Stockholders' Equity - Additional Information (Detail) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2016 USD ($) $ / shares shares	Jun. 30, 2016 USD ($) $ / shares shares
Disclosure - Stockholders' Equity - Additional Information (Detail) [Line Items]
Shares repurchased | shares	0	0
Remaining capacity for authorized repurchase shares | $	$ 458	$ 458
Dividends paid | $	$ 63	$ 126
Dividends paid per share | $ / shares	$ 0.375	$ 0.75
Dividends record date	May 20, 2016
Maximum [Member]
Disclosure - Stockholders' Equity - Additional Information (Detail) [Line Items]
Common stock issued as a result of option exercises | shares	100,000	100,000