CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Millions, except Share data in Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Operating Revenues
Passenger, Mainline	$ 3,176.2		$ 2,763.4		$ 2,438.8
Passenger, Regional	774.5		725.2		668.6
Total passenger revenue	3,950.7		3,488.6		3,107.4
Freight and mail	108.7		106.2		95.9
Other - net	258.4		237.5		196.5
Total Operating Revenues	4,317.8		3,832.3		3,399.8
Operating Expenses
Wages and benefits	990.5		960.9		988.1
Variable incentive pay	71.9		92.0		76.0
Aircraft fuel, including hedging gains and losses	1,297.7	[1]	900.9	[1]	658.1	[1]
Aircraft maintenance	205.6		216.5		223.1
Aircraft rent	116.3		138.9		153.7
Landing fees and other rentals	238.2		232.8		223.2
Contracted services	185.1		163.0		150.6
Selling expenses	175.3		153.8		131.8
Depreciation and amortization	246.9		230.5		219.2
Food and beverage service	67.2		57.5		50.1
Other	235.3		200.7		213.9
Fleet transition and restructuring related expenses	38.9		13.2		44.6
Total Operating Expenses	3,868.9		3,360.7		3,132.4
Operating Income	448.9		471.6		267.4
Nonoperating income (expense)
Interest income	21.9		29.4		32.6
Interest expense	(87.3)		(108.3)		(104.3)
Interest capitalized	12.5		6.2		7.6
Other - net	(2.3)		7.0		(0.4)
Nonoperating Income (Expense) Total	(55.2)		(65.7)		(64.5)
Income before income tax	393.7		405.9		202.9
Income tax expense	149.2		154.8		81.3
Net Income	$ 244.5		$ 251.1		$ 121.6
Basic Earnings Per Share:	$ 6.81		$ 7.01		$ 3.39
Diluted Earnings Per Share:	$ 6.66		$ 6.83		$ 3.36
Shares used for computation:
Basic	35,878		35,822		35,815
Diluted	36,710		36,786		36,154

[1] Represents adjustments to reflect the timing of gain or loss recognition resulting from mark-to-market fuel-hedge accounting.