The following table summarizes the computation of basic and diluted earnings per common share for the periods presented (in millions, except per share data):


	Three Months Ended March 31,
		2024		2023
Earnings per common share—basic
Net income		$	6.5	$	25.0
Weighted-average common shares outstanding—basic		183.7		185.2
Earnings per common share—basic		$	0.04	$	0.13

Earnings per common share—diluted
Net income		$	6.5	$	25.0
Interest expense attributable to convertible notes		—		1.6
Net income attributable to earnings per common share—diluted		$	6.5	$	26.6

Weighted-average common shares outstanding—basic		183.7		185.2
Convertible Notes weighted-average common shares outstanding		—		14.7
Outstanding options, restricted stock units and performance share units		0.7		1.6
Weighted-average common shares outstanding—diluted		184.4		201.5
Earnings per common share—diluted		$	0.04	$	0.13

For the three months ended March 31, 2024, approximately 17.1 million securities outstanding, comprised of shares subject to conversion from the Convertible Notes, stock options and restricted stock units, were excluded from the calculation of diluted earnings per common share as they would be anti-dilutive. For the three months ended March 31, 2023, approximately 1.2 million securities outstanding, comprised of stock options and restricted stock units, were excluded from the calculation of diluted earnings per common share as they would be anti-dilutive.