Note 10 — Earnings Per Share

Basic earnings per share are calculated by dividing net income by the weighted-average shares of common stock outstanding during each period, excluding non-vested shares. Our diluted earnings per share are based on the weighted-average shares of common stock outstanding during each period plus the maximum dilutive effect of common stock issuable upon exercise of stock options or vesting of restricted shares. The weighted-average number of shares and equivalents are determined after giving retroactive effect to stock dividends and stock splits.

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 for per share amounts)	2019		2018
Basic earnings per common share:
Net income	$	44,367	$	42,326
Weighted-average basic common shares		35,445		36,646
Basic earnings per common share	$	1.25	$	1.15
Diluted earnings per share:
Net income	$	44,367	$	42,326
Weighted-average basic common shares		35,445		36,646
Effect of dilutive securities		174		253
Weighted-average dilutive shares		35,619		36,899
Diluted earnings per common share	$	1.25	$	1.15

The calculation of diluted earnings per common share excludes outstanding stock options for which the results would have been anti-dilutive under the treasury stock method as follows:


	Three Months Ended March 31,
(Dollars in thousands)	2019					2018
Number of shares					87,917					61,272
Range of exercise prices	$	63.54	to	$	91.35	$	91.05	to	$	91.35