Commitments and Contingencies (Self Insurance) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Crestwood Equity Partners LP
Other Commitments [Line Items]
Self-insurance reserves	$ 6.7	$ 7.7
Self-insurance reserves expected to be paid	4.8
Crestwood Midstream Partners LP
Other Commitments [Line Items]
Self-insurance reserves	5.8	$ 6.7
Self-insurance reserves expected to be paid	$ 4.1

Carrying amount (including both current and noncurrent portions) of accrued known and estimated losses incurred as of the balance sheet date for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.24)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_SelfInsuranceReserve
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant