Earnings Per Common Share - Summary of Reconciliation of Earnings (Loss) Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Basic Earnings (Loss) per Common Share:
Net loss	$ (7,933)	$ (8,038)	$ (16,396)	$ (16,150)
Distributed earnings to common shares	0	0	0	0
Distributed earnings to participating securities	0	0	0	0
Total distributed earnings	0	0	0	0
Undistributed loss allocable to common shares	(7,933)	(8,038)	(16,396)	(16,150)
Undistributed earnings allocable to participating securities	0	0	0	0
Total undistributed loss	(7,933)	(8,038)	(16,396)	(16,150)
Loss to common shares — basic	$ (7,933)	$ (8,038)	$ (16,396)	$ (16,150)
Weighted average common shares outstanding — basic	11,665	11,337	11,576	11,302
Basic earnings (loss) per common share	$ (0.68)	$ (0.71)	$ (1.42)	$ (1.43)
Diluted Earnings (Loss) per Common Share:
Loss to common shares — basic	$ (7,933)	$ (8,038)	$ (16,396)	$ (16,150)
Undistributed earnings allocated to participating securities	0	0	0	0
Undistributed earnings reallocated to participating securities	0	0	0	0
Loss to common shares — diluted	$ (7,933)	$ (8,038)	$ (16,396)	$ (16,150)
Weighted average common shares outstanding — basic	11,665	11,337	11,576	11,302
Dilutive effect of stock options	0	0	0	0
Weighted average common shares outstanding — diluted	11,665	11,337	11,576	11,302
Diluted earnings (loss) per common share	$ (0.68)	$ (0.71)	$ (1.42)	$ (1.43)