LONG-TERM DEBT (Details) $ in Thousands				3 Months Ended
	Nov. 11, 2020 USD ($)	Nov. 10, 2020 USD ($)	Nov. 14, 2019 USD ($) Facility	Mar. 31, 2022 USD ($) School	Dec. 31, 2021 USD ($)	Oct. 29, 2021 USD ($)
Term Loan [Member]
Long-term debt [Abstract]
Repayment of term loan and swap termination fee						$ 16,700
Credit Agreement [Member]
Long-term debt [Abstract]
Minimum quarterly average aggregate balances to be maintained				$ 5,000
Bank fees if minimum quarterly average aggregate balances is not maintained				$ 12,500
Limit on payment of cash dividends	$ 2,300	$ 1,700
Period of consideration for payment of cash dividend				24 months
Credit Facility [Member]
Long-term debt [Abstract]
Line of credit facility, maximum borrowing capacity			$ 60,000
Number of facilities available in 2019 credit agreement | Facility			4
Letters of credit outstanding				$ 4,000	$ 4,000
Number of schools in states covered under first priority lien | School				3
Credit agreement				$ 0	$ 0
Credit Facility [Member] | Letter of Credit [Member]
Long-term debt [Abstract]
Percentage of letter of credit fee, quarterly installment			0.25%
Percentage of letter of credit fee, annual payment			0.50%
Credit Facility [Member] | Term Loan [Member]
Long-term debt [Abstract]
Line of credit facility, maximum borrowing capacity			$ 20,000	$ 0
Expiration date of credit facility				Dec. 01, 2024
Line of credit facility, amortization schedule based period for interest and principal payments				120 months
Line of credit facility, frequency of principal and interest periodic payment				monthly
Percentage of swap transaction of principal balance			100.00%
Credit Facility [Member] | Term Loan [Member] | LIBOR [Member]
Long-term debt [Abstract]
Term of variable rate				1 month
Interest rate on credit facility			3.50%
Credit Facility [Member] | Term Loan [Member] | LIBOR [Member] | Interest Rate Floor [Member]
Long-term debt [Abstract]
Interest rate on credit facility			0.25%
Credit Facility [Member] | Delayed Draw Term Loan [Member]
Long-term debt [Abstract]
Line of credit facility, maximum borrowing capacity			$ 10,000	$ 0
Expiration date of credit facility				Dec. 01, 2024
Line of credit facility, amortization schedule based period for interest and principal payments				120 months
Line of credit facility, monthly interest payment period				18 months
Line of credit facility, frequency of principal and interest periodic payment				monthly
Credit Facility [Member] | Delayed Draw Term Loan [Member] | LIBOR [Member]
Long-term debt [Abstract]
Term of variable rate				1 month
Interest rate on credit facility			3.50%
Credit Facility [Member] | Delayed Draw Term Loan [Member] | LIBOR [Member] | Interest Rate Floor [Member]
Long-term debt [Abstract]
Interest rate on credit facility			0.25%
Credit Facility [Member] | Credit Agreement [Member]
Long-term debt [Abstract]
Line of credit facility, maximum borrowing capacity			$ 15,000
Expiration date of credit facility				Jan. 31, 2021
Credit Facility [Member] | Revolving Loan [Member]
Long-term debt [Abstract]
Line of credit facility, maximum borrowing capacity			$ 15,000
Expiration date of credit facility				Nov. 13, 2022
Loan repayment period				30 days
Credit Facility [Member] | Revolving Loan [Member] | Interest Rate Floor [Member]
Long-term debt [Abstract]
Interest rate on credit facility			4.00%
Credit Facility [Member] | Revolving Loan [Member] | Prime Rate [Member]
Long-term debt [Abstract]
Interest rate on credit facility			0.50%
Credit Facility [Member] | Revolving Loan [Member] | Letter of Credit [Member]
Long-term debt [Abstract]
Line of credit facility, maximum borrowing capacity			$ 10,000