal 2011 and no payment was made by either party.
	During the second quarter of fiscal 2012, the Company completed the purchase price allocation of the Aker Entities. The Company recorded a number of Fair Value adjustments affecting, among other things, the estimated liabilities related to certain projects; the final, estimated liabilities relating to acquired professional liability exposures; and other adjustments to the working capital of the balance sheets of the acquired businesses, the total of which fell within the purchase price adjustment band described in the preceding paragraph.
	The following table presents the final allocation of the purchase price to the net assets acquired, excluding intangibles and goodwill (in thousands):
	Assets:
	Cash and cash equivalents	$	329,689
	Receivables and other current assets	163,214
	Property and equipment, and other assets	115,688
	Total assets	608,591
Liabilities:
Current liabilities	292,003
Long-term liabilities	22,534
Total liabilities	314,537
Net assets acquired	$	294,054
The following table presents the values assigned to the identifiable intangible assets acquired in the Aker Entities transactions (in thousands):
Customer relationships / backlog	$	136,000
Technology	23,000
Total	$	159,000
The carrying values of intangible assets subject to amortization are included in “Other Noncurrent Assets” in the accompanying Consolidated Balance Sheet at September 28, 2012, and are being amortized over lives that range from 1 year to 15 years (the weighted average life for all intangibles is 12.8 years).
The amount of goodwill created as a result of the Aker Entities transactions is summarized as follows (in thousands):
Purchase price	$	910,000
Amount assigned to net assets acquired	(294,054		)
Amount assigned to identifiable intangible assets	(159,000		)
Deferred taxes related to intangible assets	55,000
Goodwill recognized	$	511,946
Some of the factors contributing to a purchase price that resulted in the recognition of goodwill include: (i) access to a large, highly-trained and stable workforce; (ii) the opportunity to expand our client base in the U.S., the United Kingdom, Canada, Australia, and China; (iii) the opportunity to enter new geographic markets in South America; (iv) the opportunity to expand our presence in the mining and minerals market; and (v) the opportunity of achieving operating synergies.
Other Matters
We do not expect a material amount of the goodwill recognized during fiscal 2012 and fiscal 2011 to be deductible for income tax purposes.
Included in selling, general and administrative expense for fiscal 2012 and fiscal 2011 is $5.8 million and $15.2 million, respectively of acquisition-related costs pertaining to our acquisition activities.
The Company has retrospectively adjusted certain fiscal 2011 comparative financial information for significant purchase accounting adjustments identified during the respective measurement periods of the related acquisitions. During fiscal 2012, the Company recorded adjustments increasing the Fair Values of accrued liabilities by $100.1 million, income taxes payable by $10.4 million, and other deferred liabilities by $39.3 million. These amounts were offset by an increase in goodwill of $127.1 million and $22.7 million in deferred income tax assets. These purchase price adjustments related primarily to income tax exposures and project exposures. The basis for valuing the liabilities recorded for the income tax exposure was assessments received from taxing authorities, and the basis for valuing the projected-related liabilities was management's best estimate of the costs to complete the associated projects in excess of the respective contract values.
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 period(s) 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 Company's Consolidated Financial Statements.
The following table presents our stock-based compensation expense for the various types of awards made by the Company for each of the fiscal years presented (in thousands):
Award Type		2013		2012		2011
Restricted Stock and Restricted		$12,836		$11,021		$10,710
Stock Units (excluding Market and
Performance Awards)
Stock Options		11,385		14,067		16,468
Market and Performance Awards		15,297		7,354		1,906
Total Expense		$39,518		$32,442		$29,084
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 year are awarded on the same date (although the date is different for employees and directors). The following table presents the assumptions used in the Black-Scholes option-pricing model during each of the last three fiscal years for awards made to employees and directors:
		Awards Made to Employees									Awards Made to Directors
		2013			2012			2011			2013		2012			2011
Dividend yield		0	%		0	%		0	%		0	%	0	%		0	%
Expected volatility		38.37	%		43.28	%		41.54	%		37.65	%	41.42	%		41.97	%
Risk-free interest rate		1.11	%		0.95	%		2	%		0.95	%	1.11	%		2.4	%
Expected term of options (in years)		5.82			5.82			5.82			5.82		5.82			5.82
Performance Awards— During fiscal year 2011, the Company granted restricted stock units containing service and performance conditions. The number of restricted stock units in which the employee may ultimately vest is determined using a stock performance multiplier (“SPM”). The SPM is the quotient obtained by dividing the 60 calendar day average market price of our common stock ending on the vesting date (“Ending Average Stock Price”) by the 60 calendar day average market price of our common stock ending on the grant date (“Beginning Average Stock Price”). The maximum SPM is 2 and will be zero if the Ending Average Market Price of our common stock is less than 50% of the Beginning Average Market Price. The number of restricted stock units earned is equal to the target restricted stock units awarded to an employee multiplied by the SPM.
The Company's chief executive officer's restricted stock units are further subject to an additional Total Shareholder Return ("TSR") condition. Specifically, in order to receive full payout of whatever restricted stock unit award was otherwise earned at the end of the three-year performance period, the Company's TSR compared to its peers must be no less than at the 50th percentile. If performance is at the 25th percentile, 50% of the otherwise payable award is paid. No award is payable if TSR is below the 25th percentile. If performance is between the 25th and 50th percentile, the amount of the otherwise payable award is increased from 50% to 100% of the full award on a linear basis.
Substantially all of the restricted stock units with market conditions granted during the year are awarded on the same date. The following table presents the assumptions used to value these restricted stock units:
	2011
Dividend yield	—	%
Expected volatility	46.67	%
Risk-free interest rate	0.83	%
Expected term (in years)	3
During fiscal years 2013 and 2012, the Company granted restricted stock units containing service, performance, and market conditions. The restricted stock unit award is split equally between Earned Relative TSR Restricted Stock Units and Earned Net Earnings Growth Restricted Stock Units.
The number of Earned Relative TSR Restricted Stock Units in which the employee may ultimately vest shall be equal to 50% of the grant multiplied by the TSR Performance Multiplier. The TSR Performance Multiplier will be 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 will be the average closing stock price over the 30 calendar day period ending on the award date ("Performance Period"), and the ending stock price will be 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 will be deemed re-invested on the ex-dividend data in additional shares of the related Company.
The following table presents the basis on which the Earned Relative TSR Restricted Stock Units are determined:
Company TSR Percentile Rank		TSR Performance Multiplier
Below 30th percentile		—%
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 restricted stock units market conditions granted during the year are awarded on the same date. The following table presents the assumptions used to value the Earned Relative TSR Restricted Stock Units:
	2013		2012
Dividend yield	—	%	—	%
Expected volatility	29.18	%	36.3	%
Risk-free interest rate	0.42	%	0.42	%
Expected term (in years)	3		3
The number of Earned Net Earnings Growth Restricted Stock Units awarded in fiscal year 2012 in which an employee may ultimately vest shall be equal to the sum of the following: (1) an amount, not less than zero, equal to one-third of the Target Restricted Stock Units multiplied by 50% multiplied by the Net Earnings Growth Performance Multiplier (or, "NEGPM", as defined) determined based upon the growth in the Company's Net Earnings (as defined) over the period from April 1, 2012 to March 31, 2013; plus, (2) an amount, not less than zero, equal to (A) two-thirds of the Target Restricted Stock Units multiplied by 50% multiplied by the NEGPM determined based upon the average growth in the Company's Net Earnings over the period from April 1, 2012 to March 31, 2014, minus (B) the amount determined pursuant to (1) above; plus, (3) an amount, not less than zero, equal to (A) the Target Restricted Stock Units multiplied by 50% multiplied by the NEGPM determined based upon the average growth in the Company's Net Earnings over the period from April 1, 2012 to March 31, 2015, minus (B) the amount determined pursuant to (1) and (2) above.
For Earned Net Earnings Growth Restricted Stock Units awarded in fiscal year 2013 all the criteria are the same over the three year vesting period as those referenced in the paragraph above with the exception of the performance period which is based upon the Company's Net Earnings (as defined) over the period starting on the first day of the Company's third quarter of fiscal 2013 and ending on the last day of the Company's second quarter of fiscal 2016.
If the Company's average growth in 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 consolidated net earnings.
The following table presents the basis on which the Earned Net Earnings Growth Restricted Stock Units are determined:
Average Net		Net Earnings Growth
Earnings Growth		Performance
		Multiplier
Less than 5%		—%
5%		50%
10%		100%
15%		150%
20%		200%
Unless stated otherwise, all other awards 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 date.
Concentrations of Credit Risk
Our cash balances and short-term investments are maintained in accounts held by major banks and financial institutions located primarily in North America, South America, Europe, Australia, 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 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 provision 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.
New Accounting Pronouncements
In February 2013, the FASB adopted ASU No. 2013-02—Comprehensive Income. ASU 2013-02 requires an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the statement of earnings or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income, but only if the amount reclassified is required under U.S. GAAP to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required under U.S. GAAP to be reclassified in their entirety to net income in the same reporting period, an entity is required to cross-reference to other disclosures required under U.S. GAAP that provide additional detail about these amounts. ASU 2013-02 is effective for annual and interim periods beginning after December 15, 2012. The adoption of ASU 2013-02 has not had a material effect on the Company's consolidated financial statements.
In July 2012, the FASB adopted ASU No. 2012-02—Testing Indefinite-Lived Intangible Assets for Impairment. ASU 2012-02 amends Topic 350 of the FASB's ASC regarding how entities test indefinite-lived intangible assets other than goodwill for possible impairment. ASU 2012-02 permits entities first to assess qualitative factors to determine whether it is more likely than not that an indefinite lived intangible asset is impaired as a basis for determining whether it is necessary to perform the quantitative impairment test pursuant to ASC Subtopic 350-30. If the entity determines that is more likely than not that such asset is not impaired based on its qualitative assessment, no further testing is required. The amendments in ASU 2012-02 are effective for annual and interim impairment tests performed for fiscal years beginning after September 15, 2012. The adoption of ASU 2012-02 has not had a material effect on the Company's Consolidated Financial Statements.
Also in December 2011, the FASB adopted ASU No. 2011-11—Disclosures about Offsetting Assets and Liabilities. ASU 2011-11 amends Topic 210 of the ASC and requires entities to disclose information about offsetting and related arrangements to enable users of their financial statements to understand the effect of those arrangements on their respective financial positions. The scope of this ASU includes derivatives, sale and repurchase agreements, reverse sale and repurchase agreements, and securities borrowing and securities lending agreements. Entities are required to apply the provisions of ASU 2011-11 for annual reporting periods beginning on or after January 1, 2013. The Company does not believe that the adoption of ASU 2011-11 will have a material effect on its consolidated financial statements.

Stock_Purchase_And_Stock_Optio

Stock Purchase And Stock Option Plans	12 Months Ended
	Sep. 27, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock Purchase And Stock Option Plans	'
	Stock Purchase and Stock Option Plans
	Broad-Based, Employee Stock Purchase Plans
	The 1989 ESPP and the GESPP are employee stock purchase plans under which employees 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 during each of the last three fiscal years:
			2013				2012				2011
	Aggregate Purchase Price Paid for Shares Sold:
	Under the 1989 ESPP		$	30,012,848			$	32,236,660			$	31,887,660
	Under the GESPP		3,068,578				2,944,987				2,894,302
	Total		$	33,081,426			$	35,181,647			$	34,781,962
	Aggregate Number of Shares Sold:
	Under the 1989 ESPP		642,675				853,819				771,818
	Under the GESPP		64,963				76,360				69,386
	Total		707,638				930,179				841,204
	At September 27, 2013, there were 2,414,021 shares reserved for issuance under the 1989 ESPP and 272,068 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 ("SAR"), 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 1999 SIP and the 1999 ODSP (together, the “1999 Plans”) replaced the1981 Plan. The following table sets forth certain information about the 1999 Plans:
			1999 SIP			1999 ODSP			Total
	Number of shares authorized		25,600,000			800,000			26,400,000
	Number of remaining shares reserved for issuance at September 27, 2013		9,456,344			389,625			9,845,969
	Number of shares relating to outstanding stock options at September 27, 2013		4,356,712			249,500			4,606,212
	Number of shares available for future awards:
	At September 27, 2013		5,099,632			140,125			5,239,757
	At September 28, 2012		446,994			188,625			635,619
	Effective September 28, 2012, all grants of shares under the 1999 SIP are issued on a fungible share basis. An award of an option or SAR counts as 1 share issued under the 1999 SIP Plan. A grant other than an option or SAR counts as 1.92 shares issued under the 1999 SIP Plan.
	The following table presents the Fair Value of shares (of restricted stock and restricted stock units) vested during each of the last three fiscal years (in thousands):
	2013				2012				2011
	$	13,054			$	7,955			$	4,848
	No market or performance awards vested during the last three fiscal years.
	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 (in thousands):
	2013				2012				2011
	$	39,518			$	32,442			$	29,084
	The following table summarizes the stock option activity for each of the last three fiscal years:
			Number of			Weighted
			Stock			Average
			Options			Exercise
						Price
	Outstanding at October 1, 2010		7,410,580			$	39.1
	Granted		433,600			$	46.04
	Exercised		(1,363,005	)		$	21.37
	Cancelled or expired		(19,665	)		$	47.81
	Outstanding at September 30, 2011		6,461,510			$	43.28
	Granted		658,700			$	37.45
	Exercised		(1,281,449	)		$	22.54
	Cancelled or expired		(82,027	)		$	43.92
	Outstanding at September 28, 2012		5,756,734			$	47.23
	Granted		753,450			$	54.71
	Exercised		(1,782,371	)		$	37
	Cancelled or expired		(121,601	)		$	50.22
	Outstanding at September 27, 2013		4,606,212			$	52.33
	Stock options outstanding at September 27, 2013 consisted entirely of nonqualified stock options. The following table presents the total intrinsic value of stock options exercised during each of the last three fiscal years (in thousands):
	2013				2012				2011
	$	22,163			$	26,196			$	34,665
	The total intrinsic value of stock options exercisable at September 27, 2013, was approximately $30.5 million. The following table presents certain other information regarding our 1999 Plans:
			2013				2012				2011
	At fiscal year end:
	Range of exercise prices for options outstanding		$20.98–$94.11				$18.49–$94.11				$13.29–$94.11
	Number of options exercisable		3,034,111				4,219,557				4,822,297
	For the fiscal year:
	Range of prices relating to options exercised		$18.49–$56.95				$13.29–$37.73				$10.79–$41.18
	Estimated weighted average Fair Values of options granted		$	20.64			$	15.55			$	19.43
	The following table presents certain information regarding stock options outstanding, and stock options exercisable at September 27, 2013:
			Options Outstanding									Options Exercisable
	Range of Exercise Prices		Number			Weighted		Weighted				Number	Weighted
Average						Average			Average
Remaining						Price			Exercise
Contractual									Price
Life
(years)
$20.98 - $26.80		91,800			0.67		$	23.14			91,800	$	23.14
$32.51 - $37.32		569,500			8.55		37.01				157,125	36.98
$37.43 - $46.86		1,757,213			6.15		42.54				1,388,287	42.41
$47.11 - $55.04		972,925			8.72		52.74				247,825	48.32
$55.13 - $57.81		503,975			0.93		56.94				494,975	56.97
$58.26 - $83.61		136,075			5.41		72.43				79,375	81.34
$88.19 - $94.11		574,724			1.63		92.57				574,724	92.57
		4,606,212			5.72		$	52.33			3,034,111	$	54.93
The 1999 Plans 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.
At September 27, 2013, the amount of compensation cost relating to nonvested awards not yet recognized in the financial statements is approximately $122.8 million. The majority of the unrecognized compensation costs will be recognized by the third quarter of fiscal 2015. The weighted average remaining contractual term of options currently exercisable is 4.1 years.
The following table presents the number of shares of restricted stock and restricted stock units issued under the 1999 SIP during each of the last three fiscal years:
		2013(1)			2012			2011
Restricted stock		445,200			497,100			226,850
Restricted stock units (service condition)		107,500			116,450			2,100
Restricted stock units (service, market, and performance conditions at target)		471,250			525,000			291,700
The amount of restricted stock units issued for awards with performance and market conditions in the above table are based on 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 following table presents the number of shares of restricted stock and restricted stock units cancelled and withheld under the 1999 SIP during each of the last three fiscal years:
		2013(1)(2)			2012			2011
Restricted stock		128,923			80,460			33,200
Restricted stock units (service condition)		3,385			5,650			—
Restricted stock units (service, market, and performance conditions at target)		32,000			22,000			—
The amount of restricted stock units cancelled for awards with market and performance conditions in the above table is based on the target amount.
(1) The share amounts in the above tables for fiscal 2013 reflect the fungible share counting of 1.92 shares for each share of restricted stock and restricted stock unit issued.
(2) Commencing in fiscal 2013, shares withheld for withholding tax liabilities are available for awards under the 1999 SIP and have been included in the table above for fiscal 2013 only.
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 27, 2013 under the 1999 SIP. Shares granted prior to September 29, 2012 were granted on a 1-to-1 basis ("Not Fungible"). Shares Granted after September 28, 2012 were issued on a 1.92-to-1 basis ("Fungible"):
		Not Fungible			Fungible			Total
Restricted stock		1,144,370			441,200			1,585,570
Restricted stock units (service condition)		109,030			106,500			215,530
Restricted stock units (service, market, and performance conditions at target)		762,700			471,250			1,233,950
The following table presents the number of shares of restricted stock and restricted stock units issued under the 1999 ODSP during each of the last three fiscal years:
		2013			2012			2011
Restricted stock units (service condition)		13,500			8,000			10,000
The following table provides the number of shares of restricted stock and restricted stock units outstanding at September 27, 2013 under the 1999 ODSP:
		2013
Restricted stock		40,000
Restricted stock units (service condition)		47,500
All shares granted under the 1999 ODSP are issued on a 1-to-1 basis.

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Sep. 27, 2013
Earnings Per Share Reconciliation [Abstract]	'
Earnings Per Share	'
	Earnings Per Share
	The following table (i) reconciles the denominator used to compute Basic EPS to the denominator used to compute Diluted EPS for each of the last three fiscal years, and (ii) discloses the number of antidilutive stock options, restricted stock, and restricted stock units outstanding at the end of each of the fiscal years indicated (in thousands):
		2013	2012	2011
	Shares used to calculate EPS:
	Weighted average shares outstanding	129,288	127,644	125,686
	(denominator used to compute basic EPS)
	Effect of stock options and restricted stock	1,657	1,048	1,549
	Denominator used to compute diluted EPS	130,945	128,692	127,235
	Antidilutive stock options, restricted stock, and restricted stock units	2,603	5,093	4,507

Borrowings

Borrowings	12 Months Ended
	Sep. 27, 2013
Debt Disclosure [Abstract]	'
Borrowings	'
	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 overdrafts of $22.8 million outstanding, primarily in our India operations, under these short-term credit facilities at a weighted average interest rate of 10.7% at September 27, 2013, and there were no amounts outstanding under these short-term credit facilities at September 28, 2012.
	Long-term Debt
	The following table presents certain information regarding the Company’s long-term revolving credit facility at September 27, 2013, and September 28, 2012 (dollars in thousands):
			2013						2012
			Principal				Range		Principal		Range
			Balance				of Interest		Balance		of Interest
			Outstanding				Rates		Outstanding		Rates
	2012 Facility		$	415,086			0.96% – 1.37%		$	528,260	0.95% – 1.41%
	The Company has a long-term, unsecured, revolving credit facility (the "2012 Facility") providing $1.21 billion of borrowing capacity with a syndicate of large, U.S. and international banks and financial institutions. The total amount outstanding under the 2012 Facility at September 27, 2013, was $425.9 million ($415.1 million in the form of direct borrowings and $10.8 million utilized in the form of letters of credit).
	The 2012 Facility expires in March 2017 and permits the Company to borrow under three 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 2012 Facility. Depending on the Company's Consolidated Leverage Ratio, borrowings under the 2012 Facility will bear interest at either a eurocurrency rate plus a margin of between 0.875% and 1.225% or a base rate plus a margin of between 0% and 0.225%. The 2012 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 Company pays a facility fee of between 0.125% and 0.275% per annum depending on the Company's Consolidated Leverage Ratio. Amounts outstanding under the 2012 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 2012 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 2012 Facility contains customary events of default. We were in compliance with our debt covenants at September 27, 2013.
	The following table presents certain additional information regarding the Company’s 2012 Facility for the fiscal years shown:
			2013				2012
	Maximum amount outstanding at any month-end during the fiscal year		$	526,602			$	586,933
	Average amount outstanding during the year		$	470,343			$	537,131
	Weighted average interest rate during the year		1.11				1.32
	The following table presents the amount of interest paid by the Company during each of the last three fiscal years (in thousands):
	2013				2012				2011
	$	6,685			$	8,572			$	7,778

