Available-For-Sale Securities (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities
Cost Basis	$ 1,393	$ 1,421
Unrealized Pretax Net Gains (Losses)	142	133
Fair Value	1,535	1,554
U.S. treasury bonds
Schedule of Available-for-sale Securities
Cost Basis	10	10
Unrealized Pretax Net Gains (Losses)	0	0
Fair Value	10	10
Other U.S. and non-U.S. government bonds
Schedule of Available-for-sale Securities
Cost Basis	97	94
Unrealized Pretax Net Gains (Losses)	1	0
Fair Value	98	94
Corporate bonds
Schedule of Available-for-sale Securities
Cost Basis	642	677
Unrealized Pretax Net Gains (Losses)	20	16
Fair Value	662	693
Asset-backed securities
Schedule of Available-for-sale Securities
Cost Basis	101	103
Unrealized Pretax Net Gains (Losses)	2	2
Fair Value	103	105
U.S. governmental agency mortgage-backed securities
Schedule of Available-for-sale Securities
Cost Basis	277	292
Unrealized Pretax Net Gains (Losses)	4	2
Fair Value	281	294
Residential
Schedule of Available-for-sale Securities
Cost Basis	14	15
Unrealized Pretax Net Gains (Losses)	0	0
Fair Value	14	15
Commercial
Schedule of Available-for-sale Securities
Cost Basis	60	63
Unrealized Pretax Net Gains (Losses)	4	4
Fair Value	64	67
Large capitalization value
Schedule of Available-for-sale Securities
Cost Basis	169	150
Unrealized Pretax Net Gains (Losses)	87	83
Fair Value	256	233
Smaller company growth
Schedule of Available-for-sale Securities
Cost Basis	23	17
Unrealized Pretax Net Gains (Losses)	24	26
Fair Value	$ 47	$ 43