Related Party Transactions (Details) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended			6 Months Ended	9 Months Ended			9 Months Ended				9 Months Ended
	Sep. 30, 2010 USD ($)	Sep. 30, 2011 USD ($)	Sep. 30, 2010 USD ($)	Dec. 31, 2010 USD ($)	Jun. 30, 2011 Plantation Pipe Line Company [Member] Notes Receivable [Member] USD ($)	Sep. 30, 2011 Plantation Pipe Line Company [Member] Notes Receivable [Member]	Dec. 31, 2010 Plantation Pipe Line Company [Member] Notes Receivable [Member] USD ($)	Sep. 30, 2011 Plantation Pipe Line Company [Member]	Sep. 30, 2011 Express pipeline system [Member] Notes Receivable [Member] USD ($)	Sep. 30, 2011 Express pipeline system [Member] Notes Receivable [Member] CAD	Dec. 31, 2010 Express pipeline system [Member] Notes Receivable [Member] USD ($)	Sep. 30, 2011 Express pipeline system [Member]	Sep. 30, 2011 Kinder Morgan, Inc. [Member] USD ($)	Sep. 30, 2010 Kinder Morgan, Inc. [Member] USD ($)	Dec. 31, 2010 Kinder Morgan, Inc. [Member] USD ($)	Sep. 30, 2011 Rockies Express [Member] Accrued other current liabilities [Member] USD ($)	Dec. 31, 2010 Rockies Express [Member] Accrued other current liabilities [Member] USD ($)	Sep. 30, 2011 NGPL [Member] USD ($)	Dec. 31, 2010 NGPL [Member] USD ($)
Related Party Transaction [Line Items]
Related party interest rate (in hundredths)					4.72%				12.00%	12.00%
Maturity date						Jul. 20, 2011			Jan. 09, 2023	Jan. 09, 2023
Due from related parties, total		$ 7.1		$ 15.4	$ 80.7		$ 82.1
Due from related parties, current													3.1		8.2			4.0	7.2
Total amount of initial investment in long-term debt security										113.6
Due from related parties, noncurrent									108.4		114.2
Due to related parties, current		11.0		8.8									7.1		5.1	3.9	3.7
Amount of debt for which KMI agreed to indemnify us and our general partner													733.5
Non-cash compensation expense allocated from parent		89.9	3.7										89.9	3.7
Non-cash compensation expense associated with KMI's going-private transaction	1.0												2.8
Schedule of Equity Method Investments [Line Items]
Ownership interest (in hundredths)								51.17%				33.33%
Derivative counterparties [Abstract]
Percentage of ownership Goldman Sachs has in our train terminal assets which were acquired from US Development Group LLC (in hundredths)		49.00%
Derivatives - asset/(liability) [Abstract]
Current assets		36.7		0
Noncurrent assets		49.7		12.7
Current liabilities		(41.3)		(221.4)
Noncurrent liabilities		(11.3)		(57.5)
Amount of principal payments on Plantation Note received during period		30.9
Date Plantation note amended		Jul. 20, 2011
Amount of outstanding principal on amended plantation note after payment		100.0
Payment made by Plantation on amendment date		57.9
Kinder Morgan's share of amended note with Plantation		51.2
Maturity date of amended Plantation note		Jul. 20, 2016
Interest rate on amended Plantation note		4.25
Principal amount to be paid on final payment of amended Plantation note		87.8
Related party receivables included in Accounts, notes and interest receivable, net		1.1
RCI and Devco Related Party Matters
Aggregate amount of credit Kinder Morgan has made available to RCI and Devco		3.0
Expiration date of lines of credit		Dec. 31, 2012
Credit available to RCI		2.7
Credit available to Devco		0.3
Interest rate on RCI and Devco credit agreements		9.5
Amount RCI has borrowed under credit agreement		$ 1.6