Pension_Plans

Pension Plans	12 Months Ended
	Sep. 27, 2013
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]	'
Pension Plans	'
	Pension 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, 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, amongst others.  The discount rates used in valuing the plans' benefit obligations were determined with reference to high quality corporate/government bonds that are appropriately matched to the duration of each plan's obligations.  The expected long-term rate of return on plan assets, with the exception of plans in Belgium (where the assets are invested in an insurance product that provides guaranteed returns) and India (where asset returns are generally set using government bond yields), is based on a simulation model which selects a single outcome for expected return based on the target asset allocation.  The model simulates interest rates, inflation, and asset class returns for up to 20 years and for 1,000 or 2000 economic scenarios to generate a range of likely outcomes.  The expected long-term-rate 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.) during each of the fiscal years presented (in thousands):
			U.S. Pension Plans								Non-U.S. Pension Plans
			2013				2012				2013			2012
	Net benefit obligation at the		$	509,605			$	482,542			$	1,191,345		$	968,938
	beginning of the year
	Service cost		13,814				12,838				30,117			22,723
	Interest cost		18,569				20,923				51,331			54,287
	Participants’ contributions		3,071				3,200				11,805			11,614
	Actuarial (gains)/losses		(42,689		)		20,342				57,764			142,935
	Benefits paid		(33,960		)		(10,978		)		(34,058		)	(30,180		)
	Curtailments and settlements		—				(27,702		)		(6,297		)	(6,118		)
	Plan amendments		—				—				109			(2,294		)
	Business combinations/consolidations		—				8,440				—			8,933
	Special termination benefits		29				—				—			—
	Effect of exchange rate changes		—				—				5,215			20,507
	Net benefit obligation at the end		$	468,439			$	509,605			$	1,307,331		$	1,191,345
	of the year
	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.) during each of the fiscal years presented (in thousands):
			U.S. Pension Plans								Non-U.S. Pension Plans
			2013				2012				2013			2012
	Fair Value of plan assets at the		$	359,348			$	285,777			$	877,950		$	744,689
	beginning of the year
	Actual return on plan assets		53,495				62,635				72,368			91,987
	Employer contributions		8,823				42,606				53,885			48,374
	Participants’ contributions		3,071				3,200				11,805			11,614
	Gross benefits paid		(33,960		)		(10,978		)		(34,058		)	(30,180		)
	Business combinations/consolidations		—				3,810				—			4,272
	Curtailments/settlements		—				(27,702		)		(4,973		)	(6,085		)
	Effect of exchange rate changes		—				—				5,502			13,279
	Fair Value of plan assets at the		$	390,777			$	359,348			$	982,479		$	877,950
	end of the year
	The following table reconciles the combined funded statuses of the plans recognized in the accompanying Consolidated Balance Sheets at September 27, 2013, and September 28, 2012 (segregated between plans existing within and outside the U.S.) (in thousands):
			U.S. Pension Plans								Non-U.S. Pension Plans
			2013				2012				2013			2012
	Net benefit obligation at the end		$	468,439			$	509,605			$	1,307,331		$	1,191,345
	of the year
	Fair Value of plan assets at the end		390,777				359,348				982,479			877,950
	of the year
	Under-funded amount recognized		$	77,662			$	150,257			$	324,852		$	313,395
	at the end of the year
	The following table presents the accumulated benefit obligation at September 27, 2013, and September 28, 2012 (segregated between plans existing within and outside the U.S.) (in thousands):
			U.S. Pension Plans								Non-U.S. Pension Plans
			2013				2012				2013			2012
	Accumulated benefit obligation at the		$	431,726			$	460,618			$	1,222,234		$	1,109,413
	end of the year
	The following table presents the amounts recognized in the accompanying Consolidated Balance Sheets at September 27, 2013, and September 28, 2012 (segregated between plans existing within and outside the U.S.) (in thousands):
			U.S. Pension Plans								Non-U.S. Pension Plans
			2013				2012				2013			2012
	Accrued benefit cost included in		$	—			$	—			$	15,193		$	13,174
	prepaid assets
	Accrued benefit cost included in		—				—				1,000			2,271
	current liabilities
	Accrued benefit cost included in		77,662				150,257				339,045			324,298
	noncurrent liabilities
	Net amount recognized at the end of		$	77,662			$	150,257			$	324,852		$	313,395
	the year
	Included in the tables are amounts relating to a U.S. pension plan, the participating employees in which are assigned to, and work exclusively on, a specific operating contract with the U.S. federal government. It is the intention of the parties to this contract that the cost of this pension plan will be fully reimbursed by the U.S. federal government pursuant to applicable cost accounting standards. Accordingly, included in “Other Noncurrent Assets” in the accompanying Consolidated Balance Sheet at September 27, 2013 is a receivable from the U.S. federal government of approximately $58.4 million ($101.4 million at September 28, 2012) representing the underfunded amount for this pension plan.
	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 each fiscal year presented:
			2013			2012			2011
Weighted average discount rates		4.4% to 5.0%			3.4% to 3.9%			4.3% to 4.6%
Rates of compensation increases		2.8	%		3.25	%		3.5	%
Expected long-term rates of return		7.7	%		7.5	%		7.5	%
on plan assets
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 each fiscal year presented:
		2013		2012		2011
Weighted average discount rates		0.4% to 9.3%		0.6% to 8.4%		2.6% to 5.9%
Rates of compensation increases		2.5% to 7.5%		2.8% to 7.5%		3.0% to 3.5%
Expected long-term rates of return		0.4% to 8.5%		2.4% to 8.5%		4.75% to 7.1%
on plan assets
The following table presents certain amounts relating to our U.S. pension plans recognized in accumulated other comprehensive loss at September 27, 2013, and September 28, 2012 (in thousands):
		2013				2012				2011
Arising during the period:
Net actuarial (gain) loss		$	(15,850	)		$	2,756			$	7,486
Reclassification adjustments:
Net actuarial gain		(2,674		)		(2,011		)		(2,011		)
Total		$	(18,524	)		$	745			$	5,475
The following table presents certain amounts relating to our Non-U.S. pension plans recognized in accumulated other comprehensive loss at September 27, 2013, and September 28, 2012 (in thousands):
		2013				2012				2011
Arising during the period:
Net actuarial loss (gain)		$	27,417			$	83,298			$	(73,258	)
Prior service cost (benefit)		297				(1,947		)		1,005
Total		27,714				81,351				(72,253		)
Reclassification adjustments:
Net actuarial gain		(9,778		)		(6,131		)		(4,990		)
Prior service cost (benefit)		41				(23		)		(1,406		)
Total		(9,737		)		(6,154		)		(6,396		)
Total		$	17,977			$	75,197			$	(78,649	)
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 pension cost at September 27, 2013, and September 28, 2012 (segregated between plans existing within and outside the U.S.) (in thousands):
		U.S. Pension Plans								Non-U.S. Pension Plans
		2013				2012				2013			2012
Net actuarial loss		$	50,446			$	68,970			$	228,074		$	201,726
Prior service cost		—				—				(466		)	(803		)
Total		$	50,446			$	68,970			$	227,608		$	200,923
The following table presents the amount of accumulated comprehensive income that will be amortized against earnings as part of our net periodic pension cost in fiscal 2013(segregated between plans existing within and outside the U.S.) (in thousands):
		U.S.				Non-U.S.
		Pension				Pension
		Plans				Plans
Unrecognized net actuarial loss		$	3,608			$	15,527
Unrecognized prior service cost		(103		)		(25		)
Accumulated comprehensive loss to be recorded against earnings		$	3,505			$	15,502
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 27, 2013, and September 28, 2012 (the measurement dates used in valuing the plans’ assets and liabilities) were as follows:
		U.S. Pension Plans						Non-U.S. Pension Plans
		2013			2012			2013			2012
Equity securities		74	%		72	%		32	%		41	%
Debt securities		20	%		21	%		31	%		37	%
Real estate investments		1	%		1	%		6	%		6	%
Other		5	%		6	%		31	%		16	%
The following table presents the Fair Value of the Company’s U.S. pension plan assets at September 27, 2013, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands):
		Fair Values By Level of
		Fair Value Measurement Inputs
		Level 1				Level 3				Total
U.S. Domestic equities		$	247,155			$	—			$	247,155
Overseas equities		40,719				—				40,719
U.S. Domestic bonds		79,482				—				79,482
Cash and equivalents		3,499				—				3,499
Real estate		—				4,411				4,411
Hedge funds		—				15,511				15,511
Total		$	370,855			$	19,922			$	390,777
The following table presents the Fair Value of the Company’s Non-U.S. pension plan assets at September 27, 2013, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands):
		Fair Values By Level of
		Fair Value Measurement Inputs
		Level 1				Level 3				Total
U.S. Domestic equities		$	108,261			$	—			$	108,261
Overseas equities		207,607				—				207,607
U.S. Domestic bonds		230,202				—				230,202
Overseas bonds		76,372				—				76,372
Cash and equivalents		28,185				—				28,185
Infrastructure / raw goods		—				7,076				7,076
Real estate		—				57,173				57,173
Insurance contracts		—				21,214				21,214
Hedge funds		—				246,389				246,389
Total		$	650,627			$	331,852			$	982,479
The following table presents the Fair Value of the Company’s U.S. pension plan assets at September 28, 2012, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands):
		Fair Values By Level of
		Fair Value Measurement Inputs
		Level 1				Level 3				Total
U.S. Domestic equities		$	230,862			$	—			$	230,862
Overseas equities		27,343				—				27,343
U.S. Domestic bonds		75,648				—				75,648
Cash and equivalents		6,183				—				6,183
Real estate		—				4,841				4,841
Hedge funds		—				14,471				14,471
Total		$	340,036			$	19,312			$	359,348
The following table presents the Fair Value of the Company’s Non-U.S. pension plan assets at September 28, 2012, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands):
		Fair Values By Level of
		Fair Value Measurement Inputs
		Level 1				Level 3				Total
U.S. Domestic equities		$	193,715			$	—			$	193,715
Overseas equities		168,097				—				168,097
U.S. Domestic bonds		306,974				—				306,974
Overseas bonds		14,254				—				14,254
Cash and equivalents		27,571				—				27,571
Infrastructure / raw Goods		—				6,111				6,111
Real estate		—				49,537				49,537
Insurance contracts		—				18,291				18,291
Hedge funds		—				93,400				93,400
Total		$	710,611			$	167,339			$	877,950
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 27, 2013 (in thousands):
		Real				Hedge
		Estate				Funds
Balance, beginning of year		$	4,841			$	14,471
Transfers		—				—
Realized and unrealized gains (losses)		(430		)		1,040
Balance, end of year		$	4,411			$	15,511
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 27, 2013 (in thousands):
		Infrastructure				Real				Insurance			Hedge
		/ Raw Goods				Estate				Contracts			Funds
Balance, beginning of year		$	6,111			$	49,537			$	18,291		$	93,400
Purchases, sales, and settlements		—				—				1,646			144,441
Realized and unrealized gains		678				7,670				1,058			4,664
Effect of exchange rate changes		287				(34		)		219			3,884
Balance, end of year		$	7,076			$	57,173			$	21,214		$	246,389
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 28, 2012 (in thousands):
		Real				Hedge
		Estate				Funds
Balance, beginning of year		$	5,353			$	14,845
Transfers		—				—
Realized and unrealized losses		(512		)		(374		)
Balance, end of year		$	4,841			$	14,471
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 28, 2012 (in thousands):
		Infrastructure				Real				Insurance			Hedge
		/ Raw Goods				Estate				Contracts			Funds
Balance, beginning of year		$	4,776			$	43,997			$	17,293		$	81,776
Purchases, sales, and settlements		—				106				389			—
Realized and unrealized gains		1,572				3,836				1,422			7,975
Transfers		—				—				—			—
Effect of exchange rate changes		(237		)		1,598				(813		)	3,649
Balance, end of year		$	6,111			$	49,537			$	18,291		$	93,400
The following table presents the amount of cash contributions we anticipate making into the plans during fiscal 2014 (in thousands):
U.S.				Non-U.S.
Pension Plans				Pension  Plans
$	12,500			$	53,561
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  Plans
2014		$	39,259			$	39,298
2015		36,319				41,989
2016		38,455				46,714
2017		41,162				49,767
2018		38,808				54,413
For the period 2019 through 2023		204,246				344,800
The following table presents the components of net periodic pension cost for the Company’s U.S. pension plans recognized in the accompanying Consolidated Statements of Earnings for each of the last three fiscal years (in thousands):
		2013				2012				2011
Service cost		$	13,814			$	12,838			$	10,684
Interest cost		18,569				20,923				21,377
Expected return on plan assets		(25,826		)		(23,764		)		(23,558		)
Actuarial loss		8,030				10,981				7,025
Prior service cost		(103		)		(103		)		(103		)
Net pension cost, before special items		14,484				20,875				15,425
Special termination benefits		29				—				120
Settlement loss		—				6,035				—
Total net periodic pension cost recognized		$	14,513			$	26,910			$	15,545
The following table presents the components of net periodic pension cost for the Company’s Non-U.S. pension plans recognized in the accompanying Consolidated Statements of Earnings for each of the last three fiscal years (in thousands):
		2013				2012				2011
Service cost		$	30,117			$	22,723			$	30,816
Interest cost		51,331				54,287				54,631
Expected return on plan assets		(54,817		)		(50,996		)		(50,033		)
Actuarial loss		13,276				8,227				13,535
Prior service cost		(43		)		152				303
Net pension cost, before special		39,864				34,393				49,252
items
Curtailments and settlements		(383		)		1,326				381
Total net periodic pension cost		$	39,481			$	35,719			$	49,633
recognized
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 is 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, we have concluded that none of the multiemployer pension plans into which we contribute are individually significant to our consolidated financial statements.
The following table presents the Company’s contributions to these multiemployer plans during each of the last three fiscal years (in thousands):
		2013				2012				2011
Canada		$	72,660			$	72,053			$	81,608
Europe and Australia		12,930				10,808				12,613
United States		4,366				4,420				4,049
Total		$	89,956			$	87,281			$	98,270

Other_Comprehensive_Income_Not

Other Comprehensive Income (Notes)	12 Months Ended
	Sep. 27, 2013
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax [Abstract]	'
Other Comprehensive Income	'
	Other Comprehensive Income
	The following table presents amounts reclassified from changes in pension liabilities in other comprehensive income to direct cost of contracts and selling, general and administrative expenses in the Company's Consolidated Statements of Earnings for the periods presented related to the Company's defined benefit pension plans (in thousands):
		2013			2012			2011
	Amortization of Defined Benefit Items:
	Actuarial losses	$	(17,554	)	$	(11,444	)	$	(16,182	)
	Prior service benefit (cost)	43			(152		)	(97		)
	Total Before Income Tax	(17,511		)	(11,596		)	(16,279		)
	Income Tax Benefit	5,859			3,955			5,716
	Total reclassifications after-tax	$	(11,652	)	$	(7,641	)	$	(10,563	)

Savings_And_Deferred_Compensat

Savings And Deferred Compensation Plans	12 Months Ended
	Sep. 27, 2013
Savings And Deferred Compensation Plans [Abstract]	'
Savings And Deferred Compensation Plans	'
	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. IRC. 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 during each of the last three fiscal years (in thousands):
	2013		2012		2011
	$	74,686	$	70,211	$	61,065
	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 during each of the last three fiscal years (in thousands):
	2013		2012		2011
	$	4,470	$	4,349	$	3,075

Income_Taxes

Income Taxes	12 Months Ended
	Sep. 27, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	The following table presents the components of our consolidated income tax expense for each of the last three fiscal years (in thousands):
			2013				2012				2011
	Current income tax expense:
	Federal		$	121,302			$	111,035			$	102,903
	State		23,246				23,303				25,067
	Foreign		74,107				69,080				37,617
	Total current tax expense		218,655				203,418				165,587
	Deferred income tax expense (benefit):
	Federal		(4,718		)		(2,505		)		10,482
	State		(582		)		(1,985		)		(1,760		)
	Foreign		8,011				3,454				7,131
	Total deferred income tax		2,711				(1,036		)		15,853
	expense (benefit)
	Consolidated income tax expense		$	221,366			$	202,382			$	181,440
	Deferred taxes reflect the tax effects of the 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 27, 2013, and September 28, 2012 (in thousands):
			2013				2012
	Deferred tax assets:
	Obligations relating to:
	Defined benefit pension plans		$	97,349			$	103,984
	Other employee benefit plans		198,869				173,515
	Self-insurance programs		1,758				10,847
	Contract revenues and costs		19,468				39,894
	Other		11,100				10,749
	Gross deferred tax assets		328,544				338,989
	Deferred tax liabilities:
	Depreciation and amortization		(127,974		)		(125,704		)
	Residual US tax on unremitted non-US		(6,724		)		(9,024		)
	earnings
	Other, net		(7,560		)		(10,709		)
	Gross deferred tax liabilities		(142,258		)		(145,437		)
	Net deferred tax assets		$	186,286			$	193,552
	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 during each of the last three fiscal years (in millions):
	2013				2012				2011
	$	7.3			$	9.3			$	11.9
	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 each of the last three fiscal years (dollars in thousands):
			2013				2012				2011
	Statutory amount		$	231,542			$	207,668			$	180,831
	State taxes, net of the federal		14,892				13,538				15,150
	benefit
	Tax differential on foreign		(18,700		)		(16,667		)		(7,841		)
	earnings
	Other, net		(6,368		)		(2,157		)		(6,700		)
	Consolidated income tax expense		$	221,366			$	202,382			$	181,440
	Rates used to compute statutory		35		%		35		%		35		%
	amount
	Consolidated effective income		33.5		%		34.1		%		35.1		%
	tax rate
	The following table presents income tax payments made during each of the last three fiscal years (in millions):
	2013				2012				2011
	$	235.8			$	191.4			$	139.2
	The following table presents the components of our consolidated earnings before taxes for each of the last three fiscal years (in thousands):
			2013				2012				2011
	United States earnings		$	352,404			$	286,987			$	341,059
	Foreign earnings		309,144				306,349				175,602
			$	661,548			$	593,336			$	516,661
	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 are expected to be permanently reinvested. At September 27, 2013, approximately $26.1 million of such undistributed earnings of certain foreign subsidiaries was expected to be permanently reinvested. Should these earnings be repatriated, approximately $7.7 million of income taxes would be payable.
	The Company accounts for unrecognized tax benefits in accordance with ASC Topic 740. It accounts for interest and penalties on unrecognized tax benefits as interest and penalties (i.e., not as part of income tax expense). The Company’s liability for gross unrecognized tax benefits was $51.8 million and $53.6 million at September 27, 2013, and September 28, 2012, respectively, all of which, if recognized, would affect the Company’s consolidated effective income tax rate. The Company had $44.8 million and $48.8 million in accrued interest and penalties at September 27, 2013, and September 28, 2012, respectively. The Company estimates that, within 12 months, $5.0 million of gross, primarily non-U.S. unrecognized tax benefits will reverse due to the anticipated expiration of time to assess tax. As of September 27, 2013, the Company’s U.S. federal income tax returns for tax years 2010 through 2013 remain subject to examination.
	The following table presents the reconciliation of the beginning and ending amount of unrecognized tax benefits for the years presented (in thousands):
			2013				2012				2011
	Balance, beginning of year		$	53,637			$	31,130			$	27,825
	Additions based on tax positions related to the current year		5,447				6,110				6,731
	Additions for tax positions of prior years		—				21,438				4,252
Reductions for tax positions of prior years		(6,354		)		(4,441		)		(7,678		)
Settlement		(960		)		(600		)		—
Balance, end of year		$	51,770			$	53,637			$	31,130

Commitments_And_Contingencies_

Commitments And Contingencies, And Derivative Financial Instruments	12 Months Ended
	Sep. 27, 2013
Commitments And Contingencies, And Derivative Financial Instruments [Abstract]	'
Commitments And Contingencies, And Derivative Financial Instruments	'
	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 $909.8 million at September 27, 2013, payable as follows (in thousands):
	In fiscal years,
	2014	$	150,448
	2015	177,493
	2016	118,984
	2017	99,942
	2018	83,884
	Thereafter	288,944
		919,695
	Amounts representing sublease income	(9,937		)
	Total, net aggregate future lease payments	$	909,758
	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 during each of the last three fiscal years (in thousands):
			2013			2012			2011
	Rent expense		$	173,340		$	165,221		$	157,955
	Sublease income		(7,914		)	(8,402		)	(8,315		)
	Net rent		$	165,426		$	156,819		$	149,640
	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	2015
	End of term purchase option (in thousands)	$	52,200
	Residual value guaranty (in thousands)	$	38,800
	The lease agreement 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. In connection with the lease, we entered into a floating-to-fixed interest rate swap agreement with a U.S. bank which fixes the amount of the Company’s lease payments. The notional amount of this hedge at September 27, 2013, was $52.2 million. This instrument allows us to receive a floating rate payment tied to the 1-month LIBOR from the counterparty in exchange for a fixed-rate payment from us. We’ve determined this interest rate swap to be “highly effective” according to U.S. GAAP. 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 27, 2013.
	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 27, 2013 totaled $243.3 million. Of this amount $10.8 million has been issued under our revolving credit facility and $232.5 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. 27, 2013
Contractual Guarantees, Litigation, Investigations, And Insurance [Abstract]	'
Contractual Guarantees, Litigation, Investigations, And Insurance	'
	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.
	Management 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 January 20, 2010, Clark County Nevada ("Clark County") filed suit against Jacobs and two of its subsidiaries asserting claims arising out of certain construction projects to which Clark County Nevada was the owner and for which Jacobs' subsidiaries served as the project management consultant. Clark County's lawsuit against Jacobs followed years of litigation and arbitration between Clark County and its construction contractor on the applicable projects which had ended unsuccessfully for Clark County and resulted in Clark County paying more than $60 million in settlement and awards. Jacobs denies liability and has vigorously defended against the County's claims. In September 2012, the parties agreed to dismiss the litigation in U.S. District Court and proceed, in lieu thereof, in arbitration before three arbitrators. A hearing on the merits was scheduled to begin in September 2013. Prior to the arbitration, the case settled. Even though some of our insurers have contested coverage, the Company does not expect this matter to have any material adverse effect on its consolidated financial statements.
	The Company is a defendant in numerous matters pending in North Carolina's Superior Courts arising out of a June 9, 2009, natural gas explosion at a ConAgra Foods Inc. plant in Garner, Wake County, North Carolina. The claims that have been brought against the Company include wrongful death claims, personal injury claims and a claim for property losses to the plant property itself. The Company has settled many of the personal injury claims and is vigorously defending the remaining claims and believes it has meritorious defenses. In addition, the Company believes it has adequate insurance coverage as well as a right to indemnification from ConAgra. Accordingly, the Company does not expect these matters to have any material adverse effect on its consolidated financial statements.

Common_And_Preferred_Stock

Common And Preferred Stock	12 Months Ended
	Sep. 27, 2013
Class of Stock Disclosures [Abstract]	'
Common And Preferred Stock	'
	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 Board of Directors at the time each series is issued. Except as may be provided by the 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 all other matters requiring stockholder action. The holders of shares of common stock are entitled to dividends if and when declared by the Board of Directors from whatever assets are legally available for that purpose.

