Outstanding Balance of Loans Sold by Vintage and Type of Buyer (Detail) (USD $) In Billions	Sep. 30, 2011
Outstanding balance remaining of loans sold to outside investors	$ 119.2
Vintage 2005
Outstanding balance remaining of loans sold to outside investors	9.6
Vintage 2005 | Non-Agency Securities
Outstanding balance remaining of loans sold to outside investors	4.1
Vintage 2005 | Agency Securities
Outstanding balance remaining of loans sold to outside investors	4.8	[1]
Vintage 2005 | Ginnie Mae
Outstanding balance remaining of loans sold to outside investors	0.7	[1]
Vintage 2006
Outstanding balance remaining of loans sold to outside investors	12.2
Vintage 2006 | Non-Agency Securities
Outstanding balance remaining of loans sold to outside investors	6.0
Vintage 2006 | Agency Securities
Outstanding balance remaining of loans sold to outside investors	5.7	[1]
Vintage 2006 | Ginnie Mae
Outstanding balance remaining of loans sold to outside investors	0.5	[1]
Vintage 2007
Outstanding balance remaining of loans sold to outside investors	16.3
Vintage 2007 | Non-Agency Securities
Outstanding balance remaining of loans sold to outside investors	4.8
Vintage 2007 | Agency Securities
Outstanding balance remaining of loans sold to outside investors	11.0	[1]
Vintage 2007 | Ginnie Mae
Outstanding balance remaining of loans sold to outside investors	0.5	[1]
Vintage 2008
Outstanding balance remaining of loans sold to outside investors	14.6
Vintage 2008 | Non-Agency Securities
Outstanding balance remaining of loans sold to outside investors	0
Vintage 2008 | Agency Securities
Outstanding balance remaining of loans sold to outside investors	12.1	[1]
Vintage 2008 | Ginnie Mae
Outstanding balance remaining of loans sold to outside investors	2.5	[1]
Vintage 2009
Outstanding balance remaining of loans sold to outside investors	33.1
Vintage 2009 | Non-Agency Securities
Outstanding balance remaining of loans sold to outside investors	0
Vintage 2009 | Agency Securities
Outstanding balance remaining of loans sold to outside investors	27.3	[1]
Vintage 2009 | Ginnie Mae
Outstanding balance remaining of loans sold to outside investors	5.8	[1]
Vintage 2010
Outstanding balance remaining of loans sold to outside investors	19.6
Vintage 2010 | Non-Agency Securities
Outstanding balance remaining of loans sold to outside investors	0
Vintage 2010 | Agency Securities
Outstanding balance remaining of loans sold to outside investors	15.4	[1]
Vintage 2010 | Ginnie Mae
Outstanding balance remaining of loans sold to outside investors	4.2	[1]
Fiscal Year 2011
Outstanding balance remaining of loans sold to outside investors	13.8
Fiscal Year 2011 | Non-Agency Securities
Outstanding balance remaining of loans sold to outside investors	0
Fiscal Year 2011 | Agency Securities
Outstanding balance remaining of loans sold to outside investors	11.5	[1]
Fiscal Year 2011 | Ginnie Mae
Outstanding balance remaining of loans sold to outside investors	2.3	[1]
Agency Securities
Outstanding balance remaining of loans sold to outside investors	87.8	[1]
Ginnie Mae
Outstanding balance remaining of loans sold to outside investors	16.5	[1]
Non-Agency Securities
Outstanding balance remaining of loans sold to outside investors	$ 14.9

[1] Balances based on loans serviced by the Company.