Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Total unrecognized tax benefits	$ 21	$ 243
Tax benefits affecting effective tax rate		84
Unrecognized tax benefits impact in the next twelve months		9
Payment of interest accrued		16
Accrued penalties related to unrecognized tax benefits		5
Tax benefit related to foreign operating losses	52
Reversal of interest accruals	2
Deferred tax asset relating to net operating losses	$ 29