Basic earnings per common share is computed by dividing net income by the weighted average number of common shares outstanding during the year.

For diluted earnings per common share, the denominator includes the dilutive effect of outstanding common share equivalents. The dilutive effects of outstanding common share equivalents, including outstanding restricted stock units, stock options and performance-based restricted stock units, are determined using the treasury stock method. Performance-based restricted stock units are considered contingently issuable shares, the vesting of which may be based on achievement of specified company performance conditions (“attainment-based PSUs”), certain market conditions (“market-based PSUs”) or a hybrid of specified company performance conditions and market conditions (“hybrid PSUs”). The dilutive effects of market-based PSUs are included in the weighted average common share calculation based on the number of shares, if any, that would be issuable as of the end of the reporting period, assuming the end of the reporting period is also the end of the performance period. The dilutive effects of attainment-based and hybrid PSUs are included in the weighted average common share calculation based on the cumulative achievement against the performance targets only when the performance targets have been achieved as of the end of the reporting period.

The following table sets forth the computation of basic and diluted earnings per common share (in thousands, except per share amounts):


	Year Ended December 31,
	2023		2022		2021
Numerators:
Net income	$	72,878	$	74,051	$	50,331

Denominators:
Weighted average common shares outstanding— basic		35,844		35,652		35,396
Dilutive potential common shares		187		257		385
Weighted average common shares outstanding— diluted		36,031		35,909		35,781
Antidilutive potential common shares excluded from above		99		91		13

Earnings per Common Share:
Basic	$	2.03	$	2.08	$	1.42
Diluted	$	2.02	$	2.06	$	1.41

For the year ended December 31, 2023, 104 thousand shares of attainment-based and hybrid PSUs were excluded from the calculation of the denominator because they were considered contingently issuable shares and the related performance targets had not been achieved as of December 31, 2023.

For the year ended December 31, 2022, 99 thousand shares of attainment-based PSUs were excluded from the calculation of the denominator because they were considered contingently issuable shares and the related performance targets had not been achieved of December 31, 2022.

For the year ended December 31, 2021, 82 thousand shares of attainment-based PSUs granted to certain members of the executive management team and 213 thousand shares of attainment-based restricted stock issued to Laser Quantum former non-controlling interest shareholders were excluded from the calculation of the denominator because they were considered contingently issuable shares and the related performance targets had not been achieved as of December 31, 2021.