Accounts Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivable amounts	$ 279,622	$ 276,558
Less allowance for doubtful accounts	2,589	2,621
Accounts receivable, net	277,033	273,937
Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivable amounts	276,087	269,844
Other Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivable amounts	$ 3,535	$ 6,714