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Share-Based Compensation - Schedule of Fair Value of Each Stock Option Award is Estimated on Grant Date, Using Option Valuation Models (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 1.20% 1.18% 0.89%
Expected volatility 45.00% 50.00% 41.00%
Expected life, in years 6 years 3 months 6 years 3 months 5 years
Expected dividend yield