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Employee Stock-Based Compensation - Additional Information (Detail) - 2014 Incentive Plan
3 Months Ended
Mar. 31, 2018
$ / shares
shares
Time Based Restricted Stock Unit Grants  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
RSUs Granted | shares 261,000
Stock award granted vesting period 3 years
Weighted average grant date fair value, granted | $ / shares $ 21.19
Time Based Restricted Stock Unit Grants | Share Based Compensation Award Tranche One  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Stock award vesting percentage 33.00%
Time Based Restricted Stock Unit Grants | Share Based Compensation Award Tranche Two  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Stock award vesting percentage 33.00%
Time Based Restricted Stock Unit Grants | Share Based Compensation Award Tranche Three  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Stock award vesting percentage 33.00%
Performance and Service Condition Based Restricted Stock Unit Grants  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
RSUs Granted | shares 131,000
Weighted average grant date fair value, granted | $ / shares $ 21.19
Market and Service Condition Based Restricted Stock Unit Grants  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
RSUs Granted | shares 131,000
Stock award granted vesting period 3 years
Weighted average grant date fair value, granted | $ / shares $ 22.57
Market and Service Condition Based Restricted Stock Unit Grants | Minimum  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Percentage of number of shares of common stock earned 0.00%
Market and Service Condition Based Restricted Stock Unit Grants | Maximum  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Percentage of number of shares of common stock earned 150.00%
Market and Service Condition Based Restricted Stock Unit Grants | Vesting Based On Market And Service Contingent On Positive Total Shareholder Return Of Peer Group Measure  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Percentage of shareholder return 75.00%
Market and Service Condition Based Restricted Stock Unit Grants | Vesting Based On Market And Service Contingent On Negative Total Shareholder Return Of Peer Group Measure  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Percentage of shareholder return 125.00%