Basic earnings per share is computed by dividing net income by the weighted average number of shares of common stock outstanding. Diluted earnings per share is computed by dividing net income by the weighted average common and potentially dilutive common equivalent shares outstanding, determined as follows:



	Three Months Ended		Nine Months Ended
	September 30,		September 30,
(In thousands)	2019	2018	2019	2018
Weighted average shares outstanding used to compute basic earnings per share	33,271	33,110	33,222	33,056
Incremental dilutive shares attributable to stock options and restricted stock	14	—	8	—
Shares used to compute diluted earnings per share	33,285	33,110	33,230	33,056

Incremental shares attributable to stock options and restricted stock are computed under the treasury stock method using the average market price during the related period. For the three and nine months ended September 30, 2019, average out-of-the-money options to purchase shares that were excluded from the calculation of incremental shares attributable to stock options and restricted stock were 1,222,000 and 1,224,222, respectively. For the three and nine months ended September 30, 2018, average out-of-the-money options to purchase shares that were excluded from the calculation of incremental shares attributable to stock options and restricted stock were 178,676 and 236,138, respectively.