Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 112	$ 87
Additions Charged to Revenues and Expenses	75	74
Deductions	(144)	(49)
Balance at End of Period	$ 43	$ 112