Schedule II-Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Change in valuation and qualifying accounts
Balance at Beginning of Year	$ 2,981
Balance at End of Year	3,392	$ 2,981
Valuation Allowance on Deferred Tax Assets
Change in valuation and qualifying accounts
Balance at Beginning of Year	2,981	2,507	$ 5,665
Additions Charged to Expense	411	474	169
Deductions			(3,327)
Balance at End of Year	3,392	2,981	2,507
Reserve for Inventory Obsolescence
Change in valuation and qualifying accounts
Balance at Beginning of Year	10,537	18,301	16,679
Additions Charged to Expense	7,913	3,431	3,341
Deductions	(6,286)	(11,195)	(1,719)
Balance at End of Year	$ 12,164	$ 10,537	$ 18,301