Accrued Interest Receivable Schedule of Accounts, Notes, Loans and Financing Receivable (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest Receivable	$ 46,724	$ 50,303
Loans Held-for-sale, Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest Receivable	864	4,136
Loans Held-for-investment, Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest Receivable	4,516	4,506
US Treasury Securities [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest Receivable	777	2,361
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest Receivable	10,160	10,583
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest Receivable	16,784	15,034
Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest Receivable	9,987	10,007
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest Receivable	3,636	3,676
Available-for-sale Securities [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest Receivable	$ 40,567	$ 39,300