Loss Per Common Share - Computation of Basic and Diluted Net loss Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator:
Net loss:	$ (5,986)	$ (14,941)
Adjustments for basic net loss per common share:
Dividend requirements	(75)	(75)
Net loss attributable to common stockholders	$ (13,196)	$ (24,609)
Denominator:
Denominator for basic and dilutive net loss per common share - weighted- average shares	27,248,059	22,868,307
Basic and diluted:
Loss from continuing operations	$ (0.48)	$ (1.11)
Income from discontinued operations, net of taxes		0.03
Net loss	$ (0.48)	$ (1.08)
Series E Redeemable Preferred Stock [Member]
Adjustments for basic net loss per common share:
Dividend requirements on Series E Redeemable Preferred	$ (5,536)	$ (7,350)
Accretion of redeemable preferred stock	(1,599)	(2,243)
Series B Preferred Stock [Member]
Adjustments for basic net loss per common share:
Dividend requirements	(60)	(60)
Series D Preferred Stock [Member]
Adjustments for basic net loss per common share:
Dividend requirements	$ (15)	$ (15)