Quarterly report pursuant to Section 13 or 15(d)

Earnings Per Share and Other Equity Related Information - Narrative (Details)

v3.19.3
Earnings Per Share and Other Equity Related Information - Narrative (Details) - USD ($)
 3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Aug. 31, 2019
Feb. 28, 2017
Apr. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Stock options excluded from calculation of dilutive shares as the effect would be anti-dilutive (in shares) 1,152,000 758,000 642,000 1,273,000      
Stock-based compensation expense $ 413,000 $ 390,000 $ 1,195,000 $ 1,137,000      
Open market purchase of treasury shares 139,000   139,000 1,772,000      
Open market purchase of treasury shares, fees 400     $ 9,000      
Stock Options              
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Non-vested stock options unrecognized compensation expense $ 4,641,000   $ 4,641,000        
Non-vested stock options unrecognized compensation expense, weighted-average period of recognition     2 years 11 months 15 days        
Options granted in period (in shares) 1,000            
Stock options, vesting period 10 years            
Stock options, contractual period 3 years            
Common Class A              
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Stock repurchase program, authorized amount (up to)         $ 17,553,000 $ 15,000,000 $ 10,000,000
Treasury Stock              
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Open market purchase of common shares (in shares) 10,000 0 10,000 212,231      
Open market purchase of treasury shares $ 139,000   $ 139,000 $ 1,772,000