Income Tax (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Effective income tax rate (benefit)	(12.40%)	(12.60%)
Unrecognized tax benefits, related to deficiency interest on positions	$ 15.9		$ 2.4
Increase in potential payment of interest on uncertain tax positions due to acquisitions	9.3
Unrecognized tax benefits, income tax penalties accrued	60.7		$ 27.6
The increase in accrued penalties related to uncertain tax positions due to acquisitions	$ 25.6