NET INCOME PER SHARE

12 Months Ended

Dec. 31, 2019

The following table sets forth the calculation of basic and diluted net income per share (in thousands except per share data):



	Year Ended December 31,
	2019		2018		2017
Numerator:
Net income	$	314,963	$	238,334	$	122,695
Denominator:
Denominator for basic net income per share — weighted-average outstanding shares	36,310		36,058		33,200
Effect of dilutive securities:
Stock options, restricted stock awards and restricted stock units	320		390		359
Denominator for diluted net income per share — weighted-average outstanding shares	36,630		36,448		33,559

Net income per share — basic	$	8.67	$	6.61	$	3.70
Net income per share — diluted	$	8.60	$	6.54	$	3.66

The Company’s potentially dilutive securities include outstanding stock options, unvested stock-based awards which include restricted stock awards that vest over a specific service period, restricted stock awards that vest based on achievement of a performance condition, restricted stock awards with a performance and a market condition, restricted stock units and Matching RSUs awarded under the Company's Management Stock Purchase Plan. Shares underlying unvested restricted stock awards that vest based on performance and market conditions that have not been achieved as of the end of the period are not included in the computation of basic or diluted earnings per share. Diluted net income per share considers the impact of potentially dilutive securities except when the inclusion of the potentially dilutive securities would have an anti-dilutive effect.

The following table summarizes the shares underlying the unvested performance-based restricted stock and anti-dilutive securities excluded from the basic and diluted earnings per share calculations (in thousands):



	Year Ended December 31,
	2019	2018	2017
Performance-based restricted stock awards	60	53	58
Anti-dilutive securities	42	100	126