LONG-TERM DEBT: (Details) - USD ($) $ in Thousands		12 Months Ended
	Jul. 31, 2015	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015	Nov. 30, 2016
Long-term debt
Total long-term debt and capital leases		$ 230,612	$ 192,856
Less current installments		39,819	32,243
Less deferred debt financing costs		1,552	2,716
Long-term debt, excluding current installments and deferred debt financing costs		189,241	157,897
Discontinued operations, held-for-sale or disposed of by sale | ITO
Long-term debt
Interest expense			681
Credit Agreement
Long-term debt
Outstanding indebtedness repaid with proceeds from sale	$ 55,000
Credit Agreement | Discontinued operations, held-for-sale or disposed of by sale | ITO
Long-term debt
Interest expense			400	$ 1,300
Term loans
Long-term debt
Total long-term debt and capital leases		155,000	185,000
Aggregate amount of borrowing commitment		$ 300,000
Weighted-average interest rate on long-term debt (as a percent)		2.98%
Term loans | Quarterly installments payable through September 2017
Long-term debt
Required quarterly installment payments		$ 7,500
Term loans | Quarterly installments payable through June 2018
Long-term debt
Required quarterly installment payments		11,300
Term loans | Final payment due on October 9, 2018
Long-term debt
Final payment of long-term debt		$ 106,300
Term loans | LIBOR
Long-term debt
Long-term debt basis spread on variable interest rate (as a percent)		2.00%
Long-term debt variable interest rate description		LIBOR
Term loans | Alternative base rate
Long-term debt
Long-term debt variable interest rate description		Alternative base rate
Revolving credit facility
Long-term debt
Total long-term debt and capital leases		$ 70,000			$ 70,000
Aggregate amount of borrowing commitment		$ 300,000
Weighted-average interest rate on long-term debt (as a percent)		3.00%
Outstanding letters of credit		$ 0
Revolving credit facility dividend restrictions amount, maximum		$ 30,000
Revolving credit facility | LIBOR
Long-term debt
Long-term debt variable interest rate description		LIBOR
Revolving credit facility | Alternative base rate
Long-term debt
Long-term debt variable interest rate description		alternative base rate
Other debt and long-term liabilities
Long-term debt
Total long-term debt and capital leases		$ 5,612	$ 7,856