Intangible Assets (Future Amortization) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2010
Finite-Lived Intangible Assets [Line Items]
2012 (remainder)	$ 3,482
2013	3,634
2014	2,096
2015	3,444
2016	3,732
Thereafter	47,560
Intangible assets, net	63,948	66,592
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Weighted Average Original Useful Lives	2 years
2012 (remainder)	2,960
2013	2,591
2014	0
2015	0
2016	0
Thereafter	0
Intangible assets, net	5,551	7,674	7,129	14,000
Favorable Lease Rates
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Weighted Average Original Useful Lives	43 years 9 months 18 days
2012 (remainder)	522
2013	1,043
2014	1,043
2015	1,043
2016	1,043
Thereafter	32,330
Intangible assets, net	37,024	37,545	38,067	38,588
Development Agreement
Finite-Lived Intangible Assets [Line Items]
2012 (remainder)	0
2013	0
2014	1,053
2015	2,401
2016	2,689
Thereafter	15,230
Intangible assets, net	$ 21,373	$ 21,373	$ 0	$ 0