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Stock-Based Compensation - Restricted Stock Awards (Details) - Restricted stock awards - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vested in period, fair value   $ 2,200,000 $ 2,700,000
Unrecognized compensation expense $ 0    
Executive Officer      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting period (years) 3 years