Commitments and Contingencies (Swapped Variable Cost for Fixed Cost and Terms of Interest Rate Swap Agreements) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 Contract, One	Dec. 31, 2012 Contract, Two	Dec. 31, 2012 Contract, Three	Dec. 31, 2012 Contract, Four	Dec. 31, 2012 Contract, Five	Dec. 31, 2012 Interest rate swaps	Dec. 31, 2011 Interest rate swaps
Derivative [Line Items]
Notional Amount	$ 10,000	$ 10,000	$ 10,000	$ 5,000	$ 8,000	$ 43,000	$ 43,000
Fixed Cost	5.09%	5.84%	5.71%	4.35%	4.14%
Maturity Date	Jun. 30, 2021	Jun. 30, 2029	Jun. 30, 2030	Mar. 30, 2031	Jul. 07, 2031