Debt and Financing Arrangements (Details) - USD ($) $ in Millions		Oct. 31, 2015	Apr. 30, 2015	Mar. 20, 2015	Mar. 02, 2015
Debt and Financing Arrangements [Abstract]
Total long-term debt		$ 5,494.5	$ 5,944.9
Long-term debt
Debt instrument face amount		$ 5,500.0	5,950.0
Senior Notes [Member]
Long-term debt
Debt instrument face amount				$ 3,700.0
1.75% Senior Notes due March 15, 2018 [Member]
Long-term debt
Company issued Senior Notes	[1]		496.9
Interest rate on notes		1.75%
Debt instrument face amount		$ 500.0	500.0
Notes Payable, Noncurrent	[1]	$ 497.4
2.50% Senior Notes due March 15, 2020 [Member]
Long-term debt
Company issued Senior Notes	[1]		494.3
Interest rate on notes		2.50%
Debt instrument face amount		$ 500.0	500.0
Notes Payable, Noncurrent	[1]	$ 494.9
3.50% Senior Notes due October 15, 2021 [Member]
Long-term debt
Interest rate on notes		3.50%
Debt instrument face amount		$ 750.0	750.0
Notes Payable, Noncurrent	[1]	$ 792.7	796.0
3.00% Senior Notes due March 15, 2022 [Member]
Long-term debt
Company issued Senior Notes	[1]		395.3
Interest rate on notes		3.00%
Debt instrument face amount		$ 400.0	400.0
Notes Payable, Noncurrent	[1]	$ 395.6
3.50% Senior Notes due March 15, 2025 [Member]
Long-term debt
Company issued Senior Notes	[1]		991.9
Interest rate on notes		3.50%
Debt instrument face amount		$ 1,000.0	1,000.0
Notes Payable, Noncurrent	[1]	$ 992.3
4.25% Senior Notes due March 15, 2035 [Member]
Long-term debt
Company issued Senior Notes	[1]		641.8
Interest rate on notes		4.25%
Debt instrument face amount		$ 650.0	650.0
Notes Payable, Noncurrent	[1]	$ 642.1
4.38% Senior Notes due March 15, 2045 [Member]
Long-term debt
Company issued Senior Notes	[1]		583.8
Interest rate on notes		4.38%
Debt instrument face amount		$ 600.0	600.0
Notes Payable, Noncurrent	[1]	584.1
Term Loan Credit Agreement due March 23, 2020 [Member]
Long-term debt
Debt instrument face amount		1,100.0	1,550.0		$ 1,800.0
Term loan credit agreement carrying value	[1]	$ 1,095.4	$ 1,544.9

[1] Represents the carrying amount included in the Condensed Consolidated Balance Sheets, which includes the impact of interest rate swaps, offering discounts, and capitalized debt issuance costs.