Earnings Per Share of Common Stock (Tables)

12 Months Ended

Dec. 31, 2021

Earnings Per Share of Common Stock

Summary of basic and diluted earnings per share calculations

	Year ended December 31,
	2021		2020		2019
	(in thousands, except per share data)
Net income	$	1,003,490	$	1,646,884	$	392,965
Weighted average basic shares of common stock outstanding		63,799		75,161		78,206
Effect of dilutive securities - shares issuable under stock-based compensation plan		3,672		3,567		2,134
Weighted average shares of common stock applicable to diluted earnings per share		67,471		78,728		80,340
Basic earnings per share	$	15.73	$	21.91	$	5.02
Diluted earnings per share	$	14.87	$	20.92	$	4.89

Schedule of anti-dilutive shares outstanding

	Year ended December 31,
	2021		2020		2019
	(in thousands except for weighted average exercise price)
Performance-based RSUs (1)		223		322		1,032
Time-based RSUs		1		—		—
Stock options (2)		211		83		572
Total anti-dilutive units and options		435		405		1,604
Weighted average exercise price of anti-dilutive stock options (2)	$	58.85	$	43.89	$	23.70

(1) Certain performance-based RSUs were outstanding but not included in the computation of earnings per share because the performance thresholds included in such RSUs have not been achieved.

(2) Certain stock options were outstanding but not included in the computation of diluted earnings per share because the weighted-average exercise prices were above the average stock prices during the year.