Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accrued compensation and benefits:
Accrued compensation	$ 24,526	$ 22,480
Accrued vacation pay	12,670	12,107
Accrued compensation and benefits	37,196	34,587
Accrued expenses and other current liabilities:
Refunds due to payors	20,085	26,659
Income tax payable	0	13,618
Other	10,935	13,198
Accrued settlement (Note 20)	6,573	7,641
Accrued expenses and other current liabilities	$ 37,593	$ 61,116