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		Six Months Ended
	June 30,		June 30,
(In thousands)	2018	2017	2018	2017
Weighted average shares outstanding used to compute basic earnings per share	33,074	32,961	33,028	32,941
Incremental dilutive shares attributable to stock options and restricted stock	34	90	20	58
Shares used to compute diluted earnings per share	33,108	33,051	33,048	32,999

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 six months ended June 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 215,903 and 264,868, respectively. For the three and six months ended June 30, 2017, 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 416,941 and 340,268, respectively.