Accrued Expenses and Other Current Liabilities and Other Liabilities - Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued Expenses and Other Current Liabilities and Other Liabilities
Patient prepayments, deposits, and refunds payable	$ 27,195	$ 24,183
Accrued sales taxes and other taxes	9,863	8,543
Derivative liability	7,686	3,516
Insurance and self-insurance accruals	7,651	8,033
Accrued professional fees	1,016	2,533
Accrued interest payable	440	266
Other current liabilities	9,010	8,751
Total	$ 62,861	$ 55,825