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Tax - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2015 | Mar. 31, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014
Tax Credit Carryforward [Line Items] |  |  |  |  |
Effective tax rate | 26.90% |  | 31.80% | 32.90% | 31.10%
Effective tax rate excluding discrete items | 29.90% |  |  | 29.40% |
U.S. federal statutory rate |  |  |  | 35.00% |
Unrecognized tax benefit | $ 125 |  |  | $ 125 |
Reserve of uncertain tax position identified in foreign jurisdiction |  | $ 69 |  |  |
Uncertain tax position settled |  |  |  | 60 |
Uncertain tax position remaining amount | 9 |  |  | 9 |
Realized [Member] |  |  |  |  |
Tax Credit Carryforward [Line Items] |  |  |  |  |
Unrecognized tax benefit | $ 52 |  |  | $ 52 |

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