Goodwill and Other Intangibles (Amortizable Intangibles) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Amortizable intangible assets, cost	$ 52,453	$ 52,589
Amortizable intangible assets, accumulated amortization expense	(24,396)	(18,638)
Favorable Leases [Member]
Amortizable intangible assets, cost	51,660	52,010
Amortizable intangible assets, accumulated amortization expense	(23,969)	(18,329)
Noncompete Agreements [Member]
Amortizable intangible assets, cost	793	579
Amortizable intangible assets, accumulated amortization expense	(427)	(309)
Unfavorable Leases [Member]
Amortizable intangibles, cost	49,380	49,570
Amortizable intangible, accumulated amortization benefit	$ 26,560	$ 20,071