Financial Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Total foreign currency forward-exchange contracts		$ (71)	$ 19
Unrecognized net gains/(losses) on derivative instruments	[1]	44	(23)	$ 36
Foreign Exchange Forward | Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Total foreign currency forward-exchange contracts		(12)	0
Gain (loss) on derivative contracts not designated as hedging instruments		$ (11)	(25)
Foreign Exchange Forward | Derivatives Not Designated as Hedging Instruments | Maximum
Derivatives, Fair Value [Line Items]
Derivative, Term of Contract		3 years
Foreign Exchange Forward | Derivatives Not Designated as Hedging Instruments | Minimum
Derivatives, Fair Value [Line Items]
Derivative, Term of Contract		60 days
Foreign Exchange Forward | Derivatives Not Designated as Hedging Instruments | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 18	11
Foreign Exchange Forward | Derivatives Not Designated as Hedging Instruments | Other current liabilities
Derivatives, Fair Value [Line Items]
Foreign currency forward-exchange contracts		6	11
Forward Starting Interest Rate Swap Contract [Member] | Derivatives Designated as Hedging Instruments | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Total foreign currency forward-exchange contracts		(26)	(12)
Cross-currency interest rate swap contracts | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Unrecognized net gains/(losses) on derivative instruments		44	(23)
Gains/(losses) on derivative instruments		17	19
Collateral received		20	33
Additional Collateral, Aggregate Fair Value		$ 51	13
Cross-currency interest rate swap contracts | Derivatives Designated as Hedging Instruments | Maximum
Derivatives, Fair Value [Line Items]
Derivative, Term of Contract		3 years
Cross-currency interest rate swap contracts | Derivatives Designated as Hedging Instruments | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 55	5
Cross-currency interest rate swap contracts | Derivatives Designated as Hedging Instruments | Other current liabilities
Derivatives, Fair Value [Line Items]
Foreign currency forward-exchange contracts		0	(20)
Cross-currency interest rate swap contracts | Derivatives Designated as Hedging Instruments | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		4	11
Cross-currency interest rate swap contracts | Derivatives Designated as Hedging Instruments | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Foreign currency forward-exchange contracts		0	(1)
Forward starting interest rate swap contracts | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Foreign currency forward-exchange contracts		59	19
Unrecognized net gains/(losses) on derivative instruments		11	2
zts_FixedtoFloatInterestRateSwap | Derivatives Designated as Hedging Instruments | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ (26)	$ (26)

[1] Presented net of reclassification adjustments, which are not material in any period presented. Reclassification adjustments related to benefit plans are generally reclassified, as part of net periodic pension cost, into Cost of sales, Selling, general and administrative expenses, and/or Research and development expenses, as appropriate, in the Consolidated Statements of Income.