Other_Financial_Information

Other Financial Information	12 Months Ended
	Sep. 27, 2013
Other Financial Information [Abstract]	'
Other Financial Information	'
	Other Financial Information
	Receivables
	The following table presents the components of “Receivables” as shown in the accompanying Consolidated Balance Sheets at September 27, 2013, and September 28, 2012 as well as certain other related information (in thousands):
			2013			2012
	Amounts billed, net		$	1,389,278		$	1,193,500
	Unbilled receivables and other		1,109,931			1,110,008
	Retentions receivable		49,781			45,384
	Total receivables, net		$	2,548,990		$	2,348,892
	Other information about receivables:
	Amounts due from the United States federal		$	292,698		$	294,327
	government included above, net of
	advanced billings
	Claims receivable		$	25,237		$	26,309
	Billed receivables, net consist of amounts invoiced to clients in accordance with the terms of our 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 27, 2013, and September 28, 2012 (in thousands):
			2013			2012
	Land		$	22,027		$	23,786
	Buildings		131,690			136,193
	Equipment		537,835			502,568
	Leasehold improvements		204,940			163,916
	Construction in progress		22,678			29,595
			919,170			856,058
	Accumulated depreciation and amortization		(539,874		)	(524,927		)
			$	379,296		$	331,131
	Miscellaneous Noncurrent Assets
	The following table presents the components of “Miscellaneous noncurrent assets” as shown in the accompanying Consolidated Balance Sheets at September 27, 2013, and September 28, 2012 (in thousands):
			2013			2012
	Deferred income taxes		$	197,458		$	196,620
	Cash surrender value of life insurance policies		100,253			86,502
	Intangible assets (a)		217,904			243,762
	Investments		194,782			187,248
	Notes receivable		11,689			11,128
	Reimbursable pension costs (b)		84,348			132,463
	Other		26,025			28,162
	Total		$	832,459		$	885,885
	(a)    Consists primarily of intangible assets acquired in connection with various business combinations.
	(b)	Consists of costs incurred relating to a defined benefit pension plan covering employees providing services on a contract with, and for the benefit of, the U.S. federal government pursuant to which such costs are fully reimbursable.
	Accrued Liabilities
	The following table presents the components of “Accrued liabilities” as shown in the accompanying Consolidated Balance Sheets at September 27, 2013 and September 28, 2012 (in thousands):
			2013			2012
	Accrued payroll and related liabilities		$	688,391		$	641,340
	Project-related accruals		115,418			196,836
	Insurance liabilities		48,209			63,908
	Sales and other similar taxes		47,973			41,951
	Deferred rent		57,581			41,342
	Other		72,244			76,592
	Total		$	1,029,816		$	1,061,969
	Other Deferred Liabilities
	The following table presents the components of “Other deferred liabilities” as shown in the accompanying Consolidated Balance Sheets at September 27, 2013 and September 28, 2012 (in thousands):
			2013			2012
	Liabilities relating to defined benefit pension		$	416,707		$	474,555
	and early retirement plans
	Liabilities relating to nonqualified deferred		101,653			92,618
	compensation arrangements
	Deferred income taxes		142,258			145,437
	Miscellaneous		62,486			83,728
	Total		$	723,104		$	796,338
	Total Accumulated Other Comprehensive Loss
	The following table presents the components of “Total accumulated other comprehensive loss” as shown in the accompanying Consolidated Balance Sheets at September 27, 2013, and September 28, 2012 (in thousands):
			2013			2012
Foreign currency translation adjustments		$	(32,853	)	$	(9,149	)
Adjustments relating to defined benefit pension plans		(269,345		)	(269,892		)
Other		(1,929		)	(2,846		)
Total		$	(304,127	)	$	(281,887	)
Supplemental Cash Flow Information
During fiscal 2013 and fiscal 2012, the Company acquired businesses for cash and stock of $39.4 million and $91.6 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):
		2013			2012
Working capital		$	4,197		$	9,937
Property and equipment		386			3,378
Noncurrent assets		—			17,591
Deferred liabilities		2,181			(8,177		)
Non-controlling interests		18,589			40
Foreign currency translation		(3,461		)	21
Goodwill		17,537			68,785

Segment_Information

Segment Information	12 Months Ended
	Sep. 27, 2013
Segment Reporting [Abstract]	'
Segment Information	'
	Segment Information
	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.
	All of our operations share similar economic characteristics. For example, all of our operations are highly influenced by the general availability of qualified engineers and other technical professional staff. They also provide similar services as well as share similar processes for delivering our services. There is also a high degree of similarity of the workforces employed among the various categories of services we provide. For example, engineering and design services (i.e., services provided by persons who are degreed, and in certain circumstances licensed, professionals such as engineers, architects, scientists, and economists) exist in all four service categories. In addition, there is a high degree of similarity among a significant component of the workforces we employ to perform construction and operations and maintenance projects. In providing construction and operations and maintenance services, we employ a large number of skilled craft labor personnel. These include welders, pipe fitters, electricians, crane operators, and other personnel who work on very large capital projects (in the case of projects classified within the construction services category) or on smaller capital projects (in the case of maintenance projects classified within the operations and maintenance services category). In addition, the use of technology is highly similar and consistent throughout our organization, as is our client base (with the exception of our operations outside the U.S., which perform very little work for the U.S. federal government), and our quality assurance and safety programs. Furthermore, the types of information and internal reports used by the Company’s chief operating decision maker and other members of management to monitor performance, evaluate results of operations, allocate resources, and otherwise manage the business support a single reportable segment. Accordingly, based on these operational similarities and the way management monitors the Company’s results of operations, we have concluded that our operations may be aggregated into one reportable segment for purposes of this disclosure.
	The following table presents certain financial information by geographic area for fiscal 2013, 2012, and 2011 (in thousands):
		2013			2012		2011
	Revenues:
	United States	$	6,993,594		$	6,749,583	$	6,435,078
	Europe	2,148,504			1,681,421		1,649,678
	Canada	1,652,386			1,564,883		1,656,487
	Asia	204,203			156,748		102,272
	India	158,908			124,362		103,842
	Australia	141,507			253,932		194,560
	South America and Mexico	241,590			158,141		109,520
	Middle East and Africa	277,684			204,708		130,227
	Total	$	11,818,376		$	10,893,778	$	10,381,664
	Long-Lived Assets:
	United States	$	230,281		$	203,746	$	169,914
	Europe	47,128			46,763		49,372
	Canada	61,122			47,539		42,496
	Asia	4,272			3,580		1,653
	India	15,049			17,094		16,831
	Australia	8,329			7,859		1,040
	South America and Mexico	6,159			2,400		1,533
	Middle East and Africa	6,956			2,150		1,794
	Total	$	379,296		$	331,131	$	284,633
	Revenues were earned from unaffiliated clients located primarily within the various and respective geographic areas shown. Long-lived assets consist of property and equipment, net of accumulated depreciation and amortization.
	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 fiscal 2013, 2012, and 2011:
	2013	2012		2011
	19.9	22.1		24.4

Selected_Quarterly_Information

Selected Quarterly Information - Unaudited	12 Months Ended
	Sep. 27, 2013
Selected Quarterly Financial Information [Abstract]	'
Selected Quarterly Information - Unaudited	'
	Selected Quarterly Information — Unaudited
	The following table presents selected quarterly financial information for each of the last three fiscal years. Amounts are presented in thousands, except for per share amounts:
			First		Second		Third		Fourth			Fiscal
			Quarter		Quarter		Quarter		Quarter			Year
	2013
	Revenues		$	2,759,641	$	2,835,084	$	3,080,995	$	3,142,656		$	11,818,376
	Operating profit (a)		160,269		165,203		168,359		175,148			668,979
	Earnings before taxes		156,311		161,908		168,423		174,906			661,548
	Net earnings of the Group		104,523		107,089		112,089		116,481			440,182
	Net earnings attributable to		99,010		104,401		108,871		110,811			423,093
	Jacobs
	Earnings per share:
	Basic		0.77		0.81		0.84		0.85			3.27
	Diluted		0.76		0.8		0.83		0.84			3.23
	2012
	Revenues		$	2,631,768	$	2,702,851	$	2,772,874	$	2,786,285		$	10,893,778
	Operating profit (a)		141,952		133,138		153,366		167,617			596,073
	Earnings before taxes		139,554		132,315		151,371		170,096			593,336
	Net earnings of the Group		91,436		87,446		100,990		111,082			390,954
	Net earnings attributable to		89,710		83,933		97,900		107,411		(b)	378,954		(b)
	Jacobs
	Earnings per share:
	Basic		0.71		0.66		0.77		0.84		(b)	2.97		(b)
	Diluted		0.7		0.65		0.76		0.83		(b)	2.94		(b)
	2011
	Revenues		$	2,356,175	$	2,558,016	$	2,744,178	$	2,723,295		$	10,381,664
	Operating profit (a)		103,619		128,015		139,380		147,904			518,918
	Earnings before taxes		103,723		126,481		141,301		145,156			516,661
	Net earnings of the Group		66,697		81,341		91,936		95,247			335,221
	Net earnings attributable to		65,823		80,250		90,676		94,280			331,029
	Jacobs
	Earnings per share:
	Basic		0.53		0.64		0.72		0.75			2.63
	Diluted		0.52		0.63		0.71		0.74			2.6
	(a)	Operating profit represents revenues less (i) direct costs of contracts, and (ii) selling, general and administrative expenses.
	(b)	Includes a one-time, after-tax gain of $4.0 million, or $0.03 per diluted share, related to the sale of the Company's intellectual property for iron ore pelletizing and certain other related assets.

Definitions

Definitions	12 Months Ended
	Sep. 27, 2013
Definitions [Abstract]	'
Definitions	'
	Definitions
	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. The 1989 ESPP is a shareholder-approved, broad-based, employee stock purchase plan qualified under Section 423 of the U.S. IRC.
	“1999 ODSP" means the Jacobs Engineering Group Inc. 1999 Outside Director Stock Plan, as amended. The 1999 ODSP is a shareholder-approved, equity-based compensation plan covering Jacobs' non-management directors.
	“1999 SIP” means the Jacobs Engineering Group Inc. Stock Incentive Plan, as amended. The 1999 SIP is a shareholder-approved, equity-based compensation plan covering the Company's officers and key employees.
	“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 is 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_Policie1

Significant Accounting Policies (Policy)	12 Months Ended
	Sep. 27, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Revenue Accounting For Contracts And Use Of Joint Ventures Policy	'
	Revenue Accounting for Contracts and Use of Joint Ventures
	In general, we recognize revenues at the time we provide services. Depending on the commercial terms of the contract, we recognize revenues either when costs are incurred, or using the percentage-of-completion method of accounting by relating contract costs incurred to date to the total estimated costs at completion. Contract losses are provided for in their entirety in the period they become known, without regard to the percentage-of-completion. For multiple contracts with a single customer we account for each contract separately. We also recognize as revenues costs associated with claims and unapproved change orders to the extent it is probable that such claims and change orders will result in additional contract revenue, and the amount of such additional revenue can be reliably estimated.
	Certain cost-reimbursable contracts include incentive-fee arrangements. The incentive fees in such contracts 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 for each of the last three fiscal years (in millions):
	2013				2012			2011
	$	2,624.80			$	2,328.40		$	2,118.50
	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. Our joint ventures, therefore, are simply mechanisms used to deliver engineering and construction services to clients. Rarely do they, in and of themselves, present any risk of loss to us or to our partners separate from those that we would carry if we were performing the contract on our own. Under U.S. GAAP, our share of losses associated with the contracts held by the joint ventures, if and when they occur, has always been 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.
	For the Company’s unconsolidated joint ventures, we use either the equity method of accounting or proportional consolidation. The Company does not currently participate in any significant VIEs in which it has a controlling financial interest that it does not consolidate.
	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 10 —Commitments and Contingencies, and Derivative Financial Instruments are required to be carried in our Consolidated Financial Statements at Fair Value.
	The Fair Value of the Company’s reporting units (needed for purposes of determining whether there is an indication of possible impairment of the carrying value of goodwill) was determined in fiscal year 2011 using a market approach that multiplies the after-tax earnings of each reporting unit for the trailing twelve months by the Company’s overall average market earnings multiple. For fiscal years 2012 and 2013, we used both an income approach and a market approach to test our goodwill for possible impairment. Such approaches require us to make 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 value (both end of the range) for each reporting unit, exceeded the respective book values by more than 60%.
	With respect to 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 highly 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 drastically different Fair Values to be assigned to our stock option awards. For restricted stock units containing service and market conditions, compensation expense is based on the Fair Value of such units using a Monte Carlo simulation. Due to the uncertainties inherent in the use of assumptions and the results of applying Monte Carlo simulations, the amount of expense recorded in the accompanying consolidated financial statements may not be representative of the effects on our future consolidated financial statements because equity awards tend to vest over several years and additional equity awards may be made in the future.
	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 of the plans. 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. They are valued using the best information available, including quoted market prices or market prices for similar assets when available or internal cash flow estimates discounted at an appropriate interest rate or independent appraisals, as appropriate. Insurance contracts, investments in infrastructure/raw goods, and hedge funds are valued using actuarial assumptions and values reported by the 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 27, 2013 and September 28, 2012 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 the cost of intangible assets with indefinite lives are not amortized; instead, we test goodwill for possible impairment. We conduct such tests annually (or more frequently if events occur or circumstances change that would more likely than not reduce the Fair Values of our reporting units below their respective carrying values). The first step in the test is to compare the implied Fair Value of each of the Company’s reporting units to their respective carrying amounts, including goodwill. In the event that the carrying value of a reporting unit exceeds its Fair Value, a second test is performed to measure the amount of the impairment loss, if any. In performing the annual impairment test, the Company evaluates goodwill at the reporting unit level. We have determined that our operating segment is comprised of two reporting units based on geography. Based on the results of these tests, we have determined that the Fair Value of our reporting units substantially exceeded their respective carrying values for fiscal years 2013, 2012, and 2011.
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 period(s) 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 Company's Consolidated Financial Statements.
	The following table presents our stock-based compensation expense for the various types of awards made by the Company for each of the fiscal years presented (in thousands):
	Award Type		2013		2012		2011
	Restricted Stock and Restricted		$12,836		$11,021		$10,710
	Stock Units (excluding Market and
	Performance Awards)
	Stock Options		11,385		14,067		16,468
	Market and Performance Awards		15,297		7,354		1,906
	Total Expense		$39,518		$32,442		$29,084
	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 year are awarded on the same date (although the date is different for employees and directors). The following table presents the assumptions used in the Black-Scholes option-pricing model during each of the last three fiscal years for awards made to employees and directors:
			Awards Made to Employees							Awards Made to Directors
			2013			2012		2011		2013		2012		2011
	Dividend yield		0	%		0	%	0	%	0	%	0	%	0	%
	Expected volatility		38.37	%		43.28	%	41.54	%	37.65	%	41.42	%	41.97	%
	Risk-free interest rate		1.11	%		0.95	%	2	%	0.95	%	1.11	%	2.4	%
	Expected term of options (in years)		5.82			5.82		5.82		5.82		5.82		5.82
	Performance Awards— During fiscal year 2011, the Company granted restricted stock units containing service and performance conditions. The number of restricted stock units in which the employee may ultimately vest is determined using a stock performance multiplier (“SPM”). The SPM is the quotient obtained by dividing the 60 calendar day average market price of our common stock ending on the vesting date (“Ending Average Stock Price”) by the 60 calendar day average market price of our common stock ending on the grant date (“Beginning Average Stock Price”). The maximum SPM is 2 and will be zero if the Ending Average Market Price of our common stock is less than 50% of the Beginning Average Market Price. The number of restricted stock units earned is equal to the target restricted stock units awarded to an employee multiplied by the SPM.
	The Company's chief executive officer's restricted stock units are further subject to an additional Total Shareholder Return ("TSR") condition. Specifically, in order to receive full payout of whatever restricted stock unit award was otherwise earned at the end of the three-year performance period, the Company's TSR compared to its peers must be no less than at the 50th percentile. If performance is at the 25th percentile, 50% of the otherwise payable award is paid. No award is payable if TSR is below the 25th percentile. If performance is between the 25th and 50th percentile, the amount of the otherwise payable award is increased from 50% to 100% of the full award on a linear basis.
	Substantially all of the restricted stock units with market conditions granted during the year are awarded on the same date. The following table presents the assumptions used to value these restricted stock units:
		2011
	Dividend yield	—	%
	Expected volatility	46.67	%
	Risk-free interest rate	0.83	%
	Expected term (in years)	3
	During fiscal years 2013 and 2012, the Company granted restricted stock units containing service, performance, and market conditions. The restricted stock unit award is split equally between Earned Relative TSR Restricted Stock Units and Earned Net Earnings Growth Restricted Stock Units.
	The number of Earned Relative TSR Restricted Stock Units in which the employee may ultimately vest shall be equal to 50% of the grant multiplied by the TSR Performance Multiplier. The TSR Performance Multiplier will be 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 will be the average closing stock price over the 30 calendar day period ending on the award date ("Performance Period"), and the ending stock price will be 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 will be deemed re-invested on the ex-dividend data in additional shares of the related Company.
	The following table presents the basis on which the Earned Relative TSR Restricted Stock Units are determined:
	Company TSR Percentile Rank		TSR Performance Multiplier
	Below 30th percentile		—%
	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 restricted stock units market conditions granted during the year are awarded on the same date. The following table presents the assumptions used to value the Earned Relative TSR Restricted Stock Units:
		2013		2012
	Dividend yield	—	%	—	%
	Expected volatility	29.18	%	36.3	%
	Risk-free interest rate	0.42	%	0.42	%
	Expected term (in years)	3		3
	The number of Earned Net Earnings Growth Restricted Stock Units awarded in fiscal year 2012 in which an employee may ultimately vest shall be equal to the sum of the following: (1) an amount, not less than zero, equal to one-third of the Target Restricted Stock Units multiplied by 50% multiplied by the Net Earnings Growth Performance Multiplier (or, "NEGPM", as defined) determined based upon the growth in the Company's Net Earnings (as defined) over the period from April 1, 2012 to March 31, 2013; plus, (2) an amount, not less than zero, equal to (A) two-thirds of the Target Restricted Stock Units multiplied by 50% multiplied by the NEGPM determined based upon the average growth in the Company's Net Earnings over the period from April 1, 2012 to March 31, 2014, minus (B) the amount determined pursuant to (1) above; plus, (3) an amount, not less than zero, equal to (A) the Target Restricted Stock Units multiplied by 50% multiplied by the NEGPM determined based upon the average growth in the Company's Net Earnings over the period from April 1, 2012 to March 31, 2015, minus (B) the amount determined pursuant to (1) and (2) above.
	For Earned Net Earnings Growth Restricted Stock Units awarded in fiscal year 2013 all the criteria are the same over the three year vesting period as those referenced in the paragraph above with the exception of the performance period which is based upon the Company's Net Earnings (as defined) over the period starting on the first day of the Company's third quarter of fiscal 2013 and ending on the last day of the Company's second quarter of fiscal 2016.
	If the Company's average growth in 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 consolidated net earnings.
	The following table presents the basis on which the Earned Net Earnings Growth Restricted Stock Units are determined:
	Average Net		Net Earnings Growth
	Earnings Growth		Performance
			Multiplier
	Less than 5%		—%
	5%		50%
	10%		100%
	15%		150%
	20%		200%
	Unless stated otherwise, all other awards 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 date.
Concentrations Of Credit Risk	'
	Concentrations of Credit Risk
	Our cash balances and short-term investments are maintained in accounts held by major banks and financial institutions located primarily in North America, South America, Europe, Australia, 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 provision 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.
New Accounting Pronouncements	'
	New Accounting Pronouncements
	In February 2013, the FASB adopted ASU No. 2013-02—Comprehensive Income. ASU 2013-02 requires an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the statement of earnings or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income, but only if the amount reclassified is required under U.S. GAAP to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required under U.S. GAAP to be reclassified in their entirety to net income in the same reporting period, an entity is required to cross-reference to other disclosures required under U.S. GAAP that provide additional detail about these amounts. ASU 2013-02 is effective for annual and interim periods beginning after December 15, 2012. The adoption of ASU 2013-02 has not had a material effect on the Company's consolidated financial statements.
	In July 2012, the FASB adopted ASU No. 2012-02—Testing Indefinite-Lived Intangible Assets for Impairment. ASU 2012-02 amends Topic 350 of the FASB's ASC regarding how entities test indefinite-lived intangible assets other than goodwill for possible impairment. ASU 2012-02 permits entities first to assess qualitative factors to determine whether it is more likely than not that an indefinite lived intangible asset is impaired as a basis for determining whether it is necessary to perform the quantitative impairment test pursuant to ASC Subtopic 350-30. If the entity determines that is more likely than not that such asset is not impaired based on its qualitative assessment, no further testing is required. The amendments in ASU 2012-02 are effective for annual and interim impairment tests performed for fiscal years beginning after September 15, 2012. The adoption of ASU 2012-02 has not had a material effect on the Company's Consolidated Financial Statements.
	Also in December 2011, the FASB adopted ASU No. 2011-11—Disclosures about Offsetting Assets and Liabilities. ASU 2011-11 amends Topic 210 of the ASC and requires entities to disclose information about offsetting and related arrangements to enable users of their financial statements to understand the effect of those arrangements on their respective financial positions. The scope of this ASU includes derivatives, sale and repurchase agreements, reverse sale and repurchase agreements, and securities borrowing and securities lending agreements. Entities are required to apply the provisions of ASU 2011-11 for annual reporting periods beginning on or after January 1, 2013. The Company does not believe that the adoption of ASU 2011-11 will have a material effect on its consolidated financial statements.

