Income Taxes - Reconciliation of Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
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| Income Tax Disclosure [Abstract] | |||
| Unrecognized tax benefits, beginning balance | $ 379 | $ 467 | $ 404 |
| Additions for tax positions of prior years | 39 | 21 | 11 |
| Reductions for tax positions of prior years | (25) | (24) | (5) |
| Additions based on tax positions related to current year | 75 | 85 | 67 |
| Lapse of statute of limitations | (2) | (2) | 0 |
| Settlements | (168) | (12) | |
| Positions assumed in acquisitions | 0 | 0 | 2 |
| Unrecognized tax benefits, ending balance | $ 466 | $ 379 | $ 467 |
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- References No definition available.
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- Definition Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of increase in unrecognized tax benefits resulting from acquisitions. No definition available.
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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