SCHEDULE II - VALUATION ACCOUNTS (Details) - Accounts receivable, allowance for doubtful accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation accounts
Balance at Beginning of Period	$ 912	$ 215	$ 296
Additions Charged (Credited) to Expense	(125)	697	(26)
Net (Deductions) Recoveries			(55)
Balance at End of Period	$ 787	$ 912	$ 215