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						365 Months Ended	401 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2013
Earnings Per Share [Abstract]
Net loss	$ (8,820)	$ (42,030)	$ (19,051)	$ (42,084)	$ (62,067)	$ (49,554)	$ 8,038	$ (17,704)	$ (111,985)		$ (121,287)		$ (2,318)		$ (307,646)	$ (543,236)
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	33,850		23,602		21,599
Dilutive effect of warrants and stock options after application of the treasury stock method										[1]		[1]		[1]
Weighted average number of common shares outstanding for computing diluted earnings per share	37,596	33,943	31,984	31,813					33,850		23,602		21,599
Net loss per share-basic and diluted	$ (0.23)	$ (1.24)	$ (0.60)	$ (1.32)					$ (3.31)		$ (5.14)		$ (0.11)

[1] Warrants, stock options, restricted stock units and stock appreciation rights to purchase approximately 5,158,382, 5,858,000 and 7,285,000 shares of common stock as of December 31, 2013, 2012 and 2011, respectively, were excluded from the net loss per share calculation as their effect would have been anti-dilutive.