Condensed Consolidated Balance Sheets (Parentheticals) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Allowance for doubtful accounts	$ 20,600,000	$ 21,700,000
Unamortized debt discount, current	0	0
Deferred Costs, Current	920,000	575,000
Unamortized debt discount, noncurrent	0	0
Deferred Costs, Noncurrent	$ 1,524,000	$ 1,534,000
Stockholders' Equity Note [Abstract]
Common stock, shares issued	30,507,903	30,492,044
Common stock, shares outstanding	30,507,903	30,492,044
Treasury stock, shares	0	0
Preferred stock, shares outstanding	0	0
Series Y Preferred Stock, Par or Stated Value Per Share	$ 0.10	$ 0.10
Series Y Preferred Stock, Shares Authorized	350,000	350,000.00
Series Y Preferred Stock, Shares Issued	0.00	0.00
Series Y Preferred Stock, Shares Outstanding	0.00	0.00
Common stock, par value (per share)	$ 0.10	$ 0.10
Common stock, shares authorized	220,000,000	220,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares authorized	500,000	500,000
Preferred stock, par value (per share)	$ 0.10	$ 0.10