Segments (Reconciliation of Net Income (Loss) to EBITDA) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net loss	$ (2,303.7)	$ (10.4)	$ (50.6)
Interest Expense	140.1	127.1	77.9
Loss on modification/extinguishment of debt	20.0	0.0	0.0
Provision (benefit) for income taxes	(1.4)	1.1	1.0
Depreciation, amortization and accretion	300.1	285.3	167.9
EBITDA	(1,844.9)	403.1	196.2
CMLP
Segment Reporting Information [Line Items]
Net loss	(1,410.6)	14.7	(12.4)
Interest Expense	130.5	111.4	71.7
Loss on modification/extinguishment of debt	18.9	0.0	0.0
Provision (benefit) for income taxes	0.0	0.9	0.7
Depreciation, amortization and accretion	278.5	255.4	139.4
EBITDA	$ (982.7)	$ 382.4	$ 199.4