Stockholders Equity - Additional Information (Detail) (USD $)	9 Months Ended			0 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	0 Months Ended	3 Months Ended		9 Months Ended			9 Months Ended		0 Months Ended
	Sep. 30, 2013	Sep. 30, 2014	Dec. 31, 2013	Aug. 15, 2013 SAR [Member]	Sep. 30, 2014 SAR [Member]	Sep. 30, 2014 Restricted Stock [Member]	Sep. 30, 2014 Restricted Stock [Member]	Jul. 16, 2013 Underwritten Public Offering [Member]	Sep. 30, 2014 Private Placement Warrants [Member]	Sep. 30, 2013 Private Placement Warrants [Member]	Sep. 30, 2014 Private Placement Warrants [Member]	Sep. 30, 2013 Private Placement Warrants [Member]	Dec. 31, 2013 Private Placement Warrants [Member]	Sep. 30, 2014 Private Placement [Member]	Dec. 31, 2013 Private Placement [Member]	Feb. 14, 2014 Shelf Registration [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Series A convertible preferred stock, shares authorized		114,000	114,000
Series A convertible preferred stock, par value		$ 0.001	$ 0.001
Series A convertible preferred stock, shares issued		0	0
Series A convertible preferred stock, shares outstanding		0	0
Common stock exercise price		$ 0.001	$ 0.001						$ 13.00		$ 13.00
Common stock, shares authorized		50,000,000	50,000,000
Common stock, shares issued		11,559,803	11,352,812
Common stock, shares outstanding		10,728,878	10,521,887
Public offering shares								2,005,000
Underwritten public offering Price per share								$ 35.00						$ 69.00	$ 75.10
Shares sold through Public offering								1,050,000
Share sold by stockholders through public offering								955,000
Proceeds to the company from Public offering	$ 36,750,000							$ 34,530,000
Public offering expense								514,000
Grantee exercised Stock appreciation right				181,291	120,000
Common stock issued				96,504	85,903	656	11,503
Income tax benefit realized in connection with exercise of stock appreciation right					2,248,000		221,000
Shares vested and unexercised					61,291
Shares issued withheld to satisfy income tax obligation, Value						21,000	361,000
Shares of common stock issuable upon exercise of the private placement warrant											750,002
Warrants expiry date														Apr. 29, 2016
Shares issued for warrants exercised									0	88,167	109,585	297,334
Common stock reserved for the exercise of the Private Placement Warrants									287,257		287,257		396,842
Aggregate offering value																$ 150,000,000