Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts [Member]
Balance at Beginning of Period	$ 1,348	$ 1,519	$ 1,597
Additions Charged to Costs and Expenses	$ 506	$ 467	$ 83
Additions Charged to Other Accounts
Deductions	$ (555)	$ (638)	$ (161)
Balance at End of Period	1,299	1,348	1,519
Valuation Allowance of Deferred Tax Assets [Member]
Balance at Beginning of Period	$ 1,381	1,298	1,200
Additions Charged to Costs and Expenses		$ 83	$ 98
Additions Charged to Other Accounts
Deductions	$ (351)
Balance at End of Period	$ 1,030	$ 1,381	$ 1,298