Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 0	$ 14,235
Common stock, shares authorized	20,000,000	20,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares issued	6,751,000	6,687,000
Common stock, shares outstanding	6,519,000	6,455,000
Treasury stock, shares	232,000	232,000