Earnings Per Share Components of Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Weighted Average Number of Shares Outstanding, Basic	89,407	89,509	89,505	89,476
Dilutive effect of potential common shares	159	0	141	153
Weighted Average Number of Shares Outstanding, Diluted	89,566	89,509	89,646	89,629