Information About Employee Stock Warrants and Options Outstanding (Detail) (Employee Stock Options and Warrants, USD $)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	682,141	259,299
Weighted Average Remaining Contractual Life	8 years 6 months 7 days	7 years 8 months 9 days
Weighted Average Exercise Price, Outstanding	$ 6.47	$ 7.75
Number Exercisable	262,952	201,790
Weighted Average Exercise Price, Exercisable	$ 7.31	$ 7.44
Exercise Price Four Point Five Eight
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	10,167
Weighted Average Remaining Contractual Life	1 month 21 days
Weighted Average Exercise Price, Outstanding	$ 4.58
Number Exercisable	10,167
Weighted Average Exercise Price, Exercisable	$ 4.58
Exercise Price Five Point Seven
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	39,750	41,750
Weighted Average Remaining Contractual Life	4 months 13 days	1 year 2 months 1 day
Weighted Average Exercise Price, Outstanding	$ 5.70	$ 5.70
Number Exercisable	39,750	41,750
Weighted Average Exercise Price, Exercisable	$ 5.70	$ 5.70
Exercise Price Six
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	330,000
Weighted Average Remaining Contractual Life	4 years 8 months 12 days
Weighted Average Exercise Price, Outstanding	$ 6.00
Number Exercisable	27,500
Weighted Average Exercise Price, Exercisable	$ 6.00
Exercise Price Four Point Five Six
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	84,675
Weighted Average Remaining Contractual Life	1 year 1 month 24 days
Weighted Average Exercise Price, Outstanding	$ 4.56
Number Exercisable
Weighted Average Exercise Price, Exercisable	$ 4.56
Exercise Price Seven Point Five
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	124,573	124,573
Weighted Average Remaining Contractual Life	1 year 1 month 6 days	3 years 4 months 13 days
Weighted Average Exercise Price, Outstanding	$ 7.50	$ 7.50
Number Exercisable	124,573	117,372
Weighted Average Exercise Price, Exercisable	$ 7.50	$ 7.50
Exercise Price Nine Point Zero
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	92,976	92,976
Weighted Average Remaining Contractual Life	1 year 22 days	3 years 1 month 24 days
Weighted Average Exercise Price, Outstanding	$ 9.00	$ 9.00
Number Exercisable	60,962	42,668
Weighted Average Exercise Price, Exercisable	$ 9.00	$ 9.00

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

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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 Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(c)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: 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

+ Details

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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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(a, b)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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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

+ Details

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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

+ Details

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