Mortgage Banking Activities Mortgage Banking Activities, Loans Serviced for Others (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others current	$ 11,316,487
Loans Serviced For Others30 To59 Days Past Due	247,512
Loans Serviced For Others60 To89 Days Past Due	57,525
Loans Serviced For Otherst Equal To Greater Than90 Days Past Due	134,826
Loans Serviced For Others	11,756,350
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others current	4,783,550
Loans Serviced For Others30 To59 Days Past Due	56,493
Loans Serviced For Others60 To89 Days Past Due	12,786
Loans Serviced For Otherst Equal To Greater Than90 Days Past Due	42,081
Loans Serviced For Others	4,894,910
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others current	2,301,369
Loans Serviced For Others30 To59 Days Past Due	26,034
Loans Serviced For Others60 To89 Days Past Due	6,524
Loans Serviced For Otherst Equal To Greater Than90 Days Past Due	20,044
Loans Serviced For Others	2,353,971
Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others current	3,774,396
Loans Serviced For Others30 To59 Days Past Due	155,146
Loans Serviced For Others60 To89 Days Past Due	35,604
Loans Serviced For Otherst Equal To Greater Than90 Days Past Due	19,349
Loans Serviced For Others	3,984,495
Other Investor Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others current	457,172
Loans Serviced For Others30 To59 Days Past Due	9,839
Loans Serviced For Others60 To89 Days Past Due	2,611
Loans Serviced For Otherst Equal To Greater Than90 Days Past Due	53,352
Loans Serviced For Others	$ 522,974