Partners' Capital (Details) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2010	Mar. 31, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Schedule of Distributions Made to Member or Limited Partner [Line Items]
Payment date of distributions	May 13, 2011		May 14, 2010
Amount of distribution per unit	$ 1.15	$ 1.14	$ 1.09	$ 1.07	$ 2.29	$ 2.16
Units distributed (in shares)	1,599,149		1,556,130
Schedule of Limited Partners' Capital Account by Class [Line Items]
Units outstanding (in shares)	329,708,902				329,708,902		316,101,490
Effective limited partners' interest exclusive of general partner's incentive distribution rights (in hundredths)	9800.00%				9800.00%
Effective general partner's interest exclusive of incentive distribution rights (in hundredths)	200.00%				200.00%
Changes in Partners' Capital [Roll Forward]
Beginning Balance	7,097,600,000	7,292,500,000	6,691,300,000	6,724,100,000	7,292,500,000	6,724,100,000
Units issued as consideration pursuant to common unit compensation plan for non-employee directors					200,000	200,000
Units issued as consideration in the acquisition of assets	23,700,000		0		23,700,000	81,700,000
Units issued for cash	624,600,000		433,100,000		705,800,000	433,100,000
Distributions paid in cash	(547,600,000)		(486,200,000)		(1,085,800,000)	(961,000,000)
KMI special bonus expense to non-senior management employees					89,900,000	2,700,000
KMI going-private transaction expenses	0	2,800,000	1,300,000	1,400,000
Cash contributions	11,300,000		5,500,000		13,100,000	7,200,000
Other adjustments	(100,000)		0		1,200,000	0
Comprehensive income (loss):
Net Income	231,900,000		365,100,000		572,800,000	592,500,000
Other comprehensive income (loss):
Change in fair value of derivatives utilized for hedging purposes	164,600,000		143,100,000		(97,800,000)	167,700,000
Reclassification of change in fair value of derivatives to net income	86,800,000		39,500,000		139,800,000	87,000,000
Foreign currency translation adjustments	11,100,000		(86,400,000)		61,700,000	(26,600,000)
Adjustments to pension and other postretirement benefit plan liabilities	0		(100,000)		(13,200,000)	(2,400,000)
Total other comprehensive income (loss)	262,500,000		96,100,000		90,500,000	225,700,000
Comprehensive income	494,400,000		461,200,000		663,300,000	818,200,000
Ending Balance	7,703,900,000	7,097,600,000	7,106,200,000	6,691,300,000	7,703,900,000	7,106,200,000
Schedule of Partnership Equity Issuance Transactions [Line Items]
Net proceeds from units issued	624,600,000		433,100,000		705,800,000	433,100,000
Income Allocation and Declared Distributions [Abstract]
Percentage of incentive distributions allocated to general partner (in hundredths)					100.0
Percentage in excess of which distributions to general partner are deemed incentive distributions (in hundredths)					2.0
Reduction in required incentive distribution to general partner			173,600,000
Total reduction in incentive distributions			170,000,000
Equity distribution agreement with UBS
Date of second amendment to Equity distribution agreement with UBS	Feb. 25, 2011				Feb. 25, 2011
Value of units available for sale under second amendment of equity distribution agreement with UBS	1,200,000,000				1,200,000,000
Value of units available for sale under first amendment of equity distribution agreement with UBS	600,000,000				600,000,000
Net proceeds from sale of units under equity distribution agreement with UBS	90,700,000				171,900,000
Equity issued as part of TGS acquisition
Number of units issued as part of TGS acquisition	324,961				324,961
Closing market price of units on date issued	73.01				73.01
Public equity offering
Date of public offering	Jun. 17, 2011				Jun. 17, 2011
Number of units offered	6,700,000				6,700,000
Public offering price	71.44				71.44
Number of units offered as part of underwriters overallotment option	1,005,000				1,005,000
Date of overallotment offering	Jun. 27, 2011				Jun. 27, 2011
Net proceeds from offering	533,900,000				533,900,000
Total number of units offered	7,705,000				7,705,000
Information relating to distributions
Declaration date for distributions arising from first quarter activity	Apr. 20, 2011	Apr. 21, 2011			Apr. 20, 2011
Record date to received distributions arising from first quarter activity		Apr. 29, 2011
Date of incentive distribution arising from first quarter activity	May 13, 2011				May 13, 2011
Subsequent event distributions date to be paid	Aug. 12, 2011				Aug. 12, 2011
Subsequent events distribution date of record	Aug. 01, 2011				Aug. 01, 2011
Incentive distribution required arising from distribution to limited partners declared			263,400,000			263,400,000
Amount of incentive distribution waived as a result of Kinderhawk acquisition			5,300,000			5,300,000
Amount of incentive distribution waived as a result of interim capital transaction			168,300,000			168,300,000
Common Units [Member]
Schedule of Limited Partners' Capital Account by Class [Line Items]
Units outstanding (in shares)	229,289,810				229,289,810		218,880,103
Common Units [Member] | KMI and Consolidated Affiliates [Member]
Schedule of Limited Partners' Capital Account by Class [Line Items]
