RETIREMENT BENEFIT PLANS - Funded status of plans with ABO in excess of plan assets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ (2,401)	$ (633)
Plan assets	1,924	425
Funded status of plan	(477)	(208)
United States
Defined Benefit Plan Disclosure [Line Items]
Funded status of plan	(15)	(22)
United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Funded status of plan	(202)	0
Germany
Defined Benefit Plan Disclosure [Line Items]
Funded status of plan	(139)	(107)
Other foreign
Defined Benefit Plan Disclosure [Line Items]
Funded status of plan	$ (121)	$ (79)