Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 87	$ 153	$ 662
Additions Charged to Revenues and Expenses	74	85	1,576
Deductions	(49)	(151)	(2,085)
Balance at End of Period	112	87	153
Reduction to revenues	$ 0	$ 0	$ 1,600