Fair Value (Assets And Liabilities Measured At Fair Value) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2011
Total available-for-sale securities	$ 10,503
Executive deferred compensation plan trust	2,321	[1]
Total fuel price derivatives - liabilities	17,820
Total interest rate swap arrangements	361
Contingent Consideration	10,000
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Total available-for-sale securities	5,033
Executive deferred compensation plan trust	2,321	[1]
Total fuel price derivatives - liabilities
Total interest rate swap arrangements
Contingent Consideration
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Mortgage-Backed Securities [Member]
Total available-for-sale securities
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Asset-Backed Securities [Member]
Total available-for-sale securities
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Municipal Bonds [Member]
Total available-for-sale securities
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Equity Securities [Member]
Total available-for-sale securities	5,033
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fuel Price Derivatives - Unleaded Fuel [Member]
Total fuel price derivatives - liabilities
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fuel Price Derivatives - Diesel [Member]
Total fuel price derivatives - liabilities
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Interest Rate Swap Arrangements With Base Rate Of 1.35% [Member]
Total interest rate swap arrangements		[2]
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Interest Rate Swap Arrangements With Base Rate Of 0.56% [Member]
Total interest rate swap arrangements		[2]
Significant Other Observable Inputs (Level 2) [Member]
Total available-for-sale securities	5,470
Executive deferred compensation plan trust		[1]
Total fuel price derivatives - liabilities	12,295
Total interest rate swap arrangements	361
Contingent Consideration
Significant Other Observable Inputs (Level 2) [Member] | Mortgage-Backed Securities [Member]
Total available-for-sale securities	3,284
Significant Other Observable Inputs (Level 2) [Member] | Asset-Backed Securities [Member]
Total available-for-sale securities	2,042
Significant Other Observable Inputs (Level 2) [Member] | Municipal Bonds [Member]
Total available-for-sale securities	144
Significant Other Observable Inputs (Level 2) [Member] | Equity Securities [Member]
Total available-for-sale securities
Significant Other Observable Inputs (Level 2) [Member] | Fuel Price Derivatives - Unleaded Fuel [Member]
Total fuel price derivatives - liabilities	12,295
Significant Other Observable Inputs (Level 2) [Member] | Fuel Price Derivatives - Diesel [Member]
Total fuel price derivatives - liabilities
Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swap Arrangements With Base Rate Of 1.35% [Member]
Total interest rate swap arrangements	48	[2]
Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swap Arrangements With Base Rate Of 0.56% [Member]
Total interest rate swap arrangements	313	[2]
Significant Unobservable Inputs (Level 3) [Member]
Total available-for-sale securities
Executive deferred compensation plan trust		[1]
Total fuel price derivatives - liabilities	5,525
Total interest rate swap arrangements
Contingent Consideration	10,000
Significant Unobservable Inputs (Level 3) [Member] | Mortgage-Backed Securities [Member]
Total available-for-sale securities
Significant Unobservable Inputs (Level 3) [Member] | Asset-Backed Securities [Member]
Total available-for-sale securities
Significant Unobservable Inputs (Level 3) [Member] | Municipal Bonds [Member]
Total available-for-sale securities
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member]
Total available-for-sale securities
Significant Unobservable Inputs (Level 3) [Member] | Fuel Price Derivatives - Unleaded Fuel [Member]
Total fuel price derivatives - liabilities
Significant Unobservable Inputs (Level 3) [Member] | Fuel Price Derivatives - Diesel [Member]
Total fuel price derivatives - liabilities	5,525
Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Swap Arrangements With Base Rate Of 1.35% [Member]
Total interest rate swap arrangements		[2]
Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Swap Arrangements With Base Rate Of 0.56% [Member]
Total interest rate swap arrangements		[2]
Mortgage-Backed Securities [Member]
Total available-for-sale securities	3,284
Asset-Backed Securities [Member]
Total available-for-sale securities	2,042
Municipal Bonds [Member]
Total available-for-sale securities	144
Equity Securities [Member]
Total available-for-sale securities	5,033
Fuel Price Derivatives - Unleaded Fuel [Member]
Total fuel price derivatives - liabilities	12,295
Fuel Price Derivatives - Diesel [Member]
Total fuel price derivatives - liabilities	5,525
Interest Rate Swap Arrangements With Base Rate Of 1.35% [Member]
Total interest rate swap arrangements	48	[2]
Weighted-average base rate	1.35%
Aggregate notional amount	50,000
Interest Rate Swap Arrangements With Base Rate Of 0.56% [Member]
Total interest rate swap arrangements	313	[2]
Weighted-average base rate	0.56%
Aggregate notional amount	$ 150,000

[1] The fair value of these instruments is recorded in other assets.

[2] The fair value of these instruments is recorded in accrued expenses.