Amount of gain (loss), after tax expense or benefit and not previously recognized, resulting from the sale of a business component.

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After tax income (loss) from operations of a business component (exclusive of any gain (loss) on disposal, or provision therefore) during the reporting period, until its disposal.

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Amount of sales or other form of revenues attributable to the disposal group, including a component of the entity (discontinued operation), during the reporting period.

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Pretax lease income allocated in proportionate amounts from unearned income.

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Other expenses or losses included in net income that result in no cash outflows or inflows in the period and are not separately disclosed.

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Discontinued Operations - Operating Results for Cross-Border Energy Lease Investments (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended			12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) income from discontinued operations, net of income taxes	$ 8	$ (11)	$ (319)	$ (322)	$ 67
Cross-Border Energy Lease Investments [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating revenue from PHI's cross-border energy lease investments				7	50
Non-cash charge to reduce carrying value of PHI's cross-border energy lease investments				(373)
Total operating revenue				(366)	50
(Loss) income from operations of discontinued operations, net of income taxes				(325)	32
Net (losses) gains associated with the early termination of the cross-border energy lease investments, net of income taxes				(2)	9
(Loss) income from discontinued operations, net of income taxes				$ (327)	$ 41