Goodwill and Intangibles (Details) (USD $)	3 Months Ended
Jan. 01, 2012	Jan. 01, 2012 Engineering and consulting services (ECS)	Jan. 01, 2012 Technical support services (TSS)	Oct. 02, 2011 Technical support services (TSS)	Jan. 01, 2012 Engineering and architecture services (EAS)	Oct. 02, 2011 Engineering and architecture services (EAS)	Jan. 01, 2012 Remediation and construction management (RCM)	Oct. 02, 2011 Remediation and construction management (RCM)
Goodwill
Balance at beginning of the period	$ 569,414,000	$ 376,340,000	$ 127,526,000	$ 127,526,000	$ 17,710,000	$ 17,710,000	$ 47,838,000	$ 47,838,000
Adjustments	35,000	35,000
Currency translation adjustments	7,957,000	7,957,000
Balance at end of the period	577,406,000	384,332,000	127,526,000	127,526,000	17,710,000	17,710,000	47,838,000	47,838,000
Gross amount of goodwill					122,700,000	122,700,000
Accumulated impairment losses					$ 105,000,000	$ 105,000,000

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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-Name Statement of Financial Accounting Standard (FAS)

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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