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Stock-based Compensation and Other Employee Benefit Plans Employee Benefit Plans (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 16.4	$ 16.2	$ 13.0
Deferred Compensation Liability, Current and Noncurrent	14.4	11.8
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	32.3	39.3	31.5
Share-based Payment Arrangement, Expense, Tax Benefit	$ 1.6	$ 1.1	$ 2.7
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	0.1
Restricted Stock Units and Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	2.6

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- Definition

Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]

+ References

No definition available.

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Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

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Amount of discretionary contributions made by an employer to a defined contribution plan.

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
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Amount of noncash expense for share-based payment arrangement.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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