RETIREMENT BENEFIT PLANS - Defined contribution and defined benefit pension plans and other post employment defined benefit plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Defined contribution expense	$ 38	$ 37	$ 35
Defined benefit pension expense	15	45	8
Other postretirement employee benefit (income) expense	(1)
Total	$ 52	$ 82	$ 43