Derivative Financial Instruments - Effect of Derivative Financial Instruments on Income Statement (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Not Designated as Hedging Instrument | Interest rate contracts | Other income
Derivative [Line Items]
Amount of Gain (Loss) Recognized Income on Derivative	$ 43	$ (16)	$ 31	$ 249
Designated as Hedging Instrument | Cash Flow Hedging | Interest Expense
Derivative [Line Items]
Amount of Gain (Loss) Reclassified from Other Comprehensive Income into Income (Effective Portion)	(356)	(207)	(1,051)	(587)
Designated as Hedging Instrument | Interest rate contracts | Cash Flow Hedging
Derivative [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	$ 28	$ (248)	$ (2,530)	$ 1,550