Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total	Common stock	Common stock in treasury	Additional contributed capital	Retained earnings	Accumulated other comprehensive income (loss)	Total Baxter stockholders' equity	Noncontrolling interests
Beginning of year (in shares) at Dec. 31, 2016		683,000,000
Beginning of year at Dec. 31, 2016	$ 8,221	$ 683	$ (7,995)	$ 5,958	$ 13,846	$ (4,261)	$ 8,231	$ (10)
Beginning of year (in shares) at Dec. 31, 2016			144,000,000
Net income attributable to Baxter stockholders	602				602		602
Net income	602
Other comprehensive income (loss)	$ 722					722	722
Purchases of common stock (in shares)	9,200,000		9,000,000
Purchases of common stock	$ (564)		$ (564)				(564)
Stock issued under employee benefit plans and other (in shares)			11,000,000
Stock issued under employee benefit plans and other	426		$ 578	(18)	(134)		426
Dividends declared on common stock	(334)				(334)		(334)
Distribution	34				34		34
Changes in noncontrolling interests	2							2
End of year at Dec. 31, 2017	9,109	$ 683	$ (7,981)	5,940	14,014	(3,539)	9,117	(8)
End of year (in shares) at Dec. 31, 2017		683,000,000
End of year (in shares) at Dec. 31, 2017			142,000,000
Net income	602
Adoption of new accounting standards	(23)				(20)	(3)	(23)
Net income attributable to Baxter stockholders	382				382		382
Net income	382
Other comprehensive income (loss)	115					115	115
Purchases of common stock (in shares)			8,000,000
Purchases of common stock	(522)		$ (522)				(522)
Stock issued under employee benefit plans and other (in shares)			(3,000,000)
Stock issued under employee benefit plans and other	85		$ 149	(28)	(36)		85
Dividends declared on common stock	(86)				(86)		(86)
Changes in noncontrolling interests	2							2
End of year at Mar. 31, 2018	$ 9,062	$ 683	$ (8,354)	5,912	14,254	(3,427)	9,068	(6)
End of year (in shares) at Mar. 31, 2018	683,494,944	683,000,000
End of year (in shares) at Mar. 31, 2018	146,993,164		147,000,000
Net income	$ 382
Beginning of year (in shares) at Dec. 31, 2017		683,000,000
Beginning of year at Dec. 31, 2017	9,109	$ 683	$ (7,981)	5,940	14,014	(3,539)	9,117	(8)
Beginning of year (in shares) at Dec. 31, 2017			142,000,000
Adoption of new accounting standards	(23)				(20)	(3)	(23)
Net income attributable to Baxter stockholders	723				723		723
Net income	723
Other comprehensive income (loss)	(214)					(214)	(214)
Purchases of common stock (in shares)			11,000,000
Purchases of common stock	(781)		$ (781)				(781)
Stock issued under employee benefit plans and other (in shares)			(5,000,000)
Stock issued under employee benefit plans and other	208		$ 277	(24)	(45)		208
Dividends declared on common stock	(188)				(188)		(188)
Changes in noncontrolling interests	(4)							(4)
End of year at Jun. 30, 2018	$ 8,830	$ 683	$ (8,485)	5,916	14,484	(3,756)	8,842	(12)
End of year (in shares) at Jun. 30, 2018	683,494,944	683,000,000
End of year (in shares) at Jun. 30, 2018	148,485,202		148,000,000
Net income	$ 723
Beginning of year (in shares) at Dec. 31, 2017		683,000,000
Beginning of year at Dec. 31, 2017	9,109	$ 683	$ (7,981)	5,940	14,014	(3,539)	9,117	(8)
Beginning of year (in shares) at Dec. 31, 2017			142,000,000
Adoption of new accounting standards	(25)				(22)	(3)	(25)
Net income attributable to Baxter stockholders	1,546				1,546		1,546
Net income	1,546
Other comprehensive income (loss)	$ (281)					(281)	(281)
Purchases of common stock (in shares)	35,800,000		36,000,000
Purchases of common stock	$ (2,475)		$ (2,415)	(60)			(2,475)
Stock issued under employee benefit plans and other (in shares)			8,000,000
Stock issued under employee benefit plans and other	354		$ 407	18	(71)		354
Dividends declared on common stock	(392)				(392)		(392)
Changes in noncontrolling interests	30							30
End of year at Dec. 31, 2018	$ 7,866	$ 683	$ (9,989)	5,898	15,075	(3,823)	7,844	22
End of year (in shares) at Dec. 31, 2018	683,494,944	683,000,000
End of year (in shares) at Dec. 31, 2018	170,495,859		170,000,000
Net income	$ 1,546
Beginning of year (in shares) at Mar. 31, 2018	683,494,944	683,000,000
Beginning of year at Mar. 31, 2018	$ 9,062	$ 683	$ (8,354)	5,912	14,254	(3,427)	9,068	(6)
Beginning of year (in shares) at Mar. 31, 2018	146,993,164		147,000,000
Net income attributable to Baxter stockholders	$ 341				341		341
Net income	341
Other comprehensive income (loss)	(329)					(329)	(329)
Purchases of common stock (in shares)			3,000,000
Purchases of common stock	(259)		$ (259)				(259)
Stock issued under employee benefit plans and other (in shares)			(2,000,000)
Stock issued under employee benefit plans and other	123		$ 128	4	(9)		123
