Summary of Warrants Outstanding and Exercisable (Detail) (USD $)	12 Months Ended
Dec. 31, 2014
Share Based Compensation Plans [Line Items]
Warrants Outstanding, Number Outstanding	5,427,778
Warrants Outstanding, Weighted Average Remaining Contractual Life (Years)	6 years
Warrants Outstanding, Weighted Average Exercise Price	$ 1.03
Warrants Exercisable, Number Exercisable	4,734,861
Warrants Exercisable Weighted Average Exercise Price	$ 0.99
Warrant
Share Based Compensation Plans [Line Items]
Warrants Outstanding, Number Outstanding	10,000
Warrants Outstanding, Weighted Average Remaining Contractual Life (Years)	3 years 3 months 18 days
Warrants Outstanding, Weighted Average Exercise Price	$ 0.90
Warrants Exercisable, Number Exercisable	10,000
Warrants Exercisable Weighted Average Exercise Price	$ 0.90
Exercise Price 0.90 \| Warrant
Share Based Compensation Plans [Line Items]
Warrants Outstanding, Number Outstanding	10,000
Warrants Outstanding, Weighted Average Remaining Contractual Life (Years)	3 years 3 months 18 days
Warrants Outstanding, Weighted Average Exercise Price	$ 0.90
Warrants Exercisable, Number Exercisable	10,000
Warrants Exercisable Weighted Average Exercise Price	$ 0.90

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Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

+ 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)(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 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

The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are 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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