Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Allowance for doubtful accounts	$ 2,600	$ 4,280
Stockholders' Equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	30,303,395	29,611,989
Common stock, shares outstanding	29,592,164	28,900,758
Treasury stock, shares (in shares)	711,231	711,231