Earnings per Common Share
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 upon exercise or vesting of outstanding awards 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.
 Year Ended December 31,
 202520242023
Numerator — basic and diluted
Net income$270,871 $280,088 $274,892 
Denominator
Weighted average number of common shares outstanding — basic32,531 35,208 33,924 
Effect of dilutive share-based awards318 517 559 
Effect of dilutive stock options32 120 295 
Effect of dilutive convertible notes (1)
— — 868 
Weighted average number of common shares outstanding — diluted32,881 35,845 35,646 
Earnings per common share — basic$8.33 $7.96 $8.10 
Earnings per common share — diluted$8.24 $7.81 $7.71 
Antidilutive stock options and share-based awards217 45 
(1)    On August 17, 2023, we issued a total of 1,460,740 shares of our common stock to holders in connection with the conversion of their 2.0% convertible senior notes due 2023 at maturity.

About Earnings Per Share Disclosures

The earnings per share disclosure breaks down the calculation from net income to both basic and diluted EPS, revealing the full impact of a company's capital structure on per-share economics. The reconciliation between basic and diluted share counts exposes how many stock options, RSUs, convertible securities, and warrants are potentially dilutive to existing shareholders.

Key signals: a widening gap between basic and diluted shares indicates growing dilution from equity compensation or convertible instruments. Anti-dilutive securities excluded from the diluted calculation deserve attention — they represent latent dilution that will materialize if the stock price rises. Watch for the effect of share buybacks on per-share metrics: EPS growth driven primarily by repurchases rather than income growth signals weakening fundamentals. Compare year-over-year changes in the diluted share count against equity compensation expense to assess whether management is effectively managing dilution.