Restructuring Charges (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost and Reserve [Line Items]
Severance and termination costs	$ 0.6	$ 44.6	$ 2.1	$ 44.6
Lease impairment costs	(0.9)	65.7	(1.1)	65.7
Other restructuring costs	0.1	2.3	0.1	2.3
Restructuring charges	(0.2)	112.6	1.1	112.6
Severance and termination costs	0.6	44.6	2.1	44.6
Lease impairment costs	(0.9)	65.7	(1.1)	65.7
Other restructuring costs	0.1	2.3	0.1	2.3
Restructuring charges	$ (0.2)	$ 112.6	$ 1.1	$ 112.6

Amount of loss from impairment of right-of-use asset from operating lease.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 25
-Paragraph 6
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123399704&loc=SL77918431-209957

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Amount of other expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses associated with a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 45
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-URI http://asc.fasb.org/extlink&oid=109237686&loc=d3e17752-110868

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Topic 230
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Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

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