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								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Basic Earnings (Loss) per Common Share:
Net loss	$ (7,816)	$ (8,352)	$ (7,461)	$ (8,908)	$ (8,683)	$ (7,761)	$ (7,933)	$ (8,463)	$ (32,537)	$ (32,840)
Beneficial conversion feature	$ (11,443)								(11,443)	0
Net loss attributable to common shares									$ (43,980)	$ (32,840)
Weighted average common shares outstanding — basic	15,222	12,241	12,108	12,037	11,967	11,924	11,665	11,487	12,906	11,762
Basic earnings (loss) per common share	$ (1.27)	$ (0.68)	$ (0.62)	$ (0.74)	$ (0.73)	$ (0.65)	$ (0.68)	$ (0.74)	$ (3.41)	$ (2.79)
Diluted Earnings (Loss) per Common Share:
Net loss attributable to common shares — diluted									$ (43,980)	$ (32,840)
Weighted average common shares outstanding — diluted	15,222	12,241	12,108	12,037	11,967	11,924	11,665	11,487	12,906	11,762
Diluted earnings (loss) per common share	$ (1.27)	$ (0.68)	$ (0.62)	$ (0.74)	$ (0.73)	$ (0.65)	$ (0.68)	$ (0.74)	$ (3.41)	$ (2.79)