 | us-gaap:InterestIncomeSecuritiesUSTreasury | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncomeInterestBasedRevenue |
 | us-gaap:InterestIncomeSecuritiesOtherUSGovernment | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncomeInterestBasedRevenue |
 | us-gaap:InterestIncomeSecuritiesUSTreasuryAndOtherUSGovernment | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncomeInterestBasedRevenue |
 | us-gaap:InterestIncomeSecuritiesUSTreasury | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeInterestBasedRevenueStatementTable |
 | us-gaap:InterestIncomeSecuritiesOtherUSGovernment | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeInterestBasedRevenueStatementTable |
 | us-gaap:InterestIncomeSecuritiesUSTreasuryAndOtherUSGovernment | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeInterestBasedRevenueStatementTable |
 | us-gaap:InterestIncomeSecuritiesUSTreasury | parent-child | http://fasb.org/us-gaap/role/disclosure/FinancialServicesBankingAndThriftInterest |
 | us-gaap:InterestIncomeSecuritiesOtherUSGovernment | parent-child | http://fasb.org/us-gaap/role/disclosure/FinancialServicesBankingAndThriftInterest |
 | us-gaap:InterestIncomeSecuritiesUSTreasuryAndOtherUSGovernment | parent-child | http://fasb.org/us-gaap/role/disclosure/FinancialServicesBankingAndThriftInterest |