CONSOLIDATED BALANCE SHEETS (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Current Assets
Cash and cash equivalents	$ 102.2	$ 89.5
Marketable securities	1,038.7	1,118.7
Total cash and marketable securities	1,140.9	1,208.2
Receivables - less allowance for doubtful accounts	136.4	120.1
Inventories and supplies - net	44.3	45.1
Deferred income taxes	134.2	120.5
Fuel hedge contracts	46.7	61.4
Prepaid expenses and other current assets	93.0	106.7
Total Current Assets	1,595.5	1,662.0
Property and Equipment
Aircraft and other flight equipment	4,041.8	3,807.6
Other property and equipment	762.3	647.8
Deposits for future flight equipment	262.5	202.5
Property and Equipment Total	5,066.6	4,657.9
Less accumulated depreciation and amortization	1,665.1	1,509.5
Total Property and Equipment - Net	3,401.5	3,148.4
Fuel Hedge Contracts	70.2	69.9
Other Assets	127.8	136.3
Total Assets	5,195.0	5,016.6
Current Liabilities
Accounts payable	103.6	60.2
Accrued aircraft rent	31.6	43.1
Accrued wages, vacation and payroll taxes	163.8	176.6
Other accrued liabilities	513.3	501.2
Air traffic liability	489.4	422.4
Current portion of long-term debt	207.9	221.2
Total Current Liabilities	1,509.6	1,424.7
Long-Term Debt, Net of Current Portion	1,099.0	1,313.0
Other Liabilities and Credits
Deferred income taxes	362.9	279.9
Deferred revenue	410.2	403.5
Obligation for pension and postretirement medical benefits	463.4	367.1
Other liabilities	176.7	123.0
Other Liabilities and Credits Totals	1,413.2	1,173.5
Commitments and Contingencies
Shareholders' Equity
Preferred stock	0	0
Common stock	37.9	37.0
Capital in excess of par value	840.0	815.5
Treasury stock (common)	(125.3)	(46.0)
Accumulated other comprehensive loss	(390.0)	(267.2)
Retained earnings	810.6	566.1
Shareholders' Equity Total	1,173.2	1,105.4
Total Liabilities and Shareholders' Equity	$ 5,195.0	$ 5,016.6