XML 39 R87.htm IDEA: XBRL DOCUMENT v2.4.1.9
BORROWED FUNDS - Narrative (Details) (USD $)
Mar. 31, 2015
Dec. 31, 2014
Debt Instrument [Line Items]    
Short-term borrowed funds $ 11,425,000,000us-gaap_ShortTermBorrowings $ 10,529,000,000us-gaap_ShortTermBorrowings
Federal Home Loan Bank Advances and Letters of Credit [Member] | Secured Debt    
Debt Instrument [Line Items]    
Short-term borrowed funds 11,300,000,000us-gaap_ShortTermBorrowings
/ us-gaap_CreditFacilityAxis
= us-gaap_SecuredDebtMember
/ us-gaap_LongtermDebtTypeAxis
= cfg_FederalHomeLoanBankAdvancesandLettersofCreditMember		 11,300,000,000us-gaap_ShortTermBorrowings
/ us-gaap_CreditFacilityAxis
= us-gaap_SecuredDebtMember
/ us-gaap_LongtermDebtTypeAxis
= cfg_FederalHomeLoanBankAdvancesandLettersofCreditMember
Federal Home Loan advances    
Debt Instrument [Line Items]    
Available borrowing capacity 3,900,000,000us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_FederalHomeLoanBankAdvancesMember		 3,500,000,000us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_FederalHomeLoanBankAdvancesMember
Federal Reserve Bank Advances    
Debt Instrument [Line Items]    
Available borrowing capacity $ 25,900,000,000us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_FederalReserveBankAdvancesMember