Note 1 - Organization, Description of Business and Summary of Significant Accounting Policies - Schedule of Third-party Payers as a Percentage of Total (Details) - Customer Concentration Risk [Member]

3 Months Ended

9 Months Ended

12 Months Ended

Sep. 30, 2020

Sep. 30, 2019

Sep. 30, 2020

Sep. 30, 2019

Dec. 31, 2019

Revenue from Contract with Customer Benchmark [Member]

Concentrations of credit risk

36.00%

50.00%

35.00%

47.00%

Johnson and Johnson Services Inc JJSI [Member] | Accounts Receivable [Member]

Concentrations of credit risk

10.00%

Johnson and Johnson Services Inc JJSI [Member] | Revenue from Contract with Customer Benchmark [Member]

Concentrations of credit risk

13.00%

12.00%

Medicare [Member] | Accounts Receivable [Member]

Concentrations of credit risk

12.00%

15.00%

Medicare [Member] | Revenue from Contract with Customer Benchmark [Member]

Concentrations of credit risk

25.00%

26.00%

24.00%

United Healthcare [Member] | Accounts Receivable [Member]

Concentrations of credit risk

10.00%

United Healthcare [Member] | Revenue from Contract with Customer Benchmark [Member]

Concentrations of credit risk

11.00%