Debt - Summary of Debt Instruments (Detail) In Millions, unless otherwise specified	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Mar. 31, 2015 1.450% Senior Notes due 2017 [Member] USD ($)	Mar. 31, 2015 2.000% Senior Notes due 2018 [Member] USD ($)	Mar. 31, 2015 4.625% Senior Notes due 2019 [Member] USD ($)	Dec. 31, 2014 4.625% Senior Notes due 2019 [Member] USD ($)	Mar. 31, 2015 2.700% Senior Notes due 2020 [Member] USD ($)	Mar. 31, 2015 3.375% Senior Notes due 2021 [Member] USD ($)	Dec. 31, 2014 3.375% Senior Notes due 2021 [Member] USD ($)	Mar. 31, 2015 3.150% Senior Notes due 2022 [Member] USD ($)	Mar. 31, 2015 3.550% Senior Notes due 2025 [Member] USD ($)	Mar. 31, 2015 4.250% Senior Notes due 2035 [Member] USD ($)	Mar. 31, 2015 5.750% Senior Notes due 2039 [Member] USD ($)	Dec. 31, 2014 5.750% Senior Notes due 2039 [Member] USD ($)	Mar. 31, 2015 4.450% Senior Notes due 2045 [Member] USD ($)	Mar. 31, 2015 Japan Term Loan [Member] USD ($)	Mar. 31, 2015 Japan Term Loan [Member] JPY (¥)	Dec. 31, 2014 Japan Term Loan [Member] USD ($)
Long-term debt
Senior Notes due	$ 8,950.0		$ 500.0	$ 1,150.0	$ 500.0	$ 500.0	$ 1,500.0	$ 300.0	$ 300.0	$ 750.0	$ 2,000.0	$ 500.0	$ 500.0	$ 500.0	$ 1,250.0
Term loan																98.2	11,700.0	98.0
Other long-term debt	4.9	4.9
Debt discount	(23.1)	(1.4)
Adjustment related to interest rate swaps	31.2	24.0
Total long-term debt	$ 9,061.2	$ 1,425.5