INVESTMENTS (REPURCHASE AGREEMENTS ACCCOUNTED FOR AS BORROWINGS) (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Repurchase agreements accounted for as secured borrowings [Line Items]
Repurchase agreements	$ 1,791	$ 1,992
Reverse repurchase agreements	0
Net amounts presented in the balance sheets		(35)
Maturity Overnight
Repurchase agreements accounted for as secured borrowings [Line Items]
Repurchase agreements	0	0
Reverse repurchase agreements	0
Maturity up to 30 days
Repurchase agreements accounted for as secured borrowings [Line Items]
Repurchase agreements	1,791	1,992
Reverse repurchase agreements	0
Maturity 30 to 90 Days
Repurchase agreements accounted for as secured borrowings [Line Items]
Repurchase agreements	0	0
Reverse repurchase agreements	0
Maturity over 90 days
Repurchase agreements accounted for as secured borrowings [Line Items]
Repurchase agreements	0	0
Reverse repurchase agreements	0
U.S. Treasury, government and agency
Repurchase agreements accounted for as secured borrowings [Line Items]
Repurchase agreements	1,791	1,992
U.S. Treasury, government and agency | Maturity Overnight
Repurchase agreements accounted for as secured borrowings [Line Items]
Repurchase agreements	0	0
U.S. Treasury, government and agency | Maturity up to 30 days
Repurchase agreements accounted for as secured borrowings [Line Items]
Repurchase agreements	1,791	1,992
U.S. Treasury, government and agency | Maturity 30 to 90 Days
Repurchase agreements accounted for as secured borrowings [Line Items]
Repurchase agreements	0	0
U.S. Treasury, government and agency | Maturity over 90 days
Repurchase agreements accounted for as secured borrowings [Line Items]
Repurchase agreements	0	0
Public corporate
Repurchase agreements accounted for as secured borrowings [Line Items]
Reverse repurchase agreements	0
Public corporate | Maturity Overnight
Repurchase agreements accounted for as secured borrowings [Line Items]
Reverse repurchase agreements	0
Public corporate | Maturity up to 30 days
Repurchase agreements accounted for as secured borrowings [Line Items]
Reverse repurchase agreements	0
Public corporate | Maturity 30 to 90 Days
Repurchase agreements accounted for as secured borrowings [Line Items]
Reverse repurchase agreements	0
Public corporate | Maturity over 90 days
Repurchase agreements accounted for as secured borrowings [Line Items]
Reverse repurchase agreements	0
Investment Management
Repurchase agreements accounted for as secured borrowings [Line Items]
Net amounts presented in the balance sheets	22	13
Securities Loaned		0
Securities Borrowed | Investment Management
Repurchase agreements accounted for as secured borrowings [Line Items]
Net amounts presented in the balance sheets	$ 55	$ 83