CONCENTRATIONS OF CREDIT RISK (Details) - Total investments - Geographic - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
U.S.
Concentration Risk [Line Items]
Credit exposure from investment securities, loans and trading assets	$ 250.9	$ 250.0
GERMANY
Concentration Risk [Line Items]
Credit exposure from investment securities, loans and trading assets	29.8	45.6
JAPAN
Concentration Risk [Line Items]
Credit exposure from investment securities, loans and trading assets	33.3	28.8
State and Municipalities
Concentration Risk [Line Items]
Credit exposure from investment securities, loans and trading assets	$ 23.8	$ 27.9