Consolidated Statement of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 2,181	$ 1,136	$ 754
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	1,015	938	867
Unrealized (gain) loss on fuel derivative instruments	113	279	(5)
Deferred income taxes	(109)	501	50
Changes in certain assets and liabilities:
Accounts and other receivables	(88)	54	(17)
Other assets	103	142	(46)
Accounts payable and accrued liabilities	961	36	343
Air traffic liability	94	326	400
Cash collateral received from (provided to) derivative counterparties	(570)	(233)	57
Other, net	(462)	(277)	74
Net cash provided by operating activities	3,238	2,902	2,477
Net cash used in investing activities
Capital expenditures	(2,041)	(1,748)	(1,433)
Assets constructed for others	(102)	(80)	(14)
Purchases of short-term investments	(1,986)	(3,080)	(3,135)
Proceeds from sales of short-term and other investments	2,223	3,185	3,198
Other, net	(7)	(4)	0
Net cash used in investing activities	(1,913)	(1,727)	(1,384)
Net cash used in financing activities
Proceeds from issuance of long-term debt	500	300	0
Proceeds from Employee stock plans	46	110	96
Reimbursement for assets constructed for others	24	27	0
Proceeds from termination of interest rate derivative instrument	12	0	0
Payments of long-term debt and capital lease obligations	(213)	(561)	(313)
Payments of cash dividends	(180)	(139)	(71)
Repayment of construction obligation	(10)	(11)	(5)
Repurchase of common stock	(1,180)	(955)	(540)
Other, net	(23)	(19)	(18)
Net cash used in financing activities	(1,024)	(1,248)	(851)
NET CHANGE IN CASH AND CASH EQUIVALENTS	301	(73)	242
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	1,282	1,355	1,113
CASH AND CASH EQUIVALENTS AT END OF PERIOD	1,583	1,282	1,355
CASH PAYMENTS FOR:
Interest	105	128	133
Income taxes	1,440	155	346
SUPPLEMENTAL DISCLOSURE OF NONCASH TRANSACTIONS:
Flight equipment under capital leases	193	153	26
Assets constructed for others	$ 192	$ 88	$ 105