Description_Of_Business_And_Ba1

Description Of Business And Basis Of Presentation (Tables)	12 Months Ended
	Sep. 27, 2013
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 each of the last three fiscal years was as follows:
		2013		2012		2011
	Cost-reimbursable	85	%	85	%	84	%
	Fixed-price	15	%	15	%	16	%

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	12 Months Ended
	Sep. 27, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Pass-Through Costs Included In Revenues	'
	The following table sets forth pass-through costs included in revenues for each of the last three fiscal years (in millions):
	2013				2012				2011
	$	2,624.80			$	2,328.40			$	2,118.50
Schedule Of Acquired Intangible Assets	'
	The following table provides certain information related to the Company’s acquired intangible assets for each of the fiscal years presented (in thousands):
			Customer				Developed				Trade			Other				Total
			Relationships,				Technology				Names
			Contracts, and
			Backlog
	Balances, October 1, 2010		$	95,478			$	—			$	2,052		$	2,515			$	100,045
	Acquisitions		155,512				23,000				2,744			2,542				183,798
	Amortization		(21,239		)		(1,023		)		(1,214		)	(1,225		)		(24,701		)
	Foreign currency translation		(13		)		—				(109		)	(14		)		(136		)
	Balances, September 30, 2011		229,738				21,977				3,473			3,818				259,006
	Acquisitions		13,010				—				1,200			410				14,620
	Amortization		(24,406		)		(1,533		)		(1,430		)	(1,597		)		(28,966		)
	Foreign currency translation		(613		)		—				(161		)	(124		)		(898		)
	Balances, September 28, 2012		217,729				20,444				3,082			2,507				243,762
	Amortization		(20,731		)		(1,533		)		(614		)	(1,130		)		(24,008		)
	Foreign currency translation		(1,471		)		—				(289		)	(90		)		(1,850		)
	Balances, September 27, 2013		$	195,527			$	18,911			$	2,179		$	1,287			$	217,904
	Weighted average amortization period		10.2				13				13.4			7.2				10.5
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	'
	The following table presents the final allocation of the purchase price to the net assets acquired, excluding intangibles and goodwill (in thousands):
	Assets:
	Cash and cash equivalents	$	329,689
	Receivables and other current assets	163,214
	Property and equipment, and other assets	115,688
	Total assets	608,591
	Liabilities:
	Current liabilities	292,003
	Long-term liabilities	22,534
	Total liabilities	314,537
	Net assets acquired	$	294,054
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination	'
	The following table presents the values assigned to the identifiable intangible assets acquired in the Aker Entities transactions (in thousands):
	Customer relationships / backlog	$	136,000
	Technology	23,000
	Total	$	159,000
Summary Of Goodwill In The Consolidated Balance Sheet	'
	The amount of goodwill created as a result of the Aker Entities transactions is summarized as follows (in thousands):
	Purchase price	$	910,000
	Amount assigned to net assets acquired	(294,054		)
	Amount assigned to identifiable intangible assets	(159,000		)
	Deferred taxes related to intangible assets	55,000
	Goodwill recognized	$	511,946
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 for each of the fiscal years presented (in thousands):
	Award Type		2013		2012		2011
	Restricted Stock and Restricted		$12,836		$11,021		$10,710
	Stock Units (excluding Market and
	Performance Awards)
	Stock Options		11,385		14,067		16,468
	Market and Performance Awards		15,297		7,354		1,906
	Total Expense		$39,518		$32,442		$29,084
	The following table sets forth certain information about the 1999 Plans:
			1999 SIP			1999 ODSP			Total
	Number of shares authorized		25,600,000			800,000			26,400,000
	Number of remaining shares reserved for issuance at September 27, 2013		9,456,344			389,625			9,845,969
	Number of shares relating to outstanding stock options at September 27, 2013		4,356,712			249,500			4,606,212
	Number of shares available for future awards:
	At September 27, 2013		5,099,632			140,125			5,239,757
	At September 28, 2012		446,994			188,625			635,619
Fair Value Of Option Grant Date Award	'
	The following table presents the assumptions used in the Black-Scholes option-pricing model during each of the last three fiscal years for awards made to employees and directors:
			Awards Made to Employees									Awards Made to Directors
			2013			2012			2011			2013		2012			2011
	Dividend yield		0	%		0	%		0	%		0	%	0	%		0	%
	Expected volatility		38.37	%		43.28	%		41.54	%		37.65	%	41.42	%		41.97	%
	Risk-free interest rate		1.11	%		0.95	%		2	%		0.95	%	1.11	%		2.4	%
	Expected term of options (in years)		5.82			5.82			5.82			5.82		5.82			5.82
Fair Value Of Restricted Stock Unit Grant Date Awards	'
	The following table presents the assumptions used to value these restricted stock units:
		2011
	Dividend yield	—	%
	Expected volatility	46.67	%
	Risk-free interest rate	0.83	%
	Expected term (in years)	3
Unit Basis For Earned Relative TSR Restricted Stock	'
	The following table presents the basis on which the Earned Relative TSR Restricted Stock Units are determined:
	Company TSR Percentile Rank		TSR Performance Multiplier
	Below 30th percentile		—%
	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 Earned Relative TSR Restricted Stock Units:
		2013		2012
	Dividend yield	—	%	—	%
	Expected volatility	29.18	%	36.3	%
	Risk-free interest rate	0.42	%	0.42	%
	Expected term (in years)	3		3
Unit Basis for Earned Net Earnings Growth Restricted Stock Units	'
	The following table presents the basis on which the Earned Net Earnings Growth Restricted Stock Units are determined:
	Average Net		Net Earnings Growth
	Earnings Growth		Performance
			Multiplier
	Less than 5%		—%
	5%		50%
	10%		100%
	15%		150%
	20%		200%

Stock_Purchase_And_Stock_Optio1

Stock Purchase And Stock Option Plans (Tables)	12 Months Ended
	Sep. 27, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
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 during each of the last three fiscal years:
			2013				2012				2011
	Aggregate Purchase Price Paid for Shares Sold:
	Under the 1989 ESPP		$	30,012,848			$	32,236,660			$	31,887,660
	Under the GESPP		3,068,578				2,944,987				2,894,302
	Total		$	33,081,426			$	35,181,647			$	34,781,962
	Aggregate Number of Shares Sold:
	Under the 1989 ESPP		642,675				853,819				771,818
	Under the GESPP		64,963				76,360				69,386
	Total		707,638				930,179				841,204
Stock Purchase And Stock Option Plans Information On The 1999 Plans	'
	The following table presents our stock-based compensation expense for the various types of awards made by the Company for each of the fiscal years presented (in thousands):
	Award Type		2013		2012		2011
	Restricted Stock and Restricted		$12,836		$11,021		$10,710
	Stock Units (excluding Market and
	Performance Awards)
	Stock Options		11,385		14,067		16,468
	Market and Performance Awards		15,297		7,354		1,906
	Total Expense		$39,518		$32,442		$29,084
	The following table sets forth certain information about the 1999 Plans:
			1999 SIP			1999 ODSP			Total
	Number of shares authorized		25,600,000			800,000			26,400,000
	Number of remaining shares reserved for issuance at September 27, 2013		9,456,344			389,625			9,845,969
	Number of shares relating to outstanding stock options at September 27, 2013		4,356,712			249,500			4,606,212
	Number of shares available for future awards:
	At September 27, 2013		5,099,632			140,125			5,239,757
	At September 28, 2012		446,994			188,625			635,619
Fair Value Of Shares Vested	'
	The following table presents the Fair Value of shares (of restricted stock and restricted stock units) vested during each of the last three fiscal years (in thousands):
	2013				2012				2011
	$	13,054			$	7,955			$	4,848
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 (in thousands):
	2013				2012				2011
	$	39,518			$	32,442			$	29,084
Stock Options Activity	'
	The following table summarizes the stock option activity for each of the last three fiscal years:
			Number of			Weighted
			Stock			Average
			Options			Exercise
						Price
	Outstanding at October 1, 2010		7,410,580			$	39.1
	Granted		433,600			$	46.04
	Exercised		(1,363,005	)		$	21.37
	Cancelled or expired		(19,665	)		$	47.81
	Outstanding at September 30, 2011		6,461,510			$	43.28
	Granted		658,700			$	37.45
	Exercised		(1,281,449	)		$	22.54
	Cancelled or expired		(82,027	)		$	43.92
	Outstanding at September 28, 2012		5,756,734			$	47.23
	Granted		753,450			$	54.71
	Exercised		(1,782,371	)		$	37
	Cancelled or expired		(121,601	)		$	50.22
	Outstanding at September 27, 2013		4,606,212			$	52.33
Total Intrinsic Value Of Options Exercised	'
	The following table presents the total intrinsic value of stock options exercised during each of the last three fiscal years (in thousands):
	2013				2012				2011
	$	22,163			$	26,196			$	34,665
Information Regarding Our Stock Option Plans	'
	The following table presents certain other information regarding our 1999 Plans:
			2013				2012				2011
	At fiscal year end:
	Range of exercise prices for options outstanding		$20.98–$94.11				$18.49–$94.11				$13.29–$94.11
	Number of options exercisable		3,034,111				4,219,557				4,822,297
	For the fiscal year:
	Range of prices relating to options exercised		$18.49–$56.95				$13.29–$37.73				$10.79–$41.18
	Estimated weighted average Fair Values of options granted		$	20.64			$	15.55			$	19.43
Information Regarding Options Outstanding, And Options Exercisable	'
	The following table presents certain information regarding stock options outstanding, and stock options exercisable at September 27, 2013:
			Options Outstanding									Options Exercisable
	Range of Exercise Prices		Number			Weighted		Weighted				Number	Weighted
						Average		Average					Average
						Remaining		Price					Exercise
						Contractual							Price
						Life
						(years)
	$20.98 - $26.80		91,800			0.67		$	23.14			91,800	$	23.14
	$32.51 - $37.32		569,500			8.55		37.01				157,125	36.98
	$37.43 - $46.86		1,757,213			6.15		42.54				1,388,287	42.41
	$47.11 - $55.04		972,925			8.72		52.74				247,825	48.32
	$55.13 - $57.81		503,975			0.93		56.94				494,975	56.97
	$58.26 - $83.61		136,075			5.41		72.43				79,375	81.34
	$88.19 - $94.11		574,724			1.63		92.57				574,724	92.57
			4,606,212			5.72		$	52.33			3,034,111	$	54.93
Restricted Stock and Restricted Stock Units Activity	'
	The following table presents the number of shares of restricted stock and restricted stock units issued under the 1999 SIP during each of the last three fiscal years:
			2013(1)			2012			2011
	Restricted stock		445,200			497,100			226,850
	Restricted stock units (service condition)		107,500			116,450			2,100
	Restricted stock units (service, market, and performance conditions at target)		471,250			525,000			291,700
	The amount of restricted stock units issued for awards with performance and market conditions in the above table are based on 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 following table presents the number of shares of restricted stock and restricted stock units cancelled and withheld under the 1999 SIP during each of the last three fiscal years:
			2013(1)(2)			2012			2011
	Restricted stock		128,923			80,460			33,200
	Restricted stock units (service condition)		3,385			5,650			—
	Restricted stock units (service, market, and performance conditions at target)		32,000			22,000			—
	The amount of restricted stock units cancelled for awards with market and performance conditions in the above table is based on the target amount.
	(1) The share amounts in the above tables for fiscal 2013 reflect the fungible share counting of 1.92 shares for each share of restricted stock and restricted stock unit issued.
	(2) Commencing in fiscal 2013, shares withheld for withholding tax liabilities are available for awards under the 1999 SIP and have been included in the table above for fiscal 2013 only.
	The following table provides the number of shares of restricted stock and restricted stock units outstanding at September 27, 2013 under the 1999 SIP. Shares granted prior to September 29, 2012 were granted on a 1-to-1 basis ("Not Fungible"). Shares Granted after September 28, 2012 were issued on a 1.92-to-1 basis ("Fungible"):
			Not Fungible			Fungible			Total
	Restricted stock		1,144,370			441,200			1,585,570
	Restricted stock units (service condition)		109,030			106,500			215,530
	Restricted stock units (service, market, and performance conditions at target)		762,700			471,250			1,233,950
	The following table presents the number of shares of restricted stock and restricted stock units issued under the 1999 ODSP during each of the last three fiscal years:
			2013			2012			2011
	Restricted stock units (service condition)		13,500			8,000			10,000
	The following table provides the number of shares of restricted stock and restricted stock units outstanding at September 27, 2013 under the 1999 ODSP:
			2013
	Restricted stock		40,000
	Restricted stock units (service condition)		47,500
	All shares granted under the 1999 ODSP are issued on a 1-to-1 basis.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Sep. 27, 2013
Earnings Per Share Reconciliation [Abstract]	'
Earnings Per Share	'
	The following table (i) reconciles the denominator used to compute Basic EPS to the denominator used to compute Diluted EPS for each of the last three fiscal years, and (ii) discloses the number of antidilutive stock options, restricted stock, and restricted stock units outstanding at the end of each of the fiscal years indicated (in thousands):
		2013	2012	2011
	Shares used to calculate EPS:
	Weighted average shares outstanding	129,288	127,644	125,686
	(denominator used to compute basic EPS)
	Effect of stock options and restricted stock	1,657	1,048	1,549
	Denominator used to compute diluted EPS	130,945	128,692	127,235
	Antidilutive stock options, restricted stock, and restricted stock units	2,603	5,093	4,507

Borrowings_Tables

Borrowings (Tables)	12 Months Ended
	Sep. 27, 2013
Debt Disclosure [Abstract]	'
Schedule of Long-term Debt Instruments	'
	The following table presents certain information regarding the Company’s long-term revolving credit facility at September 27, 2013, and September 28, 2012 (dollars in thousands):
			2013						2012
			Principal				Range		Principal		Range
			Balance				of Interest		Balance		of Interest
			Outstanding				Rates		Outstanding		Rates
	2012 Facility		$	415,086			0.96% – 1.37%		$	528,260	0.95% – 1.41%
Schedule Of Other Loan Agreements	'
	The following table presents certain additional information regarding the Company’s 2012 Facility for the fiscal years shown:
			2013				2012
	Maximum amount outstanding at any month-end during the fiscal year		$	526,602			$	586,933
	Average amount outstanding during the year		$	470,343			$	537,131
	Weighted average interest rate during the year		1.11				1.32
Schedule Of Interest Expense	'
	The following table presents the amount of interest paid by the Company during each of the last three fiscal years (in thousands):
	2013				2012				2011
	$	6,685			$	8,572			$	7,778

Pension_Plans_Tables

Pension Plans (Tables)	12 Months Ended
	Sep. 27, 2013
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.) during each of the fiscal years presented (in thousands):
			U.S. Pension Plans								Non-U.S. Pension Plans
			2013				2012				2013			2012
	Net benefit obligation at the		$	509,605			$	482,542			$	1,191,345		$	968,938
	beginning of the year
	Service cost		13,814				12,838				30,117			22,723
	Interest cost		18,569				20,923				51,331			54,287
	Participants’ contributions		3,071				3,200				11,805			11,614
	Actuarial (gains)/losses		(42,689		)		20,342				57,764			142,935
	Benefits paid		(33,960		)		(10,978		)		(34,058		)	(30,180		)
	Curtailments and settlements		—				(27,702		)		(6,297		)	(6,118		)
	Plan amendments		—				—				109			(2,294		)
	Business combinations/consolidations		—				8,440				—			8,933
	Special termination benefits		29				—				—			—
	Effect of exchange rate changes		—				—				5,215			20,507
	Net benefit obligation at the end		$	468,439			$	509,605			$	1,307,331		$	1,191,345
	of the year
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.) during each of the fiscal years presented (in thousands):
			U.S. Pension Plans								Non-U.S. Pension Plans
			2013				2012				2013			2012
	Fair Value of plan assets at the		$	359,348			$	285,777			$	877,950		$	744,689
	beginning of the year
	Actual return on plan assets		53,495				62,635				72,368			91,987
	Employer contributions		8,823				42,606				53,885			48,374
	Participants’ contributions		3,071				3,200				11,805			11,614
	Gross benefits paid		(33,960		)		(10,978		)		(34,058		)	(30,180		)
	Business combinations/consolidations		—				3,810				—			4,272
	Curtailments/settlements		—				(27,702		)		(4,973		)	(6,085		)
	Effect of exchange rate changes		—				—				5,502			13,279
	Fair Value of plan assets at the		$	390,777			$	359,348			$	982,479		$	877,950
	end of the year
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 27, 2013, and September 28, 2012 (segregated between plans existing within and outside the U.S.) (in thousands):
			U.S. Pension Plans								Non-U.S. Pension Plans
			2013				2012				2013			2012
	Net benefit obligation at the end		$	468,439			$	509,605			$	1,307,331		$	1,191,345
	of the year
	Fair Value of plan assets at the end		390,777				359,348				982,479			877,950
	of the year
	Under-funded amount recognized		$	77,662			$	150,257			$	324,852		$	313,395
	at the end of the year
Schedule of Accumulated and Projected Benefit Obligations	'
	The following table presents the accumulated benefit obligation at September 27, 2013, and September 28, 2012 (segregated between plans existing within and outside the U.S.) (in thousands):
			U.S. Pension Plans								Non-U.S. Pension Plans
			2013				2012				2013			2012
	Accumulated benefit obligation at the		$	431,726			$	460,618			$	1,222,234		$	1,109,413
	end of the year
Schedule Of Amount Recognized In Accompanying Balance Sheets	'
	The following table presents the amounts recognized in the accompanying Consolidated Balance Sheets at September 27, 2013, and September 28, 2012 (segregated between plans existing within and outside the U.S.) (in thousands):
			U.S. Pension Plans								Non-U.S. Pension Plans
			2013				2012				2013			2012
	Accrued benefit cost included in		$	—			$	—			$	15,193		$	13,174
	prepaid assets
	Accrued benefit cost included in		—				—				1,000			2,271
	current liabilities
	Accrued benefit cost included in		77,662				150,257				339,045			324,298
	noncurrent liabilities
	Net amount recognized at the end of		$	77,662			$	150,257			$	324,852		$	313,395
	the year
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 pension cost at September 27, 2013, and September 28, 2012 (segregated between plans existing within and outside the U.S.) (in thousands):
			U.S. Pension Plans								Non-U.S. Pension Plans
			2013				2012				2013			2012
	Net actuarial loss		$	50,446			$	68,970			$	228,074		$	201,726
	Prior service cost		—				—				(466		)	(803		)
	Total		$	50,446			$	68,970			$	227,608		$	200,923
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 pension cost in fiscal 2013(segregated between plans existing within and outside the U.S.) (in thousands):
			U.S.				Non-U.S.
			Pension				Pension
			Plans				Plans
	Unrecognized net actuarial loss		$	3,608			$	15,527
	Unrecognized prior service cost		(103		)		(25		)
	Accumulated comprehensive loss to be recorded against earnings		$	3,505			$	15,502
Schedule Of Weighted Average Measurement Of Assets And Liabilities	'
	The plans’ weighted average asset allocations at September 27, 2013, and September 28, 2012 (the measurement dates used in valuing the plans’ assets and liabilities) were as follows:
			U.S. Pension Plans						Non-U.S. Pension Plans
			2013			2012			2013			2012
	Equity securities		74	%		72	%		32	%		41	%
	Debt securities		20	%		21	%		31	%		37	%
	Real estate investments		1	%		1	%		6	%		6	%
	Other		5	%		6	%		31	%		16	%
Anticipated Cash Contributions	'
	The following table presents the amount of cash contributions we anticipate making into the plans during fiscal 2014 (in thousands):
	U.S.				Non-U.S.
	Pension Plans				Pension  Plans
	$	12,500			$	53,561
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  Plans
	2014		$	39,259			$	39,298
	2015		36,319				41,989
	2016		38,455				46,714
	2017		41,162				49,767
	2018		38,808				54,413
	For the period 2019 through 2023		204,246				344,800
Schedule Of Contribution To Multiemployer Pension Plans	'
	The following table presents the Company’s contributions to these multiemployer plans during each of the last three fiscal years (in thousands):
			2013				2012				2011
	Canada		$	72,660			$	72,053			$	81,608
	Europe and Australia		12,930				10,808				12,613
	United States		4,366				4,420				4,049
	Total		$	89,956			$	87,281			$	98,270
U.S. Pension Plans [Member]	'
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 each fiscal year presented:
			2013			2012			2011
	Weighted average discount rates		4.4% to 5.0%			3.4% to 3.9%			4.3% to 4.6%
	Rates of compensation increases		2.8	%		3.25	%		3.5	%
	Expected long-term rates of return		7.7	%		7.5	%		7.5	%
	on plan assets
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 loss at September 27, 2013, and September 28, 2012 (in thousands):
			2013				2012				2011
	Arising during the period:
	Net actuarial (gain) loss		$	(15,850	)		$	2,756			$	7,486
	Reclassification adjustments:
	Net actuarial gain		(2,674		)		(2,011		)		(2,011		)
	Total		$	(18,524	)		$	745			$	5,475
Schedule Of Fair Value Of Pension Plan Assets	'
	The following table presents the Fair Value of the Company’s U.S. pension plan assets at September 28, 2012, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands):
			Fair Values By Level of
			Fair Value Measurement Inputs
			Level 1				Level 3				Total
	U.S. Domestic equities		$	230,862			$	—			$	230,862
	Overseas equities		27,343				—				27,343
	U.S. Domestic bonds		75,648				—				75,648
	Cash and equivalents		6,183				—				6,183
	Real estate		—				4,841				4,841
	Hedge funds		—				14,471				14,471
	Total		$	340,036			$	19,312			$	359,348
	The following table presents the Fair Value of the Company’s U.S. pension plan assets at September 27, 2013, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands):
			Fair Values By Level of
			Fair Value Measurement Inputs
			Level 1				Level 3				Total
	U.S. Domestic equities		$	247,155			$	—			$	247,155
	Overseas equities		40,719				—				40,719
	U.S. Domestic bonds		79,482				—				79,482
	Cash and equivalents		3,499				—				3,499
	Real estate		—				4,411				4,411
	Hedge funds		—				15,511				15,511
	Total		$	370,855			$	19,922			$	390,777
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 27, 2013 (in thousands):
			Real				Hedge
			Estate				Funds
	Balance, beginning of year		$	4,841			$	14,471
	Transfers		—				—
	Realized and unrealized gains (losses)		(430		)		1,040
	Balance, end of year		$	4,411			$	15,511
	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 28, 2012 (in thousands):
			Real				Hedge
			Estate				Funds
	Balance, beginning of year		$	5,353			$	14,845
	Transfers		—				—
	Realized and unrealized losses		(512		)		(374		)
	Balance, end of year		$	4,841			$	14,471
Schedule Of Components Of Net Periodic Pension Cost Recognized	'
	The following table presents the components of net periodic pension cost for the Company’s U.S. pension plans recognized in the accompanying Consolidated Statements of Earnings for each of the last three fiscal years (in thousands):
			2013				2012				2011
	Service cost		$	13,814			$	12,838			$	10,684
	Interest cost		18,569				20,923				21,377
	Expected return on plan assets		(25,826		)		(23,764		)		(23,558		)
	Actuarial loss		8,030				10,981				7,025
	Prior service cost		(103		)		(103		)		(103		)
	Net pension cost, before special items		14,484				20,875				15,425
	Special termination benefits		29				—				120
	Settlement loss		—				6,035				—
	Total net periodic pension cost recognized		$	14,513			$	26,910			$	15,545
Non-U.S. Pension Plans [Member]	'
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 each fiscal year presented:
			2013		2012		2011
	Weighted average discount rates		0.4% to 9.3%		0.6% to 8.4%		2.6% to 5.9%
	Rates of compensation increases		2.5% to 7.5%		2.8% to 7.5%		3.0% to 3.5%
	Expected long-term rates of return		0.4% to 8.5%		2.4% to 8.5%		4.75% to 7.1%
	on plan assets
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 loss at September 27, 2013, and September 28, 2012 (in thousands):
			2013				2012				2011
	Arising during the period:
	Net actuarial loss (gain)		$	27,417			$	83,298			$	(73,258	)
	Prior service cost (benefit)		297				(1,947		)		1,005
	Total		27,714				81,351				(72,253		)
	Reclassification adjustments:
	Net actuarial gain		(9,778		)		(6,131		)		(4,990		)
	Prior service cost (benefit)		41				(23		)		(1,406		)
	Total		(9,737		)		(6,154		)		(6,396		)
	Total		$	17,977			$	75,197			$	(78,649	)
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 27, 2013, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands):
			Fair Values By Level of
			Fair Value Measurement Inputs
			Level 1				Level 3				Total
	U.S. Domestic equities		$	108,261			$	—			$	108,261
	Overseas equities		207,607				—				207,607
	U.S. Domestic bonds		230,202				—				230,202
	Overseas bonds		76,372				—				76,372
	Cash and equivalents		28,185				—				28,185
	Infrastructure / raw goods		—				7,076				7,076
	Real estate		—				57,173				57,173
	Insurance contracts		—				21,214				21,214
	Hedge funds		—				246,389				246,389
	Total		$	650,627			$	331,852			$	982,479
	The following table presents the Fair Value of the Company’s Non-U.S. pension plan assets at September 28, 2012, segregated by level of Fair Value measurement inputs within the Fair Value hierarchy promulgated by U.S. GAAP (in thousands):
			Fair Values By Level of
			Fair Value Measurement Inputs
			Level 1				Level 3				Total
	U.S. Domestic equities		$	193,715			$	—			$	193,715
	Overseas equities		168,097				—				168,097
	U.S. Domestic bonds		306,974				—				306,974
	Overseas bonds		14,254				—				14,254
	Cash and equivalents		27,571				—				27,571
	Infrastructure / raw Goods		—				6,111				6,111
	Real estate		—				49,537				49,537
	Insurance contracts		—				18,291				18,291
	Hedge funds		—				93,400				93,400
	Total		$	710,611			$	167,339			$	877,950
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 27, 2013 (in thousands):
			Infrastructure				Real				Insurance			Hedge
			/ Raw Goods				Estate				Contracts			Funds
	Balance, beginning of year		$	6,111			$	49,537			$	18,291		$	93,400
	Purchases, sales, and settlements		—				—				1,646			144,441
	Realized and unrealized gains		678				7,670				1,058			4,664
	Effect of exchange rate changes		287				(34		)		219			3,884
	Balance, end of year		$	7,076			$	57,173			$	21,214		$	246,389
	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 28, 2012 (in thousands):
			Infrastructure				Real				Insurance			Hedge
			/ Raw Goods				Estate				Contracts			Funds
	Balance, beginning of year		$	4,776			$	43,997			$	17,293		$	81,776
	Purchases, sales, and settlements		—				106				389			—
	Realized and unrealized gains		1,572				3,836				1,422			7,975
	Transfers		—				—				—			—
	Effect of exchange rate changes		(237		)		1,598				(813		)	3,649
	Balance, end of year		$	6,111			$	49,537			$	18,291		$	93,400
Schedule Of Components Of Net Periodic Pension Cost Recognized	'
	The following table presents the components of net periodic pension cost for the Company’s Non-U.S. pension plans recognized in the accompanying Consolidated Statements of Earnings for each of the last three fiscal years (in thousands):
			2013				2012				2011
	Service cost		$	30,117			$	22,723			$	30,816
	Interest cost		51,331				54,287				54,631
	Expected return on plan assets		(54,817		)		(50,996		)		(50,033		)
	Actuarial loss		13,276				8,227				13,535
	Prior service cost		(43		)		152				303
	Net pension cost, before special		39,864				34,393				49,252
	items
	Curtailments and settlements		(383		)		1,326				381
	Total net periodic pension cost		$	39,481			$	35,719			$	49,633
	recognized

