XML 65 R54.htm IDEA: XBRL DOCUMENT v3.4.0.3
Borrowings - Narrative (Details) - USD ($)
Mar. 31, 2016
Dec. 31, 2015
Debt Instrument [Line Items]    
Percent of assets 25.00%  
Maximum borrowing capacity $ 2,390,000,000 $ 2,360,000,000
Percent outstanding advances 100.00%  
Borrowings $ 530,495,000 $ 530,591,000
Weighted average interest rate 1.15% 1.15%
Interest rate, range minimum 0.44%  
Interest rate, range maximum 2.02%  
Unused funds $ 1,860,000,000  
Percent of qualifying assets 95.00%  
Mortgage Loans on Real Estate    
Debt Instrument [Line Items]    
Pledged as collateral $ 3,170,000,000 $ 3,130,000,000
Securities Investment    
Debt Instrument [Line Items]    
Asset balance used to determine maximum borrowing capacity from federal reserve bank 1,000,000  
Amount outstanding 0 0
Qualifying Loans    
Debt Instrument [Line Items]    
Asset balance used to determine maximum borrowing capacity from federal reserve bank 742,900,000  
Putable    
Debt Instrument [Line Items]    
Borrowings $ 20,500,000 $ 20,600,000