QUARTERLY FINANCIAL DATA (UNAUDITED) - Cash Flows (Details) - 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
Cash flows from operations
Net income attributable to Baxter stockholders	$ (23)	$ 369	$ 313	$ 342	$ 305	$ 518	$ 341	$ 382	$ 655	$ 723	$ 1,001	$ 1,546	$ 602
Adjustments to reconcile income from continuing operations to net cash from operating activities:
Depreciation and amortization				192				190	385	382	789	771	750
Deferred income taxes				(6)				(38)	(63)	(51)	(310)	(263)	211
Stock compensation				22				20	57	54	122	115	107
Net periodic pension benefit and other postretirement costs				3				10	7	21	22	39	123
Intangible asset impairment				0					31
Other				14				(1)	44	0	115	50	38
Changes in balance sheet items:
Accounts receivable, net				32				76	(60)	43	(65)	(12)	30
Inventories				(82)				(56)	(91)	(134)	4	(197)	76
Accounts payable and accrued liabilities				(335)				(119)	(299)	(124)	(212)	60	11
Other				(48)				(34)	(86)	(82)	(152)	(99)	(227)
Cash flows from operations – continuing operations				134					580		2,110	2,017	1,730
Cash flows from operations - discontinued operations				(6)					(6)		(6)	0	(16)
Cash flows from operations				128				430	574	832	2,104	2,017	1,714
Cash flows from investing activities
Capital expenditures				(193)				(152)	(338)	(303)	(696)	(659)	(616)
Acquisitions and investments, net of cash acquired				(109)				(219)	(111)	(228)	(418)	(268)	(686)
Other investing activities, net				1					1		14	11	10
Cash flows from investing activities				(301)				(371)	(448)	(531)	(1,100)	(916)	(1,292)
Cash flows from financing activities
Issuances of debt				0					1,661		1,661	0	665
Net increases in debt obligations with original maturities of three months or less				795					0
Cash dividends on common stock				(101)				(87)	(198)	(173)	(423)	(376)	(315)
Proceeds from stock issued under employee benefit plans				173				82	262	170			347
Purchases of treasury stock				(597)				(522)	(720)	(781)	(1,270)	(2,452)	(564)
Other financing activities, net				(32)				(18)	(37)	(24)	(48)	(33)	(40)
Cash flows from financing activities				238				(545)	968	(808)	498	(2,603)	93
Effect of foreign exchange rate changes on cash and cash equivalents				(1)				32	2	(38)	(5)	(63)	102
Increase (decrease) in cash and cash equivalents				64				(454)	1,096	(545)	1,497	(1,565)	617
Cash and cash equivalents at beginning of year		2,934	1,902	1,838		2,858	2,949	3,403	1,838	3,403	1,838	3,403	2,786
Cash and cash equivalents at end of year	$ 3,335		2,934	1,902	1,838		2,858	2,949	2,934	2,858	3,335	1,838	3,403
As previously reported
Cash flows from operations
Net income attributable to Baxter stockholders			343	347			343	389	690	732		1,624	717
Adjustments to reconcile income from continuing operations to net cash from operating activities:
Depreciation and amortization				195				192	393	387		785	761
Deferred income taxes				(6)				(33)	(55)	(51)		(267)	211
Stock compensation				22				20	57	54		115	107
Net periodic pension benefit and other postretirement costs				3				10	7	21		39	123
Intangible asset impairment									31
Other				19				2	34	10		43	43
Changes in balance sheet items:
Accounts receivable, net				32				76	(60)	43		(12)	30
Inventories				(82)				(56)	(91)	(134)		(197)	76
Accounts payable and accrued liabilities				(333)				(120)	(303)	(126)		64	5
Other				(49)				(33)	(86)	(84)		(105)	(229)
Cash flows from operations – continuing operations				148					617				1,853
Cash flows from operations - discontinued operations				(6)					(6)				(16)
