SHARE-BASED COMPENSATION (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Additional Disclosures [Abstract]
Vested share-based awards withheld to satisfy income tax obligations (in shares)			40,092	57,725
Vested share-based awards withheld to satisfy income tax obligations			$ 3,900	$ 4,400
Compensation Expense [Abstract]
Share-based compensation expense	$ 1,900	$ 1,500	3,561	3,180
401(k) Profit Sharing Plan [Abstract]
Contribution to profit sharing plan	$ 500	$ 500	$ 1,000	$ 1,100
Restricted Stock [Member]
Number of Shares [Roll Forward]
Nonvested at beginning of period (in shares)			282,235
Granted (in shares)			78,169
Vested (in shares)			(133,106)
Forfeited (in shares)			(914)
Nonvested at end of period (in shares)	226,384		226,384
Weighted Average Grant-date Fair Value [Roll Forward]
Nonvested at beginning of period (in dollars per share)			$ 51.69
Granted (in dollars per share)			94.31
Vested (in dollars per share)			49.15
Forfeited (in dollars per share)			58.49
Nonvested at end of period (in dollars per share)	$ 67.87		$ 67.87
Compensation Expense [Abstract]
Unrecognized compensation expense	$ 13,200		$ 13,200
Unrecognized compensation expense, period for recognition			33 months
2017 Director LTIP [Member] | Restricted Stock [Member]
Number of Shares [Roll Forward]
Granted (in shares)			8,322	5,112
2012 Employee LTIP [Member] | Restricted Stock [Member]
Number of Shares [Roll Forward]
Granted (in shares)			69,847	66,530
Additional Disclosures [Abstract]
Vested share-based awards withheld to satisfy income tax obligations (in shares)			40,092
Vested share-based awards withheld to satisfy income tax obligations			$ 3,900
2008 Director LTIP [Member] | Restricted Stock [Member]
Number of Shares [Roll Forward]
Granted (in shares)				535