Annual report pursuant to Section 13 and 15(d)

DERIVATIVE FINANCIAL INSTRUMENTS - Asset and Liability Management Add Info (Details)

v3.8.0.1
DERIVATIVE FINANCIAL INSTRUMENTS - Asset and Liability Management Add Info (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Derivative [Line Items]    
Notional Value $ 8,375 $ 10,800
Average Maturity (years) 2 years 6 months 2 years 4 months
Fair Value $ (99) $ (54)
Weighted-Average Rate Receive 1.56% 1.35%
Weighted-Average Rate Pay 1.44% 0.89%
Asset conversion swaps - Receive Fixed - Generic    
Derivative [Line Items]    
Notional Value $ 0 $ 3,325
Average Maturity (years) 0 years 7 months 6 days
Fair Value $ 0 $ (2)
Weighted-Average Rate Receive 0.00% 1.04%
Weighted-Average Rate Pay 0.00% 0.91%
Liability conversion swaps Receive Fixed Generic    
Derivative [Line Items]    
Notional Value $ 8,375 $ 7,475
Average Maturity (years) 2 years 6 months 3 years 1 month 6 days
Fair Value $ (99) $ (52)
Weighted-Average Rate Receive 1.56% 1.49%
Weighted-Average Rate Pay 1.44% 0.88%