Commitments And Contingencies, And Derivative Financial Instruments (Narrative) (Details) (USD $)	Sep. 30, 2011
Operating leases, aggregate future lease payments	$ 832,701,000
Net aggregate future lease payments	832,700,000
Notional amount of floating-to-fixed interest rate swap hedge	52,200,000
Letters of credit outstanding	309,600,000
Revolving Credit Facility [Member]
Letters of credit outstanding	28,700,000
Standby Letters Of Credit [Member]
Letters of credit outstanding	$ 280,900,000