Share-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Compensation expenses in stock compensation plans	$ 180,415	$ 172,305
Income tax benefit of stock compensation plans	63,145	60,307
Unrecognized compensation expense related to nonvested share-based compensation	931,181
Weighted average period of unrecognized compensation cost	1 year 9 months 18 days
Cash from option exercises	193,558	1,700,000
Tax benefit for tax deductions from option exercise	$ 11,515	$ 98,929