LONG-TERM DEBT: (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Mar. 31, 2018
Debt Instrument [Line Items]
Total long-term debt and capital leases		$ 233,293
Less current installments		1,583
Less deferred debt financing costs		3,873
Long-term debt, excluding current installments and deferred debt financing costs	$ 0	227,837
Revolving credit facility
Debt Instrument [Line Items]
Total long-term debt and capital leases		230,000
Other debt and long-term liabilities
Debt Instrument [Line Items]
Total long-term debt and capital leases		$ 3,293