Stockholders' Equity (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012
Range One [Member]
Stock options outstanding and exercisable
Range of Exercise Price, Lower Limit	$ 0.28
Range of Exercise Price, Upper Limit	$ 0.99
Number of Options Outstanding	209,602
Options outstanding, weighted average exercise price	$ 0.41
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	3 months 18 days
Number of Options Exercisable	209,602
Options Exercisable, Weighted Average Exercise Price	$ 0.41
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	3 months 18 days
Range Two [Member]
Stock options outstanding and exercisable
Range of Exercise Price, Lower Limit	$ 1.03
Range of Exercise Price, Upper Limit	$ 2.41
Number of Options Outstanding	106,444
Options outstanding, weighted average exercise price	$ 2.37
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	8 months 12 days
Number of Options Exercisable	106,444
Options Exercisable, Weighted Average Exercise Price	$ 2.37
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	8 months 12 days
Range Three [Member]
Stock options outstanding and exercisable
Range of Exercise Price, Lower Limit	$ 3.53
Range of Exercise Price, Upper Limit	$ 9.93
Number of Options Outstanding	5,555,961
Options outstanding, weighted average exercise price	$ 5.81
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	5 years 4 months 24 days
Number of Options Exercisable	4,513,128
Options Exercisable, Weighted Average Exercise Price	$ 6.06
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	5 years
Range Four [Member]
Stock options outstanding and exercisable
Range of Exercise Price, Lower Limit	$ 10.07
Range of Exercise Price, Upper Limit	$ 19.76
Number of Options Outstanding	425,569
Options outstanding, weighted average exercise price	$ 11.99
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	3 years 4 months 24 days
Number of Options Exercisable	425,569
Options Exercisable, Weighted Average Exercise Price	$ 11.99
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	3 years 4 months 24 days
Range Five [Member]
Stock options outstanding and exercisable
Range of Exercise Price, Lower Limit	$ 20.12
Range of Exercise Price, Upper Limit	$ 29.98
Number of Options Outstanding	23,500
Options outstanding, weighted average exercise price	$ 23.02
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	1 year 4 months 24 days
Number of Options Exercisable	23,500
Options Exercisable, Weighted Average Exercise Price	$ 23.02
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	1 year 4 months 24 days
Range Six [Member]
Stock options outstanding and exercisable
Range of Exercise Price, Lower Limit	$ 0.28
Range of Exercise Price, Upper Limit	$ 29.98
Number of Options Outstanding	6,321,076
Options outstanding, weighted average exercise price	$ 6.05
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	5 years
Number of Options Exercisable	5,278,243
Options Exercisable, Weighted Average Exercise Price	$ 6.31
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	4 years 6 months