Stock-Based Employee Compensation Plans - Stock Option Pricing Weighted Average Assumptions (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk-free interest rate	0.90%	1.00%	2.40%
Expected volatility	24.40%	24.60%	24.20%
Dividend yield	2.10%	2.40%	2.60%
Expected average term (in years)	5 years 6 months	5 years 6 months	5 years 6 months