CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Accounts receivable, allowance	$ 1,356	$ 2,570
Common stock and additional paid-in capital, par value	$ 0	$ 0
Common stock and additional paid-in capital, shares authorized	55,000,000	55,000,000
Common stock and additional paid-in capital, shares issued	1,688,000	1,647,000
Common stock and additional paid-in capital, shares outstanding	1,688,000	1,647,000
Preferred stock, par value	$ 0	$ 0
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	2,811,535	2,811,535
Preferred stock, shares outstanding	2,811,535	2,811,535
Preferred stock, redemption amount	$ 70,288	$ 70,288