8.	Common and Common Equivalent Shares:

Basic net income per common share is calculated by dividing net income by the weighted average number of common shares outstanding during the period. Diluted net income per common share is calculated by dividing net income by the weighted average number of common and potential common shares outstanding during the period. Potential common shares consist of outstanding restricted stock and stock options and is calculated using the treasury stock method. In the first quarter of 2017, the Company adopted new accounting guidance that no longer permits the Company to include the assumed excess tax benefits related to the potential exercise or vesting of its stock-based awards in the treasury stock method computation. The impact on the weighted average number of common and common equivalent shares outstanding from excluding such assumed excess tax benefits for the three and nine months ended September 30, 2017 was not material. See Note 1 for additional information on the adoption of the new accounting guidance.

The calculation of shares used in the basic and diluted net income per common share calculation for the three and nine months ended September 30, 2017 and 2016 is as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Weighted average number of common shares outstanding		92,589		92,604		92,348		92,336
Weighted average number of dilutive common share equivalents		292		542		666		709

Weighted average number of common and common equivalent shares outstanding		92,881		93,146		93,014		93,045

Antidilutive securities not included in the diluted net income per common share calculation		380		—		130		2