Stock-Based Compensation Plan (Tables)

6 Months Ended

Jun. 30, 2013

Stock-Based Compensation Plan [Abstract]

Summary of stock option plan activity

The following table summarizes the Company's stock option activities for the six months ended June 30, 2013 and 2012:

	Six Months Ended June 30,
	2013					2012
				Weighted				Weighted
				Average				Average
	Number of			Exercise		Number of		Exercise
	Shares			Price		Shares		Price
Options outstanding at January 1		1,335,680		$	13.41		1,192,680	$	12.89
Options granted - employees		51,300		$	26.41		111,000	$	17.77
Options granted - directors		40,000		$	26.41		40,000	$	17.77
Options forfeited - employees		(834	)	$	5.60		-
Options exercised - employees		(98,661	)	$	11.80		-
Options outstanding at June 30		1,327,485		$	14.43		1,343,680	$	13.44
Options exercisable		1,075,810		$	12.37		952,055	$	12.15
Weighted average remaining term	5.7 years					6.2 years

Summary of fair value assumptions

The fair value of the stock options granted to the Company's employees and independent directors was estimated using the Black-Scholes-Merton pricing model using the following weighted average assumption:

	Six Months Ended June 30,
	2013			2012
Stock price	$	26.41		$	17.77
Exercise price	$	26.41		$	17.77
Expected term:
Employees	6.25 years			6.25 years
Directors	5.5 years			5.5 years
Expected volatility:
Employees		56.7	%		49.5	%
Directors		58.6	%		50.2	%
Dividend yield		0	%		0	%
Risk free rate
Employees		1.35	%		0.75	%
Directors		1.16	%		0.75	%