REVENUE - Net Revenue Earned by Category of Payer (Details) - USD ($) $ in Thousands	3 Months Ended					6 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Net revenue	$ 915,784		$ 759,237
Commercial payers
Disaggregation of Revenue [Line Items]
Net revenue	786,278	$ 746,647	648,507	$ 690,686	$ 678,706	$ 1,395,154	$ 1,927,426	$ 2,618,112
Government payers
Disaggregation of Revenue [Line Items]
Net revenue	115,205	$ 102,581	97,841	$ 100,431	$ 93,114	$ 200,422	$ 274,509	$ 374,940
Patients
Disaggregation of Revenue [Line Items]
Net revenue	$ 14,301		$ 12,889