Stock Option Plans and Warrants to Purchase Common Stock (Details 2) (USD $)	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012
Weighted-average Range of Exercise Prices for options/warrants outstanding and exercisable
Weighted-Average Remaining Contractual Life in Years	3 years 5 months 9 days
Outstanding Options/Warrants	8,156,526
Exercisable Options/Warrants	8,156,526
Employee Stock Option [Member]
Weighted-average Range of Exercise Prices for options/warrants outstanding and exercisable
Weighted-Average Remaining Contractual Life in Years	7 years 3 months 18 days
Outstanding Options/Warrants	2,051,511	1,457,724
Exercisable Options/Warrants	1,549,693
Employee Stock Option [Member] \| $0.30-$2.20 [Member]
Weighted-average Range of Exercise Prices for options/warrants outstanding and exercisable
Exercise price range, lower range limit	0.30
Exercise price range, upper range limit	2.20
Weighted-Average Remaining Contractual Life in Years	8 years 2 months 12 days
Outstanding Options/Warrants	1,299,302
Exercisable Options/Warrants	842,305
Employee Stock Option [Member] \| $2.26-$4.10 [Member]
Weighted-average Range of Exercise Prices for options/warrants outstanding and exercisable
Exercise price range, lower range limit	2.26
Exercise price range, upper range limit	4.10
Weighted-Average Remaining Contractual Life in Years	8 years
Outstanding Options/Warrants	229,459
Exercisable Options/Warrants	184,638
Employee Stock Option [Member] \| $4.64-$8.60 [Member]
Weighted-average Range of Exercise Prices for options/warrants outstanding and exercisable
Exercise price range, lower range limit	4.64
Exercise price range, upper range limit	8.60
Weighted-Average Remaining Contractual Life in Years	4 years 10 months 24 days
Outstanding Options/Warrants	426,500
Exercisable Options/Warrants	426,500
Employee Stock Option [Member] \| $9.40-$11.60 [Member]
Weighted-average Range of Exercise Prices for options/warrants outstanding and exercisable
Exercise price range, lower range limit	9.40
Exercise price range, upper range limit	11.60
Weighted-Average Remaining Contractual Life in Years	3 years 2 months 12 days
Outstanding Options/Warrants	93,750
Exercisable Options/Warrants	93,750
Employee Stock Option [Member] \| $18.00-$25.60 [Member]
Weighted-average Range of Exercise Prices for options/warrants outstanding and exercisable
Exercise price range, lower range limit	18.00
Exercise price range, upper range limit	25.60
Weighted-Average Remaining Contractual Life in Years	1 month 6 days
Outstanding Options/Warrants	2,500
Exercisable Options/Warrants	2,500

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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