Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Long-term debt, fair value	$ 35,066	$ 48,076
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	260,000,000	260,000,000
Common stock, shares issued	14,984,000	11,162,000
Treasury stock, shares	3,369,000	3,323,000