Earnings Per Share

12 Months Ended

Dec. 31, 2020

18. Earnings Per Share

During the years ended December 31, 2020 and 2019, we used the treasury stock method of calculating earnings per share (“EPS”) as our currently non-vested RSUs and PSUs do not have participating rights. During the year ended December 31, 2018, we used the two-class method of calculating EPS as our previously outstanding unvested RSAs had non-forfeitable rights to dividends, and accordingly, represented a participating security. The two-class method is an earnings allocation method under which EPS is calculated for each class of common stock and participating security considering both dividends declared (or accumulated) and participating rights in undistributed earnings as if all such earnings had been distributed during the period.

The following table sets forth the computation of basic and diluted earnings per share for the years ended December 31, 2020, 2019 and 2018 (in thousands, except share and per share information):



	Year ended December 31,
	2020		2019		2018
Numerator
Net income	$	206,157	$	112,994	$	96,455
Less: Undistributed earnings allocated to participating securities		—		—		(59)
Net income allocable to common stockholders	$	206,157	$	112,994	$	96,396
Denominator
Weighted average common shares outstanding - basic		33,312,554		30,886,382		30,084,913
Dilutive effect of restricted stock units		297,544		300,570		306,433
Weighted average common shares outstanding - diluted		33,610,098		31,186,952		30,391,346
Earnings per share:
Basic	$	6.19	$	3.66	$	3.20
Diluted	$	6.13	$	3.62	$	3.17

Stock-based awards are excluded from the calculation of diluted EPS in the event they are subject to unsatisfied performance conditions or are antidilutive. We excluded 0.8 million, 0.6 million, and 0.3 million common stock unit equivalents from diluted earnings per share during the year ended December 31, 2020, 2019, and 2018 respectively, related to the PSUs for which performance conditions remained unsatisfied.