CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Accounts receivable, allowance	$ 3,056	$ 4,866
Preferred stock par value	$ 1.00	$ 1.00
Preferred stock shares authorized	1,000,000	1,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Common stock par value	$ 0.666	$ 0.666
Common stock shares authorized	70,000,000	70,000,000
Common stock shares issued	51,945,299	51,206,969
Common stock shares outstanding	51,945,299	51,206,969
Treasury stock, shares	1,494,080	1,457,206