Components of Calculation of Basic and Diluted Earnings Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Net loss		$ (33,473)	$ (57,165)
Less: Preferred stock dividends	[1]	(3,152)	(6,067)
Net income (loss) attributable to common shareholders, Basic		(36,625)	(63,232)
Net loss attributable to common shareholders, Diluted		$ (36,625)	$ (63,232)
Weighted-average shares – basic		85,941	71,820
Effect of dilutive securities	[2]	0	0
Weighted-average shares – diluted		85,941	71,820
Potentially dilutive securities with the effect of being anti-dilutive excluded from the calculation of diluted earnings per common share		27,600	31,300

[1] Preferred stock dividends were excluded from the computation of diluted earnings per share for the three months ended March 31, 2016 and 2015, as the assumed conversion of the outstanding preferred stock would have been anti-dilutive.

[2] For the three months ended March 31, 2016 and 2015, approximately 27.6 million and 31.3 million, respectively, of potentially dilutive securities, including the Series A Preferred Stock and Series B Preferred Stock, stock options and restricted stock units, had the effect of being anti-dilutive and were excluded from the calculation of diluted earnings per common share.