Earnings Per Share Components of Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Weighted Average Number of Shares Outstanding, Basic	89,509	89,372	89,476	89,346
Dilutive effect of potential common shares	0	222	153	209
Weighted Average Number of Shares Outstanding, Diluted	89,509	89,594	89,629	89,555