XML 77 R65.htm IDEA: XBRL DOCUMENT v3.8.0.1
Shared-Based Compensation - Additional Information (Detail)
3 Months Ended
Mar. 31, 2018
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Number of options granted 55,300
Weighted average grant date fair value of the options granted | $ / shares $ 10.68
Restricted Stock [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Stock units issued 86,516
Stock awards granted vesting period 3 years
Fair value assumptions, exercise price | $ / shares $ 24.55
TSR Awards [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Stock units issued 55,000
Percentage of shares issuable based on threshold performance 50.00%
Percentage of shares issuable based on target performance 100.00%
Percentage of shares issuable based on maximum performance 150.00%
ROIC Awards [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Stock units issued 55,000
Percentage of shares issuable based on threshold performance 35.00%
Percentage of shares issuable based on target performance 100.00%
Percentage of shares issuable based on maximum performance 150.00%
Officers and Key Employees [Member] | Restricted Stock [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Stock awards granted vesting period 3 years
Non-executive Directors [Member] | Restricted Stock [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Stock awards granted vesting period 1 year