Accumulated Other Comprehensive Income - Summary of Amounts Reclassification from AOCI to Net Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other (income) expense, net	$ (10)	$ 21
Income tax expense	45	44
Cost of sales	1,639	1,558
Net income (loss) attributable to Baxter	332	342
Amounts reclassified from AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss) attributable to Baxter	(13)	(7)
Amortization of pension and OPEB items | Amounts reclassified from AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other (income) expense, net	(15)	(8)
Income tax expense	3	1
Net income (loss) attributable to Baxter	(12)	(7)
Gains (losses) on hedging activities | Amounts reclassified from AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense	0	0
Net income (loss) attributable to Baxter	(1)	0
Gains (losses) on hedging activities | Foreign exchange contracts | Amounts reclassified from AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	$ (1)	$ 0