Share-Based Compensation - Stock Options Assumptions Table (Detail) (Stock Option [Member])	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected option life—years	4 years 9 months 18 days	4 years 10 months 24 days	4 years 9 months 18 days
Volatility	33.90%	44.20%	42.00%
Risk-free interest rate	1.30%	0.70%	1.50%
Dividend yield	0.80%	0.50%	0.50%