Debt - Summary of Debt Instruments (Detail) $ in Millions, ¥ in Billions	Mar. 31, 2016 USD ($)	Mar. 31, 2016 JPY (¥)	Dec. 31, 2015 USD ($)
Long-term debt
Senior Notes due	$ 8,950.0
Other long-term debt	4.6		$ 4.6
Debt discount and issuance costs	(78.0)		(80.8)
Adjustment related to interest rate swaps	37.6		26.8
Total long-term debt	11,117.4		11,497.4
Senior Notes [Member] | 1.450% [Member] | Due in 2017 [Member]
Long-term debt
Senior Notes due	500.0		500.0
Senior Notes [Member] | 2.0% [Member] | Due in 2018 [Member]
Long-term debt
Senior Notes due	1,150.0		1,150.0
Senior Notes [Member] | 4.625% [Member] | Due in 2019 [Member]
Long-term debt
Senior Notes due	500.0		500.0
Senior Notes [Member] | 2.70% [Member] | Due in 2020 [Member]
Long-term debt
Senior Notes due	1,500.0		1,500.0
Senior Notes [Member] | 3.375% [Member] | Due in 2021 [Member]
Long-term debt
Senior Notes due	300.0		300.0
Senior Notes [Member] | 3.150% [Member] | Due in 2022 [Member]
Long-term debt
Senior Notes due	750.0		750.0
Senior Notes [Member] | 3.550% [Member] | Due in 2025 [Member]
Long-term debt
Senior Notes due	2,000.0		2,000.0
Senior Notes [Member] | 4.250% [Member] | Due in 2035 [Member]
Long-term debt
Senior Notes due	500.0		500.0
Senior Notes [Member] | 5.750% [Member] | Due in 2039 [Member]
Long-term debt
Senior Notes due	500.0		500.0
Senior Notes [Member] | 4.450% [Member] | Due in 2045 [Member]
Long-term debt
Senior Notes due	1,250.0		1,250.0
U.S. Term Loan [Member]
Long-term debt
Term loan	2,100.0		2,500.0
Japan Term Loan [Member]
Long-term debt
Term loan	$ 103.2	¥ 11.7	$ 96.8