Units outstanding (in shares)	14,646,428				14,646,428		14,646,428
Common Units [Member] | General Partner [Member]
Schedule of Limited Partners' Capital Account by Class [Line Items]
Units outstanding (in shares)	1,724,000				1,724,000		1,724,000
Common Units [Member] | Third Parties [Member]
Schedule of Limited Partners' Capital Account by Class [Line Items]
Units outstanding (in shares)	212,919,382				212,919,382		202,509,675
Class B Units [Member] | Wholly Owned Subsidiary of KMI [Member]
Schedule of Limited Partners' Capital Account by Class [Line Items]
Units outstanding (in shares)	5,313,400				5,313,400		5,313,400
i-Units [Member] | KMR [Member]
Schedule of Limited Partners' Capital Account by Class [Line Items]
Units outstanding (in shares)	95,105,692				95,105,692		91,907,987
General Partner [Member]
Income Allocation and Declared Distributions [Abstract]
Incentive distribution payments made during period	280,000,000		249,400,000
Amount of waived incentive distribution related to equity issued to finance the acquisition of interest in the KinderHawk Field Services LLC joint venture	7,100,000
KMP [Member]
Changes in Partners' Capital [Roll Forward]
Beginning Balance	7,018,400,000		6,612,600,000	6,644,500,000		6,644,500,000
Units issued as consideration pursuant to common unit compensation plan for non-employee directors					200,000	200,000
Units issued as consideration in the acquisition of assets	23,700,000		0		23,700,000	81,700,000
Units issued for cash	624,600,000		433,100,000		705,800,000	433,100,000
Distributions paid in cash	(540,700,000)		(480,200,000)		(1,072,300,000)	(949,000,000)
KMI special bonus expense to non-senior management employees					89,000,000
KMI going-private transaction expenses	0		1,300,000			2,700,000
Cash contributions	0		0		0	0
Other adjustments	(100,000)		0		1,200,000	0
Comprehensive income (loss):
Net Income	230,500,000		361,200,000		568,300,000	586,500,000
Other comprehensive income (loss):
Change in fair value of derivatives utilized for hedging purposes	163,000,000		141,600,000		(96,800,000)	166,000,000
Reclassification of change in fair value of derivatives to net income	85,900,000		39,100,000		138,400,000	86,100,000
Foreign currency translation adjustments	10,900,000		(85,500,000)		61,000,000	(26,300,000)
Adjustments to pension and other postretirement benefit plan liabilities	0		(100,000)		(13,000,000)	(2,400,000)
Total other comprehensive income (loss)	259,800,000		95,100,000		89,600,000	223,400,000
Comprehensive income	490,300,000		456,300,000		657,900,000	809,900,000
Ending Balance			7,023,100,000			7,023,100,000
Schedule of Partnership Equity Issuance Transactions [Line Items]
Net proceeds from units issued	624,600,000		433,100,000		705,800,000	433,100,000
Noncontrolling Interests [Member]
Changes in Partners' Capital [Roll Forward]
Beginning Balance	79,200,000		78,700,000	79,600,000		79,600,000
Units issued as consideration pursuant to common unit compensation plan for non-employee directors					0	0
Units issued as consideration in the acquisition of assets	0		0		0	0
Units issued for cash	0		0		0	0
Distributions paid in cash	(6,900,000)		(6,000,000)		(13,500,000)	(12,000,000)
KMI special bonus expense to non-senior management employees					900,000
KMI going-private transaction expenses	0		0			0
Cash contributions	11,300,000		5,500,000		13,100,000	7,200,000
Other adjustments	0		0		0	0
Comprehensive income (loss):
Net Income	1,400,000		3,900,000		4,500,000	6,000,000
Other comprehensive income (loss):
Change in fair value of derivatives utilized for hedging purposes	1,600,000		1,500,000		(1,000,000)	1,700,000
Reclassification of change in fair value of derivatives to net income	900,000		400,000		1,400,000	900,000
Foreign currency translation adjustments	200,000		(900,000)		700,000	(300,000)
Adjustments to pension and other postretirement benefit plan liabilities	0		0		(200,000)	0
Total other comprehensive income (loss)	2,700,000		1,000,000		900,000	2,300,000
Comprehensive income	4,100,000		4,900,000		5,400,000	8,300,000
Ending Balance			83,100,000			83,100,000
Schedule of Partnership Equity Issuance Transactions [Line Items]
Net proceeds from units issued	0		0		0	0
Units issued under Equity Distribution Agreement with UBS [Member]
Schedule of Partnership Equity Issuance Transactions [Line Items]
Units issued for cash (in shares)	1,247,090				2,377,296
Commissions on units issued under equity distribution agreement	700,000				1,300,000
Term of option granted to underwriters to purchase additional common units (in days)					30
Dividend Declared [Member]
Subsequent Event [Line Items]
Date of subsequent event			2010-08-13		2011-07-20
Amount of distribution occurring subsequent to period end, per unit	$ 1.15		$ 1.09
i-Units to be issued subsequent to period end	1,701,916				1,701,916
Fractional i-units to be issued subsequent to period end for each i-unit outstanding	0.017895
Average ten day trading price, per share	64.265
Incentive distribution to be paid to general partner subsequent to period end, net of amount waived related to KinderHawk acquisition	292,800,000		89,800,000
Amount of incentive distribution to be paid subsequent to period end that was waived	$ 7,100,000