Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accrued Liabilities [Abstract]
Commissions	$ 9,144	$ 12,079
Warranty	10,548	10,183	$ 9,537	$ 14,336
Accrued dividend	36,077	30,436
Billings in excess of cost	12,381	5,464
Customer deposits	16,707	15,094
Interest	21,742	19,776
Rebates	19,414	16,511
Other	93,326	58,970
Total	$ 219,339	$ 168,513