Condensed Consolidated Balance Sheets (Parentheticals) - $ / shares shares in Thousands	Jun. 30, 2019	Dec. 31, 2018
Common Stock, Par or Stated Value Per Share	$ 0.25
Preferred Stock, Shares Authorized	300	300
Preferred Stock, Shares Outstanding	0	0
Treasury Stock, Shares	3,950	3,841
Common Shares [Member]
Common Stock, Shares Authorized	150,000	100,000
Common Stock, Shares, Issued	37,617	37,010
Common Stock, Par or Stated Value Per Share	$ 0	$ 0
Class B Common Shares [Member]
Common Stock, Shares Authorized	12,000	12,000
Common Stock, Shares, Issued	6	6
Common Stock, Par or Stated Value Per Share	$ 0	$ 0