Other_Comprehensive_Income_Tab

Other Comprehensive Income (Tables)	12 Months Ended
	Sep. 27, 2013
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax [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 selling, general and administrative expenses in the Company's Consolidated Statements of Earnings for the periods presented related to the Company's defined benefit pension plans (in thousands):
		2013			2012			2011
	Amortization of Defined Benefit Items:
	Actuarial losses	$	(17,554	)	$	(11,444	)	$	(16,182	)
	Prior service benefit (cost)	43			(152		)	(97		)
	Total Before Income Tax	(17,511		)	(11,596		)	(16,279		)
	Income Tax Benefit	5,859			3,955			5,716
	Total reclassifications after-tax	$	(11,652	)	$	(7,641	)	$	(10,563	)

Savings_And_Deferred_Compensat1

Savings And Deferred Compensation Plans (Tables)	12 Months Ended
	Sep. 27, 2013
Savings And Deferred Compensation Plans [Abstract]	'
Schedule Of Savings Plans Contributions	'
	The following table presents the Company’s contributions to these savings plans during each of the last three fiscal years (in thousands):
	2013		2012		2011
	$	74,686	$	70,211	$	61,065
Schedule Of Deferred Compensation Plans Expense	'
	The following table presents the amount charged to expense for the Company’s deferred compensation plans during each of the last three fiscal years (in thousands):
	2013		2012		2011
	$	4,470	$	4,349	$	3,075

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Sep. 27, 2013
Income Tax Disclosure [Abstract]	'
Components Of Consolidated Income Tax Expense	'
	The following table presents the components of our consolidated income tax expense for each of the last three fiscal years (in thousands):
			2013				2012				2011
	Current income tax expense:
	Federal		$	121,302			$	111,035			$	102,903
	State		23,246				23,303				25,067
	Foreign		74,107				69,080				37,617
	Total current tax expense		218,655				203,418				165,587
	Deferred income tax expense (benefit):
	Federal		(4,718		)		(2,505		)		10,482
	State		(582		)		(1,985		)		(1,760		)
	Foreign		8,011				3,454				7,131
	Total deferred income tax		2,711				(1,036		)		15,853
	expense (benefit)
	Consolidated income tax expense		$	221,366			$	202,382			$	181,440
Components Of Deferred Tax Assets	'
	The following table presents the components of our net deferred tax assets at September 27, 2013, and September 28, 2012 (in thousands):
			2013				2012
	Deferred tax assets:
	Obligations relating to:
	Defined benefit pension plans		$	97,349			$	103,984
	Other employee benefit plans		198,869				173,515
	Self-insurance programs		1,758				10,847
	Contract revenues and costs		19,468				39,894
	Other		11,100				10,749
	Gross deferred tax assets		328,544				338,989
	Deferred tax liabilities:
	Depreciation and amortization		(127,974		)		(125,704		)
	Residual US tax on unremitted non-US		(6,724		)		(9,024		)
	earnings
	Other, net		(7,560		)		(10,709		)
	Gross deferred tax liabilities		(142,258		)		(145,437		)
	Net deferred tax assets		$	186,286			$	193,552
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 during each of the last three fiscal years (in millions):
	2013				2012				2011
	$	7.3			$	9.3			$	11.9
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 each of the last three fiscal years (dollars in thousands):
			2013				2012				2011
	Statutory amount		$	231,542			$	207,668			$	180,831
	State taxes, net of the federal		14,892				13,538				15,150
	benefit
	Tax differential on foreign		(18,700		)		(16,667		)		(7,841		)
	earnings
	Other, net		(6,368		)		(2,157		)		(6,700		)
	Consolidated income tax expense		$	221,366			$	202,382			$	181,440
	Rates used to compute statutory		35		%		35		%		35		%
	amount
	Consolidated effective income		33.5		%		34.1		%		35.1		%
	tax rate
Income Tax Payments	'
	The following table presents income tax payments made during each of the last three fiscal years (in millions):
	2013				2012				2011
	$	235.8			$	191.4			$	139.2
Components Of Our Consolidated Earnings Before Taxes	'
	The following table presents the components of our consolidated earnings before taxes for each of the last three fiscal years (in thousands):
			2013				2012				2011
	United States earnings		$	352,404			$	286,987			$	341,059
	Foreign earnings		309,144				306,349				175,602
			$	661,548			$	593,336			$	516,661
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 presented (in thousands):
			2013				2012				2011
	Balance, beginning of year		$	53,637			$	31,130			$	27,825
	Additions based on tax positions related to the current year		5,447				6,110				6,731
	Additions for tax positions of prior years		—				21,438				4,252
	Reductions for tax positions of prior years		(6,354		)		(4,441		)		(7,678		)
	Settlement		(960		)		(600		)		—
	Balance, end of year		$	51,770			$	53,637			$	31,130

Commitments_And_Contingencies_1

Commitments And Contingencies, And Derivative Financial Instruments (Tables)	12 Months Ended
	Sep. 27, 2013
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 $909.8 million at September 27, 2013, payable as follows (in thousands):
	In fiscal years,
	2014	$	150,448
	2015	177,493
	2016	118,984
	2017	99,942
	2018	83,884
	Thereafter	288,944
		919,695
	Amounts representing sublease income	(9,937		)
	Total, net aggregate future lease payments	$	909,758
Rent Expense And Sublease Income	'
	The following table presents rent expense and sublease income offsetting the Company’s rent expense during each of the last three fiscal years (in thousands):
			2013			2012			2011
	Rent expense		$	173,340		$	165,221		$	157,955
	Sublease income		(7,914		)	(8,402		)	(8,315		)
	Net rent		$	165,426		$	156,819		$	149,640
Significant Terms Of The Lease	'
	Significant terms of the lease are as follows:
	End of lease term	2015
	End of term purchase option (in thousands)	$	52,200
	Residual value guaranty (in thousands)	$	38,800

Other_Financial_Information_Ta

Other Financial Information (Tables)	12 Months Ended
	Sep. 27, 2013
Other Financial Information [Abstract]	'
Receivables	'
	The following table presents the components of “Receivables” as shown in the accompanying Consolidated Balance Sheets at September 27, 2013, and September 28, 2012 as well as certain other related information (in thousands):
			2013			2012
	Amounts billed, net		$	1,389,278		$	1,193,500
	Unbilled receivables and other		1,109,931			1,110,008
	Retentions receivable		49,781			45,384
	Total receivables, net		$	2,548,990		$	2,348,892
	Other information about receivables:
	Amounts due from the United States federal		$	292,698		$	294,327
	government included above, net of
	advanced billings
	Claims receivable		$	25,237		$	26,309
Property, Equipment, and Improvements, Net	'
	The following table presents the components of our property, equipment, and improvements, net at September 27, 2013, and September 28, 2012 (in thousands):
			2013			2012
	Land		$	22,027		$	23,786
	Buildings		131,690			136,193
	Equipment		537,835			502,568
	Leasehold improvements		204,940			163,916
	Construction in progress		22,678			29,595
			919,170			856,058
	Accumulated depreciation and amortization		(539,874		)	(524,927		)
			$	379,296		$	331,131
Miscellaneous Noncurrent Assets	'
	The following table presents the components of “Miscellaneous noncurrent assets” as shown in the accompanying Consolidated Balance Sheets at September 27, 2013, and September 28, 2012 (in thousands):
			2013			2012
	Deferred income taxes		$	197,458		$	196,620
	Cash surrender value of life insurance policies		100,253			86,502
	Intangible assets (a)		217,904			243,762
	Investments		194,782			187,248
	Notes receivable		11,689			11,128
	Reimbursable pension costs (b)		84,348			132,463
	Other		26,025			28,162
	Total		$	832,459		$	885,885
	(a)    Consists primarily of intangible assets acquired in connection with various business combinations.
	(b)	Consists of costs incurred relating to a defined benefit pension plan covering employees providing services on a contract with, and for the benefit of, the U.S. federal government pursuant to which such costs are fully reimbursable.
Components of Accrued Liabilities	'
	The following table presents the components of “Accrued liabilities” as shown in the accompanying Consolidated Balance Sheets at September 27, 2013 and September 28, 2012 (in thousands):
			2013			2012
	Accrued payroll and related liabilities		$	688,391		$	641,340
	Project-related accruals		115,418			196,836
	Insurance liabilities		48,209			63,908
	Sales and other similar taxes		47,973			41,951
	Deferred rent		57,581			41,342
	Other		72,244			76,592
	Total		$	1,029,816		$	1,061,969
Components Of Other Deferred Liabilities	'
	The following table presents the components of “Other deferred liabilities” as shown in the accompanying Consolidated Balance Sheets at September 27, 2013 and September 28, 2012 (in thousands):
			2013			2012
	Liabilities relating to defined benefit pension		$	416,707		$	474,555
	and early retirement plans
	Liabilities relating to nonqualified deferred		101,653			92,618
	compensation arrangements
	Deferred income taxes		142,258			145,437
	Miscellaneous		62,486			83,728
	Total		$	723,104		$	796,338
Components Of Total Accumulated Other Comprehensive Loss	'
	The following table presents the components of “Total accumulated other comprehensive loss” as shown in the accompanying Consolidated Balance Sheets at September 27, 2013, and September 28, 2012 (in thousands):
			2013			2012
	Foreign currency translation adjustments		$	(32,853	)	$	(9,149	)
	Adjustments relating to defined benefit pension plans		(269,345		)	(269,892		)
	Other		(1,929		)	(2,846		)
	Total		$	(304,127	)	$	(281,887	)
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):
			2013			2012
	Working capital		$	4,197		$	9,937
	Property and equipment		386			3,378
	Noncurrent assets		—			17,591
	Deferred liabilities		2,181			(8,177		)
	Non-controlling interests		18,589			40
	Foreign currency translation		(3,461		)	21
	Goodwill		17,537			68,785

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Sep. 27, 2013
Segment Reporting [Abstract]	'
Financial Information By Geographic Area	'
	The following table presents certain financial information by geographic area for fiscal 2013, 2012, and 2011 (in thousands):
		2013			2012		2011
	Revenues:
	United States	$	6,993,594		$	6,749,583	$	6,435,078
	Europe	2,148,504			1,681,421		1,649,678
	Canada	1,652,386			1,564,883		1,656,487
	Asia	204,203			156,748		102,272
	India	158,908			124,362		103,842
	Australia	141,507			253,932		194,560
	South America and Mexico	241,590			158,141		109,520
	Middle East and Africa	277,684			204,708		130,227
	Total	$	11,818,376		$	10,893,778	$	10,381,664
	Long-Lived Assets:
	United States	$	230,281		$	203,746	$	169,914
	Europe	47,128			46,763		49,372
	Canada	61,122			47,539		42,496
	Asia	4,272			3,580		1,653
	India	15,049			17,094		16,831
	Australia	8,329			7,859		1,040
	South America and Mexico	6,159			2,400		1,533
	Middle East and Africa	6,956			2,150		1,794
	Total	$	379,296		$	331,131	$	284,633
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 fiscal 2013, 2012, and 2011:
	2013	2012		2011
	19.9	22.1		24.4

Selected_Quarterly_Information1

Selected Quarterly Information - Unaudited (Tables)	12 Months Ended
	Sep. 27, 2013
Selected Quarterly Financial Information [Abstract]	'
Schedule Of Quarterly Financial Information	'
	The following table presents selected quarterly financial information for each of the last three fiscal years. Amounts are presented in thousands, except for per share amounts:
			First		Second		Third		Fourth			Fiscal
			Quarter		Quarter		Quarter		Quarter			Year
	2013
	Revenues		$	2,759,641	$	2,835,084	$	3,080,995	$	3,142,656		$	11,818,376
	Operating profit (a)		160,269		165,203		168,359		175,148			668,979
	Earnings before taxes		156,311		161,908		168,423		174,906			661,548
	Net earnings of the Group		104,523		107,089		112,089		116,481			440,182
	Net earnings attributable to		99,010		104,401		108,871		110,811			423,093
	Jacobs
	Earnings per share:
	Basic		0.77		0.81		0.84		0.85			3.27
	Diluted		0.76		0.8		0.83		0.84			3.23
	2012
	Revenues		$	2,631,768	$	2,702,851	$	2,772,874	$	2,786,285		$	10,893,778
	Operating profit (a)		141,952		133,138		153,366		167,617			596,073
	Earnings before taxes		139,554		132,315		151,371		170,096			593,336
	Net earnings of the Group		91,436		87,446		100,990		111,082			390,954
	Net earnings attributable to		89,710		83,933		97,900		107,411		(b)	378,954		(b)
	Jacobs
	Earnings per share:
	Basic		0.71		0.66		0.77		0.84		(b)	2.97		(b)
	Diluted		0.7		0.65		0.76		0.83		(b)	2.94		(b)
	2011
	Revenues		$	2,356,175	$	2,558,016	$	2,744,178	$	2,723,295		$	10,381,664
	Operating profit (a)		103,619		128,015		139,380		147,904			518,918
	Earnings before taxes		103,723		126,481		141,301		145,156			516,661
	Net earnings of the Group		66,697		81,341		91,936		95,247			335,221
	Net earnings attributable to		65,823		80,250		90,676		94,280			331,029
	Jacobs
	Earnings per share:
	Basic		0.53		0.64		0.72		0.75			2.63
	Diluted		0.52		0.63		0.71		0.74			2.6
	(a)	Operating profit represents revenues less (i) direct costs of contracts, and (ii) selling, general and administrative expenses.
	(b)	Includes a one-time, after-tax gain of $4.0 million, or $0.03 per diluted share, related to the sale of the Company's intellectual property for iron ore pelletizing and certain other related assets.

Description_Of_Business_And_Ba2

Description Of Business And Basis Of Presentation (Details)	12 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Basis of Presentation [Line Items]	'	'	'
Cost-reimbursable	85.00%	85.00%	84.00%
Fixed-price	15.00%	15.00%	16.00%
Minimum [Member]	'	'	'
Basis of Presentation [Line Items]	'	'	'
Frequency of fiscal year with an additional week of activity (in years)	'5 years	'	'
Maximum [Member]	'	'	'
Basis of Presentation [Line Items]	'	'	'
Frequency of fiscal year with an additional week of activity (in years)	'6 years	'	'

Significant_Accounting_Policie3

Significant Accounting Policies (Narrative) (Details)

12 Months Ended

0 Months Ended

12 Months Ended

12 Months Ended

Sep. 27, 2013

Sep. 28, 2012

Sep. 30, 2011

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 08, 2013

Sep. 08, 2013

Sep. 28, 2012

Apr. 01, 2011

Sep. 28, 2012

Sep. 28, 2012

Sep. 28, 2012

Sep. 30, 2011

USD ($)

USD ($)

Minimum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

CEO Restricted Stock [Member]

Restricted Stock Units (RSUs) [Member]

Earned Relative TSR Restricted Stock Units [Member]

Earned Net Earnings Growth Restricted Stock Units [Member]

Twenty-Fifth Percentile [Member]

Between 25th and 50th Percentile [Member]

April 1, 2012 to March 31, 2013 [Member]

April 1, 2012 to March 31, 2014 [Member]

April 1, 2012 to March 31, 2015 [Member]

Between 5% and 10% [Member]

Between 5% and 10% [Member]

Between 10% and 15% [Member]

Between 10% and 15% [Member]

Between 15% and 20% [Member]

Between 15% and 20% [Member]

Sinclair Knight Merz [Member]

Sinclair Knight Merz [Member]

Aker Entity [Member]

Aker Entity [Member]

Aker Entity [Member]

Aker Entity [Member]

Selling, General and Administrative Expenses [Member]

Selling, General and Administrative Expenses [Member]

unit

Building [Member]

Equipment [Member]

Leasehold Improvements [Member]

Building [Member]

Equipment [Member]

Leasehold Improvements [Member]

CEO Restricted Stock [Member]

CEO Restricted Stock [Member]

Earned Net Earnings Growth Restricted Stock Units [Member]

Earned Net Earnings Growth Restricted Stock Units [Member]

Earned Net Earnings Growth Restricted Stock Units [Member]

Earned Net Earnings Growth Restricted Stock Units [Member]

Earned Net Earnings Growth Restricted Stock Units [Member]

Earned Net Earnings Growth Restricted Stock Units [Member]

Earned Net Earnings Growth Restricted Stock Units [Member]

Earned Net Earnings Growth Restricted Stock Units [Member]

Earned Net Earnings Growth Restricted Stock Units [Member]

USD ($)

AUD

USD ($)

Minimum [Member]

Maximum [Member]

USD ($)

USD ($)

plans

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

employee

Significant Accounting Policies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair value, reporting unit, duration of trailing months of after-tax earnings

'

'

'12 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Reporting units percent of fair value above book value

'

'

'

60.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unbilled amounts billed and collected, collection period (in months)

'12 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Estimated useful life of assets

'

'

'

'

'20 years

'3 years

'4 years

'40 years

'10 years

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of reporting units

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of intangible assets year one

$24,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of intangible assets year two

23,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of intangible assets year three

23,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of intangible assets year four

23,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of intangible assets year five

23,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of employees

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6,500

6,500

'

'

'

'

'

'

Acquisition agreement, expected percentage of interests to be acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

100.00%

'

'

'

'

'

'

Acquisition agreement, expected payments to acquire business

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,200,000,000

1,300,000,000

'

'

'

'

'

'

Acquisition Agreement, Fair Value of Acquired Entity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,100,000,000

1,200,000,000

'

'

'

'

'

'

Purchase price, before estimate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

675,000,000

'

'

'

'

Specified transactions added to share purchase agreement price

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

234,600,000

'

'

'

'

Intangible assets useful life

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'1 year

'15 years

'

'

Weighted average useful life for intangibles

'10 years 6 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'12 years 9 months 18 days

'

'

'

'

'

Acquisition-related costs

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,800,000

15,200,000

Purchase accounting adjustment, accrued liabilities

'

100,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase accounting adjustment, income taxes payable

'

10,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase accounting adjustment, other deferred liabilities

'

39,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase accounting adjustment, goodwill

