Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts and returns
Changes in Valuation and Qualifying Accounts
Balance at Beginning of Period		$ 390	$ 404
Charged to Costs and Expenses	$ 106
Deductions	(29)	(390)
Other			(14)
Balance at End of Period	77		390
Inventory reserves
Changes in Valuation and Qualifying Accounts
Balance at Beginning of Period	10,465	23,642	25,091
Charged to Costs and Expenses	1,051	1,185	1,003
Deductions	(2,619)	(14,362)	(2,452)
Balance at End of Period	$ 8,897	$ 10,465	$ 23,642