ACCUMULATED OTHER COMPREHENSIVE INCOME - Summary of Amounts Reclassification from AOCI to Net Income (Detail) - USD ($) $ in Millions	3 Months Ended								6 Months Ended		12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other (income) expense, net			$ (4)	$ 21	$ 33		$ 38	$ 6	$ 17	$ 44	$ (731)	$ 78	$ (133)
Settlement charge	$ 755										(755)	(1)	(2)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest			326	386	413		404	428	712	832	970	1,617	1,100
Cost of sales			(1,681)	(1,558)	(1,650)		(1,590)	(1,571)	(3,239)	(3,161)	(6,601)	(6,340)	(6,110)
Reclassifications, Income tax expense (benefit)			(13)	(44)	(102)		(63)	(46)	(57)	(109)	41	(65)	(491)
Net income attributable to Baxter stockholders	$ (23)	$ 369	$ 313	$ 342	$ 305	$ 518	$ 341	$ 382	$ 655	$ 723	1,001	1,546	$ 602
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income attributable to Baxter stockholders											(589)	(66)
Amortization of pension and other employee benefits items | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other (income) expense, net											(31)	(69)
Settlement charge											(755)	(1)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest											(786)	(70)
Reclassifications, Income tax expense (benefit)											194	14
Net income attributable to Baxter stockholders											(592)	(56)
Hedging activities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales											(4)
Reclassifications, Income tax expense (benefit)											(1)
Net income attributable to Baxter stockholders											$ 3
Gains (losses) on hedging activities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales												12
Reclassifications, Income tax expense (benefit)												2
Net income attributable to Baxter stockholders												$ (10)