	For the Three Months Ended June 30,				For the Six Months Ended June 30,
(unaudited, in thousands, except shares and per share amounts)	2019		2018		2019		2018
Numerator for both basic and diluted earnings per common share:
Net income	$	44,814	$	33,169	$	85,151	$	66,698
Denominator:
Total average basic common shares outstanding		54,628,029		46,498,305		54,613,346		45,281,264
Effect of dilutive stock options and other stock compensation		105,492		141,475		110,863		135,746
Total diluted average common shares outstanding		54,733,521		46,639,780		54,724,209		45,417,010
Earnings per common share - basic	$	0.82	$	0.71	$	1.56	$	1.47
Earnings per common share - diluted	$	0.82	$	0.71	$	1.56	$	1.47

Options to purchase 353,829 and 117,600 shares at June 30, 2019 and 2018, respectively, were not included in the computation of net income per diluted share for the three months ended June 30, 2019 and 2018, respectively, because the exercise price was greater than the average market price of the common shares and, therefore, the effect would be antidilutive. Options to purchase 117,600 shares at both June 30, 2019 and 2018 were not included in the computation of net income per diluted shares for the six months ended June 30, 2019 and 2018, because the exercise price was greater than the average market price of the common shares and, therefore, the effect would be antidilutive.

As of June 30, 2019, 40,608 contingently issuable shares were estimated to be awarded under the 2018 and 2017 total shareholder return plans as stock performance targets were met and are therefore included in the diluted calculation. As of June 30, 2019, the shares related to the 2019 total shareholder return plan were not included in the calculation because the effect would be antidilutive. Performance based restricted stock compensation totaling 30,137 shares were estimated to be awarded as of June 30, 2019 and are included in the diluted calculation. As of June 30, 2018, 42,912 contingently issuable shares were estimated to be awarded under the 2018 and 2017 total shareholder return plans as stock performance targets were met and are included in the diluted calculation. Performance based restricted stock compensation totaling 17,081 shares were estimated to be awarded as of June 30, 2018 and are included in the diluted calculation.