Derivative Financial Instruments (Gains (losses) recognized on derivatives (cash flow hedges)) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Interest Expense | Interest Rate Swap 1
Trading Activity, Gains and Losses, Net [Line Items]
Effective Portion, Recognized in OCI, Amount of Gain (Loss)	$ 176	$ (44)
Effective Portion, Reclassified from AOCI into Income, Amount of Gain (Loss)	(141)	(151)
Interest Expense | Interest Rate Swap 2
Trading Activity, Gains and Losses, Net [Line Items]
Effective Portion, Recognized in OCI, Amount of Gain (Loss)	281	132
Effective Portion, Reclassified from AOCI into Income, Amount of Gain (Loss)	(289)	(262)
Interest Expense | Interest Rate Swap 3
Trading Activity, Gains and Losses, Net [Line Items]
Effective Portion, Recognized in OCI, Amount of Gain (Loss)	541	(150)
Effective Portion, Reclassified from AOCI into Income, Amount of Gain (Loss)	(295)	(276)
Interest Expense | Interest Rate Swap 4
Trading Activity, Gains and Losses, Net [Line Items]
Effective Portion, Recognized in OCI, Amount of Gain (Loss)	1,130	(406)
Effective Portion, Reclassified from AOCI into Income, Amount of Gain (Loss)	(304)	(296)
Other Income | Interest Rate Swap 1
Trading Activity, Gains and Losses, Net [Line Items]
Ineffective Portion, Recognized in Income on Derivatives, Amount of Gain (Loss)	0	0
Other Income | Interest Rate Swap 2
Trading Activity, Gains and Losses, Net [Line Items]
Ineffective Portion, Recognized in Income on Derivatives, Amount of Gain (Loss)	0	0
Other Income | Interest Rate Swap 3
Trading Activity, Gains and Losses, Net [Line Items]
Ineffective Portion, Recognized in Income on Derivatives, Amount of Gain (Loss)	0	0
Other Income | Interest Rate Swap 4
Trading Activity, Gains and Losses, Net [Line Items]
Ineffective Portion, Recognized in Income on Derivatives, Amount of Gain (Loss)	$ 0	$ 0