Basic and Diluted Net Income (Loss) Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended						353 Months Ended	389 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009	Dec. 31, 2012
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net income (loss)	$ (62,067)	$ (49,554)	$ 8,038	$ (17,704)	$ (1,410)	$ (4,020)	$ 1,279	$ 1,833	$ (121,287)		$ (2,318)		$ (32,177)		$ (275,469)	$ (431,251)
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	26,313	22,824	22,624	22,624	22,624	22,623	22,348	18,747	23,602		21,599		18,539
Dilutive effect of warrants and stock options after application of the treasury stock method									0	[1]	0	[1]	0	[1]
Weighted average number of common shares outstanding for computing diluted earnings per share									23,602		21,599		18,539
Net income (loss) per share-basic and diluted									$ (5.14)		$ (0.11)		$ (1.74)

[1] Warrants, stock options, restricted stock units and stock appreciation rights to purchase approximately 5,858,000, 7,285,000 and 6,359,000 shares of common stock as of December 31, 2012, 2011 and 2010, respectively, were excluded from the net loss per share calculation as their effect would have been anti-dilutive.