Partners' Capital Net Income (Loss) Attributable to NonControlling Partners (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Limited Partners' Capital Account [Line Items]
Net income (loss) attributable to non-controlling partners in subsidiary	$ 34.8	$ 16.2	$ 25.3
CMLP
Limited Partners' Capital Account [Line Items]
Net income (loss) attributable to non-controlling partners in subsidiary	$ 34.8	$ 16.2	$ 25.3

Amount of Net Income (Loss) attributable to noncontrolling interest.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
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-URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580

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-Publisher FASB
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