Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation - Narrative (Details)

v3.20.4
Stock-Based Compensation - Narrative (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Mar. 24, 2020
Sep. 11, 2019
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Apr. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Excess tax benefit     $ 0.3 $ 0.1 $ 0.1  
Stock based comp percent of award earned after first hurdle     50.00%      
Stock based comp percent of award earned after subsequent hurdle     25.00%      
Monte-Carlo Model            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Performance Achievement, Stock Price Hurdle, Weighted Average Value $ 0.90 $ 4.77        
Performance Share Awards (PSAs)            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Performance condition based on earnings before interest, taxes, depreciation and amortization     75.00%      
Performance condition based on cumulative free cash flow     25.00%      
Restricted Stock Units (RSUs)            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of shares accounted for as liability awards (in shares)     638,300 670,800    
Performance Share Units that may be settled in cash            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of shares accounted for as liability awards (in shares)       4,174    
Restricted Stock Units that may be settled in cash            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of shares accounted for as liability awards (in shares)     8,334 14,118    
Performance Shares, Performance Share Units and Restricted Stock Units            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Total unrecognized compensation expense     $ 4.1      
Weighted average period     2 years 9 months 18 days      
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period   371,430 691,130      
Number of shares accounted for as liability awards (in shares)     1,257,400 868,300    
Performance Shares, Performance Share Units and Restricted Stock Units | Hurdle Price One            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Performance Achievement, Stock Price Hurdle 6.00 $ 10.50        
Performance Shares, Performance Share Units and Restricted Stock Units | Hurdle Price One | Monte-Carlo Model            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Performance Achievement, Stock Price Hurdle, Fair Value   5.93        
Performance Shares, Performance Share Units and Restricted Stock Units | Hurdle Price Two            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Performance Achievement, Stock Price Hurdle 7.50 12.25        
Performance Shares, Performance Share Units and Restricted Stock Units | Hurdle Price Two | Monte-Carlo Model            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Performance Achievement, Stock Price Hurdle, Fair Value   5.28        
Performance Shares, Performance Share Units and Restricted Stock Units | Hurdle Price Three            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Performance Achievement, Stock Price Hurdle 9.00 14.00        
Performance Shares, Performance Share Units and Restricted Stock Units | Hurdle Price Three | Monte-Carlo Model            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Performance Achievement, Stock Price Hurdle, Fair Value   4.70        
Performance Shares, Performance Share Units and Restricted Stock Units | Hurdle Price Four            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Performance Achievement, Stock Price Hurdle $ 10.50 15.75        
Performance Shares, Performance Share Units and Restricted Stock Units | Hurdle Price Four | Monte-Carlo Model            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Performance Achievement, Stock Price Hurdle, Fair Value   4.20        
Performance Shares, Performance Share Units and Restricted Stock Units | Hurdle Price Five            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Performance Achievement, Stock Price Hurdle   17.50        
Performance Shares, Performance Share Units and Restricted Stock Units | Hurdle Price Five | Monte-Carlo Model            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Performance Achievement, Stock Price Hurdle, Fair Value   $ 3.75        
2016 LTIP Plan            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of shares available for grant (in shares)     1,185,860      
2016 Directors' Plan            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of shares available for grant (in shares)     17,101      
2016 Directors' Plan | Restricted Stock Units (RSUs)            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of shares accounted for as liability awards (in shares)     412,500      
Weighted-average grant date fair value of PSUs and RSUs (in dollars per share)     $ 3.83 $ 11.05 $ 13.30  
Award vesting period     1 year      
Common Stock | 2016 LTIP Plan            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of shares authorized (in shares)           7,600,000
Common Stock | 2016 Directors' Plan            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of shares authorized (in shares)           600,000