Schedule II - Valuation and Qualifying Accounts - Summary of Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts [Member]
Balance Beginning of Year	$ 304	$ 346	$ 1,058
Additions Charged/(Credited) to Cost and Expenses	61	(11)	61
Additions Charged/(Credited) to Other Accounts	(24)	(31)	(130)
Deductions			643
Balance End of Year	341	304	346
Valuation Allowance of Deferred Tax Assets [Member]
Balance Beginning of Year	9,863	8,944	32,407
Additions Charged/(Credited) to Cost and Expenses	1,673	3,134	(25,169)
Additions Charged/(Credited) to Other Accounts	(77)	(2,215)	1,706
Deductions
Balance End of Year	$ 11,459	$ 9,863	$ 8,944