Intangible Assets Narrative (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended							12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Concession Fees [Member]	Dec. 31, 2011 Concession Fees [Member]	Dec. 31, 2012 Other Intangible Assets [Member]	Dec. 31, 2011 Other Intangible Assets [Member]	Dec. 31, 1997 Service Agreements [Member]	Dec. 31, 2012 Service Agreements [Member]	Dec. 31, 2012 Contractual Rights [Member]	Dec. 31, 2012 Other Miscellaneous Intangibles [Member]	Dec. 31, 2012 Minimum [Member]	Dec. 31, 2012 Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 15,561	$ 14,732		$ 6,800	$ 6,800	$ 8,761	$ 7,932		$ 7,362	$ 1,040	$ 359
Accumulated amortization of intangible assets				4,148	3,876	712	643
Net intangible assets	10,701	10,213
Useful life of intangible assets								25 years				5 years	70 years
Amortization of Intangible Assets	340	340	335
Future Amortization of Intangible Assets
2013	340
2014	340
2015	340
2016	340
2017	$ 340