Basis of Presentation - Share Repurchase Agreements (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Feb. 12, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Stock repurchase program, number of shares authorized to be repurchased (shares)			10,000,000.0
Total number of shares repurchased (in shares)	0	200,000
Payments for Repurchase of Common Stock	$ 0.0	$ 11.9
Shares repurchased, average price per share (in USD per share)		$ 57.94

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- Definition

The cash outflow to reacquire common stock during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
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- Definition

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

+ References

No definition available.

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 45
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