REVENUE RECOGNITION (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Disaggregation of Revenue [Abstract]
Total revenues	$ 61,120	$ 61,865	$ 123,009	$ 127,144
Unearned tuition	19,419		19,419		$ 24,647
Revenue recognized included in contract liability	5,100		23,200
ASU 2016-10 [Member]
Disaggregation of Revenue [Abstract]
Unearned tuition	19,400		19,400		$ 24,600
Services Transferred at a Point in Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	2,614	2,072	5,397	4,603
Services Transferred over Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	58,506	59,793	117,612	122,541
Transportation and Skilled Trades Segment [Member]
Disaggregation of Revenue [Abstract]
Total revenues	42,085	42,331	84,832	85,490
Transportation and Skilled Trades Segment [Member] | Services Transferred at a Point in Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	1,657	1,599	3,705	3,374
Transportation and Skilled Trades Segment [Member] | Services Transferred over Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	40,428	40,732	81,127	82,116
Healthcare and Other Professions Segment [Member]
Disaggregation of Revenue [Abstract]
Total revenues	19,035	16,911	38,177	34,756
Healthcare and Other Professions Segment [Member] | Services Transferred at a Point in Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	957	538	1,692	1,302
Healthcare and Other Professions Segment [Member] | Services Transferred over Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	18,078	16,373	36,485	33,454
Transitional Segment [Member]
Disaggregation of Revenue [Abstract]
Total revenues	0	2,623	0	6,898
Transitional Segment [Member] | Services Transferred at a Point in Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	0	(65)	0	(73)
Transitional Segment [Member] | Services Transferred over Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues	$ 0	$ 2,688	$ 0	$ 6,971