Quarterly report pursuant to Section 13 or 15(d)

DERIVATIVE FINANCIAL INSTRUMENTS - Asset and Liability Management (Details)

v3.19.3
DERIVATIVE FINANCIAL INSTRUMENTS - Asset and Liability Management (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2019
Sep. 30, 2019
Dec. 31, 2018
Credit Derivatives [Line Items]      
Document Period End Date   Sep. 30, 2019  
Notional Disclosures [Abstract]      
Derivative, Notional Amount $ 24,702 $ 24,702 $ 4,877
Fair Value Hedging      
Notional Disclosures [Abstract]      
Derivative, Notional Amount 7,540 7,540 4,865
Cash Flow Hedging      
Notional Disclosures [Abstract]      
Derivative, Notional Amount 17,162 17,162 12
Loans Payable [Member]      
Notional Disclosures [Abstract]      
Derivative, Notional Amount 17,150 17,150  
Loans Payable [Member] | Fair Value Hedging      
Notional Disclosures [Abstract]      
Derivative, Notional Amount 0 0  
Loans Payable [Member] | Cash Flow Hedging      
Notional Disclosures [Abstract]      
Derivative, Notional Amount 17,150 17,150  
Securities Investment [Member]      
Notional Disclosures [Abstract]      
Derivative, Notional Amount 12 12 12
Securities Investment [Member] | Fair Value Hedging      
Notional Disclosures [Abstract]      
Derivative, Notional Amount 0 0 0
Securities Investment [Member] | Cash Flow Hedging      
Notional Disclosures [Abstract]      
Derivative, Notional Amount 12 12 12
Other long-term debt      
Notional Disclosures [Abstract]      
Derivative, Notional Amount 7,540 7,540 4,865
Other long-term debt | Fair Value Hedging      
Notional Disclosures [Abstract]      
Derivative, Notional Amount 7,540 7,540 4,865
Other long-term debt | Cash Flow Hedging      
Notional Disclosures [Abstract]      
Derivative, Notional Amount $ 0 $ 0 $ 0
Asset conversion swaps Receive Fixed Generic      
Credit Derivatives [Line Items]      
Derivative, Average Remaining Maturity 3 years 6 months 3 years 6 months 1 year 2 months 12 days
Notional Disclosures [Abstract]      
Derivative, Notional Amount $ 8,287 $ 8,287 $ 12
Liability conversion swaps Receive Fixed Generic      
Credit Derivatives [Line Items]      
Derivative, Average Remaining Maturity   2 years 6 months 2 years 7 months 6 days
Notional Disclosures [Abstract]      
Derivative, Notional Amount 7,540 $ 7,540 $ 4,865
Interest Rate Floor [Member]      
Credit Derivatives [Line Items]      
Derivative, Average Remaining Maturity   1 year 7 months 6 days  
Notional Disclosures [Abstract]      
Derivative, Notional Amount 8,875 $ 8,875  
Interest Rate Floor [Member] | Assigned [Member]      
Credit Derivatives [Line Items]      
Derivative, Average Remaining Maturity   1 year 7 months 6 days  
Notional Disclosures [Abstract]      
Derivative, Notional Amount $ 8,875 $ 8,875  
Interest Rate Floor [Member] | Unassigned [Member]      
Credit Derivatives [Line Items]      
Derivative, Average Remaining Maturity   0 years