Discontinued Operations - Additional Information (Detail) $ in Millions	Dec. 31, 2014 USD ($)
Discontinued Operations And Disposal Groups [Abstract]
Assets of discontinued operations	$ 1,035
Liabilities of discontinued operations	$ 797

Amount classified as assets attributable to disposal group held for sale or disposed of, expected to be disposed of within one year or the normal operating cycle, if longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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