Revenue Recognition (Costs to Obtain a Contract) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Deferred commission costs	$ 19.0	$ 19.0	$ 17.5
Commissions expense recognized	$ 1.3	$ 4.3
Minimum
Disaggregation of Revenue [Line Items]
Amortization period	3 years	3 years
Maximum
Disaggregation of Revenue [Line Items]
Amortization period	7 years	7 years

Amortization period of cost capitalized in obtaining or fulfilling contract with customer, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123353750&loc=SL49131251-203054

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- Definition

Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123353750&loc=SL49131252-203054

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Primarily represents commissions incurred in the period based upon the sale by commissioned employees or third parties of the entity's goods or services, and fees for sales assistance or product enhancements performed by third parties (such as a distributor or value added reseller).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.4)
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

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