Intangible Assets and Goodwill, Goodwill (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Changes in carrying amount of goodwill [Roll Forward]
Balance at beginning of period	$ 4,199.9
Reclassification of Oiltanking IDR balances to goodwill in connection with the cancellation of such rights in February 2015	1,454.1
Balance at end of period	5,654.0
NGL Pipelines & Services [Member]
Changes in carrying amount of goodwill [Roll Forward]
Balance at beginning of period	2,180.4
Reclassification of Oiltanking IDR balances to goodwill in connection with the cancellation of such rights in February 2015	432.6
Balance at end of period	2,613.0
Onshore Natural Gas Pipelines & Services [Member]
Changes in carrying amount of goodwill [Roll Forward]
Balance at beginning of period	296.3
Reclassification of Oiltanking IDR balances to goodwill in connection with the cancellation of such rights in February 2015	0
Balance at end of period	296.3
Onshore Crude Oil Pipelines & Services [Member]
Changes in carrying amount of goodwill [Roll Forward]
Balance at beginning of period	859.9
Reclassification of Oiltanking IDR balances to goodwill in connection with the cancellation of such rights in February 2015	850.7
Balance at end of period	1,710.6
Offshore Pipelines & Services [Member]
Changes in carrying amount of goodwill [Roll Forward]
Balance at beginning of period	82.0
Reclassification of Oiltanking IDR balances to goodwill in connection with the cancellation of such rights in February 2015	0
Balance at end of period	82.0
Petrochemical & Refined Products Services [Member]
Changes in carrying amount of goodwill [Roll Forward]
Balance at beginning of period	781.3
Reclassification of Oiltanking IDR balances to goodwill in connection with the cancellation of such rights in February 2015	170.8
Balance at end of period	$ 952.1