Net Income (Loss) Per Share - Additional Information (Detail) (USD $)	9 Months Ended			9 Months Ended		1 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013 Senior Convertible Notes [Member]	Sep. 30, 2013 Convertible Notes [Member]	Sep. 30, 2013 Series B Convertible Preferred Stock [Member]	Sep. 30, 2013 Series A Convertible Preferred Stock [Member]	Mar. 31, 2013 Series B Redeemable Convertible Preferred Stock [Member]	Mar. 31, 2013 Series A Redeemable Convertible Preferred Stock [Member]	Sep. 30, 2013 Series A and Series B Redeemable Convertible Preferred Stock [Member]	Sep. 30, 2013 Series B [Member]	Sep. 30, 2013 Series A [Member]
Earnings Per Share [Line Items]
Dividend recorded, preferred stock	$ 85,165,000			$ 300,000	$ 600,000				$ 29,622,000	$ 55,543,000
Change in preferred stock redemption value						30,000,000	56,100,000
Gain on extinguishment of shares								86,200,000
Additional paid-in-capital upon reclassification from temporary to permanent equity	1,085,000							1,100,000
Preferred stock deemed dividends									29,600,000	55,500,000
Senior convertible notes, outstanding		$ 25,900,000	$ 84,600,000