Note 15 - Stockholders' Equity (Details Textual) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Common Stock, Shares Authorized	100,000,000	100,000,000
Common Stock, Par or Stated Value Per Share	$ 0.10	$ 0.10
Preferred Stock, Shares Authorized	5,000,000	5,000,000
Preferred Stock, Par or Stated Value Per Share	$ 0.10	$ 0.10
Treasury Stock, Shares	1,583,909	1,729,727
Common Stock, Capital Shares Reserved for Future Issuance	1,366,025
Preferred Stock, Shares Outstanding	0	0
Nonvoting Common Stock [Member]
Common Stock, Shares Authorized	730,746	730,746
Common Stock, Par or Stated Value Per Share	$ 0.10	$ 0.10
Common Stock, Shares, Outstanding	0	0