Preferred and Common Stock - Schedule of Options Fully Vested and/or Expected to Vest (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Schedule Of Stock Options [Line Items]
Options Fully Vested and/or Expected to Vest, Number of options	45.3
Options Fully Vested and/or Expected to Vest, Weighted average remaining contractual life, years	4 years 11 months 9 days
Options Fully Vested and/or Expected to Vest, Weighted average exercise price	$ 10.78
Options Fully Vested and/or Expected to Vest, Intrinsic value	$ 55
$8.33 [Member]
Schedule Of Stock Options [Line Items]
Range of exercise price, lower unit	$ 8.33
Options Fully Vested and/or Expected to Vest, Number of options	16.3
Options Fully Vested and/or Expected to Vest, Weighted average remaining contractual life, years	1 year 22 days
Options Fully Vested and/or Expected to Vest, Weighted average exercise price	$ 8.33
Options Fully Vested and/or Expected to Vest, Intrinsic value	38
$8.34 - $11.33 [Member]
Schedule Of Stock Options [Line Items]
Range of exercise price, lower unit	$ 8.34
Range of exercise price, upper unit	$ 11.33
Options Fully Vested and/or Expected to Vest, Number of options	17.1
Options Fully Vested and/or Expected to Vest, Weighted average remaining contractual life, years	8 years 2 months 19 days
Options Fully Vested and/or Expected to Vest, Weighted average exercise price	$ 9.60
Options Fully Vested and/or Expected to Vest, Intrinsic value	$ 17
$11.34 - $17.40 [Member]
Schedule Of Stock Options [Line Items]
Range of exercise price, lower unit	$ 11.34
Range of exercise price, upper unit	$ 17.40
Options Fully Vested and/or Expected to Vest, Number of options	10.8
Options Fully Vested and/or Expected to Vest, Weighted average remaining contractual life, years	6 years 1 month 21 days
Options Fully Vested and/or Expected to Vest, Weighted average exercise price	$ 14.46
$17.41 - $34.84 [Member]
Schedule Of Stock Options [Line Items]
Range of exercise price, lower unit	$ 17.41
Range of exercise price, upper unit	$ 34.84
Options Fully Vested and/or Expected to Vest, Number of options	1.1
Options Fully Vested and/or Expected to Vest, Weighted average remaining contractual life, years	18 days
Options Fully Vested and/or Expected to Vest, Weighted average exercise price	$ 28.92