STOCK-BASED COMPENSATION - Vesting Conditions (Details) - shares		12 Months Ended
		Dec. 31, 2022		Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of share of restricted stock (units)		55,410
Restricted stock units, type 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of share of restricted stock (units)	[1],[2]	34,493
Target, Regional adjusted EBITDA, percentage		70.00%
Target, Group adjusted EBITDA, percentage		30.00%
Restricted stock units, type 1 | Performance Conditions, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target, Group adjusted EBITDA, percentage		100.00%
Restricted stock units, type 1 | First Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of share of restricted stock (units)		53,075
Vesting rights, percentage		33.00%
Restricted stock units, type 1 | Second Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights, percentage		33.00%
Restricted stock units, type 1 | Third Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights, percentage		34.00%
Restricted stock units, type 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of share of restricted stock (units)	[1],[2]	15,667
Restricted stock units, type 2 | First Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of share of restricted stock (units)				73,596
Vesting rights, percentage		66.60%
Restricted stock units, type 2 | Second Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights, percentage		16.70%
Restricted stock units, type 2 | Third Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights, percentage		16.70%
Restricted stock units, time
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of share of restricted stock (units)		5,250	[2]	47,500
Restricted stock units, time | Performance Conditions, 2021 | Coit Staffing, Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target, Group adjusted EBITDA, percentage		100.00%

[1] The performance conditions with respect to restricted stock units may be satisfied as follows: (a)For employees from the Americas, Asia Pacific, and Europe 70% of the restricted stock units may be earned on the basis of performance as measured by a “regional adjusted EBITDA”, and 30% of the restricted stock units may be earned on the basis of performance as measured by a “group adjusted EBITDA”; and (b)For grants to Corporate office employees subject to 2022 performance conditions, 100% of the restricted stock units may be earned on the basis of performance as measured by a “group adjusted EBITDA”; and (c)For grants to Coit Staffing Principals subject to 2022 performance conditions, 100% of the restricted stock units may be earned on the basis of performance as measured by a “Coit EBITDA”.

[2] To the extent restricted stock units are earned, such restricted stock units will vest on the basis of service as follows: (a)33% and 66.6% for Type 1 and Type 2, respectively, of the restricted stock units will vest on the first anniversary of the grant date; (b)33% and 16.7% for Type 1 and Type 2, respectively, of the restricted stock units will vest on the second anniversary of the grant date; and (c)34% and 16.7% for Type 1 and Type 2, respectively, of the restricted stock units will vest on the third anniversary of the grant date; provided that, in each case, the employee remains employed by the Company from the grant date through the applicable service vesting date.