Derivative Instruments (Details 4) (Not Designated as Hedging Instrument [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Not Designated as Hedging Instrument [Member]
Effect of Non-designated Derivative Instruments on the Consolidated Statement of Operations
Amount of Gain (Loss) Recognized in Derivative Expense	$ 233	$ (233)