Earnings per Common Share

3 Months Ended

Mar. 31, 2022

Basic earnings per common share is calculated by dividing net income by the weighted average number of common shares outstanding during the period. Diluted earnings per common share adjusts basic earnings per common share for the effects of potentially dilutive common shares. Potentially dilutive common shares include the dilutive effects of shares issuable under our equity compensation plans, including stock options and share-based awards (restricted share awards, restricted stock units and performance stock units), each using the treasury stock method.

For the three months ended March 31, 2022, we used the if-converted method for calculating the potential dilutive effect of the conversion feature of the principal amount of the 2023 Convertible Notes on earnings per common share, as required by the adoption of ASU 2020-06. Prior to the adoption of ASU 2020-06, we used the treasury stock method for calculating the potential dilutive effect of the conversion feature of the principal amount of the 2023 Convertible Notes on earnings per common share because we had the ability and intent to settle the principal amount of the outstanding 2023 Convertible Notes in cash. The conversion feature had a dilutive impact on earnings per common share for the three months ended March 31, 2022 and 2021, as the average market price per share of our common stock for the periods exceeded the conversion price of $101.38 per share. See Note 8, "Debt" for additional information about the 2023 Convertible Notes.


	Three Months Ended March 31,
		2022		2021
Numerator — basic and diluted
Net income		$	59,321	$	64,496
Denominator
Weighted average number of common shares outstanding — basic		33,619		33,483
Effect of dilutive share-based awards		691		760
Effect of dilutive stock options		338		370
Effect of dilutive convertible notes		998		450
Weighted average number of common shares outstanding — diluted		35,646		35,063
Earnings per common share — basic		$	1.76	$	1.93
Earnings per common share — diluted		$	1.66	$	1.84
Antidilutive stock options and share-based awards		6		8