GOODWILL AND LONG-LIVED ASSETS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Dec. 31, 2016	Dec. 31, 2015
GOODWILL AND LONG-LIVED ASSETS [Abstract]
Impairment of long-lived assets			$ 0	$ 0
Changes in carrying amount of goodwill [Abstract]
Gross Goodwill Balance		$ 117,176		117,176	$ 117,176	$ 117,176	$ 117,176
Accumulated Impairment Losses		(93,881)		(93,881)	(102,640)	(102,640)	(93,881)
Adjustments			0	0
Net Goodwill Balance		23,295		23,295	14,536	$ 14,536	$ 23,295
Finite-Lived Intangible Assets [Line Items]
Net carrying amount	$ 25		25
Estimated future amortization expense [Abstract]
Remainder of 2017					12
2018					13
Total	25		25		25
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization	100	100	100	100
Transportation and Skilled Trades [Member]
Changes in carrying amount of goodwill [Abstract]
Net Goodwill Balance		14,500		14,500
Healthcare and Other Professions [Member]
Changes in carrying amount of goodwill [Abstract]
Net Goodwill Balance		$ 8,800		$ 8,800
Curriculum [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount, beginning balance			160
Adjustments			0
Gross carrying amount, ending balance	160		160
Accumulated amortization, beginning balance			128
Amortization			7
Accumulated amortization, ending balance	135		135
Net carrying amount	25		$ 25
Weighted average amortization period			10 years
Estimated future amortization expense [Abstract]
Total	$ 25		$ 25		$ 25