Fair Value Measurements (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Fair Value Measurements (Textual) [Abstract]
Loans held for sale		$ 15	$ 15
Nonexit price methodology for valuing loan portfolio		0.10%
Loans, net of allowance		48,571	48,503
Loans held for sale		728	467	443
Deconsolidated direct and indirect investments	234
Residential Real Estate Mortgage Loans [Member]
Fair Value Measurements (Textual) [Abstract]
Loans, net of allowance		1,900	1,800
Carrying Amount [Member]
Fair Value Measurements (Textual) [Abstract]
Loans, net of allowance		48,571	48,503
Loans held for sale		728	467
Fair Value [Member]
Fair Value Measurements (Textual) [Abstract]
Loans, net of allowance		47,561	46,140
Loans held for sale		728	467
Level 3 [Member]
Fair Value Measurements (Textual) [Abstract]
Loans held for sale		$ 15	$ 15