Mortgage Servicing Rights (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Changes in fair value of capitalized MSRs
Balance at beginning of period	$ 2,073,000,000	$ 1,778,000,000	$ 1,837,000,000	$ 1,749,000,000
Rights purchased	4,000,000	33,000,000	11,000,000	38,000,000
Rights Capitalized	102,000,000	117,000,000	315,000,000	249,000,000
Changes in fair value of MSRs
Due to change in valuation assumptions	(112,000,000)	(314,000,000)	(10,000,000)	(350,000,000)
Other changes in fair value	(78,000,000)	(71,000,000)	(164,000,000)	(143,000,000)
Balance at end of period	1,989,000,000	1,543,000,000	1,989,000,000	1,543,000,000
MSRs and related characteristics by portfolio
Servicing portfolio	184,858,000,000		184,858,000,000		173,919,000,000
Fair market value	1,989,000,000	1,543,000,000	1,989,000,000	1,543,000,000
Value (bps)	108		108		106
Weighted-average servicing fees (bps)	31		31		32
Multiple (value/servicing fees)	3.48		3.48		3.31
Weighted-average note rate	0.0514		0.0514		0.0532
Age (in years)	2.7		2.7		2.7
Expected prepayment (constant prepayment rate)	14.90%		14.90%		16.10%
Expected life (in years)	5.6		5.6		5.4
Discount rate	10.50%		10.50%		10.60%
Mortgage Servicing Rights (Textuals) [Abstract]
Company serviced residential mortgage loan for others	184,900,000,000		184,900,000,000		173,900,000,000
Gain/Loss on the fair value of mortgage servicing rights and fair value changes of derivatives used to offset MSR	82,000,000	55,000,000	144,000,000	97,000,000
Loan servicing fees	160,000,000	143,000,000	317,000,000	285,000,000
25 bps [Member] | Up Scenario [Member]
Sensitivity to the changes in interest rates of the fair value of the MSRs portfolio and the related derivative instruments
Net fair value	6,000,000		6,000,000		5,000,000
25 bps [Member] | Down Scenario [Member]
Sensitivity to the changes in interest rates of the fair value of the MSRs portfolio and the related derivative instruments
Net fair value	3,000,000		3,000,000		(5,000,000)
50 bps [Member] | Up Scenario [Member]
Sensitivity to the changes in interest rates of the fair value of the MSRs portfolio and the related derivative instruments
Net fair value	4,000,000		4,000,000		1,000,000
50 bps [Member] | Down Scenario [Member]
Sensitivity to the changes in interest rates of the fair value of the MSRs portfolio and the related derivative instruments
Net fair value	7,000,000		7,000,000		6,000,000
MRBP [Member]
Changes in fair value of capitalized MSRs
Balance at beginning of period					166,000,000
Changes in fair value of MSRs
Balance at end of period	168,000,000		168,000,000		166,000,000
MSRs and related characteristics by portfolio
Servicing portfolio	12,927,000,000		12,927,000,000		12,646,000,000
Fair market value	168,000,000		168,000,000		166,000,000
Value (bps)	130		130		131
Weighted-average servicing fees (bps)	40		40		40
Multiple (value/servicing fees)	325		325		3.28
Weighted-average note rate	0.0563		0.0563		0.0575
Age (in years)	4.2		4.2		4.1
Expected prepayment (constant prepayment rate)	12.20%		12.20%		12.30%
Expected life (in years)	6.7		6.7		6.7
Discount rate	11.90%		11.90%		11.90%
Government [Member]
Changes in fair value of capitalized MSRs
Balance at beginning of period					342,000,000
Changes in fair value of MSRs
Balance at end of period	387,000,000		387,000,000		342,000,000
MSRs and related characteristics by portfolio
Servicing portfolio	31,450,000,000		31,450,000,000		28,880,000,000
Fair market value	387,000,000		387,000,000		342,000,000
Value (bps)	123		123		118
Weighted-average servicing fees (bps)	36		36		38
Multiple (value/servicing fees)	3.42		3.42		3.11
Weighted-average note rate	0.0520		0.0520		0.0535
Age (in years)	2.3		2.3		2.2
Expected prepayment (constant prepayment rate)	15.30%		15.30%		17.20%
Expected life (in years)	5.6		5.6		5.1
Discount rate	11.30%		11.30%		11.40%
Conventional Loan [Member]
Changes in fair value of capitalized MSRs
Balance at beginning of period					1,329,000,000
Changes in fair value of MSRs
Balance at end of period	1,434,000,000		1,434,000,000		1,329,000,000
MSRs and related characteristics by portfolio
Servicing portfolio	140,481,000,000		140,481,000,000		132,393,000,000
Fair market value	1,434,000,000		1,434,000,000		1,329,000,000
Value (bps)	102		102		100
Weighted-average servicing fees (bps)	29		29		30
Multiple (value/servicing fees)	$ 3.52		$ 3.52		$ 3.33
Weighted-average note rate	0.0508		0.0508		0.0527
Age (in years)	2.6		2.6		2.7
Expected prepayment (constant prepayment rate)	15.00%		15.00%		16.20%
Expected life (in years)	5.5		5.5		5.3
Discount rate	10.20%		10.20%		10.30%