XML 36 R25.htm IDEA: XBRL DOCUMENT v3.7.0.1
Stock-Based Employee Compensation - Additional Information (Detail)
$ / shares in Units, $ in Millions
3 Months Ended
Mar. 31, 2017
USD ($)
Installment
$ / shares
shares
Mar. 31, 2016
USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock-based compensation $ 0.5 $ 0.4
Number of installments of restricted shares | Installment 3  
Restricted Stock [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Unrecognized compensation expense of restricted stock $ 4.9 $ 2.2
2005 Executive Incentive Compensation Plan [Member] | Restricted Stock [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Restricted stock shares granted | shares 397,461  
Fair market value of restricted shares granted | $ / shares $ 6.63  
Cliff Vest [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Restricted shares, vesting period 5 years