Income Taxes (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended				9 Months Ended		12 Months Ended
	May 31, 2016	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2016
One-time Transaction [Table] [Line Items]
Incentive period for SEZs, years						15 years
Regular corporate income tax rate in India						34.60%
Current MAT rate						21.30%
Income tax expense			$ 168.9		$ 145.8	$ 659.2	$ 402.2
India Cash Remittance [Member]
One-time Transaction [Table] [Line Items]
Foreign Earnings Repatriated	$ 2,800.0
Income tax expense						$ 213.7
India Cash Remittance [Member] | U.S.
One-time Transaction [Table] [Line Items]
Foreign Earnings Repatriated	1,200.0
Foreign Earnings Repatriated, Net of Tax	1,000.0
India Cash Remittance [Member] | Outside of U.S.
One-time Transaction [Table] [Line Items]
Foreign Earnings Repatriated	$ 1,600.0
India Cash Remittance [Member] | Scenario, Forecast
One-time Transaction [Table] [Line Items]
Income tax expense								$ 237.5
India Cash Remittance Current Year Earnings [Member] [Domain] | Scenario, Forecast
One-time Transaction [Table] [Line Items]
Income tax expense		$ 23.8
India Cash Remittance - Historic Undistributed Accumulated Earnings [Member] [Domain]
One-time Transaction [Table] [Line Items]
Income tax expense				$ 142.6