Mortgage Banking Activities Mortgage Banking Activities, Loans Serviced for Others (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others current	$ 11,641,774
Loans Serviced For Others30 To59 Days Past Due	200,258
Loans Serviced For Others60 To89 Days Past Due	55,910
Loans Serviced For Otherst Equal To Greater Than90 Days Past Due	83,682
Loans Serviced For Others	11,981,624
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others current	4,668,434
Loans Serviced For Others30 To59 Days Past Due	41,298
Loans Serviced For Others60 To89 Days Past Due	12,981
Loans Serviced For Otherst Equal To Greater Than90 Days Past Due	39,509
Loans Serviced For Others	4,762,222
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others current	2,622,914
Loans Serviced For Others30 To59 Days Past Due	18,803
Loans Serviced For Others60 To89 Days Past Due	5,393
Loans Serviced For Otherst Equal To Greater Than90 Days Past Due	18,991
Loans Serviced For Others	2,666,101
Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others current	3,903,284
Loans Serviced For Others30 To59 Days Past Due	130,869
Loans Serviced For Others60 To89 Days Past Due	35,408
Loans Serviced For Otherst Equal To Greater Than90 Days Past Due	18,958
Loans Serviced For Others	4,088,519
Other Investor Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans Serviced For Others current	447,142
Loans Serviced For Others30 To59 Days Past Due	9,288
Loans Serviced For Others60 To89 Days Past Due	2,128
Loans Serviced For Otherst Equal To Greater Than90 Days Past Due	6,224
Loans Serviced For Others	$ 464,782