Goodwill and Other Intangibles (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Increase (decrease) in goodwill	$ 14,503,000	$ (68,000)
Goodwill impairment	0	0
Unamortizable intangible assets, other than goodwill	0	0
Amortization expense of amortizable intangible assets	4,700,000	6,100,000	8,500,000
Favorable Leases [Member]
Weighted-average remaining useful life of favorable leases, in years	10 years 0 months 21 days
Unfavorable Leases [Member]
Weighted-average remaining useful life of unfavorable leases, in years	5 years 4 months 2 days
Amortization benefit of unfavorable operating leases	$ 5,700,000	$ 6,700,000	$ 7,000,000