Basic and Diluted Net Loss Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				392 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Mar. 31, 2013
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net loss	$ (42,084)		$ (17,704)		$ (473,335)
Weighted-average number of shares of common stock and common stock equivalents outstanding:
Weighted-average number of common shares outstanding for computing basic earnings per share	31,813		22,624
Dilutive effect of outstanding warrants and stock awards after application of the treasury stock method		[1]		[1]
Weighted-average number of common shares outstanding for computing diluted earnings per share	31,813		22,624
Net loss per share - basic and diluted	$ (1.32)		$ (0.78)

[1] Warrants, stock options, restricted stock units (RSUs) and stock appreciation rights (SARs) to purchase approximately 5,997,000 and 7,159,000 shares of common stock were excluded from the net loss per share calculation for the three months ended March 31, 2013 and 2012, respectively, as their effect would have been anti-dilutive.