Note 9 - Estimated Liability for Appeals (Details Textual) - USD ($)	3 Months Ended	6 Months Ended
	Mar. 31, 2018	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Estimated Liability for Appeals Gain (Loss) Included in Earnings	$ 8,400,000	$ 8,436,000
Estimated Liability for Appeals		22,252,000		$ 30,787,000
Estimated Liability for Appeals, Amount Adjudicated		19,400,000		19,300,000
Estimated Liability for Appeals, Amount Probable of Being Returned		0		8,500,000
Estimated Liability for Appeals, Commercial Customers Claim Findings, Adjudicated in Favor of Providers		$ 2,900,000		$ 3,200,000