v3.10.0.1

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2018
Income Taxes [Line Items]
2017 U.S. Tax Cuts and Jobs Act, provisional liability recorded					$ 289.6
Unrecognized tax benefits					585.1
Unrecognized tax benefits that would have a favorable impact					425.9
Decrease in unrecognized tax benefits reasonable possible amount					$ 125.0
Domestic Tax Authority
Income Taxes [Line Items]
Income tax rate	20.00%	19.00%		19.25%
Forecast | Domestic Tax Authority
Income Taxes [Line Items]
Income tax rate			19.00%

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Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Liability

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Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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