Offsetting Assets and Liabilities (Offsetting Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Offsetting Assets and Liabilities [Abstract]
Securities loaned, Gross Liabilities	$ 1,956	[1]	$ 1,477	[1]
Securities loaned, Net Amounts Presented in the Consolidated Balance Sheet	1,956	[1]	1,477	[1]
Securities loaned, Gross Amounts Not Offset in the Consolidated Balance Sheet, Counterparty Offsetting	(40)	[1]	(69)	[1]
Securities loaned, Gross Amounts Not Offset in the Consolidated Balance Sheet, Collateral	(1,770)	[1]	(1,293)	[1]
Securities loaned, Net Amount	146	[1]	115	[1]
Total Gross Liabilities	1,956		1,477
Total Liabilities, Net Amounts Presented in the Consolidated Balance Sheet	1,956		1,477
Total Liabilities, Gross Amounts Not Offset in the Consolidated Balance Sheet, Counterparty Offsetting	(40)		(69)
Total Liabilities, Gross Amounts Not Offset in the Consolidated Balance Sheet, Collateral	(1,770)		(1,293)
Total Liabilities, Net Amount	$ 146		$ 115

[1] Included in payables to brokers, dealers, and clearing organizations in the Company’s consolidated balance sheets.