Dividends declared on common stock	(102)				(102)		(102)
Changes in noncontrolling interests	(6)							(6)
End of year at Jun. 30, 2018	$ 8,830	$ 683	$ (8,485)	5,916	14,484	(3,756)	8,842	(12)
End of year (in shares) at Jun. 30, 2018	683,494,944	683,000,000
End of year (in shares) at Jun. 30, 2018	148,485,202		148,000,000
Net income	$ 341
Net income attributable to Baxter stockholders	518
End of year at Sep. 30, 2018	$ 9,090
End of year (in shares) at Sep. 30, 2018	683,494,944
End of year (in shares) at Sep. 30, 2018	150,213,621
Net income attributable to Baxter stockholders	$ 305
Net income	305
End of year at Dec. 31, 2018	$ 7,866	$ 683	$ (9,989)	5,898	15,075	(3,823)	7,844	22
End of year (in shares) at Dec. 31, 2018	683,494,944	683,000,000
End of year (in shares) at Dec. 31, 2018	170,495,859		170,000,000
Net income	$ 305
Adoption of new accounting standards	0				161	(161)
Net income attributable to Baxter stockholders	342				342		342
Net income	342
Other comprehensive income (loss)	(98)					(98)	(98)
Purchases of common stock (in shares)			8,000,000
Purchases of common stock	(586)		$ (586)				(586)
Stock issued under employee benefit plans and other (in shares)			(5,000,000)
Stock issued under employee benefit plans and other	166		$ 291	(59)	(66)		166
Dividends declared on common stock	(98)				(98)		(98)
Changes in noncontrolling interests	1							1
End of year at Mar. 31, 2019	$ 7,593	$ 683	$ (10,284)	5,839	15,414	(4,082)	7,570	23
End of year (in shares) at Mar. 31, 2019	683,494,944	683,000,000
End of year (in shares) at Mar. 31, 2019	173,447,198		173,000,000
Net income	$ 342
Beginning of year (in shares) at Dec. 31, 2018	683,494,944	683,000,000
Beginning of year at Dec. 31, 2018	$ 7,866	$ 683	$ (9,989)	5,898	15,075	(3,823)	7,844	22
Beginning of year (in shares) at Dec. 31, 2018	170,495,859		170,000,000
Adoption of new accounting standards	$ 0				161	(161)
Net income attributable to Baxter stockholders	655				655		655
Net income	655
Other comprehensive income (loss)	(102)					(102)	(102)
Purchases of common stock (in shares)			10,000,000
Purchases of common stock	(697)		$ (743)	46			(697)
Stock issued under employee benefit plans and other (in shares)			(7,000,000)
Stock issued under employee benefit plans and other	289		$ 410	(38)	(83)		289
Dividends declared on common stock	(210)				(210)		(210)
Changes in noncontrolling interests	2							2
End of year at Jun. 30, 2019	$ 7,803	$ 683	$ (10,322)	5,906	15,598	(4,086)	7,779	24
End of year (in shares) at Jun. 30, 2019	683,494,944	683,000,000
End of year (in shares) at Jun. 30, 2019	173,275,586		173,000,000
Net income	$ 655
Beginning of year (in shares) at Dec. 31, 2018	683,494,944	683,000,000
Beginning of year at Dec. 31, 2018	$ 7,866	$ 683	$ (9,989)	5,898	15,075	(3,823)	7,844	22
Beginning of year (in shares) at Dec. 31, 2018	170,495,859		170,000,000
Adoption of new accounting standards	$ 0				161	(161)
Net income attributable to Baxter stockholders	1,001				1,001		1,001	10
Net income	1,011
Other comprehensive income (loss)	$ 274					274	274
Purchases of common stock (in shares)	16,500,000		16,000,000
Purchases of common stock	$ (1,247)		$ (1,293)	46			(1,247)
Stock issued under employee benefit plans and other (in shares)			9,000,000
Stock issued under employee benefit plans and other	445		$ 518	11	(84)		445
Dividends declared on common stock	(435)				(435)		(435)
Changes in noncontrolling interests	(2)							(2)
End of year at Dec. 31, 2019	$ 7,912	$ 683	$ (10,764)	5,955	15,718	(3,710)	7,882	30
End of year (in shares) at Dec. 31, 2019	683,494,944	683,000,000
End of year (in shares) at Dec. 31, 2019	177,340,358		177,000,000
Net income	$ 1,011
Beginning of year (in shares) at Mar. 31, 2019	683,494,944	683,000,000
Beginning of year at Mar. 31, 2019	$ 7,593	$ 683	$ (10,284)	5,839	15,414	(4,082)	7,570	23
Beginning of year (in shares) at Mar. 31, 2019	173,447,198		173,000,000
Net income attributable to Baxter stockholders	$ 313				313		313
Net income	313
Other comprehensive income (loss)	(4)					(4)	(4)
Purchases of common stock (in shares)			2,000,000
Purchases of common stock	(111)		$ (157)	46			(111)
Stock issued under employee benefit plans and other (in shares)			(2,000,000)
Stock issued under employee benefit plans and other	123		$ 119	21	(17)		123
Dividends declared on common stock	(112)				(112)		(112)
Changes in noncontrolling interests	1							1
End of year at Jun. 30, 2019	$ 7,803	$ 683	$ (10,322)	$ 5,906	$ 15,598	$ (4,086)	$ 7,779	$ 24
End of year (in shares) at Jun. 30, 2019	683,494,944	683,000,000
End of year (in shares) at Jun. 30, 2019	173,275,586		173,000,000
Net income	$ 313