Income Taxes - Schedule of Income Tax Balance Sheet Presentation (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Deferred income tax assets-current	$ 23	$ 23	$ 76
Deferred income tax assets-non-current	195	193	104
Deferred income tax liabilities-current		0	(1)
Deferred income tax liabilities-non-current	(5,137)	(5,053)	(4,948)
Net deferred taxes		$ (4,837)	$ (4,769)

Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards expected to be realized or consumed within one year or operating cycle, if longer.

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Amount after allocation of valuation allowances of noncurrent deferred tax asset attributable to deductible temporary differences and carryforwards. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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- Definition

Amount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances expected to be realized or consumed within one year or operating cycle, if longer.

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