v2.4.1.9
Basis of Presentation - Additional Information (Detail)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Basis of Presentation [Line Items]    
Restricted stock units outstanding to purchase shares included in diluted earnings per common share 5us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements 5us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements