Stock Compensation and Share Repurchase Plan (Narrative) (Details) - USD ($) shares in Thousands, $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Shareholders Equity and Share-Based Payments [Line Items]
Share-based Compensation, Excluding Accelerated Compensation Cost	$ 8.1	$ 7.0	$ 6.3
Total income tax benefit recognized related to stock-based compensation	2.1	1.8	1.6
Restricted Stock
Shareholders Equity and Share-Based Payments [Line Items]
Total unrecognized compensation cost related to nonvested stock awards	$ 10.9
Expected recognized over a weighted-average period, years	1 year 9 months 14 days
Share-based compensation award, vesting period	3 years
Fair value of restricted shares	$ 9.1	6.7	11.9
Income tax benefits received	$ 2.1	$ 1.8	$ 3.4
Stock Repurchase Plan
Shareholders Equity and Share-Based Payments [Line Items]
Stock repurchase program number of shares authorized, amended	15,000
Stock repurchase program, remaining number of shares authorized to be repurchased	9,500
Stock repurchased during period, shares	331	300	327
Cancellation of restricted stock shares to pay withholding (in shares)	163	115	187

Cancellation of restricted stock shares to pay withholding.

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Restricted Stock Units At Fair Value

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- Definition

Share-based Compensation, Excluding Accelerated Compensation Cost

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Shareholders Equity and Share-Based Payments [Line Items]

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- Definition

Stock repurchase program number of shares authorized, amended.

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- Definition

Amount of deferred tax expense from write-off of the deferred tax asset related to deductible stock options at exercise.

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No definition available.

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- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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- Definition

The remaining number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

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- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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