Number of underlying matters.

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Carrying value of the obligation (known or estimated) arising from requirements to perform activities to remediate one or more sites, payable after twelve months or beyond the next operating cycle if longer.

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Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

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Amount of contractual obligation due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of contractual obligation due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of judgment or settlement awarded to (against) the entity in respect of litigation.

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Amount of loss contingency liability.

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The value (monetary amount) of the award the plaintiff seeks in the legal matter.

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Number of defendants named in a legal action.

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Commitments and Contingencies - Additional Information (Detail) $ in Millions			3 Months Ended
	Oct. 15, 2015 USD ($)	Aug. 23, 2004 Defendant LegalMatter	Jun. 30, 2015 USD ($)	Sep. 30, 2015 USD ($)
Loss Contingencies [Line Items]
Number of defendants \| Defendant		2
Number of underlying matters in a cross-claim requesting declaration of non-coverage \| LegalMatter		20
Environmental reserves, Noncurrent				$ 1.6
Aggregate possible liquidated damage due to failure to meet specified contractual milestone dates, offshore oil and gas construction segment				31.0
Liquidated damage contingencies, accrued				6.0
Outstanding obligation in 2015				22.3
Outstanding obligation in 2016				180.2
Outstanding obligation				$ 202.5
AT1 [Member] \| Minimum
Loss Contingencies [Line Items]
Alleged damage claims amount			$ 170.0
Subsequent Event [Member] \| AT1 [Member]
Loss Contingencies [Line Items]
Claims settlement amount	$ 16.7