Schedule II - Condensed Financial Information of Registrant Debt (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Condensed Financial Statements, Captions [Line Items]
Debt and Lease Obligation	$ 966.4	$ 974.0
Senior Notes Due 2026 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt and Lease Obligation	$ 546.8	$ 546.2
Debt Instrument, Interest Rate, Stated Percentage	3.875%	3.875%
Debt Instrument, Face Amount	$ 550.0
Senior Notes Due 2024 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt and Lease Obligation	$ 397.9	$ 397.3
Debt Instrument, Interest Rate, Stated Percentage	4.875%	4.875%
Debt Instrument, Face Amount	$ 400.0

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Amount of short-term and long-term debt and lease obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13,16)
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Face (par) amount of debt instrument at time of issuance.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
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Contractual interest rate for funds borrowed, under the debt agreement.

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-SubTopic 10
-Section S99
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