Earnings Per Common Share

6 Months Ended

Jun. 30, 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 stock options and restricted shares, each using the treasury stock method.

Because we expect to settle the principal amount of the outstanding 2.0% convertible senior notes due 2023 ("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 will have a dilutive impact on earnings per common share when the average market price of our common stock for a given period exceeds the conversion price of $101.38 per share. As we did not meet this threshold during the three and six months ended June 30, 2019, any shares of common stock potentially issuable upon conversion of the 2023 Convertible Notes are excluded from the calculation of diluted earnings per share.



	Three Months Ended June 30,				Six Months Ended June 30,
	2019		2018		2019		2018
Numerator — basic and diluted
Net income	$	64,598	$	43,609	$	127,243	$	82,554
Denominator
Weighted average number of common shares outstanding — basic	36,960		37,001		36,970		36,851
Effect of dilutive stock options	459		558		445		430
Effect of dilutive restricted shares	749		712		778		661
Weighted average number of common shares outstanding — diluted	38,168		38,271		38,193		37,942
Earnings per common share — basic	$	1.75	$	1.18	$	3.44	$	2.24
Earnings per common share — diluted	$	1.69	$	1.14	$	3.33	$	2.18
Antidilutive stock options and restricted shares	25		44		38		330