Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2015
Income Taxes [Line Items]
Total unrecognized tax benefits		$ 274
Tax benefits affecting effective tax rate		89
Unrecognized tax benefits impact in the next twelve months		9
Payment of interest accrued		18
Accrued penalties related to unrecognized tax benefits		$ 3
Tax benefit related to foreign operating losses	$ 52
Recognition of Previously Unrecognized Tax Benefit [Member]
Income Taxes [Line Items]
Tax benefit related to foreign operating losses	21
Reversal of Interest Accruals [Member]
Income Taxes [Line Items]
Tax benefit related to foreign operating losses	2
Recognition of Deferred Tax Asset Relating to Net Operating Losses [Member]
Income Taxes [Line Items]
Tax benefit related to foreign operating losses	$ 29