GOODWILL AND LONG-LIVED ASSETS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 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
Accumulated Impairment Losses		(93,881)	(102,640)	(102,640)	(93,881)
Adjustments	0	0
Net Goodwill Balance		23,295	14,536	$ 14,536	$ 23,295
Finite-Lived Intangible Assets [Line Items]
Net carrying amount	29
Estimated future amortization expense [Abstract]
Remainder of 2017			13
2018			16
Total	29		29
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization	100	100
Amortization of intangible assets	100	100
Transportation and Skilled Trades [Member]
Changes in carrying amount of goodwill [Abstract]
Net Goodwill Balance		14,500
Healthcare and Other Professions [Member]
Changes in carrying amount of goodwill [Abstract]
Net Goodwill Balance		$ 8,800
Curriculum [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount, beginning balance	160
Adjustments	0
Gross carrying amount, ending balance	160
Accumulated amortization, beginning balance	128
Amortization	3
Accumulated amortization, ending balance	131
Net carrying amount	$ 29
Weighted average amortization period	10 years
Amortization of intangible assets	$ 3
Estimated future amortization expense [Abstract]
Total	$ 29		$ 29