Quarterly report pursuant to Section 13 or 15(d)

Accrued Interest Receivable (Details)

v3.8.0.1
Accrued Interest Receivable (Details) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Accrued interest receivable $ 67,370 $ 68,309
Loans Held-for-Sale, Residential Mortgages [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Accrued interest receivable 151 162
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Accrued interest receivable 46,490 46,517
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Accrued interest receivable 11,401 12,255
Government National Mortgage Association Certificates and Obligations (GNMA) [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Accrued interest receivable 4,687 4,635
Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Accrued interest receivable 4,641 4,740
Available-for-sale Securities [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Accrued interest receivable $ 67,219 $ 68,147