Consolidated Statement of Changes in Equity (Unaudited) (USD $) In Millions, except Share data, unless otherwise specified	Total	General partner [Member]	Limited partners [Member]	Treasury Stock [Member]	Parent [Member]	Noncontrolling Interest [Member]
Equity at Dec. 31, 2011	$ 7,833	$ (271)	$ 4,038	$ (12)	$ 3,755	$ 4,078
Treasury units at Dec. 31, 2011	1,137,200			1,137,200
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	651	17	361	0	378	273
Other comprehensive income	19	1	13	0	14	5
Cancellation of treasury units	0	0	(12)	12	0	0
Cancellation of treasury units (in units)				(1,137,200)
Partnership contributions	513	13	500	0	513	0
Partnership distributions	(31)	(1)	(30)	0	(31)	0
Investment segment distributions	(79)	0	0	0	0	(79)
Acquisition of CVR	910	0	0	0	0	910
LP unit issuance	135	0	135	0	135	0
Changes in subsidiary equity and other	(153)	0	11	0	11	(164)
Equity at Sep. 30, 2012	$ 9,798	$ (241)	$ 5,016	$ 0	$ 4,775	$ 5,023
Treasury units at Sep. 30, 2012	0			0