Debt - Additional Information (Detail)		1 Months Ended				12 Months Ended
	Oct. 05, 2014 USD ($)	Sep. 30, 2015 USD ($)	Jul. 31, 2015 USD ($)	Apr. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Mar. 17, 2015 USD ($)	Feb. 28, 2015 USD ($)	Sep. 30, 2014
Debt Instrument [Line Items]
Short-term debt, weighted average interest rate		0.64%				0.64%					0.40%
Aggregate annual maturities of long-term debt, 2016		$ 750,000,000				$ 750,000,000
Aggregate annual maturities of long-term debt, 2017		800,000,000				800,000,000
Aggregate annual maturities of long-term debt, 2018		1,450,000,000				1,450,000,000
Aggregate annual maturities of long-term debt, 2019		1,200,000,000				1,200,000,000
Aggregate annual maturities of long-term debt, 2020		1,250,000,000				1,250,000,000
Term Loan Facility
Debt Instrument [Line Items]
Short term debt maximum borrowing capacity					$ 1,000,000,000
Loans Payable		0				0
Debt instrument, term					364 days
Repayments of short-term debt		100,000,000	$ 250,000,000	$ 650,000,000
Bridge Loan
Debt Instrument [Line Items]
Payments to acquire business secured bridge financing	$ 9,100,000,000
Syndicated Credit Facility
Debt Instrument [Line Items]
Borrowings under credit facility		0				0
Maximum aggregate commitment		1,500,000,000				1,500,000,000
Syndicated Credit Facility | Domestic Debt
Debt Instrument [Line Items]
Maximum borrowing capacity of syndicated credit facility		1,000,000,000				1,000,000,000
Additional commitments made by the lenders		500,000,000				$ 500,000,000
Covenant compliance, minimum interest expense coverage ratio						5
Notes Due June 2016
Debt Instrument [Line Items]
Debt instrument, face amount		750,000,000				$ 750,000,000	$ 750,000,000
Unsecured Debt
Debt Instrument [Line Items]
Debt instrument, face amount		6,200,000,000.0				6,200,000,000.0
Care Fusion Corporation
Debt Instrument [Line Items]
Long-term debt assumed									$ 2,181,000,000
Business combination interest and financing costs						107,000,000
Care Fusion Corporation | Unsecured Debt
Debt Instrument [Line Items]
Debt instrument, face amount								$ 2,000,000,000
Long-term debt assumed									$ 2,174,000,000
Principal amount outstanding after exchange		51,000,000				51,000,000
Commercial Paper Program
Debt Instrument [Line Items]
Short term debt maximum borrowing capacity		1,000,000,000				1,000,000,000
Loans Payable		700,000,000				700,000,000
Commercial Paper Program | Care Fusion Corporation
Debt Instrument [Line Items]
Used proceeds of new financing		$ 500,000,000				$ 500,000,000
Former Commercial Paper Program
Debt Instrument [Line Items]
Loans Payable										$ 200,000,000