REVENUE RECOGNITION (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Disaggregation of Revenue [Abstract]
Total revenues	$ 63,263	$ 61,889
Unearned tuition	18,328		$ 22,545
Revenue recognized included in contract liability	19,100
ASU 2016-10 [Member]
Disaggregation of Revenue [Abstract]
Unearned tuition	18,300		$ 22,500
Services Transferred at a Point in Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	3,156	2,783
Services Transferred over Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	60,107	59,106
Transportation and Skilled Trades Segment [Member]
Disaggregation of Revenue [Abstract]
Total revenues	44,325	42,747
Transportation and Skilled Trades Segment [Member] | Services Transferred at a Point in Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	2,081	2,048
Transportation and Skilled Trades Segment [Member] | Services Transferred over Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	42,244	40,699
Healthcare and Other Professions Segment [Member]
Disaggregation of Revenue [Abstract]
Total revenues	18,938	16,741
Healthcare and Other Professions Segment [Member] | Services Transferred at a Point in Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	1,075	732
Healthcare and Other Professions Segment [Member] | Services Transferred over Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	17,863	16,009
Transitional Segment [Member]
Disaggregation of Revenue [Abstract]
Total revenues	0	2,401
Transitional Segment [Member] | Services Transferred at a Point in Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	0	3
Transitional Segment [Member] | Services Transferred over Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	$ 0	$ 2,398