Intangible Assets and Goodwill (Goodwill) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Goodwill Activity
Aggregate goodwill acquired/divested	$ 3,074	$ 2,992	$ 2,993	$ 2,993
Accumulated impairment losses	(1,564)	(1,564)	(1,564)	(1,564)
Goodwill, net of impairment losses	1,428	1,429		1,429
Goodwill acquired	83	20
Goodwill divested	(1)	(21)
Goodwill, net of impairment losses	1,510	1,428		1,429
Government
Goodwill Activity
Aggregate goodwill acquired/divested	349	350	350	350
Accumulated impairment losses	0	0	0	0
Goodwill, net of impairment losses	350	350		350
Goodwill acquired	0	0
Goodwill divested	(1)	0
Goodwill, net of impairment losses	349	350		350
Enterprise
Goodwill Activity
Aggregate goodwill acquired/divested	2,725	2,642	2,643	2,643
Accumulated impairment losses	(1,564)	(1,564)	(1,564)	(1,564)
Goodwill, net of impairment losses	1,078	1,079		1,079
Goodwill acquired	83	20
Goodwill divested	0	(21)
Goodwill, net of impairment losses	$ 1,161	$ 1,078		$ 1,079