Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Mar. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivable amounts	$ 477,478	$ 292,723
Less allowance for doubtful accounts	2,385	2,540
Accounts receivable, net	475,093	290,183
Trade Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivable amounts	472,871	289,013
Other Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivable amounts	$ 4,607	$ 3,710