Basis of Presentation and Significant Accounting Policies Restatement of Previously Reported Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2016	Mar. 31, 2016	Mar. 31, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Inventories	$ 935,600	$ 935,600	$ 845,133	$ 791,340
Retained deficit	(246,668)	(246,668)	(208,476)	(145,856)	$ (211,388)
Pension, postretirement and other long-term liabilities	91,518	91,518	$ 78,809	$ 81,753
Restatement Adjustment | Adjustment For Accounting Errors
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of goods sold	165	801
Inventories	581	581
Recoverable income tax	1,822	1,822
Retained deficit	2,403	2,403
Accounts receivable, related parties	(11,808)	(11,808)
Pension, postretirement and other long-term liabilities	$ 11,808	$ 11,808