Stockholders' Equity - Number of Shares (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Reconciliation of the number of shares outstanding with the number of shares used in computing basic and diluted earnings per share
Common shares outstanding, end of period	35,781	36,349	35,781	36,349
Effect of using weighted average common shares outstanding	189	54	241	(4)
Shares used in computing earnings per share-basic	35,970	36,403	36,022	36,345
Effect of shares issuable under stock option plans based on the treasury stock method	42	97	42	114
Effect of restricted and contingently issuable shares	61	66	66	74
Shares used in computing earnings per share-diluted	36,073	36,566	36,130	36,533