Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Warranty	$ 8,092	$ 8,130
Due to representatives	9,510	10,188
Payroll	3,266	3,153
Profit sharing	2,029	2,016
Worker's compensation	322	535
Medical self-insurance	527	532
Customer prepayments	1,933	1,639
Donations	600	1,600
Employee benefits and other	4,476	3,550
Total	$ 30,755	$ 31,343