Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 359	$ 252
Property and Equipment, Accumulated depreciation	$ 128,533	$ 128,457
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	35,000,000	35,000,000
Common stock, shares issued	11,084,318	10,952,268