Risk Management and Financial Instruments (Details 1) In Millions, unless otherwise specified			3 Months Ended					3 Months Ended	6 Months Ended									3 Months Ended	6 Months Ended																					6 Months Ended					3 Months Ended
	Jun. 30, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2010 Fuel Hedge Swaps Collars and Call Options [Member] Designated as Hedging Instrument [Member]	Dec. 31, 2010 Fuel Hedge Swaps Collars and Call Options [Member] Designated as Hedging Instrument [Member] Other Noncurrent Liabilities [Member] USD ($)	Dec. 31, 2010 Fuel Hedge Swaps Collars and Call Options [Member] Designated as Hedging Instrument [Member] Other Accrued Liabilities [Member] USD ($)	Dec. 31, 2010 Fuel Hedge Swaps Collars and Call Options [Member] Designated as Hedging Instrument [Member] Other Noncurrent Assets [Member] USD ($)	Dec. 31, 2010 Fuel Hedge Swaps Collars and Call Options [Member] Designated as Hedging Instrument [Member] Prepaid expenses and other assets [Member] USD ($)	Dec. 31, 2010 Interest Rate Swaps and Call Options [Member] Designated as Hedging Instrument [Member] USD ($)	Jun. 30, 2011 Interest Rate Swaps and Call Options [Member] Designated as Hedging Instrument [Member] USD ($)	Jun. 30, 2011 Interest Rate Swaps and Call Options [Member] Designated as Hedging Instrument [Member] Other Noncurrent Liabilities [Member] USD ($)	Dec. 31, 2010 Interest Rate Swaps and Call Options [Member] Designated as Hedging Instrument [Member] Other Noncurrent Liabilities [Member] USD ($)	Jun. 30, 2011 Interest Rate Swaps and Call Options [Member] Designated as Hedging Instrument [Member] Other Accrued Liabilities [Member] USD ($)	Dec. 31, 2010 Interest Rate Swaps and Call Options [Member] Designated as Hedging Instrument [Member] Other Accrued Liabilities [Member] USD ($)	Jun. 30, 2011 Interest Rate Swaps and Call Options [Member] Designated as Hedging Instrument [Member] Other Noncurrent Assets [Member] USD ($)	Dec. 31, 2010 Interest Rate Swaps and Call Options [Member] Designated as Hedging Instrument [Member] Other Noncurrent Assets [Member] USD ($)	Jun. 30, 2011 Interest Rate Swaps and Call Options [Member] Designated as Hedging Instrument [Member] Prepaid expenses and other assets [Member] USD ($)	Dec. 31, 2010 Interest Rate Swaps and Call Options [Member] Designated as Hedging Instrument [Member] Prepaid expenses and other assets [Member] USD ($)	Dec. 31, 2010 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member]	Jun. 30, 2011 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member]	Jun. 30, 2011 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] Other Noncurrent Liabilities [Member] USD ($)	Dec. 31, 2010 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] Other Noncurrent Liabilities [Member] USD ($)	Jun. 30, 2011 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] Other Accrued Liabilities [Member] USD ($)	Dec. 31, 2010 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] Other Accrued Liabilities [Member] USD ($)	Jun. 30, 2011 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] Other Noncurrent Assets [Member] USD ($)	Dec. 31, 2010 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] Other Noncurrent Assets [Member] USD ($)	Jun. 30, 2011 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] Prepaid expenses and other assets [Member] USD ($)	Dec. 31, 2010 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] Prepaid expenses and other assets [Member] USD ($)	Jun. 30, 2011 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] Japanese Yen Notional Balance [Member] JPY (¥)	Dec. 31, 2010 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] Japanese Yen Notional Balance [Member] JPY (¥)	Jun. 30, 2011 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] Canadian Dollars Notional Balance [Member] CAD	Dec. 31, 2010 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] Canadian Dollars Notional Balance [Member] CAD	Jun. 30, 2011 Designated as Hedging Instrument [Member] Other Noncurrent Liabilities [Member] USD ($)	Dec. 31, 2010 Designated as Hedging Instrument [Member] Other Noncurrent Liabilities [Member] USD ($)	Jun. 30, 2011 Designated as Hedging Instrument [Member] Other Accrued Liabilities [Member] USD ($)	Dec. 31, 2010 Designated as Hedging Instrument [Member] Other Accrued Liabilities [Member] USD ($)	Jun. 30, 2011 Designated as Hedging Instrument [Member] Other Noncurrent Assets [Member] USD ($)	Dec. 31, 2010 Designated as Hedging Instrument [Member] Other Noncurrent Assets [Member] USD ($)	Jun. 30, 2011 Designated as Hedging Instrument [Member] Prepaid expenses and other assets [Member] USD ($)	Dec. 31, 2010 Designated as Hedging Instrument [Member] Prepaid expenses and other assets [Member] USD ($)	Jun. 30, 2011 Fuel Hedge Swaps Collars and Call Options [Member] Not Designated as Hedging Instrument [Member]	Jun. 30, 2011 Fuel Hedge Swaps Collars and Call Options [Member] Not Designated as Hedging Instrument [Member] Other Noncurrent Liabilities [Member] USD ($)	Jun. 30, 2011 Fuel Hedge Swaps Collars and Call Options [Member] Not Designated as Hedging Instrument [Member] Other Accrued Liabilities [Member] USD ($)	Jun. 30, 2011 Fuel Hedge Swaps Collars and Call Options [Member] Not Designated as Hedging Instrument [Member] Other Noncurrent Assets [Member] USD ($)	Jun. 30, 2011 Fuel Hedge Swaps Collars and Call Options [Member] Not Designated as Hedging Instrument [Member] Prepaid expenses and other assets [Member] USD ($)	Dec. 31, 2010 Not Designated as Hedging Instrument [Member] Fuel Hedge Swaps [Member]	Dec. 31, 2010 Not Designated as Hedging Instrument [Member] Fuel Hedge Swaps [Member] Other Noncurrent Liabilities [Member] USD ($)	Dec. 31, 2010 Not Designated as Hedging Instrument [Member] Fuel Hedge Swaps [Member] Other Accrued Liabilities [Member] USD ($)	Dec. 31, 2010 Not Designated as Hedging Instrument [Member] Fuel Hedge Swaps [Member] Other Noncurrent Assets [Member] USD ($)	Dec. 31, 2010 Not Designated as Hedging Instrument [Member] Fuel Hedge Swaps [Member] Prepaid expenses and other assets [Member] USD ($)	Jun. 30, 2011 Other Noncurrent Liabilities [Member] USD ($)	Dec. 31, 2010 Other Noncurrent Liabilities [Member] USD ($)	Jun. 30, 2011 Other Accrued Liabilities [Member] USD ($)	Dec. 31, 2010 Other Accrued Liabilities [Member] USD ($)	Jun. 30, 2011 Other Noncurrent Assets [Member] USD ($)	Dec. 31, 2010 Other Noncurrent Assets [Member] USD ($)	Jun. 30, 2011 Prepaid expenses and other assets [Member] USD ($)	Dec. 31, 2010 Prepaid expenses and other assets [Member] USD ($)
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives								$ 1,143	$ 1,066																			¥ 155,000	¥ 141,100	333	233
Notional Amount of Derivatives Decimal			1,500,000,000																																					1,400,000,000					192,000,000
Maturity Date			January 2011 - February 2012					August 2011 - May 2019	August 2011 - May 2019									January 2011 - November 2013	July 2011 - January 2014																					July 2011 - June 2012					January 2011 - December 2011
Derivative Asset, Fair Value						24	328							0	0	0	0							3	0	1	0									3	24	1	328				0	201				14	27					3	38	202	355
Liability designated as hedges				0	0					(37)	(39)	(31)	(35)							(21)	(36)	(53)	(60)									(58)	(75)	(84)	(95)						0	(66)				(8)	(19)			(58)	(83)	(150)	(114)
Hedge Margin Payable, Net	$ 9	$ (119)