EMPLOYEE STOCK PLANS - Equity Incentive Plan (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	12 Months Ended			1 Months Ended		1 Months Ended		12 Months Ended
	Oct. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2007 2005 Equity Incentive Plan	May 31, 2005 2005 Equity Incentive Plan	May 31, 2012 2012 Equity Incentive Plan	Dec. 31, 2013 2012 Equity Incentive Plan	Dec. 31, 2013 2012 Equity Incentive Plan Stock Options	Dec. 31, 2013 2012 Equity Incentive Plan Stock Options Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for issuance						12,000,000	17,000,000
Number of shares of additional common stock approved					2,500,000		2,500,000
Number of shares available for future grant								5,500,000
Award terms										7 years
Exercise price, as a percent of fair market value of common stock on grant date									100.00%
Options Vested on the First Anniversary, Vesting Percentage		25.00%							25.00%
Award Ratable Vesting Percentage									2.78%
Award Ratable Vesting Period									36 months
Option retention grant (in shares)	1,700,000
Option retention grant vesting period	15 months
Options granted in period (in shares)		1,579,000	3,100,000	1,600,000
Options, grant date fair value		$ 1.4	$ 2.9	$ 2.2