INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2014	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
INCOME TAXES [Abstract]
Impact of recognizing the unrecognized tax benefit	$ 106				$ 104				$ 106	$ 104
Interest on income taxes expense included in statement of operation									4	4
Accrued interest on income taxes	52				48				$ 52	$ 48
Reconciliation of income taxes to the statutory rate [Abstract]
Statutory federal income tax rate									35.00%	35.00%	35.00%
Income tax expense computed at the U.S. statutory federal rate									$ 30,134	$ 26,513	$ 27,410
State income tax expense - net of federal benefit									4,193	3,544	4,193
Non-deductible executive compensation									512	331	222
Other									717	616	648
Provision for income taxes	8,246	$ 8,687	$ 11,808	$ 6,815	6,422	$ 7,348	$ 10,982	$ 6,252	$ 35,556	$ 31,004	$ 32,473
Effective income tax rate									41.30%	40.90%	41.50%
Current [Abstract]
Federal									$ 29,619	$ 21,361	$ 27,665
State									7,001	6,114	6,667
Foreign									132	13	3
Total current expense									36,752	27,488	34,335
Deferred [Abstract]
Federal									(622)	3,727	(1,591)
State									(432)	(211)	(271)
Foreign									(142)	0	0
Total deferred expense (benefit)									(1,196)	3,516	(1,862)
Provision for income taxes	8,246	$ 8,687	$ 11,808	$ 6,815	6,422	$ 7,348	$ 10,982	$ 6,252	35,556	31,004	$ 32,473
Deferred Tax Assets [Abstract]
Accrued vacation	2,217				2,116				2,217	2,116
Deferred revenue	3,107				1,046				3,107	1,046
Foreign net operating loss carryforward	462				461				462	461
Reserve for credit losses	2,026				1,929				2,026	1,929
Restricted stock	1,779				1,778				1,779	1,778
Other accruals and reserves	2,555				1,556				2,555	1,556
Other credits and carryforwards	1,166				1,275				1,166	1,275
Gross deferred tax assets	13,312				10,161				13,312	10,161
Less: valuation allowance	(1,270)				(1,270)				(1,270)	(1,270)
Net deferred tax assets	12,042				8,891				12,042	8,891
Deferred Tax Liabilities [Abstract]
Basis difference in fixed assets	(1,399)				(1,170)				(1,399)	(1,170)
Basis difference in operating lease items	(9,926)				(7,749)				(9,926)	(7,749)
Basis difference in tax deductible goodwill	(2,516)				(2,973)				(2,516)	(2,973)
Total deferred tax liabilities	(13,841)				(11,892)				(13,841)	(11,892)
Net deferred tax liabilities	(1,799)				$ (3,001)				(1,799)	$ (3,001)
State [Member]
Operating Loss Carryforwards [Line Items]
Capital loss carryforwards	1,300								$ 1,300
Capital loss carryforwards expiration term									5 years
Foreign [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 500								$ 500