'

127,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase accounting adjustment, deferred tax assets

'

$22,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of incentive plans (in plans)

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock performance multiplier numerator, number of calendar days average market price of common stock ending on vesting date (in days)

'

'

'

'

'

'

'

'

'

'

'

'60 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock performance multiplier denominator, number of calendar days average market price of common stock ending on grant date (in days)

'

'

'

'

'

'

'

'

'

'

'

'60 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock performance multiplier, maximum

'

'

'

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock performance multiplier, if ending average market price of common stock less than 50 percent of beginning average market price

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Award service period

'

'

'

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

TSR performance multiplier

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50.00%

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Earned Relative TSR restricted stock unit, vesting rule, percent of grant eligible for vesting

'

'

'

'

'

'

'

'

'

'

'

'

50.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other Than Options, TSR Performance Multiplier Rule, Determination Period

'

'

'

'

'

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total stockholder return, beginning stock price, number of calendar days average closing common stock price ending on award date (in days)

'

'

'

'

'

'

'

'

'

'

'

'

'30 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total stockholder return, ending stock price, number of calendar days average closing price ending on last day of performance period (in days)

'

'

'

'

'

'

'

'

'

'

'

'

'30 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Earned Net Earnings Growth Restricted Stock, unit basis rule, multiplier

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50.00%

50.00%

50.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Earned Net Earnings Growth Restricted Stock, vesting period

'

'

'

'

'

'

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Earned Net Earnings Growth Restricted Stock, unit basis rule, percent of target RSU

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

33.33%

66.67%

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Earned 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%

10.00%

10.00%

15.00%

15.00%

20.00%

'

'

'

'

'

'

'

'

Significant_Accounting_Policie4

Significant Accounting Policies (Pass-Through Costs Included In Revenues) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'	'	'
Pass-through costs included in revenues	$2,624.80	$2,328.40	$2,118.50

Significant_Accounting_Policie5

Significant Accounting Policies (Schedule Of Acquired Intangible Assets) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013		Sep. 28, 2012		Sep. 30, 2011
Acquired Finite-Lived Intangible Assets [Roll Forward]	'		'		'
Acquired intangible assets beginning balance	$243,762	[1]	$259,006		$100,045
Acquisitions	'		14,620		183,798
Amortization	-28,985		-41,934		-37,750
Foreign currency translation	-1,850		-898		-136
Acquired intangible assets ending balance	217,904	[1]	243,762	[1]	259,006
Weighted average amortization period	'10 years 6 months		'		'
Customer Relationship, Contracts And Backlog [Member]	'		'		'
Acquired Finite-Lived Intangible Assets [Roll Forward]	'		'		'
Acquired intangible assets beginning balance	217,729		229,738		95,478
Acquisitions	'		13,010		155,512
Foreign currency translation	-1,471		-613		-13
Acquired intangible assets ending balance	195,527		217,729		229,738
Weighted average amortization period	'10 years 2 months 12 days		'		'
Developed Technology [Member]	'		'		'
Acquired Finite-Lived Intangible Assets [Roll Forward]	'		'		'
Acquired intangible assets beginning balance	20,444		21,977		'
Acquisitions	'		'		23,000
Foreign currency translation	'		'		'
Acquired intangible assets ending balance	18,911		20,444		21,977
Weighted average amortization period	'13 years		'		'
Trade Names [Member]	'		'		'
Acquired Finite-Lived Intangible Assets [Roll Forward]	'		'		'
Acquired intangible assets beginning balance	3,082		3,473		2,052
Acquisitions	'		1,200		2,744
Foreign currency translation	-289		-161		-109
Acquired intangible assets ending balance	2,179		3,082		3,473
Weighted average amortization period	'13 years 4 months 24 days		'		'
Other [Member]	'		'		'
Acquired Finite-Lived Intangible Assets [Roll Forward]	'		'		'
Acquired intangible assets beginning balance	2,507		3,818		2,515
Acquisitions	'		410		2,542
Foreign currency translation	-90		-124		-14
Acquired intangible assets ending balance	1,287		2,507		3,818
Weighted average amortization period	'7 years 2 months 12 days		'		'
Excluding Investment in AWE Management Ltd [Member]	'		'		'
Acquired Finite-Lived Intangible Assets [Roll Forward]	'		'		'
Amortization	-24,008		-28,966		-24,701
Excluding Investment in AWE Management Ltd [Member] | Customer Relationship, Contracts And Backlog [Member]	'		'		'
Acquired Finite-Lived Intangible Assets [Roll Forward]	'		'		'
Amortization	-20,731		-24,406		-21,239
Excluding Investment in AWE Management Ltd [Member] | Developed Technology [Member]	'		'		'
Acquired Finite-Lived Intangible Assets [Roll Forward]	'		'		'
Amortization	-1,533		-1,533		-1,023
Excluding Investment in AWE Management Ltd [Member] | Trade Names [Member]	'		'		'
Acquired Finite-Lived Intangible Assets [Roll Forward]	'		'		'
Amortization	-614		-1,430		-1,214
Excluding Investment in AWE Management Ltd [Member] | Other [Member]	'		'		'
Acquired Finite-Lived Intangible Assets [Roll Forward]	'		'		'
Amortization	($1,130)		($1,597)		($1,225)
[1]	Consists primarily of intangible assets acquired in connection with various business combinations.

Significant_Accounting_Policie6

Significant Accounting Policies (Allocation of Purchase Price) (Details) (USD $)	Sep. 27, 2013	Sep. 28, 2012	Mar. 30, 2012	Mar. 30, 2012	Mar. 30, 2012
In Thousands, unless otherwise specified			Aker Entity [Member]	Customer relationships / backlog [Member]	Technology [Member]
				Aker Entity [Member]	Aker Entity [Member]
Assets:	'	'	'	'	'
Cash and cash equivalents	'	'	$329,689	'	'
Receivables and other current assets	'	'	163,214	'	'
Property and equipment, and other assets	'	'	115,688	'	'
Total assets	'	'	608,591	'	'
Liabilities:	'	'	'	'	'
Current liabilities	'	'	292,003	'	'
Long-term liabilities	'	'	22,534	'	'
Total liabilities	'	'	314,537	'	'
Net assets acquired	'	'	294,054	'	'
Amount assigned to intangible assets	'	'	159,000	136,000	23,000
Amount of Goodwill Created:	'	'	'	'	'
Purchase price	'	'	910,000	'	'
Deferred taxes related to intangible assets	'	'	55,000	'	'
Goodwill recognized	$2,022,831	$2,010,340	$511,946	'	'

Significant_Accounting_Policie7

Significant Accounting Policies (Stock-based Compensation) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock-based compensation expense	$39,518	$32,442	$29,084
Restricted Stock and Restricted Stock Units (excluding Performance Awards) [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock-based compensation expense	12,836	11,021	10,710
Stock Options [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock-based compensation expense	11,385	14,067	16,468
Performance Awards [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock-based compensation expense	$15,297	$7,354	$1,906

Significant_Accounting_Policie8

Significant Accounting Policies (Fair Value Assumptions Of Option Grant Date Award) (Details)	12 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Employee Awards [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Dividend yield	0.00%	0.00%	0.00%
Expected volatility	38.37%	43.28%	41.54%
Risk-free interest rate	1.11%	0.95%	2.00%
Expected term of options (in years)	'5 years 9 months 26 days	'5 years 9 months 26 days	'5 years 9 months 26 days
Director Awards [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Dividend yield	0.00%	0.00%	0.00%
Expected volatility	37.65%	41.42%	41.97%
Risk-free interest rate	0.95%	1.11%	2.40%
Expected term of options (in years)	'5 years 9 months 26 days	'5 years 9 months 26 days	'5 years 9 months 26 days

Significant_Accounting_Policie9

Significant Accounting Policies (Fair Value Assumptions Of Restricted Stock Unit Grant Date Awards) (Details) (Restricted Stock Units (RSUs) [Member])	12 Months Ended
	Sep. 30, 2011
Restricted Stock Units (RSUs) [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Dividend yield	0.00%
Expected volatility	46.67%
Risk-free interest rate	0.83%
Expected term (in years)	'3 years

Recovered_Sheet1

Significant Accounting Policies (Basis to Determine Earned Relative TSR Restricted Stock Units) (Details) (Earned Relative TSR Restricted Stock Units [Member])	12 Months Ended
	Sep. 27, 2013
Below 30th percentile [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
TSR performance multiplier	0.00%
30th percentile [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
TSR performance multiplier	50.00%
50th percentile [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
TSR performance multiplier	100.00%
70th percentile or above [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
TSR performance multiplier	150.00%

Recovered_Sheet2

Significant Accounting Policies (Fair Value Assumptions of Earned Relative TSR Restricted Stock Units) (Details) (Earned Relative TSR Restricted Stock Units [Member])	12 Months Ended
	Sep. 27, 2013	Sep. 28, 2012
Earned Relative TSR Restricted Stock Units [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Dividend yield	0.00%	0.00%
Expected volatility	29.18%	36.30%
Risk-free interest rate	0.42%	0.42%
Expected term (in years)	'3 years	'3 years

Recovered_Sheet3

Significant Accounting Policies (Basis to Determine Earned Net Earnings Growth Restricted Stock Units) (Details) (Earned Net Earnings Growth Restricted Stock Units [Member])	12 Months Ended
	Sep. 27, 2013
Less than 5% [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Net earnings growth performance multiplier	0.00%
5% [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Net earnings growth performance multiplier	50.00%
10% [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Net earnings growth performance multiplier	100.00%
15% [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Net earnings growth performance multiplier	150.00%
20% [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Net earnings growth performance multiplier	200.00%

Stock_Purchase_And_Stock_Optio2

Stock Purchase And Stock Option Plans (Stock Issuance Activity Under The 1989 ESPP And The GESPP) (Details) (USD $)	12 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Discount available to employees on the purchase of common stock	5.00%	'	'
Aggregate Purchase Price Paid for Shares Sold	$33,081,426	$35,181,647	$34,781,962
Aggregate Number of Shares Sold	707,638	930,179	841,204
Shares reserved for future Issuance (in shares)	9,845,969	'	'
Under The 1989 ESPP [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Aggregate Purchase Price Paid for Shares Sold	30,012,848	32,236,660	31,887,660
Aggregate Number of Shares Sold	642,675	853,819	771,818
Shares reserved for future Issuance (in shares)	2,414,021	'	'
Under The GESPP [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Aggregate Purchase Price Paid for Shares Sold	$3,068,578	$2,944,987	$2,894,302
Aggregate Number of Shares Sold	64,963	76,360	69,386
Shares reserved for future Issuance (in shares)	272,068	'	'

Stock_Purchase_And_Stock_Optio3

Stock Purchase And Stock Option Plans (Stock Purchase And Stock Option Plans Information On The 1999 Plans) (Details)	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 27, 2013	Sep. 27, 2013
			Stock Option Plans 1999 SIP [Member]	Stock Option Plans 1999 SIP [Member]	Stock Option Plans 1999 ODSP [Member]	Stock Option Plans 1999 ODSP [Member]	Stock Appreciation Rights (SARs) [Member]	Stock Options [Member]	Restricted Stock [Member]
							Stock Option Plans 1999 SIP [Member]	Stock Option Plans 1999 SIP [Member]	Stock Option Plans 1999 SIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'	'	'
Number of shares authorized (in shares)	26,400,000	'	25,600,000	'	800,000	'	'	'	'
Number of remaining shares reserved for issuance at September 27, 2013 (in shares)	9,845,969	'	9,456,344	'	389,625	'	'	'	'
Number of shares relating to outstanding stock options at September 27, 2013 (in shares)	4,606,212	'	4,356,712	'	249,500	'	'	'	'
Number of shares available for future awards (in shares)	5,239,757	635,619	5,099,632	446,994	140,125	188,625	'	'	'
Award number of shares, fungible share basis (in shares)	'	'	'	'	'	'	1	1	1.92

Stock_Purchase_And_Stock_Optio4

Stock Purchase And Stock Option Plans (Fair Value Of Shares Vested) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'	'	'
Fair value of shares vested	$13,054	$7,955	$4,848

Stock_Purchase_And_Stock_Optio5

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 $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'	'	'
Share-based compensation expense (pre-tax)	$39,518	$32,442	$29,084

Stock_Purchase_And_Stock_Optio6

Stock Purchase And Stock Option Plans (Stock Option Activity Under The 1999 Plans And The 1981 Plan) (Details) (USD $)	12 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011	Oct. 01, 2010
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'	'	'	'
Number of stock options outstanding, beginning balance (in shares)	5,756,734	6,461,510	7,410,580	'
Number of stock options granted (in shares)	753,450	658,700	433,600	'
Number of stock options exercised (in shares)	-1,782,371	-1,281,449	-1,363,005	'
Number of stock options cancelled or expired (in shares)	-121,601	-82,027	-19,665	'
Number of stock options outstanding, ending balance (in shares)	4,606,212	5,756,734	6,461,510	'
Options outstanding weighted average price (in dollars per share)	$52.33	$47.23	$43.28	$39.10
Weighted average exercise price options granted (in dollars per share)	$54.71	$37.45	$46.04	'
Weighted average exercise price options exercised (in dollars per share)	$37	$22.54	$21.37	'
Weighted average exercise price options cancelled or expired (in dollars per share)	$50.22	$43.92	$47.81	'

Stock_Purchase_And_Stock_Optio7

Stock Purchase And Stock Option Plans (Total Intrinsic Value Of Options Exercised) (Details) (USD $)	12 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'	'	'
Intrinsic value of stock options exercised	$22,163,000	$26,196,000	$34,665,000
Intrinsic value of options exercisable	$30,500,000	'	'

Stock_Purchase_And_Stock_Optio8

Stock Purchase And Stock Option Plans (Information Regarding Stock Option Plans) (Details) (USD $)	12 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
At fiscal year end:	'	'	'
Range of exercise prices for options outstanding, minimum (in dollars per share)	$20.98	$18.49	$13.29
Range of exercise prices for options outstanding, maximum (in dollars per share)	$94.11	$94.11	$94.11
Number of options exercisable (in shares)	3,034,111	4,219,557	4,822,297
For the fiscal year:	'	'	'
Range of prices relating to options exercised, minimum (in dollars per share)	$18.49	$13.29	$10.79
Range of prices relating to options exercised, maximum (in dollars per share)	$56.95	$37.73	$41.18
Estimated weighted average fair values of options granted (in dollars per share)	$20.64	$15.55	$19.43

Stock_Purchase_And_Stock_Optio9

Stock Purchase And Stock Option Plans (Information Regarding Options Outstanding, And Options Exercisable) (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011	Oct. 01, 2010
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Range of exercise prices, minimum (in dollars per share)	$20.98	$18.49	$13.29	'
Range of exercise prices, maximum (in dollars per share)	$94.11	$94.11	$94.11	'
Options outstanding number (in shares)	4,606,212	5,756,734	6,461,510	7,410,580
Options outstanding weighted average remaining contractual life (in years)	'5 years 8 months 19 days	'	'	'
Options outstanding weighted average price (in dollars per share)	$52.33	$47.23	$43.28	$39.10
Options exercisable (in shares)	3,034,111	'	'	'
Options exercisable weighted average exercise price (in dollars per share)	$54.93	'	'	'
Ownership duration of common stock for incentive plan participants for exercise price of stock options, minimum (in months)	'6 months	'	'	'
Nonvested not yet recognized	$122.80	'	'	'
Options exercisable, weighted average remaining contractual term (in years)	'4 years 1 month 6 days	'	'	'
Range of Exercise Prices $20.98 - $26.80 [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Range of exercise prices, minimum (in dollars per share)	$20.98	'	'	'
Range of exercise prices, maximum (in dollars per share)	$26.80	'	'	'
Options outstanding number (in shares)	91,800	'	'	'
Options outstanding weighted average remaining contractual life (in years)	'8 months 1 day	'	'	'
Options outstanding weighted average price (in dollars per share)	$23.14	'	'	'
Options exercisable (in shares)	91,800	'	'	'
Options exercisable weighted average exercise price (in dollars per share)	$23.14	'	'	'
Range Of Exercise Prices $32.51 - $37.32 [Member]	'	'	'	'
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)	$37.32	'	'	'
Options outstanding number (in shares)	569,500	'	'	'
Options outstanding weighted average remaining contractual life (in years)	'8 years 6 months 18 days	'	'	'
Options outstanding weighted average price (in dollars per share)	$37.01	'	'	'
Options exercisable (in shares)	157,125	'	'	'
Options exercisable weighted average exercise price (in dollars per share)	$36.98	'	'	'
Range of Exercise Prices $37.43 - $46.86 [Member]	'	'	'	'
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)	$46.86	'	'	'
Options outstanding number (in shares)	1,757,213	'	'	'
Options outstanding weighted average remaining contractual life (in years)	'6 years 1 month 24 days	'	'	'
Options outstanding weighted average price (in dollars per share)	$42.54	'	'	'
Options exercisable (in shares)	1,388,287	'	'	'
Options exercisable weighted average exercise price (in dollars per share)	$42.41	'	'	'
Range Of Exercise Prices $47.11 - $55.04 [Member]	'	'	'	'
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)	$55.04	'	'	'
Options outstanding number (in shares)	972,925	'	'	'
Options outstanding weighted average remaining contractual life (in years)	'8 years 8 months 19 days	'	'	'
Options outstanding weighted average price (in dollars per share)	$52.74	'	'	'
Options exercisable (in shares)	247,825	'	'	'
Options exercisable weighted average exercise price (in dollars per share)	$48.32	'	'	'
Range Of Exercise Prices $55.13 - $57.81 [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Range of exercise prices, minimum (in dollars per share)	$55.13	'	'	'
Range of exercise prices, maximum (in dollars per share)	$57.81	'	'	'
Options outstanding number (in shares)	503,975	'	'	'
Options outstanding weighted average remaining contractual life (in years)	'11 months 5 days	'	'	'
Options outstanding weighted average price (in dollars per share)	$56.94	'	'	'
Options exercisable (in shares)	494,975	'	'	'
Options exercisable weighted average exercise price (in dollars per share)	$56.97	'	'	'
Range Of Exercise Prices $58.26 - $83.61 [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Range of exercise prices, minimum (in dollars per share)	$58.26	'	'	'
Range of exercise prices, maximum (in dollars per share)	$83.61	'	'	'
Options outstanding number (in shares)	136,075	'	'	'
Options outstanding weighted average remaining contractual life (in years)	'5 years 4 months 28 days	'	'	'
Options outstanding weighted average price (in dollars per share)	$72.43	'	'	'
Options exercisable (in shares)	79,375	'	'	'
Options exercisable weighted average exercise price (in dollars per share)	$81.34	'	'	'
Range Of Exercise Prices $88.19 - $94.11 [Member]	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Range of exercise prices, minimum (in dollars per share)	$88.19	'	'	'
Range of exercise prices, maximum (in dollars per share)	$94.11	'	'	'
Options outstanding number (in shares)	574,724	'	'	'
Options outstanding weighted average remaining contractual life (in years)	'1 year 7 months 17 days	'	'	'
Options outstanding weighted average price (in dollars per share)	$92.57	'	'	'
Options exercisable (in shares)	574,724	'	'	'
Options exercisable weighted average exercise price (in dollars per share)	$92.57	'	'	'

Recovered_Sheet4

Stock Purchase And Stock Option Plans (Number Of Shares Of Restricted Stock And Restricted Stock Units Issued Under The 1999 Plans) (Details)	3 Months Ended	12 Months Ended
	Sep. 28, 2012	Sep. 27, 2013		Sep. 28, 2012	Sep. 30, 2011
Stock Option Plans 1999 ODSP [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award, Award Number of Shares, Non-Fungible Share Basis	1	'		'	'
Stock Option Plans 1999 ODSP [Member] | Restricted stock, non fungible [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Restricted stock and restricted stock units outstanding	'	40,000		'	'
Stock Option Plans 1999 ODSP [Member] | Service Condition [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Restricted stock and restricted stock units issued	'	13,500		8,000	10,000
Stock Option Plans 1999 ODSP [Member] | Service Condition [Member] | Restricted stock units, non fungible [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Restricted stock and restricted stock units outstanding	'	47,500		'	'
Stock Option Plans 1999 SIP [Member] | Stock Options [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Award number of shares, fungible share basis (in shares)	'	1		'	'
Stock Option Plans 1999 SIP [Member] | Restricted stock, non fungible [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Restricted stock and restricted stock units outstanding	'	1,144,370		'	'
Stock Option Plans 1999 SIP [Member] | Restricted stock, fungible [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Restricted stock and restricted stock units outstanding	'	441,200		'	'
Stock Option Plans 1999 SIP [Member] | Restricted Stock [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award, Award Number of Shares, Non-Fungible Share Basis	1	'		'	'
Restricted stock and restricted stock units issued	'	445,200	[1]	497,100	226,850
Restricted stock and restricted stock units cancelled	'	128,923	[1],[2]	80,460	33,200
Award number of shares, fungible share basis (in shares)	'	1.92		'	'
Restricted stock and restricted stock units outstanding	'	1,585,570		'	'
Stock Option Plans 1999 SIP [Member] | Restricted Stock Units (RSUs) [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award, Award Number of Shares, Non-Fungible Share Basis	1	'		'	'
Award number of shares, fungible share basis (in shares)	'	1.92		'	'
Stock Option Plans 1999 SIP [Member] | Service Condition [Member] | Restricted stock units, non fungible [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Restricted stock and restricted stock units outstanding	'	109,030		'	'
Stock Option Plans 1999 SIP [Member] | Service Condition [Member] | Restricted stock units, fungible [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Restricted stock and restricted stock units outstanding	'	106,500		'	'
Stock Option Plans 1999 SIP [Member] | Service Condition [Member] | Restricted Stock Units (RSUs) [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Restricted stock and restricted stock units issued	'	107,500	[1]	116,450	2,100
Restricted stock and restricted stock units cancelled	'	3,385	[1],[2]	5,650	0
Restricted stock and restricted stock units outstanding	'	215,530		'	'
Stock Option Plans 1999 SIP [Member] | Service, Market, And Performance Conditions [Member] | Restricted stock units, non fungible [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Restricted stock and restricted stock units outstanding	'	762,700		'	'
Stock Option Plans 1999 SIP [Member] | Service, Market, And Performance Conditions [Member] | Restricted stock units, fungible [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Restricted stock and restricted stock units outstanding	'	471,250		'	'
Stock Option Plans 1999 SIP [Member] | Service, Market, And Performance Conditions [Member] | Restricted Stock Units (RSUs) [Member]	'	'		'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Restricted stock and restricted stock units issued	'	471,250	[1]	525,000	291,700
Restricted stock and restricted stock units cancelled	'	32,000	[1],[2]	22,000	0
Restricted stock and restricted stock units outstanding	'	1,233,950		'	'
[1]	The share amounts in the above tables for fiscal 2013 reflect the fungible share counting of 1.92 shares for each share of restricted stock and restricted stock unit issued.
[2]	Commencing in fiscal 2013, shares withheld for withholding tax liabilities are available for awards under the 1999 SIP and have been included in the table above for fiscal 2013 only.

