Components of Calculation of Basic and Diluted Earnings Per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Earnings Per Share [Abstract]
Net loss	$ (409,592)		$ (143,070)		$ (104,589)
Less: Preferred stock dividends	(17,148)	[1]	(6,900)	[1]	(1,687)	[1]
Induced conversion of preferred stock	(4,256)		0		0
Net loss attributable to common shareholders – basic and diluted	$ (430,996)		$ (149,970)		$ (106,276)
Weighted-average shares – basic	68,887,000		62,335,000		47,919,000
Effect of dilutive securities	0	[2]	0	[2]	0	[2]
Weighted-average shares – diluted	68,887,000		62,335,000		47,919,000
Potentially dilutive securities with the effect of being anti-dilutive excluded from the calculation of diluted earnings per common share	26,600,000		19,800,000		19,200,000

[1] Preferred stock dividends were excluded from diluted earnings per share for the years ended December 31, 2014, 2013 and 2012, as the assumed conversion of the outstanding preferred stock would have been anti-dilutive.

[2] For 2014, approximately 26.6 million potentially dilutive securities, including the Series A 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. For 2013 and 2012, approximately 19.8 million and 19.2 million, respectively, potentially dilutive securities, including the Series A 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.