CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Trade accounts receivable, allowance for doubtful accounts	$ 10,080	$ 10,126
Shareholders' Equity:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock shares issued (in shares)	17,435,117	17,401,297
Series A preferred stock
Shareholders' Equity:
Preferred stock, par value (in dollars per share)	$ 1.00	$ 1.00
Preferred stock, authorized (in shares)	1,000,000	1,000,000
Series B Convertible Preferred Stock
Shareholders' Equity:
Preferred stock, par value (in dollars per share)	$ 1.00	$ 1.00
Preferred stock, authorized (in shares)	1,000,000	1,000,000