Earnings_Per_Share_Earnings_Pe

Earnings Per Share (Earnings Per Share) (Details)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Shares used to calculate EPS:	'	'	'
Weighted average shares outstanding (denominator used to compute basic EPS)	129,288	127,644	125,686
Effect of stock options and restricted stock	1,657	1,048	1,549
Denominator used to compute diluted EPS	130,945	128,692	127,235
Antidilutive stock options, restricted stock, and restricted stock units	2,603	5,093	4,507

Borrowings_Narrative_Details

Borrowings (Narrative) (Details) (USD $)

12 Months Ended

12 Months Ended

12 Months Ended

Sep. 27, 2013

Sep. 27, 2013

Sep. 28, 2012

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 28, 2012

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Sep. 27, 2013

Line of Credit [Member]

Line of Credit [Member]

Line of Credit [Member]

Line of Credit [Member]

Line of Credit [Member]

Line of Credit [Member]

Line of Credit [Member]

Other Loan Agreements [Member]

Other Loan Agreements [Member]

Bank Overdrafts [Member]

Option One [Member]

Option One [Member]

Option Two [Member]

Option Two [Member]

2012 Facility [Member]

2012 Facility [Member]

2012 Facility [Member]

2012 Facility [Member]

2012 Facility [Member]

2012 Facility [Member]

2012 Facility [Member]

Line of Credit [Member]

Line of Credit [Member]

Line of Credit [Member]

Line of Credit [Member]

tranche

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Letter of Credit [Member]

Subfacility For Swingline Loan [Member]

2012 Facility [Member]

2012 Facility [Member]

2012 Facility [Member]

2012 Facility [Member]

Minimum [Member]

Maximum [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Eurodollar [Member]

Eurodollar [Member]

Base Rate [Member]

Base Rate [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Line of Credit Facility [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Overdrafts outstanding

'

'

'

'

'

'

'

$22,800,000

'

'

'

'

'

'

Short-term debt interest rate

'

'

'

'

'

'

'

'

'

10.70%

'

'

'

'

Line of credit facility, current borrowing capacity

1,210,000,000

'

'

'

'

300,000,000

50,000,000

'

'

'

'

'

'

'

Line of credit facility, amount outstanding

-425,900,000

-415,086,000

-528,260,000

'

'

-10,800,000

'

'

'

'

'

'

'

'

Number of tranches in revolving credit facility

3

'

'

'

'

'

'

'

'

'

'

'

'

'

Basis spread on variable rate

'

'

'

'

'

'

'

'

'

'

0.88%

1.23%

0.00%

0.23%

Line of credit facility, commitment fee percentage

'

'

'

0.13%

0.28%

'

'

'

'

'

'

'

'

'

Short-term Debt

'

'

'

'

'

'

'

'

$0

'

'

'

'

'

Borrowings_Schedule_Of_LongTer

Borrowings (Schedule Of Long-Term Revolving Credit Facility) (Details) (2012 Facility [Member], Line of Credit [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012
Line of credit facility, amount outstanding	$425,900	'
Revolving Credit Facility [Member]	'	'
Line of credit facility, amount outstanding	$415,086	$528,260
Range of interest rates, minimum	0.96%	0.95%
Range of interest rates, maximum	1.37%	1.41%

Borrowings_Schedule_Of_Additio

Borrowings (Schedule Of Additional Informational 2012 Facility) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012
Debt Disclosure [Abstract]	'	'
Maximum amount outstanding at any month-end during the fiscal year	$526,602	$586,933
Average amount outstanding during the year	$470,343	$537,131
Weighted average interest rate during the year	1.11%	1.32%

Borrowings_Schedule_Of_Interes

Borrowings (Schedule Of Interest Paid) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Debt Disclosure [Abstract]	'	'	'
Interest paid	$6,685	$8,572	$7,778

Pension_Plans_Narrative_Detail

Pension Plans (Narrative) (Details) (U.S. Pension Plans [Member], USD $)	12 Months Ended			12 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 27, 2013
		Other Noncurrent Assets [Member]	Other Noncurrent Assets [Member]	Minimum [Member]	Maximum [Member]
				economic_scenario	economic_scenario
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'	'
Maximum duration of assumptions in return on plan assets simulation model (in years)	'20 years	'	'	'	'
Number of economic scenarios in return on plan assets simulation model	'	'	'	1,000	2,000
Period of annual average returns used in return on plan assets simulation model (in years)	'20 years	'	'	'	'
Government Contract Receivable	'	$58.40	$101.40	'	'

Pension_Plans_Schedule_Of_Chan

Pension Plans (Schedule Of Change In Plans' Combined Net Benefit Obligation) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
U.S. Pension Plans [Member]	'	'	'
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]	'	'	'
Net benefit obligation at the beginning of the year	$509,605	$482,542	'
Service cost	13,814	12,838	10,684
Interest cost	18,569	20,923	21,377
Participants’ contributions	3,071	3,200	'
Actuarial (gains)/losses	-42,689	20,342	'
Benefits paid	-33,960	-10,978	'
Curtailments and settlements	'	-27,702	'
Plan amendments	'	'	'
Business combinations/consolidations	'	8,440	'
Special termination benefits	29	'	'
Effect of exchange rate changes	'	'	'
Net benefit obligation at the end of the year	468,439	509,605	482,542
Non-U.S. Pension Plans [Member]	'	'	'
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]	'	'	'
Net benefit obligation at the beginning of the year	1,191,345	968,938	'
Service cost	30,117	22,723	30,816
Interest cost	51,331	54,287	54,631
Participants’ contributions	11,805	11,614	'
Actuarial (gains)/losses	57,764	142,935	'
Benefits paid	-34,058	-30,180	'
Curtailments and settlements	-6,297	-6,118	'
Plan amendments	109	-2,294	'
Business combinations/consolidations	'	8,933	'
Special termination benefits	'	'	'
Effect of exchange rate changes	5,215	20,507	'
Net benefit obligation at the end of the year	$1,307,331	$1,191,345	$968,938

Pension_Plans_Schedule_Of_Chan1

Pension Plans (Schedule Of Change In Combined Fair Value Of The Plans' Assets) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012
U.S. Pension Plans [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the beginning of the year	$359,348	$285,777
Actual return on plan assets	53,495	62,635
Employer contributions	8,823	42,606
Participants’ contributions	3,071	3,200
Gross benefits paid	-33,960	-10,978
Business combinations/consolidations	'	3,810
Curtailments/settlements	'	-27,702
Effect of exchange rate changes	'	'
Fair Value of plan assets at the end of the year	390,777	359,348
Non-U.S. Pension Plans [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the beginning of the year	877,950	744,689
Actual return on plan assets	72,368	91,987
Employer contributions	53,885	48,374
Participants’ contributions	11,805	11,614
Gross benefits paid	-34,058	-30,180
Business combinations/consolidations	0	4,272
Curtailments/settlements	-4,973	-6,085
Effect of exchange rate changes	5,502	13,279
Fair Value of plan assets at the end of the year	$982,479	$877,950

Pension_Plans_Reconciliation_O

Pension Plans (Reconciliation Of Combined Funded Status Of Plans And Recognized In Consolidated Balance Sheet) (Details) (USD $)	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
In Thousands, unless otherwise specified
U.S. Pension Plans [Member]	'	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'	'
Net benefit obligation at the end of the year	$468,439	$509,605	$482,542
Fair Value of plan assets at the end of the year	390,777	359,348	285,777
Under-funded amount recognized at the end of the year	77,662	150,257	'
Non-U.S. Pension Plans [Member]	'	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'	'
Net benefit obligation at the end of the year	1,307,331	1,191,345	968,938
Fair Value of plan assets at the end of the year	982,479	877,950	744,689
Under-funded amount recognized at the end of the year	$324,852	$313,395	'

Pension_Plans_Accumulated_Bene

Pension Plans (Accumulated Benefit Obligation) (Details) (USD $)	Sep. 27, 2013	Sep. 28, 2012
In Thousands, unless otherwise specified
U.S. Pension Plans [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Accumulated benefit obligation at the end of the year	$431,726	$460,618
Non-U.S. Pension Plans [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Accumulated benefit obligation at the end of the year	$1,222,234	$1,109,413

Pension_Plans_Schedule_Of_Amou

Pension Plans (Schedule Of Amount Recognized In Accompanying Balance Sheets) (Details) (USD $)	Sep. 27, 2013	Sep. 28, 2012
In Thousands, unless otherwise specified
U.S. Pension Plans [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Accrued benefit cost included in prepaid assets	$0	$0
Accrued benefit cost included in current liabilities	0	0
Accrued benefit cost included in noncurrent liabilities	77,662	150,257
Net amount recognized at the end of the year	77,662	150,257
Non-U.S. Pension Plans [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Accrued benefit cost included in prepaid assets	15,193	13,174
Accrued benefit cost included in current liabilities	1,000	2,271
Accrued benefit cost included in noncurrent liabilities	339,045	324,298
Net amount recognized at the end of the year	$324,852	$313,395

Pension_Plans_Schedule_Of_Sign

Pension Plans (Schedule Of Significant Actuarial Assumptions In Determining The Funded Status and Benefit Cost) (Details)	12 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
U.S. Pension Plans [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Rates of compensation increases	2.80%	3.25%	3.50%
Expected long-term rates of return on plan assets	7.70%	7.50%	7.50%
U.S. Pension Plans [Member] | Maximum [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Weighted average discount rates	5.00%	3.90%	4.60%
U.S. Pension Plans [Member] | Minimum [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Weighted average discount rates	4.40%	3.40%	4.30%
Non-U.S. Pension Plans [Member] | Maximum [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Weighted average discount rates	9.30%	8.40%	5.90%
Rates of compensation increases	7.50%	7.50%	3.50%
Expected long-term rates of return on plan assets	8.50%	8.50%	7.10%
Non-U.S. Pension Plans [Member] | Minimum [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Weighted average discount rates	0.40%	0.60%	2.60%
Rates of compensation increases	2.50%	2.80%	3.00%
Expected long-term rates of return on plan assets	0.40%	2.40%	4.75%

Pension_Plans_Schedule_Of_Pens

Pension Plans (Schedule Of Pension Plans Recognized In Accumulated Other Comprehensive Loss) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Reclassification adjustments:	'	'	'
Total	($547)	$75,942	($73,174)
U.S. Pension Plans [Member]	'	'	'
Arising during the period:	'	'	'
Net actuarial (gain) loss	-15,850	2,756	7,486
Reclassification adjustments:	'	'	'
Net actuarial gain	-2,674	-2,011	-2,011
Total	-18,524	745	5,475
Non-U.S. Pension Plans [Member]	'	'	'
Arising during the period:	'	'	'
Net actuarial (gain) loss	27,417	83,298	-73,258
Prior service cost (benefit)	297	-1,947	1,005
Total	27,714	81,351	-72,253
Reclassification adjustments:	'	'	'
Net actuarial gain	-9,778	-6,131	-4,990
Prior service cost (benefit)	41	-23	-1,406
Total	-9,737	-6,154	-6,396
Total	$17,977	$75,197	($78,649)

Pension_Plans_Schedule_Of_Pens1

Pension Plans (Schedule Of Pension Plans Recorded In Accumulated Other Comprehensive Loss Not Yet Recognized As Component Of Net Periodic Pension Cost) (Details) (USD $)	Sep. 27, 2013	Sep. 28, 2012
In Thousands, unless otherwise specified
U.S. Pension Plans [Member]	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'
Net actuarial loss	$50,446	$68,970
Prior service cost	'	'
Total	50,446	68,970
Non-U.S. Pension Plans [Member]	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'
Net actuarial loss	228,074	201,726
Prior service cost	-466	-803
Total	$227,608	$200,923

Pension_Plans_Schedule_Of_Accu

Pension Plans (Schedule Of Accumulated Comprehensive Income Amortized Against Earnings In The Next Year) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013
U.S. Pension Plans [Member]	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'
Unrecognized net actuarial loss	$3,608
Unrecognized prior service cost	-103
Accumulated comprehensive loss to be recorded against earnings	3,505
Non-U.S. Pension Plans [Member]	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'
Unrecognized net actuarial loss	15,527
Unrecognized prior service cost	-25
Accumulated comprehensive loss to be recorded against earnings	$15,502

Pension_Plans_Schedule_Of_Weig

Pension Plans (Schedule Of Weighted Average Measurement Of Assets And Liabilities) (Details)	Sep. 27, 2013	Sep. 28, 2012
Equity securities [Member] | U.S. Pension Plans [Member]	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'
Pension plan asset allocations	74.00%	72.00%
Equity securities [Member] | Non-U.S. Pension Plans [Member]	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'
Pension plan asset allocations	32.00%	41.00%
Debt securities [Member] | U.S. Pension Plans [Member]	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'
Pension plan asset allocations	20.00%	21.00%
Debt securities [Member] | Non-U.S. Pension Plans [Member]	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'
Pension plan asset allocations	31.00%	37.00%
Real estate investments [Member] | U.S. Pension Plans [Member]	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'
Pension plan asset allocations	1.00%	1.00%
Real estate investments [Member] | Non-U.S. Pension Plans [Member]	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'
Pension plan asset allocations	6.00%	6.00%
Other [Member] | U.S. Pension Plans [Member]	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'
Pension plan asset allocations	5.00%	6.00%
Other [Member] | Non-U.S. Pension Plans [Member]	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'
Pension plan asset allocations	31.00%	16.00%

Pension_Plans_Schedule_Of_Fair

Pension Plans (Schedule Of Fair Value Of Pension Plan Assets) (Details) (USD $)	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
In Thousands, unless otherwise specified
U.S. Pension Plans [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	$390,777	$359,348	$285,777
U.S. Pension Plans [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	370,855	340,036	'
U.S. Pension Plans [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	19,922	19,312	'
U.S. Pension Plans [Member] | U.S. Domestic Equities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	247,155	230,862	'
U.S. Pension Plans [Member] | U.S. Domestic Equities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	247,155	230,862	'
U.S. Pension Plans [Member] | U.S. Domestic Equities [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
U.S. Pension Plans [Member] | Overseas Equities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	40,719	27,343	'
U.S. Pension Plans [Member] | Overseas Equities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	40,719	27,343	'
U.S. Pension Plans [Member] | Overseas Equities [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
U.S. Pension Plans [Member] | U.S. Domestic Bonds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	79,482	75,648	'
U.S. Pension Plans [Member] | U.S. Domestic Bonds [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	79,482	75,648	'
U.S. Pension Plans [Member] | U.S. Domestic Bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
U.S. Pension Plans [Member] | Cash And Cash Equivalents [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	3,499	6,183	'
U.S. Pension Plans [Member] | Cash And Cash Equivalents [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	3,499	6,183	'
U.S. Pension Plans [Member] | Cash And Cash Equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
U.S. Pension Plans [Member] | Real Estate [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	4,411	4,841	'
U.S. Pension Plans [Member] | Real Estate [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
U.S. Pension Plans [Member] | Real Estate [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	4,411	4,841	5,353
U.S. Pension Plans [Member] | Hedge Funds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	15,511	14,471	'
U.S. Pension Plans [Member] | Hedge Funds [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
U.S. Pension Plans [Member] | Hedge Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	15,511	14,471	14,845
Non-U.S. Pension Plans [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	982,479	877,950	744,689
Non-U.S. Pension Plans [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	650,627	710,611	'
Non-U.S. Pension Plans [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	331,852	167,339	'
Non-U.S. Pension Plans [Member] | U.S. Domestic Equities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	108,261	193,715	'
Non-U.S. Pension Plans [Member] | U.S. Domestic Equities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	108,261	193,715	'
Non-U.S. Pension Plans [Member] | U.S. Domestic Equities [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
Non-U.S. Pension Plans [Member] | Overseas Equities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	207,607	168,097	'
Non-U.S. Pension Plans [Member] | Overseas Equities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	207,607	168,097	'
Non-U.S. Pension Plans [Member] | Overseas Equities [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
Non-U.S. Pension Plans [Member] | U.S. Domestic Bonds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	230,202	306,974	'
Non-U.S. Pension Plans [Member] | U.S. Domestic Bonds [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	230,202	306,974	'
Non-U.S. Pension Plans [Member] | U.S. Domestic Bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
Non-U.S. Pension Plans [Member] | Overseas Bonds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	76,372	14,254	'
Non-U.S. Pension Plans [Member] | Overseas Bonds [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	76,372	14,254	'
Non-U.S. Pension Plans [Member] | Overseas Bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
Non-U.S. Pension Plans [Member] | Cash And Cash Equivalents [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	28,185	27,571	'
Non-U.S. Pension Plans [Member] | Cash And Cash Equivalents [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	28,185	27,571	'
Non-U.S. Pension Plans [Member] | Cash And Cash Equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
Non-U.S. Pension Plans [Member] | Infrastructure \ Raw Goods [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	7,076	6,111	'
Non-U.S. Pension Plans [Member] | Infrastructure \ Raw Goods [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
Non-U.S. Pension Plans [Member] | Infrastructure \ Raw Goods [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	7,076	6,111	4,776
Non-U.S. Pension Plans [Member] | Real Estate [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	57,173	49,537	'
Non-U.S. Pension Plans [Member] | Real Estate [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
Non-U.S. Pension Plans [Member] | Real Estate [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	57,173	49,537	43,997
Non-U.S. Pension Plans [Member] | Insurance Contracts [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	21,214	18,291	'
Non-U.S. Pension Plans [Member] | Insurance Contracts [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
Non-U.S. Pension Plans [Member] | Insurance Contracts [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	21,214	18,291	17,293
Non-U.S. Pension Plans [Member] | Hedge Funds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	246,389	93,400	'
Non-U.S. Pension Plans [Member] | Hedge Funds [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	'	'
Non-U.S. Pension Plans [Member] | Hedge Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	$246,389	$93,400	$81,776

Pension_Plans_Summary_Of_Chang

Pension Plans (Summary Of Changes In The Fair Value Of The Plans' Level 3 Assets) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012
U.S. Pension Plans [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the beginning of the year	$359,348	$285,777
Effect of exchange rate changes	'	'
Fair Value of plan assets at the end of the year	390,777	359,348
U.S. Pension Plans [Member] | Real Estate [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the end of the year	4,411	4,841
U.S. Pension Plans [Member] | Hedge Funds [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the end of the year	15,511	14,471
U.S. Pension Plans [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the end of the year	19,922	19,312
U.S. Pension Plans [Member] | Significant Unobservable Inputs (Level 3) [Member] | Real Estate [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the beginning of the year	4,841	5,353
Transfers	0	0
Realized and unrealized gains (losses)	-430	-512
Fair Value of plan assets at the end of the year	4,411	4,841
U.S. Pension Plans [Member] | Significant Unobservable Inputs (Level 3) [Member] | Hedge Funds [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the beginning of the year	14,471	14,845
Transfers	0	0
Realized and unrealized gains (losses)	1,040	-374
Fair Value of plan assets at the end of the year	15,511	14,471
Non-U.S. Pension Plans [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the beginning of the year	877,950	744,689
Effect of exchange rate changes	5,502	13,279
Fair Value of plan assets at the end of the year	982,479	877,950
Non-U.S. Pension Plans [Member] | Infrastructure \ Raw Goods [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the end of the year	7,076	6,111
Non-U.S. Pension Plans [Member] | Real Estate [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the end of the year	57,173	49,537
Non-U.S. Pension Plans [Member] | Insurance Contracts [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the end of the year	21,214	18,291
Non-U.S. Pension Plans [Member] | Hedge Funds [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the end of the year	246,389	93,400
Non-U.S. Pension Plans [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the end of the year	331,852	167,339
Non-U.S. Pension Plans [Member] | Significant Unobservable Inputs (Level 3) [Member] | Infrastructure \ Raw Goods [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the beginning of the year	6,111	4,776
Transfers	'	'
Purchases, sales, and settlements	0	'
Realized and unrealized gains (losses)	678	1,572
Effect of exchange rate changes	287	-237
Fair Value of plan assets at the end of the year	7,076	6,111
Non-U.S. Pension Plans [Member] | Significant Unobservable Inputs (Level 3) [Member] | Real Estate [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the beginning of the year	49,537	43,997
Transfers	'	0
Purchases, sales, and settlements	0	106
Realized and unrealized gains (losses)	7,670	3,836
Effect of exchange rate changes	-34	1,598
Fair Value of plan assets at the end of the year	57,173	49,537
Non-U.S. Pension Plans [Member] | Significant Unobservable Inputs (Level 3) [Member] | Insurance Contracts [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the beginning of the year	18,291	17,293
Transfers	'	'
Purchases, sales, and settlements	1,646	389
Realized and unrealized gains (losses)	1,058	1,422
Effect of exchange rate changes	219	-813
Fair Value of plan assets at the end of the year	21,214	18,291
Non-U.S. Pension Plans [Member] | Significant Unobservable Inputs (Level 3) [Member] | Hedge Funds [Member]	'	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'
Fair Value of plan assets at the beginning of the year	93,400	81,776
Transfers	'	'
Purchases, sales, and settlements	144,441	0
Realized and unrealized gains (losses)	4,664	7,975
Effect of exchange rate changes	3,884	3,649
Fair Value of plan assets at the end of the year	$246,389	$93,400

Pension_Plans_Anticipated_Cash

Pension Plans (Anticipated Cash Contributions) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013
U.S. Pension Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Anticipated cash contributions	$12,500
Non-U.S. Pension Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Anticipated cash contributions	$53,561

