Stockholders' Equity - Number of Shares (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
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	36,091	36,188	36,658
Effect of using weighted average common shares outstanding	194	354	196
Shares used in computing earnings per share-basic	36,285	36,542	36,854
Effect of shares issuable under stock option plans based on the treasury stock method	89	123	204
Effect of restricted and contingently issuable shares	76	73	73
Shares used in computing earnings per share-diluted	36,450	36,738	37,131