Long-Term Debt (Commercial Paper) (Details) - Commercial Paper [Member]			12 Months Ended
	Jul. 31, 2015 USD ($)	Feb. 28, 2014 USD ($)	Dec. 31, 2015 USD ($)	Jul. 31, 2015 EUR (€)	May. 21, 2015 USD ($)
Line of Credit Facility [Line Items]
Utilized borrowings under credit facility			$ 756,867,000
UNITED STATES
Line of Credit Facility [Line Items]
Maximum borrowing capacity under credit facility	$ 1,800,000,000	$ 1,000,000,000			$ 1,800,000,000
Maturity period of debt			28 years 4 months 6 days
Weighted average interest rate on debt			0.65%
UNITED STATES | Minimum [Member]
Line of Credit Facility [Line Items]
Maturity period of debt		1 day
UNITED STATES | Maximum [Member]
Line of Credit Facility [Line Items]
Maturity period of debt		397 days
Europe
Line of Credit Facility [Line Items]
Maximum borrowing capacity under credit facility | €				€ 1,000,000,000
Maturity period of debt			34 years 9 months 26 days
Weighted average interest rate on debt			0.08%
Europe | Minimum [Member]
Line of Credit Facility [Line Items]
Maturity period of debt	1 day
Europe | Maximum [Member]
Line of Credit Facility [Line Items]
Maturity period of debt	183 days