Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v2.4.0.8
Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
3 Months Ended
Mar. 31, 2014
Mar. 31, 2013
Schedule Of Significant Accounting Policies [Line Items]    
Anti-dilutive securities excluded from earnings per share   6,174,132
Amounts of tax included on a gross basis $ 37.9 $ 31.4