Fair Values (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Investment securities:
Equity securities	$ 1.0	$ 124.0
Debt securities and other	4,749	4,892
Derivatives	822	701
Total assets	5,572	5,717
Level 1 [Member]
Investment securities:
Equity securities	1.0	124.0
Debt securities and other	349	320
Derivatives	0	0
Total assets	350	444
Level 2 [Member]
Investment securities:
Equity securities	0	0
Debt securities and other	4,400	4,572
Derivatives	822	701
Total assets	5,222	5,273
Level 3 [Member]
Investment securities:
Equity securities	0	0
Debt securities and other	0	0
Derivatives	0	0
Total assets	$ 0	$ 0