Benefit Plans - Other Plans (Details)	9 Months Ended
Sep. 30, 2021 plan
Retirement Benefits [Abstract]
Number of other share-based benefit plans	6

Share-based compensation arrangement by share-based payment award, number of share-based benefit plans.

No definition available.

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Namespace Prefix:	siri_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration