Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]

0000824142 (http://www.sec.gov/CIK)

Payables and Accruals [Abstract]	Period [Axis]
	2016-01-01 - 2016-12-31
Payables and Accruals [Abstract]
Accrued Liabilities	At December 31, accrued liabilities were comprised of the following:     December 31,   2016   2015   (in thousands) Warranty $ 7,936   $ 8,469 Due to representatives 9,907   10,597 Payroll 4,129   3,954 401(k) Contributions —   3,054 Profit sharing 1,967   2,220 Workers' compensation 580   366 Medical self-insurance 872   676 Customer prepayments 2,256   2,895 Donations 600   600 Employee benefits and other 3,693   4,404 Total $ 31,940   $ 37,235