Business Developments And Risks And Uncertainties (Assets And Liabilities Held For Sale) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Assets And Liabilities Held For Sale By Major Category [Line Items]
Assets held for sale	$ 802	$ 29
Liabilities held for sale	772	0
Investments At Fair Value [Member]
Assets And Liabilities Held For Sale By Major Category [Line Items]
Assets held for sale	6	0
Cash And Cash Equivalents [Member]
Assets And Liabilities Held For Sale By Major Category [Line Items]
Assets held for sale	15	0
Facility [Member]
Assets And Liabilities Held For Sale By Major Category [Line Items]
Assets held for sale	26	29
Other Assets [Member]
Assets And Liabilities Held For Sale By Major Category [Line Items]
Assets held for sale	4	0
Cash [Member]
Assets And Liabilities Held For Sale By Major Category [Line Items]
Assets held for sale	40	0
Loans Receivable [Member]
Assets And Liabilities Held For Sale By Major Category [Line Items]
Assets held for sale	711	0
Other Liabilities [Member]
Assets And Liabilities Held For Sale By Major Category [Line Items]
Liabilities held for sale	18	0
Variable Interest Entities Notes [Member]
Assets And Liabilities Held For Sale By Major Category [Line Items]
Liabilities held for sale	431	0
Payable For Loans Purchased [Member]
Assets And Liabilities Held For Sale By Major Category [Line Items]
Liabilities held for sale	$ 323	$ 0