Net Income Per Common Share (Tables)

12 Months Ended

Dec. 31, 2017

Basic and Diluted Net Income Per Common Share

Basic and diluted net income per common share are calculated as follows:

	Income (Numerator)		Shares (Denominator)		Per Share Amount
	(Dollars in thousands, except per share data)
Year Ended December 31, 2017
Basic
Income available to common stockholders	$	86,439		31,813,572	$	2.72
Effect of stock options		—		754,533
Diluted
Income available to common stockholders plus assumed exercises of stock options	$	86,439		32,568,105	$	2.65
Year Ended December 31, 2016
Basic
Income available to common stockholders	$	70,674		31,230,340	$	2.27
Effect of stock options		—		592,184
Diluted
Income available to common stockholders plus assumed exercises of stock options	$	70,674		31,822,524	$	2.22
Year Ended December 31, 2015
Basic
Income available to common stockholders	$	66,170		31,118,118	$	2.13
Effect of stock options		—		654,372
Diluted
Income available to common stockholders plus assumed exercises of stock options	$	66,170		31,772,490	$	2.09

Average Exercise Price of Options Excluded from Computation of Diluted Net Income Per Common Share

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

	Shares		Average Exercise Price
December 31, 2017		55,337	$	46.86
December 31, 2016		294,438		30.25
December 31, 2015		355,436		29.24