Guarantee of Securities of Subsidiaries Income Statement (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Total Revenues	$ 3,933	$ 3,381	$ 11,162	$ 9,059
Cost of Sales	1,640	1,531	4,880	3,736
Depreciation, depletion and amortization	427	377	1,234	1,062
Other operating expenses	(1)	(59)	(4)	(83)
Total Operating Costs, Expenses and Other	2,772	2,514	8,213	6,807
Operating Income	1,161	867	2,949	2,252
Other Nonoperating Income (Expense)	14	5	29	28
Income from Continuing Operations Before Income Taxes	1,000	717	2,463	2,648
Income Tax Expense	(24)	(20)	(64)	(147)
Income from Continuing Operations	976	697	2,399	2,501
Loss from Discontinued Operations	0	0	0	(2)
Net Income	976	697	2,399	2,499
Net Income Attributable to Noncontrolling Interests	(13)	(8)	(29)	(27)
Net Income Attributable to KMEP	963	689	2,370	2,472
Total Other Comprehensive (Loss)	57	(4)	(87)	(98)
Comprehensive Income	1,033	693	2,312	2,401
Comprehensive Income Attributable to Noncontrolling Interests	(13)	(8)	(28)	(26)
Comprehensive Income Attributable to KMEP	1,020	685	2,284	2,375
Parent Company [Member]
Total Revenues	0	0	0	0
Cost of Sales	0	0	0	0
Depreciation, depletion and amortization	0	0	0	0
Other operating expenses	0	0	0	0
Total Operating Costs, Expenses and Other	0	0	0	0
Operating Income	0	0	0	0
Other Nonoperating Income (Expense)	966	693	2,378	2,482
Income from Continuing Operations Before Income Taxes	966	693	2,378	2,482
Income Tax Expense	(3)	(4)	(8)	(10)
Income from Continuing Operations				2,472
Loss from Discontinued Operations				0
Net Income	963	689	2,370	2,472
Net Income Attributable to Noncontrolling Interests	0	0	0	0
Net Income Attributable to KMEP	963	689	2,370	2,472
Total Other Comprehensive (Loss)	57	(4)	(86)	(97)
Comprehensive Income	1,020	685	2,284	2,375
Comprehensive Income Attributable to Noncontrolling Interests		0	0	0
Comprehensive Income Attributable to KMEP	1,020	685	2,284	2,375
Subsidiary Issuer [Member]
Total Revenues	0	0	0	0
Cost of Sales	0	0	0	0
Depreciation, depletion and amortization	0	(2)	0	0
Other operating expenses	9	7	24	33
Total Operating Costs, Expenses and Other	9	5	24	33
Operating Income	(9)	(5)	(24)	(33)
Other Nonoperating Income (Expense)	46	40	124	75
Income from Continuing Operations Before Income Taxes	37	35	100	42
Income Tax Expense	0	0	0	0
Income from Continuing Operations				42
Loss from Discontinued Operations				0
Net Income	37	35	100	42
Net Income Attributable to Noncontrolling Interests	0	0	0	0
Net Income Attributable to KMEP	37	35	100	42
Total Other Comprehensive (Loss)	0	0	0	0
Comprehensive Income	37	35	100	42
Comprehensive Income Attributable to Noncontrolling Interests		0	0	0
Comprehensive Income Attributable to KMEP	37	35	100	42
Non-Guarantor Subsidiaries [Member]
Total Revenues	3,933	3,381	11,162	9,059
Cost of Sales	1,640	1,531	4,880	3,736
Depreciation, depletion and amortization	427	379	1,234	1,062
Other operating expenses	696	599	2,075	1,976
Total Operating Costs, Expenses and Other	2,763	2,509	8,189	6,774
Operating Income	1,170	872	2,973	2,285
Other Nonoperating Income (Expense)	(159)	(148)	(482)	389
Income from Continuing Operations Before Income Taxes	1,011	724	2,491	2,674
Income Tax Expense	(21)	(16)	(56)	(137)
Income from Continuing Operations				2,537
Loss from Discontinued Operations				(2)
Net Income	990	708	2,435	2,535
Net Income Attributable to Noncontrolling Interests	(13)	(8)	(29)	(27)
Net Income Attributable to KMEP	977	700	2,406	2,508
Total Other Comprehensive (Loss)	57	(4)	(87)	(98)
Comprehensive Income	1,047	704	2,348	2,437
Comprehensive Income Attributable to Noncontrolling Interests	(13)	(8)	(28)	(26)
Comprehensive Income Attributable to KMEP	1,034	696	2,320	2,411
Consolidation, Eliminations [Member]
Total Revenues	0	0	0	0
Cost of Sales	0	0	0	0
Depreciation, depletion and amortization	0	0	0	0
Other operating expenses	0	0	0	0
Total Operating Costs, Expenses and Other	0	0	0	0
Operating Income	0	0	0	0
Other Nonoperating Income (Expense)	(1,014)	(735)	(2,506)	(2,550)
Income from Continuing Operations Before Income Taxes	(1,014)	(735)	(2,506)	(2,550)
Income Tax Expense	0	0	0	0
Income from Continuing Operations				(2,550)
Loss from Discontinued Operations				0
Net Income	(1,014)	(735)	(2,506)	(2,550)
Net Income Attributable to Noncontrolling Interests	0	0	0	0
Net Income Attributable to KMEP	(1,014)	(735)	(2,506)	(2,550)
Total Other Comprehensive (Loss)	(57)	4	86	97
Comprehensive Income	(1,071)	(731)	(2,420)	(2,453)
Comprehensive Income Attributable to Noncontrolling Interests		0	0	0
Comprehensive Income Attributable to KMEP	(1,071)	(731)	(2,420)	(2,453)
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Total Revenues	3,933	3,381	11,162	9,059
Cost of Sales	1,640	1,531	4,880	3,736
Depreciation, depletion and amortization	427	377	1,234	1,062
Other operating expenses	705	606	2,099	2,009
Total Operating Costs, Expenses and Other	2,772	2,514	8,213	6,807
Operating Income	1,161	867	2,949	2,252
Other Nonoperating Income (Expense)	(161)	(150)	(486)	396
Income from Continuing Operations Before Income Taxes	1,000	717	2,463	2,648
Income Tax Expense	(24)	(20)	(64)	(147)
Income from Continuing Operations				2,501
Loss from Discontinued Operations				(2)
Net Income	976	697	2,399	2,499
Net Income Attributable to Noncontrolling Interests	(13)	(8)	(29)	(27)
Net Income Attributable to KMEP	963	689	2,370	2,472
Total Other Comprehensive (Loss)	57	(4)	(87)	(98)
Comprehensive Income	1,033	693	2,312	2,401
Comprehensive Income Attributable to Noncontrolling Interests	(13)	(8)	(28)	(26)
Comprehensive Income Attributable to KMEP	$ 1,020	$ 685	$ 2,284	$ 2,375
KMP 7.125% Senior Notes due April 1, 2021 (Copano) [Member]
Debt Instrument, Interest Rate, Stated Percentage	7.125%		7.125%