INCOME TAXES - Deferred Tax Assets by Jurisdiction (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred Tax Assets by Jurisdiction
Net deferred tax assets	$ 24,840	$ 23,094
U.S. federal
Deferred Tax Assets by Jurisdiction
Net operating losses (NOLs)	3,000	2,800
Foreign tax credits (FTCs)	4,400	6,300
General business credits (GBCs)	3,600	2,500
Future tax deductions and credits	7,900	6,200
Net deferred tax assets	18,900	17,800
Deferred tax liability to be reversed in carry forward period	3,700
State and Local
Deferred Tax Assets by Jurisdiction
Future tax deductions and credits	1,700	1,300
Net deferred tax assets	3,300	3,200
New York
Deferred Tax Assets by Jurisdiction
Net operating losses (NOLs)	1,500	1,700
Other state
Deferred Tax Assets by Jurisdiction
Net operating losses (NOLs)	100	200
Foreign
Deferred Tax Assets by Jurisdiction
Net operating losses (NOLs)	600	500
Future tax deductions and credits	2,000	1,600
Net deferred tax assets	$ 2,600	$ 2,100