Net Income (Loss) Per Common Share - Computations of Basic and Diluted Income (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Net income (loss) applicable to common stock	$ (5,324)	$ (5,725)
Weighted average common shares outstanding (shares)	11,218	9,109
Basic net income (loss) per share (in dollars per share)	$ (0.47)	$ (0.63)
Common shares issuable on assumed conversion of restricted stock, stock warrants and employee stock options were not included in the computation of diluted loss per common share since their inclusion would have been anti-dilutive [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common shares issuable upon assumed conversion	201	288
Common shares issuable upon conversion of the Convertible Second Lien Notes were not included in the computation of diluted loss per common share since their inclusion would have been anti-dilutive [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common shares issuable upon assumed conversion	3,791	5,664