Reconciliation of Net (loss) Income and Weighted-Average Shares of Common Stock Outstanding for Purposes of Calculating Basic and Diluted Earnings Per Share (Parenthetical) (Detail)
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Earnings Per Share Disclosure [Line Items]    
Common stock equivalents excluded from the calculation of diluted earnings per share 1,108,000 641,000
Common Stock Equivalents    
Earnings Per Share Disclosure [Line Items]    
Common stock equivalents excluded from the calculation of diluted earnings per share 570,000