Basic and Diluted Net Loss Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended		398 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013
Earnings Per Share [Abstract]
Net loss	$ (42,030)	$ (49,554)	$ (103,165)	$ (59,220)	$ (534,416)
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	33,943	22,824	32,588	22,691
Weighted-average number of common shares outstanding for computing diluted earnings per share	33,943	22,824	32,588	22,691
Net loss per share - basic	$ (1.24)	$ (2.17)	$ (3.17)	$ (2.61)
Net loss per share - diluted	$ (1.24)	$ (2.17)	$ (3.17)	$ (2.61)