Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Accounts and other receivables, allowance for doubtful accounts and sales returns	$ 3,140	$ 2,937
Common stock, no par value
Common stock, shares issued	33,350,128	33,176,024
Common stock, shares outstanding	33,350,128	33,176,024
Common Stock, Shares Held in Employee Trust, Shares	74,338	72,883