Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 21,490,000	$ 20,219,000
Convertible preferred stock, par value	$ 1.00	$ 1.00
Convertible preferred stock, authorized shares	500,000	500,000
Convertible preferred stock, outstanding shares	0	0
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	21,058,000	20,743,000
Common stock, shares issued	21,058,000	20,742,000
Treasury Stock, Shares	209	850