Goodwill and Other Intangibles (Amortizable Intangibles) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Amortizable intangible assets, cost	$ 52,342	$ 52,453
Amortizable intangible assets, accumulated amortization expense	(25,634)	(24,396)
Favorable Leases [Member]
Amortizable intangible assets, cost	51,660	51,660
Amortizable intangible assets, accumulated amortization expense	(25,284)	(23,969)
Noncompete Agreements [Member]
Amortizable intangible assets, cost	682	793
Amortizable intangible assets, accumulated amortization expense	(350)	(427)
Unfavorable Leases [Member]
Amortizable intangibles, cost	49,380	49,380
Amortizable intangibles, accumulated amortization benefit	$ 28,028	$ 26,560