PENSION AND POSTRETIREMENT BENEFIT PLANS PENSION AND POSTRETIREMENT BENEFIT PLANS (Defined Benefit Pension Plans) (Details) $ in Billions	12 Months Ended
	Dec. 31, 2019 USD ($)
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Document Period End Date	Dec. 31, 2019
Bristol-Myers Squibb Retirement Income Plan [Member]
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Payment for Pension Benefits	$ 1.3
Defined Benefit Plan, Benefit Obligation	2.6
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	$ 1.5