(8)	NET INCOME PER COMMON SHARE

Basic and diluted net income per common share based on weighted-average shares outstanding are calculated as follows:

	Income (Numerator)		Shares (Denominator)		Per Share Amount
	(Dollars in thousands, except per share data)
Three Months Ended September 30, 2018
Basic
Income available to common stockholders	$	32,883		32,742,480	$	1.01
Dilutive effect of stock options		—		761,663
Diluted
Income available to common stockholders plus assumed exercises of stock options	$	32,883		33,504,143	$	0.98
Three Months Ended September 30, 2017
Basic
Income available to common stockholders	$	21,710		31,838,392	$	0.68
Dilutive effect of stock options		—		753,885
Diluted
Income available to common stockholders plus assumed exercises of stock options	$	21,710		32,592,277	$	0.67
Nine Months Ended September 30, 2018
Basic
Income available to common stockholders	$	93,089		32,678,310	$	2.85
Dilutive effect of stock options		—		752,451
Diluted
Income available to common stockholders plus assumed exercises of stock options	$	93,089		33,430,761	$	2.78
Nine Months Ended September 30, 2017
Basic
Income available to common stockholders	$	66,942		31,792,270	$	2.11
Dilutive effect of stock options		—		741,949
Diluted
Income available to common stockholders plus assumed exercises of stock options	$	66,942		32,534,219	$	2.06

The following table shows the number of options that were excluded from the computation of diluted net income per common share for each period because the options’ exercise prices were greater than the average market price of the common shares:

	Shares
Three Months Ended September 30, 2018		83,799
Three Months Ended September 30, 2017		75,543
Nine Months Ended September 30, 2018		84,368
Nine Months Ended September 30, 2017		39,120