Financial Instruments - Effective Portion of Unrealized Gain and Loss (Details) - Interest rate swaps - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Amortization of Gain (Loss) on Derivative Instrument, Included in Net Income	$ 400	$ 400
Derivatives designated as and not designated as cash flow hedges:
Reclassified from Accumulated OCL, Gain/(Loss)	384	384
Derivative, Gain (Loss) on Derivative, Net	$ 299	$ 172