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Stock-based Compensation (Details of Weighted-Average Grant-Date Fair Values and Assumptions Used for Estimating Fair Values) (Details) - Stock Options - $ / shares
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted-average grant-date fair value (in USD per share) $ 5.94 $ 5.28 $ 6.47
Expected life, in years 6 years 5 years 2 months 12 days 5 years 7 months 6 days
Risk-free interest rate 0.80% 1.40% 2.50%
Expected volatility 40.40% 35.10% 33.90%