Share-Based Compensation (Narrative) (Details) $ / shares in Units, $ in Millions	3 Months Ended
Mar. 31, 2023 USD ($) d $ / shares shares	Mar. 31, 2022 $ / shares shares
Restricted Stock And Restricted Stock Unit (RSU)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	271,614	112,324
Restricted Stock And Restricted Stock Unit (RSU) \| Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting periods	1 year
Restricted Stock And Restricted Stock Unit (RSU) \| Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting periods	8 years
Market-based Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	167,606	100,193
Trading days \| d	20
Trading days, lookback \| d	30
Weighted-average grant-date fair values of restricted stock awards granted (in usd per share) \| $ / shares	$ 70.07	$ 87.11
Weighted-average period to recognize compensation cost (in years)	2 years 7 months 6 days
Restricted Stock, Restricted Stock Unit (RSU), Market-based Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to non-vested awards granted \| $	$ 66.2
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	439,220
Weighted-average period to recognize compensation cost (in years)	4 years 2 months 12 days
Minimum \| Restricted Stock And Restricted Stock Unit (RSU) \| Senior Staff
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting periods	4 years
Minimum \| Market-based Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair values of restricted stock awards granted (in usd per share) \| $ / shares	$ 83.61	107.97
Maximum \| Restricted Stock And Restricted Stock Unit (RSU) \| Senior Staff
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting periods	5 years
Maximum \| Market-based Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair values of restricted stock awards granted (in usd per share) \| $ / shares	$ 103.76	$ 138.73
2015 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum issuance of common stock (in shares)	4,200,000
Number of options outstanding (in shares)	435,135
2015 Stock Option Plan \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market value of common stock on the date of grant for incentive stock options	100.00%

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