Derivatives Derivatives Pre-Tax Losses (Details) (Designated as hedging instrument [Member], Interest rate swap [Member], Cash flow hedging [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Other income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on cash flow hedge ineffectiveness, net	$ 0
Maturity date December 23, 2019 [Member] | Other income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on cash flow hedge ineffectiveness, net	0
Maturity date June 22, 2020 [Member] | Other income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on cash flow hedge ineffectiveness, net	0
Maturity date September 21, 2020 [Member] | Other income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on cash flow hedge ineffectiveness, net	0
Effective portion [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months	0
Effective portion [Member] | Maturity date December 23, 2019 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on interest rate cash flow hedges, pretax, accumulated other comprehensive income (loss)	(239)
Cash flow hedge gain (loss) reclassified to interest expense, net	0
Effective portion [Member] | Maturity date June 22, 2020 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on interest rate cash flow hedges, pretax, accumulated other comprehensive income (loss)	(238)
Cash flow hedge gain (loss) reclassified to interest expense, net	0
Effective portion [Member] | Maturity date September 21, 2020 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on interest rate cash flow hedges, pretax, accumulated other comprehensive income (loss)	(267)
Cash flow hedge gain (loss) reclassified to interest expense, net	$ 0