The Corporation uses the two-class method to calculate earnings per share as the unvested restricted stock issued under the Corporation's equity incentive plans are participating shares with nonforfeitable rights to dividends. Under the two-class method, earnings per common share are computed by dividing the sum of distributed earnings to common shareholders and undistributed earnings allocated to common shareholders by the weighted average number of common shares outstanding for the period. In applying the two-class method, undistributed earnings are allocated to both common shares and participating securities based on the number of weighted average shares outstanding during the period. The table also notes anti-dilutive options which are those options with weighted average exercise prices in excess of the weighted average market value for the periods presented.

The following table sets forth the computation of basic and diluted earnings per share:



	Three Months Ended September 30,						Nine Months Ended September 30,
(Dollars and shares in thousands, except per share data)	2018			2017			2018			2017
Numerator:
Net income	$	14,964		$	11,196		$	32,171		$	33,830
Net income allocated to unvested restricted stock	(86		)	(96		)	(225		)	(330		)
Net income allocated to common shares	$	14,878		$	11,100		$	31,946		$	33,500
Denominator:
Weighted average shares outstanding	29,402			26,666			29,387			26,653
Average unvested restricted stock	(170		)	(229		)	(204		)	(265		)
Denominator for basic earnings per share—weighted-average shares outstanding	29,232			26,437			29,183			26,388
Effect of dilutive securities—employee stock options	86			105			92			102
Denominator for diluted earnings per share—adjusted weighted-average shares outstanding	29,318			26,542			29,275			26,490
Basic earnings per share	$	0.51		$	0.42		$	1.10		$	1.27
Diluted earnings per share	$	0.51		$	0.42		$	1.09		$	1.27
Average anti-dilutive options excluded from computation of diluted earnings per share	359			185			315			166