CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowances (in dollars)	$ 5,448	$ 7,380
Other accounts receivable, allowances (in dollars)	$ 476	$ 806
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	70,000,000	70,000,000
Common stock, issued shares	28,810,902	28,684,779
Treasury stock, at cost, shares	3,404,639	3,097,634