Goodwill - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Sep. 30, 2015	Dec. 31, 2015
Goodwill [Line Items]
Goodwill impairment charge		$ 20
Diamond Offshore Drilling, Inc. [Member]
Goodwill [Line Items]
Goodwill impairment charge	$ 20

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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