Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Consolidated Statements of Comprehensive Income [Abstract]
Net Income Attributable to UNBC	$ 187	$ 242	$ 382	$ 477
Other Comprehensive Income, Net of Tax:
Net change in unrealized losses on hedges	15	(4)	20
Net change in unrealized losses on securities	47	69	86	42
Foreign currency translation adjustment	(1)	(1)		1
Net change in pension and other benefits	14	8	30	21
Total other comprehensive income	75	72	136	64
Comprehensive Income Attributable to UNBC	262	314	518	541
Comprehensive loss from noncontrolling interests	(5)	(3)	(9)	(7)
Total Comprehensive Income	$ 257	$ 311	$ 509	$ 534