Debt Obligations (Outstanding Unsecured Notes in Series of Transactions) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Schedule of principal payments of debt obligations
Repurchase Amount	$ 4,294
Principal	3,981
Loss	(248)
Deferred Financing Amortization	8
2012 5.750% Notes [Member]
Schedule of principal payments of debt obligations
Repurchase Amount	309
Principal	301
Loss	(2)
Deferred Financing Amortization	0
Debt instrument stated interest rate	5.75%
2014 5.400% Notes
Schedule of principal payments of debt obligations
Repurchase Amount	3,501
Principal	3,255
Loss	(197)
Deferred Financing Amortization	6
Debt instrument stated interest rate	5.40%
2015 7.500% Notes [Member]
Schedule of principal payments of debt obligations
Repurchase Amount	484
Principal	425
Loss	(49)
Deferred Financing Amortization	$ 2
Debt instrument stated interest rate	7.50%