CONDENSED CONSOLIDATED STATEMENTS OF FINANCIAL POSITION (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Trade accounts receivable, allowances	$ 2,153	$ 2,281	$ 1,767
Treasury stock, shares	99	96	96
Common Stock
Common stock, par value (in dollars per share)	$ 0.6944	$ 0.6944	$ 0.6944
Common stock, shares authorized	120,000	120,000	120,000
Common stock, shares issued	40,379	39,344	39,700
Class B Common Stock
Common stock, par value (in dollars per share)	$ 0.6944	$ 0.6944	$ 0.6944
Common stock, shares authorized	40,000	40,000	40,000
Common stock, shares issued	28,623	27,793	27,821