Derivative Instruments (Details 3) (Not Designated as Hedging Instrument, USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Not Designated as Hedging Instrument
Effect of Non-designated Derivative Instruments on the Consolidated Statement of Operations
Amount of Unrealized Loss Recognized in Other Income Expense	$ 0	$ 594	$ 0	$ 157