Recent Accounting Changes and Accounting Pronouncements Change in accounting Policy - retrospective restatement (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Jan. 02, 2016
Statement of Cash Flows [Abstract]
Excess Tax Benefit from Share-based Compensation, Operating Activities			$ 12.3
Excess Tax Benefit from Share-based Compensation, Financing Activities			$ 12.3
Effective Income Tax Rate Reconciliation, Excess Tax Benefit, Share-based Compensation, Amount	$ 1.2	$ 10.9