Goodwill and Other Intangibles (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Increase (decrease) in goodwill	$ (68,000)	$ (338,000)
Goodwill impairment	0	0
Amortization expense of amortizable intangible assets	6,100,000	8,500,000	14,100,000
Favorable Leases [Member]
Weighted-average remaining useful life of favorable leases, in years	10.1
Unfavorable Leases [Member]
Weighted-average remaining useful life of unfavorable leases, in years	5.8
Amortization benefit of unfavorable operating leases	$ 6,700,000	$ 7,000,000	$ 9,200,000