Loans Held for Sale, Loan Servicing and Mortgage Origination (Detail) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2012	Sep. 30, 2011	Sep. 30, 2010
Servicing Asset	$ 1.4	$ 1,900,000,000	$ 1,400,000,000
Servicing Fees, Net	933,000	4,300,000	3,500,000	3,200,000
Loans Held-for-sale, Mortgages	48,300,000	55,200,000	94,900,000
Residential Loans [Member]
Loans Held-for-sale, Mortgages			40,800,000
Loan Sale Pool [Member]
Loans Held-for-sale, Mortgages			$ 54,100,000