Earnings per Common Share

12 Months Ended

Dec. 31, 2019

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 restricted shares and stock options, each using the treasury stock method.

Because we expect to settle the principal amount of the outstanding 2023 Convertible Notes in cash, we use the treasury stock method for calculating the potential dilutive effect of the conversion feature on earnings per common share, if applicable. The conversion feature had a dilutive impact on earnings per common share for the year ended December 31, 2019, as the average market price per share of our common stock for the period exceeded the conversion price of $101.38 per share. See Note 13, "Debt" for additional information about the 2023 Convertible Notes.



	Year Ended December 31,
	2019		2018		2017
Numerator — basic and diluted
Net income	$	216,726	$	150,611	$	107,962
Denominator
Weighted average number of common shares outstanding — basic	36,774		37,098		38,697
Effect of dilutive convertible notes	62		—		—
Effect of dilutive stock options	455		491		117
Effect of dilutive restricted shares	820		729		378
Weighted average number of common shares outstanding — diluted	38,111		38,318		39,192
Earnings per common share — basic	$	5.89	$	4.06	$	2.79
Earnings per common share — diluted	$	5.69	$	3.93	$	2.75
Antidilutive stock options and restricted shares	19		175		1,561