Condensed Consolidated Balance Sheets (Parentheticals) - $ / shares shares in Thousands	Mar. 31, 2020	Dec. 31, 2019
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	4,042	3,953
Common Shares [Member]
Common Stock, Shares Authorized	150,000	150,000
Common Stock, Shares, Issued	38,501	37,609
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