Pension_Plans_Schedule_Of_Expe

Pension Plans (Schedule Of Expected Payments To Participants In Pension Plan) (Details) (USD $)	Sep. 27, 2013
In Thousands, unless otherwise specified
U.S. Pension Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
2014	$39,259
2015	36,319
2016	38,455
2017	41,162
2018	38,808
For the period 2019 through 2023	204,246
Non-U.S. Pension Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
2014	39,298
2015	41,989
2016	46,714
2017	49,767
2018	54,413
For the period 2019 through 2023	$344,800

Pension_Plans_Schedule_Of_Comp

Pension Plans (Schedule Of Components Of Net Periodic Pension Cost Recognized) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
U.S. Pension Plans [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost	$13,814	$12,838	$10,684
Interest cost	18,569	20,923	21,377
Expected return on plan assets	-25,826	-23,764	-23,558
Actuarial loss	8,030	10,981	7,025
Prior service cost	-103	-103	-103
Net pension cost, before special items	14,484	20,875	15,425
Special termination benefits	29	'	120
Curtailments and settlements	0	6,035	'
Total net periodic pension cost recognized	14,513	26,910	15,545
Non-U.S. Pension Plans [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost	30,117	22,723	30,816
Interest cost	51,331	54,287	54,631
Expected return on plan assets	-54,817	-50,996	-50,033
Actuarial loss	13,276	8,227	13,535
Prior service cost	-43	152	303
Net pension cost, before special items	39,864	34,393	49,252
Curtailments and settlements	-383	1,326	381
Total net periodic pension cost recognized	$39,481	$35,719	$49,633

Pension_Plans_Schedule_Of_Cont

Pension Plans (Schedule Of Contribution To Multiemployer Pension Plans) (Details) (Multiemployer Plan, Individually Insignificant Multiemployer Plans [Member], Multiemployer Plans, Pension [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Multiemployer Plans [Line Items]	'	'	'
Contributions to multiemployer pension plans	$89,956	$87,281	$98,270
Canada [Member]	'	'	'
Multiemployer Plans [Line Items]	'	'	'
Contributions to multiemployer pension plans	72,660	72,053	81,608
Europe and Australia [Member]	'	'	'
Multiemployer Plans [Line Items]	'	'	'
Contributions to multiemployer pension plans	12,930	10,808	12,613
United States [Member]	'	'	'
Multiemployer Plans [Line Items]	'	'	'
Contributions to multiemployer pension plans	$4,366	$4,420	$4,049

Other_Comprehensive_Income_Det

Other Comprehensive Income (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Amortization of Defined Benefit Items:	'	'	'
Income Tax Benefit	($221,366)	($202,382)	($181,440)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]	'	'	'
Amortization of Defined Benefit Items:	'	'	'
Actuarial losses	-17,554	-11,444	-16,182
Prior service benefit (cost)	43	-152	-97
Total Before Income Tax	-17,511	-11,596	-16,279
Income Tax Benefit	5,859	3,955	5,716
Total reclassifications after-tax	($11,652)	($7,641)	($10,563)

Savings_And_Deferred_Compensat2

Savings And Deferred Compensation Plans (Savings Plans) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Savings And Deferred Compensation Plans [Abstract]	'	'	'
Savings plans contributions	$74,686	$70,211	$61,065

Savings_And_Deferred_Compensat3

Savings And Deferred Compensation Plans (Deferred Compensation Plans) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Savings And Deferred Compensation Plans [Abstract]	'	'	'
Deferred compensation plans expense	$4,470	$4,349	$3,075

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011	Oct. 01, 2010
Income Tax Contingency [Line Items]	'	'	'	'
Undistributed earnings of the Company's foreign subsidiaries expected to be reinvested	$26,100,000	'	'	'
Income tax payable upon repatriation of earnings	7,700,000	'	'	'
Gross unrecognized tax benefits	51,770,000	53,637,000	31,130,000	27,825,000
Accrued interest and penalties	44,800,000	48,800,000	'	'
Estimated period of unrecognized tax benefits (in months)	'12 months	'	'	'
Foreign Country [Member]	'	'	'	'
Income Tax Contingency [Line Items]	'	'	'	'
Gross unrecognized tax benefits	$5,000,000	'	'	'

Income_Taxes_Consolidated_Inco

Income Taxes (Consolidated Income Tax Expense) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Current income tax expense:	'	'	'
Federal	$121,302	$111,035	$102,903
State	23,246	23,303	25,067
Foreign	74,107	69,080	37,617
Total current tax expense	218,655	203,418	165,587
Deferred income tax expense (benefit):	'	'	'
Federal	-4,718	-2,505	10,482
State	-582	-1,985	-1,760
Foreign	8,011	3,454	7,131
Total deferred income tax expense (benefit)	2,711	-1,036	15,853
Consolidated income tax expense	$221,366	$202,382	$181,440

Income_Taxes_Components_Of_Net

Income Taxes (Components Of Net Deferred Tax Assets) (Details) (USD $)	Sep. 27, 2013	Sep. 28, 2012
In Thousands, unless otherwise specified
Obligations relating to:	'	'
Defined benefit pension plans	$97,349	$103,984
Other employee benefit plans	198,869	173,515
Self-insurance programs	1,758	10,847
Contract revenues and costs	19,468	39,894
Other	11,100	10,749
Gross deferred tax assets	328,544	338,989
Deferred tax liabilities:	'	'
Depreciation and amortization	-127,974	-125,704
Residual US tax on unremitted non-US earnings	-6,724	-9,024
Other, net	-7,560	-10,709
Gross deferred tax liabilities	-142,258	-145,437
Net deferred tax assets	$186,286	$193,552

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 $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Income Tax Disclosure [Abstract]	'	'	'
Income tax benefits realized under stock plans	$7.30	$9.30	$11.90

Income_Taxes_Income_Tax_Expens

Income Taxes (Income Tax Expense In Consolidated Statements Of Earnings) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Income Tax Disclosure [Abstract]	'	'	'
Statutory amount	$231,542	$207,668	$180,831
State taxes, net of the federal benefit	14,892	13,538	15,150
Tax differential on foreign earnings	-18,700	-16,667	-7,841
Other, net	-6,368	-2,157	-6,700
Consolidated income tax expense	$221,366	$202,382	$181,440
Rates used to compute statutory amount	35.00%	35.00%	35.00%
Consolidated effective income tax rate	33.50%	34.10%	35.10%

Income_Taxes_Income_Tax_Paymen

Income Taxes (Income Tax Payments) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Income Tax Disclosure [Abstract]	'	'	'
Income tax payments	$235.80	$191.40	$139.20

Income_Taxes_Components_Of_Our

Income Taxes (Components Of Our Consolidated Earnings Before Taxes) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Income Tax Examination [Line Items]	'	'	'
Results of operations, income before income taxes	$661,548	$593,336	$516,661
United States earnings [Member]	'	'	'
Income Tax Examination [Line Items]	'	'	'
Results of operations, income before income taxes	352,404	286,987	341,059
Foreign earnings [Member]	'	'	'
Income Tax Examination [Line Items]	'	'	'
Results of operations, income before income taxes	$309,144	$306,349	$175,602

Income_Taxes_Reconciliation_of

Income Taxes (Reconciliation of Unrecognized Tax Benefits) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]	'	'	'
Balance, beginning of year	$53,637	$31,130	$27,825
Additions based on tax positions related to the current year	5,447	6,110	6,731
Additions for tax positions of prior years	0	21,438	4,252
Reductions for tax positions of prior years	-6,354	-4,441	-7,678
Settlement	-960	-600	0
Balance, end of year	$51,770	$53,637	$31,130

Commitments_And_Contingencies_2

Commitments And Contingencies, And Derivative Financial Instruments (Narrative) (Details) (USD $)	Sep. 27, 2013
Loss Contingencies [Line Items]	'
Net aggregate future lease payments	$909,800,000
Letters of credit outstanding	243,300,000
Standby Letters Of Credit [Member]	'
Loss Contingencies [Line Items]	'
Letters of credit outstanding	232,500,000
Line of Credit [Member] | 2012 Facility [Member]	'
Loss Contingencies [Line Items]	'
Letters of credit outstanding issued under revolving credit facility	425,900,000
Line of Credit [Member] | 2012 Facility [Member] | Letter of Credit [Member]	'
Loss Contingencies [Line Items]	'
Letters of credit outstanding issued under revolving credit facility	10,800,000
Interest Rate Swap [Member]	'
Loss Contingencies [Line Items]	'
Notional amount of floating-to-fixed interest rate swap hedge	$52,200,000

Commitments_And_Contingencies_3

Commitments And Contingencies, And Derivative Financial Instruments (Commitments Under Operating Leases) (Details) (USD $)	Sep. 27, 2013
In Thousands, unless otherwise specified
Commitments And Contingencies, And Derivative Financial Instruments [Abstract]	'
2014	$150,448
2015	177,493
2016	118,984
2017	99,942
2018	83,884
Thereafter	288,944
Future minimum payments due	919,695
Amounts representing sublease income	-9,937
Total, net aggregate future lease payments	$909,758

Commitments_And_Contingencies_4

Commitments And Contingencies, And Derivative Financial Instruments (Rent Expense And Sublease Income) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Commitments And Contingencies, And Derivative Financial Instruments [Abstract]	'	'	'
Rent expense	$173,340	$165,221	$157,955
Sublease income	-7,914	-8,402	-8,315
Net rent	$165,426	$156,819	$149,640

Commitments_And_Contingencies_5

Commitments And Contingencies, And Derivative Financial Instruments (Significant Terms Of The Lease) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013
Commitments And Contingencies, And Derivative Financial Instruments [Abstract]	'
End of lease term	'2015
End of term purchase option (in thousands)	$52,200
Residual value guaranty (in thousands)	$38,800

Contractual_Guarantees_Litigat1

Contractual Guarantees, Litigation, Investigations, And Insurance (Narrative) (Details) (USD $)	12 Months Ended	44 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 27, 2013	Sep. 28, 2012	Jan. 20, 2010
	insurer	Clark County Nevada Against Jacobs Engineering Group, Inc. [Member]	Clark County Nevada Against Jacobs Engineering Group, Inc. [Member]	Clark County Nevada Against Jacobs Engineering Group, Inc. [Member]
			arbitrator	subsidiary
Loss Contingencies [Line Items]	'	'	'	'
Minimum number of insurers with possible inability to fulfill insurance obligations	1	'	'	'
Number Of subsidiaries (in subsidiaries)	'	'	'	2
Third party payment of settlement and awards (more than 60 million)	'	$60	'	'
Number Of arbitrators (in arbitrators)	'	'	3	'

Common_And_Preferred_Stock_Det

Common And Preferred Stock (Details) (USD $)	12 Months Ended
	Sep. 27, 2013	Sep. 28, 2012
	series
	class
Class of Stock Disclosures [Abstract]	'	'
Number of capital stock classes	2	'
Common stock, par value (in dollars per share)	$1	$1
Preferred stock, par value (in dollars per share)	$1	$1
Number of preferred stock series, minimum	1	'

Other_Financial_Information_Na

Other Financial Information (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012
Other Financial Information [Abstract]	'	'
Billed receivables collection period (in months)	'12 months	'
Unbilled amounts billed and collected, collection period (in months)	'12 months	'
Acquisition of business	$39.40	$91.60

Other_Financial_Information_Co

Other Financial Information (Components Of Receivables) (Details) (USD $)	Sep. 27, 2013	Sep. 28, 2012
In Thousands, unless otherwise specified
Other Financial Information [Abstract]	'	'
Amounts billed, net	$1,389,278	$1,193,500
Unbilled receivables and other	1,109,931	1,110,008
Retentions receivable	49,781	45,384
Total receivables, net	2,548,990	2,348,892
Other information about receivables:	'	'
Amounts due from the United States federal government included above, net of advanced billings	292,698	294,327
Claims receivable	$25,237	$26,309

Other_Financial_Information_Pr

Other Financial Information (Property, Equipment And Improvements, Net In The Consolidated Balance Sheets) (Details) (USD $)	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'	'
Property, equipment and improvements, gross	$919,170	$856,058	'
Accumulated depreciation and amortization	-539,874	-524,927	'
Property, plant and equipment, net, total	379,296	331,131	284,633
Land [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, equipment and improvements, gross	22,027	23,786	'
Building [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, equipment and improvements, gross	131,690	136,193	'
Equipment [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, equipment and improvements, gross	537,835	502,568	'
Leasehold Improvements [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, equipment and improvements, gross	204,940	163,916	'
Construction in progress [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, equipment and improvements, gross	$22,678	$29,595	'

Other_Financial_Information_Mi

Other Financial Information (Miscellaneous Noncurrent Assets) (Details) (USD $)	Sep. 27, 2013		Sep. 28, 2012		Sep. 30, 2011	Oct. 01, 2010
In Thousands, unless otherwise specified
Other Financial Information [Abstract]	'		'		'	'
Deferred income taxes	$197,458		$196,620		'	'
Cash surrender value of life insurance policies	100,253		86,502		'	'
Intangible assets (a)	217,904	[1]	243,762	[1]	259,006	100,045
Investments	194,782		187,248		'	'
Notes receivable	11,689		11,128		'	'
Reimbursable pension costs (b)	84,348	[2]	132,463	[2]	'	'
Other	26,025		28,162		'	'
Total	$832,459		$885,885		'	'
[1]	Consists primarily of intangible assets acquired in connection with various business combinations.
[2]	Consists of costs incurred relating to a defined benefit pension plan covering employees providing services on a contract with, and for the benefit of, the U.S. federal government pursuant to which such costs are fully reimbursable.

Other_Financial_Information_Co1

Other Financial Information (Components Of Accrued Liabilities) (Details) (USD $)	Sep. 27, 2013	Sep. 28, 2012
In Thousands, unless otherwise specified
Other Financial Information [Abstract]	'	'
Accrued payroll and related liabilities	$688,391	$641,340
Project-related accruals	115,418	196,836
Insurance liabilities	48,209	63,908
Sales and other similar taxes	47,973	41,951
Deferred rent	57,581	41,342
Other	72,244	76,592
Total	$1,029,816	$1,061,969

Other_Financial_Information_Co2

Other Financial Information (Components Of Other Deferred Liabilities) (Details) (USD $)	Sep. 27, 2013	Sep. 28, 2012
In Thousands, unless otherwise specified
Other Financial Information [Abstract]	'	'
Liabilities relating to defined benefit pension and early retirement plans	$416,707	$474,555
Liabilities relating to nonqualified deferred compensation arrangements	101,653	92,618
Deferred income taxes	142,258	145,437
Miscellaneous	62,486	83,728
Total	$723,104	$796,338

Other_Financial_Information_Co3

Other Financial Information (Components Of Total Accumulated Other Comprehensive Loss) (Details) (USD $)	Sep. 27, 2013	Sep. 28, 2012
In Thousands, unless otherwise specified
Other Financial Information [Abstract]	'	'
Foreign currency translation adjustments	($32,853)	($9,149)
Adjustments relating to defined benefit pension plans	-269,345	-269,892
Other	-1,929	-2,846
Total	($304,127)	($281,887)

Other_Financial_Information_Su

Other Financial Information (Supplemental Cash Flow Information) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012
Other Financial Information [Abstract]	'	'
Working capital	$4,197	$9,937
Property and equipment	386	3,378
Noncurrent assets	0	17,591
Deferred liabilities	2,181	-8,177
Non-controlling interests	18,589	40
Foreign currency translation	-3,461	21
Goodwill	$17,537	$68,785

Segment_Information_Financial_

Segment Information (Financial Information By Geographic Area) (Details) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Sep. 27, 2013

Jun. 28, 2013

Mar. 29, 2013

Dec. 28, 2012

Sep. 28, 2012

Jun. 29, 2012

Mar. 30, 2012

Dec. 30, 2011

Sep. 30, 2011

Jul. 01, 2011

Apr. 01, 2011

Dec. 31, 2010

Sep. 27, 2013

Sep. 28, 2012

Sep. 30, 2011

categories

segments

Revenues from External Customers and Long-Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of service categories

'

'

'

'

'

'

'

'

'

'

'

'

4

'

'

Number of reportable segments

'

'

'

'

'

'

'

'

'

'

'

'

1

'

'

Revenues

$3,142,656

$3,080,995

$2,835,084

$2,759,641

$2,786,285

$2,772,874

$2,702,851

$2,631,768

$2,723,295

$2,744,178

$2,558,016

$2,356,175

$11,818,376

$10,893,778

$10,381,664

Long-lived assets

379,296

'

'

'

331,131

'

'

'

284,633

'

'

'

379,296

331,131

284,633

United States [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues from External Customers and Long-Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

'

'

'

'

6,993,594

6,749,583

6,435,078

Long-lived assets

230,281

'

'

'

203,746

'

'

'

169,914

'

'

'

230,281

203,746

169,914

Europe [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues from External Customers and Long-Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

'

'

'

'

2,148,504

1,681,421

1,649,678

Long-lived assets

47,128

'

'

'

46,763

'

'

'

49,372

'

'

'

47,128

46,763

49,372

Canada [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues from External Customers and Long-Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

'

'

'

'

1,652,386

1,564,883

1,656,487

Long-lived assets

61,122

'

'

'

47,539

'

'

'

42,496

'

'

'

61,122

47,539

42,496

Asia [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues from External Customers and Long-Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

'

'

'

'

204,203

156,748

102,272

Long-lived assets

4,272

'

'

'

3,580

'

'

'

1,653

'

'

'

4,272

3,580

1,653

India [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues from External Customers and Long-Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

'

'

'

'

158,908

124,362

103,842

Long-lived assets

15,049

'

'

'

17,094

'

'

'

16,831

'

'

'

15,049

17,094

16,831

Australia [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues from External Customers and Long-Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

'

'

'

'

141,507

253,932

194,560

Long-lived assets

8,329

'

'

'

7,859

'

'

'

1,040

'

'

'

8,329

7,859

1,040

South America And Mexico [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues from External Customers and Long-Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

'

'

'

'

241,590

158,141

109,520

Long-lived assets

6,159

'

'

'

2,400

'

'

'

1,533

'

'

'

6,159

2,400

1,533

Middle East And Africa [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues from External Customers and Long-Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

'

'

'

'

277,684

204,708

130,227

Long-lived assets

$6,956

'

'

'

$2,150

'

'

'

$1,794

'

'

'

$6,956

$2,150

$1,794

Segment_Information_Revenues_E

Segment Information (Revenues Earned Directly Or Indirectly From The U.S. Federal Government And Its Agencies) (Details)	12 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 30, 2011
Segment Reporting [Abstract]	'	'	'
Percentage of revenue earned from the U.S. federal government and its agencies	19.90%	22.10%	24.40%

Selected_Quarterly_Information2

Selected Quarterly Information - Unaudited (Details) (USD $)	3 Months Ended																								12 Months Ended
	Sep. 27, 2013		Jun. 28, 2013		Mar. 29, 2013		Dec. 28, 2012		Sep. 28, 2012		Jun. 29, 2012		Mar. 30, 2012		Dec. 30, 2011		Sep. 30, 2011		Jul. 01, 2011		Apr. 01, 2011		Dec. 31, 2010		Sep. 27, 2013		Sep. 28, 2012		Sep. 30, 2011
Finite-Lived Intangible Assets [Line Items]	'		'		'		'		'		'		'		'		'		'		'		'		'		'		'
Gain after tax on sale of intellectual property	$4,000,000		'		'		'		'		'		'		'		'		'		'		'		'		'		'
Revenues	3,142,656,000		3,080,995,000		2,835,084,000		2,759,641,000		2,786,285,000		2,772,874,000		2,702,851,000		2,631,768,000		2,723,295,000		2,744,178,000		2,558,016,000		2,356,175,000		11,818,376,000		10,893,778,000		10,381,664,000
Operating profit	175,148,000	[1]	168,359,000	[1]	165,203,000	[1]	160,269,000	[1]	167,617,000	[1]	153,366,000	[1]	133,138,000	[1]	141,952,000	[1]	147,904,000	[1]	139,380,000	[1]	128,015,000	[1]	103,619,000	[1]	668,979,000	[1]	596,073,000	[1]	518,918,000	[1]
Earnings before taxes	174,906,000		168,423,000		161,908,000		156,311,000		170,096,000		151,371,000		132,315,000		139,554,000		145,156,000		141,301,000		126,481,000		103,723,000		661,548,000		593,336,000		516,661,000
Net Earnings of the Group	116,481,000		112,089,000		107,089,000		104,523,000		111,082,000		100,990,000		87,446,000		91,436,000		95,247,000		91,936,000		81,341,000		66,697,000		440,182,000		390,954,000		335,221,000
Net earnings attributable to Jacobs	$110,811,000		$108,871,000		$104,401,000		$99,010,000		$107,411,000	[2]	$97,900,000		$83,933,000		$89,710,000		$94,280,000		$90,676,000		$80,250,000		$65,823,000		$423,093,000		$378,954,000	[2]	$331,029,000
Earnings per share:	'		'		'		'		'		'		'		'		'		'		'		'		'		'		'
Basic (in dollars per share)	$0.85		$0.84		$0.81		$0.77		$0.84	[2]	$0.77		$0.66		$0.71		$0.75		$0.72		$0.64		$0.53		$3.27		$2.97	[2]	$2.63
Diluted (in dollars per share)	$0.84		$0.83		$0.80		$0.76		$0.83	[2]	$0.76		$0.65		$0.70		$0.74		$0.71		$0.63		$0.52		$3.23		$2.94	[2]	$2.60
Intellectual Property [Member]	'		'		'		'		'		'		'		'		'		'		'		'		'		'		'
Finite-Lived Intangible Assets [Line Items]	'		'		'		'		'		'		'		'		'		'		'		'		'		'		'
Gain after tax on sale of intellectual property per diluted share (in dollars per share)	$0.03		'		'		'		'		'		'		'		'		'		'		'		'		'		'
[1]	Operating profit represents revenues less (i) direct costs of contracts, and (ii) selling, general and administrative expenses.
[2]	Includes a one-time, after-tax gain of $4.0 million, or $0.03 per diluted share, related to the sale of the Company's intellectual property for iron ore pelletizing and certain other related assets.

Definitions_Details

Definitions (Details)	12 Months Ended
	Sep. 27, 2013
	quarter
Definitions [Abstract]	'
Number of consecutive fiscal quarters included In consolidated leverage ratio calculation	4