Stockholders' Equity- Narrative (Detail) (USD $)	12 Months Ended					0 Months Ended	12 Months Ended				12 Months Ended					12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Feb. 28, 2008	Nov. 30, 2004	Jan. 09, 2013 Loan And Security Agreement [Member]	Dec. 31, 2013 Restricted Stock [Member]	Dec. 31, 2012 Restricted Stock [Member]	Dec. 31, 2011 Restricted Stock [Member]	Dec. 31, 2013 2007 Stock Incentive Plan [Member]	Dec. 31, 2013 2007 Stock Incentive Plan [Member] Minimum [Member]	Dec. 31, 2013 2007 Stock Incentive Plan [Member] Maximum [Member]	Dec. 31, 2013 2007 Stock Incentive Plan [Member] Ten Percent Or More Stockholders [Member] Minimum [Member]	Dec. 31, 2013 2007 Stock Incentive Plan [Member] Ten Percent Or More Stockholders [Member] Maximum [Member]	Dec. 31, 2013 2007 Stock Incentive Plan [Member] Not Appreciation Awards [Member]	Dec. 31, 2013 2007 Stock Incentive Plan [Member] Restricted Stock [Member]	Dec. 31, 2013 2007 Stock Incentive Plan [Member] Stock Appreciation Rights (SARs) [Member]	Oct. 25, 2001 The 1999 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized for stock repurchase program				1,500,000
Stock repurchase and retirement(in shares)		71,653	427,043
Shares repurchased, average price per share		$ 5.22	$ 5.23
Stock repurchase and retirement		$ 374,248	$ 2,234,585
Common stock left remaining to repurchase under the plan	942,443
Aggregate stock repurchase amount						5,000,000
Aggregate number of common stock shares authorized for issuance										3,500,000					1,700,000			4,398,001
Exercise price of the fair market value of common stock											100.00%		110.00%
Stock expiration period												10 years		5 years			7 years
Stock vesting percentage per year																25.00%	25.00%
Stock vesting period																4 years	4 years
Share options outstanding at end of year	1,546,299	1,922,756
Shares options outstanding vested or expected to vest	1,433,047
Shares options outstanding vested or expected to vest ,intrinsic value	3,270,748
Shares options outstanding vested or expected to vest -weighted average exercise price	$ 9.20
Shares options outstanding vested or expected to vest -weighted average contractual life	3 years 1 month 6 days
Pretax total unrecognized compensation cost related to share options	884,579
Pretax total unrecognized compensation cost related to share options- period	2 years 6 months 15 days						2 years 7 months 3 days
Pretax of total unrecognized compensation cost related to non-vested restricted stock awards							2,372,238
Fair value of shares vested							$ 2,378,194	$ 944,976	$ 1,190,000
Registration of common stock held by three existing shareholders					11,403,455
Public offering shares		8,172,868