Intrinsic Value of Awards Exercised or Vested (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Option and Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of awards exercised	$ 14	$ 18	$ 26
Restricted Stock Units (RSUs) and Performance Share Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of awards vested	$ 5	$ 11	$ 10