Mortgage Banking Activities Mortgage Banking Activities, Loans Serviced for Others (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others, Current	$ 15,163,635
Loans Serviced For Others, 30 To 59 Days Past Due	200,905
Loans Serviced For Others, 60 To 89 Days Past Due	65,495
Loans Serviced For Others, Greater Than 90 Days or More Past Due	69,618
Loans Serviced For Others	15,499,653
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others, Current	4,952,266
Loans Serviced For Others, 30 To 59 Days Past Due	37,051
Loans Serviced For Others, 60 To 89 Days Past Due	12,343
Loans Serviced For Others, Greater Than 90 Days or More Past Due	31,874
Loans Serviced For Others	5,033,534
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others, Current	4,957,520
Loans Serviced For Others, 30 To 59 Days Past Due	29,596
Loans Serviced For Others, 60 To 89 Days Past Due	8,963
Loans Serviced For Others, Greater Than 90 Days or More Past Due	18,070
Loans Serviced For Others	5,014,149
Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others, Current	4,748,226
Loans Serviced For Others, 30 To 59 Days Past Due	128,785
Loans Serviced For Others, 60 To 89 Days Past Due	41,634
Loans Serviced For Others, Greater Than 90 Days or More Past Due	14,096
Loans Serviced For Others	4,932,741
Other Investor Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others, Current	505,623
Loans Serviced For Others, 30 To 59 Days Past Due	5,473
Loans Serviced For Others, 60 To 89 Days Past Due	2,555
Loans Serviced For Others, Greater Than 90 Days or More Past Due	5,578
Loans Serviced For Others	$ 519,229