Stock Options and Restricted Stock - Additional Information (Detail) (USD $)	3 Months Ended
Mar. 31, 2014 Incentive_Plan	Mar. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity incentive plans	3
Stock options exercised, Shares	61,167	95,000
Proceeds from stock option exercises	$ 600,000	$ 855,000
Share-based compensation expense	$ 600,000	$ 300,000
Restricted Stock Units (RSUs) [Member] \| Executive Officers [Member] \| 2012 Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock granted	4,312
Restricted common stock to executive officers	4

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.F)

-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

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