Number of Stock Options and Restricted Share Awards that were Issued or Outstanding but were Excluded in Calculating Diluted Earnings Per Share Because their Effect would have been Anti-Dilutive (Detail) - shares
shares in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]        
Anti-dilutive securities excluded from the computation of dilutive EPS 2,445 1,107 2,316 2,104
Stock options        
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]        
Anti-dilutive securities excluded from the computation of dilutive EPS 2,302 1,083 2,227 2,094
Restricted share awards        
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]        
Anti-dilutive securities excluded from the computation of dilutive EPS 143 24 89 10