Condensed Consolidating Financial Information (Statements Of Operations) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues:
Storage and transportation		$ 266.3	$ 264.6	$ 130.9
Related party (Note 16)		3.9	3.0	74.9
Revenues		2,632.8	3,931.3	1,426.7
Costs of product/services sold (exclusive of items shown separately below):
Related party (Note 16)		28.9	42.2	32.5
Total costs of products/services sold		1,883.5	3,165.3	1,002.3
Expenses:
Operations and maintenance		190.2	203.3	104.6
General and administrative		116.3	100.2	93.5
Depreciation, amortization and accretion		300.1	285.3	167.9
Goodwill impairment	$ (515.4)	(1,406.3)	(48.8)	(4.1)
Loss on contingent consideration		0.0	(8.6)	(31.4)
Operating income (loss)		(2,084.8)	117.9	28.2
Other income (expense):
Loss from unconsolidated affiliates, net		(60.8)	(0.7)	(0.1)
Interest and debt expense, net		(140.1)	(127.1)	(77.9)
Loss on modification/extinguishment of debt		(20.0)	0.0	0.0
Loss before income taxes		(2,305.1)	(9.3)	(49.6)
Provision (benefit) for income taxes		(1.4)	1.1	1.0
Net loss		(2,303.7)	(10.4)	(50.6)
Net income attributable to non-controlling partners in subsidiary		636.8	66.8	57.3
Net income (loss) attributable to parent		(1,666.9)	56.4	6.7
Net income attributable to preferred units		(6.2)	0.0	0.0
Net income (loss) attributable to partners		(1,673.1)	56.4	6.7
CMLP
Revenues:
Storage and transportation		266.3	250.8	116.8
Related party (Note 16)		3.9	3.0	74.9
Revenues		2,632.8	3,917.5	1,412.6
Costs of product/services sold (exclusive of items shown separately below):
Related party (Note 16)		28.9	42.2	32.5
Total costs of products/services sold		1,883.5	3,154.8	995.4
Expenses:
Operations and maintenance		188.7	195.4	103.4
General and administrative		105.6	91.7	84.1
Depreciation, amortization and accretion		278.5	255.4	139.4
Costs and Expenses		572.8	542.5	326.9
(Gain) loss on long-lived assets, net		(227.8)	(35.1)	5.3
Goodwill impairment	$ (470.6)	(1,149.1)	(48.8)	(4.1)
Loss on contingent consideration		0.0	(8.6)	(31.4)
Operating income (loss)		(1,200.4)	127.7	60.1
Other income (expense):
Loss from unconsolidated affiliates, net		(60.8)	(0.7)	(0.1)
Interest and debt expense, net		(130.5)	(111.4)	(71.7)
Loss on modification/extinguishment of debt		(18.9)	0.0	0.0
Loss from unconsolidated affiliates		0.0	0.0	0.0
Loss before income taxes		(1,410.6)	15.6	(11.7)
Provision (benefit) for income taxes		0.0	0.9	0.7
Net loss		(1,410.6)	14.7	(12.4)
Net income attributable to non-controlling partners in subsidiary		(23.1)	(16.8)	(4.9)
Net income (loss) attributable to parent		(1,433.7)	(2.1)	(17.3)
Net income attributable to preferred units		(23.1)	(17.2)	0.0
Net income (loss) attributable to partners		(1,456.8)	(19.3)	(17.3)
CMLP | Parent Company
Revenues:
Revenues		0.0	0.0	0.0
Costs of product/services sold (exclusive of items shown separately below):
Total costs of products/services sold		0.0	0.0	0.0
Expenses:
Operations and maintenance		0.0	0.0	0.0
General and administrative		65.3	49.4	46.5
Depreciation, amortization and accretion		0.0	0.9	1.0
Costs and Expenses		65.3	50.3	47.5
(Gain) loss on long-lived assets, net		0.0	0.0	0.0
Goodwill impairment		0.0	0.0	0.0
Loss on contingent consideration			0.0	0.0
Operating income (loss)		(65.3)	(50.3)	(47.5)
Other income (expense):
Loss from unconsolidated affiliates, net		0.0	0.0	0.0
Interest and debt expense, net		(130.5)	(111.4)	(68.7)
Loss on modification/extinguishment of debt		(18.9)
Loss from unconsolidated affiliates		(1,195.9)	176.4	103.8
Loss before income taxes		(1,410.6)	14.7	(12.4)
Provision (benefit) for income taxes		0.0	0.0	0.0
Net loss		(1,410.6)	14.7	(12.4)
Net income attributable to non-controlling partners in subsidiary		0.0	0.0	0.0
