Principles of Consolidation and Other Matters Investment Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Deferred Revenue Arrangement [Line Items]
Investment income	$ 26	$ 14	$ 37	$ 58
Trident II [Member]
Deferred Revenue Arrangement [Line Items]
Investment gains				20
Trident III [Member] | Performance Fees [Member]
Deferred Revenue Arrangement [Line Items]
Deferred performance fees	15	43	15	43
Trident III [Member] | Private Equity Funds [Member]
Deferred Revenue Arrangement [Line Items]
Carried interest			$ 31	$ 34