Quarterly report pursuant to Section 13 or 15(d)

Federal Home Loan Bank Advances (Details)

v2.4.1.9
Federal Home Loan Bank Advances (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]    
Federal Home Loan Bank advances $ 2,625,000us-gaap_AdvancesFromFederalHomeLoanBanks $ 2,500,000us-gaap_AdvancesFromFederalHomeLoanBanks
Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds 1,375,000us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresAmountOfAvailableUnusedFunds  
Federal Home Loan Bank stock 110,250us-gaap_FederalHomeLoanBankStock 100,010us-gaap_FederalHomeLoanBankStock
Federal Home Loan Bank of Des Moines [Member]    
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]    
Federal Home Loan Bank advances 2,625,000us-gaap_AdvancesFromFederalHomeLoanBanks
/ us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAxis
= us-gaap_FederalHomeLoanBankOfDesMoinesMember
2,500,000us-gaap_AdvancesFromFederalHomeLoanBanks
/ us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAxis
= us-gaap_FederalHomeLoanBankOfDesMoinesMember
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Weighted Average Interest Rate 0.40%us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresWeightedAverageInterestRate
/ us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAxis
= us-gaap_FederalHomeLoanBankOfDesMoinesMember
0.30%us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresWeightedAverageInterestRate
/ us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAxis
= us-gaap_FederalHomeLoanBankOfDesMoinesMember
Federal Home Loan Bank stock $ 110,250us-gaap_FederalHomeLoanBankStock
/ us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAxis
= us-gaap_FederalHomeLoanBankOfDesMoinesMember
$ 103,010us-gaap_FederalHomeLoanBankStock
/ us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAxis
= us-gaap_FederalHomeLoanBankOfDesMoinesMember