Net income (loss) attributable to parent		(1,410.6)	14.7	(12.4)
Net income attributable to preferred units		(23.1)	17.2	0.0
Net income (loss) attributable to partners		(1,433.7)	(2.5)	(12.4)
CMLP | Guarantor Subsidiaries
Revenues:
Revenues		2,632.8	3,917.5	1,412.6
Costs of product/services sold (exclusive of items shown separately below):
Total costs of products/services sold		1,883.5	3,154.8	995.4
Expenses:
Operations and maintenance		188.7	195.4	103.4
General and administrative		40.3	42.3	37.6
Depreciation, amortization and accretion		278.5	254.5	138.4
Costs and Expenses		507.5	492.2	279.4
(Gain) loss on long-lived assets, net		(227.8)	(35.1)	5.3
Goodwill impairment		(1,149.1)	(48.8)	(4.1)
Loss on contingent consideration			(8.6)	(31.4)
Operating income (loss)		(1,135.1)	178.0	107.6
Other income (expense):
Loss from unconsolidated affiliates, net		0.0	0.0	0.0
Interest and debt expense, net		0.0	0.0	(3.0)
Loss on modification/extinguishment of debt		0.0
Loss from unconsolidated affiliates		0.0	0.0	0.0
Loss before income taxes		(1,135.1)	178.0	104.6
Provision (benefit) for income taxes		0.0	0.9	0.7
Net loss		(1,135.1)	177.1	103.9
Net income attributable to non-controlling partners in subsidiary		0.0	0.0	0.0
Net income (loss) attributable to parent		(1,135.1)	177.1	103.9
Net income attributable to preferred units		0.0	0.0	0.0
Net income (loss) attributable to partners		(1,135.1)	177.1	103.9
CMLP | Non-Guarantor Subsidiaries
Revenues:
Revenues		0.0	0.0	0.0
Costs of product/services sold (exclusive of items shown separately below):
Total costs of products/services sold		0.0	0.0	0.0
Expenses:
Operations and maintenance		0.0	0.0	0.0
General and administrative		0.0	0.0	0.0
Depreciation, amortization and accretion		0.0	0.0	0.0
Costs and Expenses		0.0	0.0	0.0
(Gain) loss on long-lived assets, net		0.0	0.0	0.0
Goodwill impairment		0.0	0.0	0.0
Loss on contingent consideration			0.0	0.0
Operating income (loss)		0.0	0.0	0.0
Other income (expense):
Loss from unconsolidated affiliates, net		(60.8)	(0.7)	(0.1)
Interest and debt expense, net		0.0	0.0	0.0
Loss on modification/extinguishment of debt		0.0
Loss from unconsolidated affiliates		0.0	0.0	0.0
Loss before income taxes		(60.8)	$ (0.7)	(0.1)
Provision (benefit) for income taxes		0.0		0.0
Net loss		(60.8)	$ (0.7)	(0.1)
Net income attributable to non-controlling partners in subsidiary		(23.1)	(16.8)	(4.9)
Net income (loss) attributable to parent		(83.9)	(17.5)	(5.0)
Net income attributable to preferred units		0.0	0.0	0.0
Net income (loss) attributable to partners		(83.9)	(17.5)	(5.0)
CMLP | Eliminations
Revenues:
Revenues		0.0	0.0	0.0
Costs of product/services sold (exclusive of items shown separately below):
Total costs of products/services sold		0.0	0.0	0.0
Expenses:
Operations and maintenance		0.0	0.0	0.0
General and administrative		0.0	0.0	0.0
Depreciation, amortization and accretion		0.0	0.0	0.0
Costs and Expenses		0.0	0.0	0.0
(Gain) loss on long-lived assets, net		0.0	0.0	0.0
Goodwill impairment		0.0	0.0	0.0
Loss on contingent consideration			0.0	0.0
Operating income (loss)		0.0	0.0	0.0
Other income (expense):
Loss from unconsolidated affiliates, net		0.0	0.0	0.0
Interest and debt expense, net		0.0	0.0	0.0
Loss on modification/extinguishment of debt		0.0
Loss from unconsolidated affiliates		1,195.9	(176.4)	(103.8)
Loss before income taxes		1,195.9	(176.4)	(103.8)
Provision (benefit) for income taxes		0.0	0.0	0.0
Net loss		1,195.9	(176.4)	(103.8)
Net income attributable to non-controlling partners in subsidiary		0.0	0.0	0.0
Net income (loss) attributable to parent		1,195.9	(176.4)	(103.8)
Net income attributable to preferred units		0.0	0.0	0.0
Net income (loss) attributable to partners		$ 1,195.9	$ (176.4)	$ (103.8)