Restructuring and Related Implementation Charges - Narrative (Details) - Global Growth and Efficiency Program $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) position	Jun. 30, 2018 USD ($)
Restructuring Cost and Reserve [Line Items]
Expected percent of total charges resulting in cash expenditure	75.00%		75.00%
Charges against assets	$ 34		$ 46
Total Global Growth and Efficiency Program charges, pretax	$ 42	$ 61	$ 71	$ 89
Hill’s Pet Nutrition
Restructuring Cost and Reserve [Line Items]
Expected percent of total restructuring charges related to segment for the duration of the program	10.00%		10.00%
Corporate
Restructuring Cost and Reserve [Line Items]
Expected percent of total restructuring charges related to segment for the duration of the program	40.00%		40.00%
North America
Restructuring Cost and Reserve [Line Items]
Expected percent of total restructuring charges related to segment for the duration of the program	15.00%		15.00%
Europe
Restructuring Cost and Reserve [Line Items]
Expected percent of total restructuring charges related to segment for the duration of the program	20.00%		20.00%
Latin America
Restructuring Cost and Reserve [Line Items]
Expected percent of total restructuring charges related to segment for the duration of the program	5.00%		5.00%
Asia Pacific
Restructuring Cost and Reserve [Line Items]
Expected percent of total restructuring charges related to segment for the duration of the program	5.00%		5.00%
Africa/Eurasia
Restructuring Cost and Reserve [Line Items]
Expected percent of total restructuring charges related to segment for the duration of the program	5.00%		5.00%
Employee-Related Costs
Restructuring Cost and Reserve [Line Items]
Estimated percent of total cumulative pretax charges of implementing restructuring program by category	40.00%		40.00%
Charges against assets	$ 2		$ 3
Total Global Growth and Efficiency Program charges, pretax	$ 4		$ 14
Incremental Depreciation And Asset Impairment
Restructuring Cost and Reserve [Line Items]
Estimated percent of total cumulative pretax charges of implementing restructuring program by category	10.00%		10.00%
Charges Resulting Directly From Exit Activities
Restructuring Cost and Reserve [Line Items]
Estimated percent of total cumulative pretax charges of implementing restructuring program by category	30.00%		30.00%
Implementation Of New Strategies
Restructuring Cost and Reserve [Line Items]
Estimated percent of total cumulative pretax charges of implementing restructuring program by category	20.00%		20.00%
Third party Incremental Cost
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax	$ 5		$ 10
Contract Termination
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax	0		3
Other Exit Costs
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax	28		28
Minimum | Expected Completion Date 2019
Restructuring Cost and Reserve [Line Items]
Restructuring program expected cost before tax	1,820		1,820
Restructuring program expected cost after tax	1,350		1,350
Restructuring program expected cost, current fiscal year, before tax	100		100
Restructuring program expected cost, current fiscal year, after tax	70		$ 70
Restructuring and related cost, expected number of positions eliminated (in positions) | position			4,000
Maximum | Expected Completion Date 2019
Restructuring Cost and Reserve [Line Items]
Restructuring program expected cost before tax	1,870		$ 1,870
Restructuring program expected cost after tax	1,380		1,380
Restructuring program expected cost, current fiscal year, before tax	150		150
Restructuring program expected cost, current fiscal year, after tax	$ 100		$ 100
Restructuring and related cost, expected number of positions eliminated (in positions) | position			4,400