The calculation of basic earnings per share is based on the weighted average number of common shares considered outstanding during the periods. The calculation of diluted earnings per share reflects the effect of all potentially dilutive securities (principally outstanding stock options and restricted stock grants). The number of weighted average shares used in the calculation of basic earnings per share and diluted earnings per share was as follows:


	Three Months Ended September 30,		Nine Months Ended September 30,
	2024	2023	2024	2023
	(In thousands)
Weighted average shares:
Basic shares	231,342	230,691	231,292	230,431
Equity-based compensation plans	882	1,060	896	983
Diluted shares	232,224	231,751	232,188	231,414

The calculation of diluted earnings per share for the three and nine months ended September 30, 2024 excluded an immaterial number of stock options because the exercise prices of these stock options exceeded the average market price of the Company’s common shares, and the effect of their inclusion would have been antidilutive. There were no antidilutive shares for the three and nine months ended September 30, 2023.