Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average Common Shares Outstanding - Basic (in shares)	41,500	40,513	41,478	40,365
Effect of Dilutive Securities:
Total Dilutive Shares (in shares)	318	164	281	196
Weighted Average Common Shares Outstanding – Diluted (in shares)	41,818	40,677	41,759	40,561
Stock Performance Awards
Effect of Dilutive Securities:
Effect of Dilutive Securities (in shares)	223	97	183	112
Stock Awards
Effect of Dilutive Securities:
Effect of Dilutive Securities (in shares)	75	47	80	56
Employee Stock Purchase Plan Shares and Other
Effect of Dilutive Securities:
Effect of Dilutive Securities (in shares)	20	20	18	28