Derivatives (Gain Loss on Hedged Debt and Swap) (Details) (Fair Value Hedging, Interest Rate Contracts, Designated as Hedging Instrument, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Net impact	$ 3,782	$ 293	$ (730)
Loss on Redemption of Debt
Derivative Instruments, Gain (Loss) [Line Items]
Loss on redemption of debt	3,502	0	0
Other Income (Expense)
Derivative Instruments, Gain (Loss) [Line Items]
Other income (expense)	$ 280	$ 293	$ (730)