SUMMARY OF SIGNIFICANT ACCOUNTING AND BUSINESS POLICIES - Self-insured Insurance and Medical Claims (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Reinsurance Retention Policy [Line Items]
Employee-related liabilities	$ 2,500,000	$ 2,300,000
Self-insured Insurance | Maximum
Reinsurance Retention Policy [Line Items]
Reinsurance retention policy, amount retained	100,000
Medical Claims | Maximum
Reinsurance Retention Policy [Line Items]
Reinsurance retention policy, amount retained	$ 175,000
Retention percentage of employee higher risk claims	0.05%