Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation and Cash-Based Incentive Compensation - Additional Information (Details)

v3.19.1
Share-Based Compensation and Cash-Based Incentive Compensation - Additional Information (Details)
$ in Millions
 3 Months Ended
Mar. 31, 2019
USD ($)
Award
shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Common stock available for award under plans | shares 11,852,592
Number of cash based awards | Award 2
Directors Compensation Plan  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Common stock available for award under plans | shares 128,980
Restricted Stock Units (RSUs)  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Common shares available for issuance reduced conversion basis One-for-one basis
Unrecognized share-based compensation expense | $ $ 5.5
Recognition period for unrecognized compensation expense 2020-11
Restricted Shares  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Unrecognized share-based compensation expense | $ $ 0.3
Recognition period for unrecognized compensation expense 2021-04
Restricted Shares | Directors Compensation Plan  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Common shares available for issuance reduced conversion basis One-to-one basis
2018 Long-term Cash-based Awards  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Cash-based awards expected payment date Dec. 14, 2020
2018 Short-term Cash-based Awards  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Cash-based awards payment date Mar. 31, 2019
2017 Cash-based Awards  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Cash-based awards payment date Mar. 31, 2018