CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net Income	$ 180.5	$ 186.3
Adjustments to reconcile net income to net cash provided by operating activites:
Fleet transition costs	38.9	13.2
Depreciation and amortization	184.2	172.0
Stock-based Compensation	9.5	10.6
Increase in air traffic liability	118.7	95.7
Increase in other assets and liabilities – net	77.0	28.6
Net cash provided by operating activities	608.8	506.4
Cash flows from investing activities:
Aircraft and aircraft purchase deposits	(260.3)	(109.3)
Other flight equipment	(18.4)	(20.6)
Other property and equipment	15.8	24.0
Total property and equipment additions	294.5	153.9
Proceeds from disposition of assets	19.9	4.7
Purchases of marketable securities	(781.7)	(796.7)
Sales and maturities of marketable securities	697.2	646.6
Construction of Terminal 6 at LAX	(80.4)	(0.3)
Restricted deposits and other	0.9	0.6
Net cash used in investing activities	(438.6)	(299.0)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	106.5	0
Long-term debt payments	(248.3)	(231.3)
Purchase of treasury stock	(61.6)	(31.2)
Proceeds and tax benefit from issuance of common stock	16.7	29.1
Other financing activities	(5.5)	(9.0)
Net cash used in financing activities	(192.2)	(242.4)
Net change in cash and cash equivalents	(22.0)	(35.0)
Cash and cash equivalents at beginning of year	89.5	164.2
Cash and cash equivalents at end of period	67.5	129.2
Supplemental disclosure of cash paid during the period for:
Interest (net of amount capitalized)	66.0	79.3
Income taxes	2.2	(4.9)
Relocation credit and assets constructed on account related to Terminal 6 at LAX	$ 10.5	$ 0