ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Summary of Changes in AOCI by Component (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period (in usd)	$ 5,895	$ 9,121
Other comprehensive income (loss) before reclassifications	99	(13)
Amounts reclassified from AOCI	(5)	6
Net other comprehensive income (loss)	94	(7)
Balance, end of period (in usd)	5,941	9,119
CTA
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period (in usd)	(3,386)	(2,907)
Other comprehensive income (loss) before reclassifications	102	(15)
Amounts reclassified from AOCI	0	0
Net other comprehensive income (loss)	102	(15)
Balance, end of period (in usd)	(3,284)	(2,922)
Pension and OPEB plans
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period (in usd)	(331)	(347)
Other comprehensive income (loss) before reclassifications	(3)	2
Amounts reclassified from AOCI	(3)	7
Net other comprehensive income (loss)	(6)	9
Balance, end of period (in usd)	(337)	(338)
Hedging activities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period (in usd)	(119)	(126)
Other comprehensive income (loss) before reclassifications	0	(1)
Amounts reclassified from AOCI	(2)	(1)
Net other comprehensive income (loss)	(2)	(2)
Balance, end of period (in usd)	(121)	(128)
Available-for-sale debt securities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period (in usd)	3	0
Other comprehensive income (loss) before reclassifications	0	1
Amounts reclassified from AOCI	0	0
Net other comprehensive income (loss)	0	1
Balance, end of period (in usd)	3	1
Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period (in usd)	(3,833)	(3,380)
Balance, end of period (in usd)	$ (3,739)	$ (3,387)