Earnings per Share

The Corporation uses the two-class method to calculate earnings per share as the unvested restricted stock awards outstanding 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. Diluted earnings per share reflect additional common shares that would have been outstanding if options on common shares had been exercised, as well as any adjustment to income that would result from the assumed issuance, and if restricted stock units were vested. Potential common shares that may be issued by the Corporation relate to outstanding stock options and restricted stock units, and are determined using the treasury stock method. The effects of options to issue common stock and unvested restricted stock units are excluded from the computation of diluted earnings per share in periods in which the effect would be antidilutive. Anti-dilutive options are those options with weighted average exercise prices in excess of the weighted average market value. Anti-dilutive restricted stock units are those with hypothetical repurchases of shares, under the treasury stock method, exceeding the average restricted stock units outstanding for the periods presented.

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



	Three Months Ended March 31,
(Dollars and shares in thousands, except per share data)	2019			2018
Numerator:
Net income	$	16,079		$	12,850
Net income allocated to unvested restricted stock awards	(67		)	(97		)
Net income allocated to common shares	$	16,012		$	12,753
Denominator:
Weighted average shares outstanding	29,277			29,355
Average unvested restricted stock awards	(131		)	(215		)
Denominator for basic earnings per share—weighted-average shares outstanding	29,146			29,140
Effect of dilutive securities—employee stock options and restricted stock units	59			94
Denominator for diluted earnings per share—adjusted weighted-average shares outstanding	29,205			29,234
Basic earnings per share	$	0.55		$	0.44
Diluted earnings per share	$	0.55		$	0.44
Average anti-dilutive options and restricted stock units excluded from computation of diluted earnings per share	348			217