BASIS OF PRESENTATION AND ACCOUNTING POLICIES (Details 4)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Options to purchase shares of common stock and RSUs
Potential common shares excluded from the calculation of diluted net (loss) income per share
Antidilutive securities related to potential shares excluded from calculation of net (loss) income per share (in shares)	8,739,777	2,059,361	8,739,777	2,535,235
Warrants
Potential common shares excluded from the calculation of diluted net (loss) income per share
Antidilutive securities related to potential shares excluded from calculation of net (loss) income per share (in shares)	9,705,442		9,705,442
1.875% convertible senior notes due 2020 (2020 Notes)
Potential common shares excluded from the calculation of diluted net (loss) income per share
Antidilutive securities related to potential shares excluded from calculation of net (loss) income per share (in shares)	5,459,311		5,459,311
1.125% convertible senior notes due 2018 (2018 Notes)
Potential common shares excluded from the calculation of diluted net (loss) income per share
Antidilutive securities related to potential shares excluded from calculation of net (loss) income per share (in shares)	4,246,131		4,246,131
2.50% convertible senior notes due November 2017 (2017 Notes)
Potential common shares excluded from the calculation of diluted net (loss) income per share
Antidilutive securities related to potential shares excluded from calculation of net (loss) income per share (in shares)	7,842,943		7,842,943
2.25% Convertible subordinated notes due June 2013 (2013 Notes)
Potential common shares excluded from the calculation of diluted net (loss) income per share
Antidilutive securities related to potential shares excluded from calculation of net (loss) income per share (in shares)				2,521,856