NET INCOME (LOSS) PER COMMON SHARE (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Numerator:
Net income (loss)	$ 30,891	$ (3,672)	$ 26,674	$ (3,633)
Interest on Convertible Debt, Net of Tax	113	0	1,084	0
Net Income (Loss) Available to Common Stockholders, Diluted	$ 31,004	$ (3,672)	$ 27,758	$ (3,633)
Denominator:
Shares used in computing basic net income (loss) per common share	70,161	69,504	70,069	70,700
Add effect of dilutive securities:
Employee stock compensation plans (in shares)	117	0	112	0
Common stock subject to repurchase (in shares)	335	0	303	0
Incremental Common Shares Attributable to Conversion of Debt Securities	1,305	0	1,779	0
Shares used in computing diluted net income (loss) per common share (in shares)	71,918	69,504	72,263	70,700
Basic net income (loss) per common share	$ 0.44	$ (0.05)	$ 0.38	$ (0.05)
Diluted net income (loss) per common share	$ 0.43	$ (0.05)	$ 0.38	$ (0.05)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	7,806	11,108	7,842	11,108
Employee Stock Compensation Plans [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	5,780	6,311	5,785	6,311
Restricted Stock Subject to Repurchase [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,026	1,628	2,057	1,628
Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	3,169	0	3,169