SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS (Details) - Allowance for doubtful accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Changes in valuation and qualifying accounts
Balance at Beginning of Period	$ 4,047	$ 5,447	$ 4,612
Charged to Costs and Expenses		764	1,205
Reductions to Charges to Costs and Expenses	(150)
Charged to Other Accounts	(11)	(1,934)	(126)
Addition		107	130
Deduction	(640)	(337)	(374)
Balance at End of Period	$ 3,246	$ 4,047	$ 5,447