General and Basis of Presentation - Software Development Costs (Details)	9 Months Ended	12 Months Ended
Sep. 30, 2021	Dec. 31, 2020
Software development costs
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	2 years	2 years

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.

No definition available.

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Data Type:	xbrli:stringItemType
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Period Type:	duration