Weighted Average Shares Outstanding (Tables)

12 Months Ended

Dec. 31, 2017

Weighted Average Shares Outstanding [Abstract]

Schedule of Weighted Average Number of Shares

A reconciliation of the weighted-average number of common shares outstanding used in the calculation of basic and diluted earnings per share follows:

	Weighted-Average Common Shares Outstanding
	2017	2016	2015
Basic	54,073,407	54,191,013	55,028,063
Dilutive effect of:
Stock options	258,052	166,986	206,778
Performance share awards	273,839	273,314	278,378
Diluted	54,605,298	54,631,313	55,513,219