Cash flows from operations				142				447	611	852		2,096	1,837
Cash flows from investing activities
Capital expenditures				(198)				(155)	(352)	(311)		(681)	(634)
Acquisitions and investments, net of cash acquired				(109)				(219)	(111)	(228)		(268)	(686)
Other investing activities, net				1					1			11	10
Cash flows from investing activities				(306)				(374)	(462)	(539)		(938)	(1,310)
Cash flows from financing activities
Issuances of debt									1,661				633
Net increases in debt obligations with original maturities of three months or less				795
Cash dividends on common stock				(101)				(87)	(198)	(173)		(376)	(315)
Proceeds from stock issued under employee benefit plans				173				82	262	170			347
Purchases of treasury stock				(597)				(522)	(720)	(781)		(2,452)	(564)
Other financing activities, net				(32)				(18)	(37)	(24)		(33)	(40)
Cash flows from financing activities				238				(545)	968	(808)		(2,603)	61
Effect of foreign exchange rate changes on cash and cash equivalents				2				25	(24)	(42)		(117)	5
Increase (decrease) in cash and cash equivalents				76				(447)	1,093	(537)		(1,562)	593
Cash and cash equivalents at beginning of year		2,925	1,908	1,832		2,857	2,947	3,394	1,832	3,394	1,832	3,394	2,801
Cash and cash equivalents at end of year			2,925	1,908	1,832		2,857	2,947	2,925	2,857		1,832	3,394
Restatement impacts
Cash flows from operations
Net income attributable to Baxter stockholders			(30)	(5)			(2)	(7)	(35)	(9)		(78)	(115)
Adjustments to reconcile income from continuing operations to net cash from operating activities:
Depreciation and amortization				(3)				(2)	(8)	(5)		(14)	(11)
Deferred income taxes				0				(5)	(8)	0		4	0
Stock compensation				0				0	0	0		0	0
Net periodic pension benefit and other postretirement costs				0				0	0	0		0	0
Intangible asset impairment									0
Other				(5)				(3)	10	(10)		7	(5)
Changes in balance sheet items:
Accounts receivable, net				0				0	0	0		0	0
Inventories				0				0	0	0		0	0
Accounts payable and accrued liabilities				(2)				1	4	2		(4)	6
Other				1				(1)	0	2		6	2
Cash flows from operations – continuing operations				(14)					(37)				(123)
Cash flows from operations - discontinued operations				0					0				0
Cash flows from operations				(14)				(17)	(37)	(20)		(79)	(123)
Cash flows from investing activities
Capital expenditures				5				3	14	8		22	18
Acquisitions and investments, net of cash acquired				0				0	0	0		0	0
Other investing activities, net				0					0			0	0
Cash flows from investing activities				5				3	14	8		22	18
Cash flows from financing activities
Issuances of debt									0				32
Net increases in debt obligations with original maturities of three months or less				0
Cash dividends on common stock				0				0	0	0		0	0
Proceeds from stock issued under employee benefit plans				0				0	0	0			0
Purchases of treasury stock				0				0	0	0		0	0
Other financing activities, net				0				0	0	0		0	0
Cash flows from financing activities				0				0	0	0		0	32
Effect of foreign exchange rate changes on cash and cash equivalents				(3)				7	26	4		54	97
Increase (decrease) in cash and cash equivalents				(12)				(7)	3	(8)		(3)	24
Cash and cash equivalents at beginning of year		$ 9	(6)	6		$ 1	2	9	6	9	$ 6	9	(15)
Cash and cash equivalents at end of year			$ 9	(6)	$ 6		$ 1	2	9	1		6	9
Restatement impacts | Foreign Currency Denominated Monetary Assets and Liabilities
Cash flows from financing activities
Issuances of debt													32
Effect of foreign exchange rate changes on cash and cash equivalents				$ 4				$ 11	$ 33	$ 2		$ 64	$ 99