Acquisition - Additional Information (Detail) - USD ($)	3 Months Ended			6 Months Ended
	Mar. 31, 2018	Jun. 30, 2017	Mar. 31, 2017	Mar. 31, 2018	Dec. 29, 2017
Business Acquisition [Line Items]
Proceeds from issuance of equity securities		$ 4,800,000,000
BusinessCombinationConsiderationTransferredEquityInterestsRecognizedAsIncreaseToAdditionalPaidInCapitalCommonStock					$ 6,500,000,000
BusinessCombinationConsiderationTransferredEquityInterestsRecognizedAsIncreaseToTreasuryStock					$ 2,100,000,000
TransitionTaxPayableAcquiree	$ 220,000,000			$ 220,000,000
CR Bard Inc [Member]
Business Acquisition [Line Items]
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	1,000,000,000			1,000,000,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual	202,000,000			274,000,000
Business Combination Cash Consideration Transferred Per Share					$ 222.93
Business Combination Equity Interest Issued or Issuable Number of Securities Called by Each Share					0.5077
Proceeds from Issuance of Debt		$ 9,600,000,000
Business Acquisition, Goodwill, Expected Tax Deductible Amount	0			0
Product liability reserves					$ 1,634,000,000
Business Combination, Acquisition Related Costs			$ 7,000,000	$ 51,000,000
Recognition Of Fair Value Adjustment To Inventory Acquired	$ 422,000,000
Customer Relationships [Member] | CR Bard Inc [Member]
Business Acquisition [Line Items]
Fair Value Inputs, Discount Rate	8.00%
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	15 years
Customer relationships | CR Bard Inc [Member]
Business Acquisition [Line Items]
Fair Value Inputs, Discount Rate	8.00%
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	13 years