Intangible Assets and Goodwill, Goodwill (Details) $ in Millions	Sep. 30, 2016 USD ($)
Changes in carrying amount of goodwill [Roll Forward]
Balance at beginning of period	$ 5,745.2
Balance at end of period	5,745.2
NGL Pipelines & Services [Member]
Changes in carrying amount of goodwill [Roll Forward]
Balance at beginning of period	2,651.7
Balance at end of period	2,651.7
Crude Oil Pipelines & Services [Member]
Changes in carrying amount of goodwill [Roll Forward]
Balance at beginning of period	1,841.0
Balance at end of period	1,841.0
Natural Gas Pipelines & Services [Member]
Changes in carrying amount of goodwill [Roll Forward]
Balance at beginning of period	296.3
Balance at end of period	296.3
Petrochemical & Refined Products Services [Member]
Changes in carrying amount of goodwill [Roll Forward]
Balance at beginning of period	956.2
Balance at end of period	$ 956.2