SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Part 1 (Details) $ / shares in Units, $ in Thousands			3 Months Ended								12 Months Ended
	Nov. 30, 2019 USD ($) $ / shares shares	Nov. 14, 2019 USD ($) shares	Dec. 31, 2019 USD ($) State	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) School State Campus Segment shares	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Nov. 13, 2019 USD ($)	Dec. 31, 2016 USD ($)
Business Activities [Abstract]
Number of schools | School											22
Number of states in which schools operate across the United States | State			14								14
Number of campuses treated as destination schools | Campus											5
Number of reportable segments | Segment											3
Liquidity [Abstract]
Cash			$ 4,600								$ 4,600
Gross proceeds from sale of stock											0
Net income generated			9,206	$ 1,340	$ (3,064)	$ (5,467)	$ 5,033	$ (600)	$ (4,104)	$ (6,874)	2,015	$ (6,545)	$ (11,484)
Cash and cash equivalents			38,644				$ 45,946				38,644	45,946	54,554		$ 47,715
Restricted cash			15,000								15,000
Line of credit facility, remaining borrowing capacity			$ 25,000								25,000
Series A Convertible Preferred Stock [Member]
Liquidity [Abstract]
Gross proceeds from sale of stock	$ 12,000	$ 12,700									$ 11,982
Sale of stock (in shares) | shares	12,700	12,700									12,700
Preferred stock, par value (in dollars per share) | $ / shares	$ 0
Net income generated											$ 0	$ 0	$ 0
2019 Credit Facility [Member]
Liquidity [Abstract]
Line of credit facility, maximum borrowing capacity		$ 60,000												$ 47,000