Derivative Financial Instruments - Gains and Losses on Derivative Instruments (Details) - Designated as hedging instruments - Cash Flow Hedges - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Other Comprehensive Loss
Amounts of gains and losses on the derivative instruments
Amount of Gain (Loss) Deferred as a Component of Accumulated Other Comprehensive Loss	$ (677)	$ 2,497	$ (6,026)	$ 4,026
Cost of goods sold
Amounts of gains and losses on the derivative instruments
Amount of Loss (Gain) Reclassified from Accumulated Other Comprehensive Loss to Costs of Goods Sold	$ 2,248	$ (463)	$ 5,377	$ 432