Condensed Consolidated Statement of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 387	$ 463
Adjustments to reconcile net income to cash provided by (used in) operating activities:
Depreciation and amortization	297	277
Unrealized/realized gains on fuel derivative instruments	0	(7)
Deferred income taxes	13	72
Changes in certain assets and liabilities:
Accounts and other receivables	(222)	(15)
Other assets	29	(178)
Accounts payable and accrued liabilities	(257)	(501)
Air traffic liability	944	866
Other liabilities	(69)	0
Cash collateral received from derivative counterparties	15	65
Other, net	(32)	(40)
Net cash provided by operating activities	1,105	1,002
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(160)	(409)
Assets constructed for others	0	(24)
Purchases of short-term investments	(251)	(200)
Proceeds from sales of short-term and other investments	575	560
Net cash provided by (used in) investing activities	164	(73)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from Employee stock plans	10	9
Reimbursement for assets constructed for others	0	139
Payments of long-term debt and finance lease obligations	(99)	(82)
Payments of cash dividends	(178)	(148)
Repayment of construction obligation	0	(7)
Repurchase of common stock	(500)	(500)
Other, net	(12)	(13)
Net cash used in financing activities	(779)	(602)
NET CHANGE IN CASH AND CASH EQUIVALENTS	490	327
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	1,854	1,495
CASH AND CASH EQUIVALENTS AT END OF PERIOD	2,344	1,822
CASH PAYMENTS FOR:
Interest, net of amount capitalized	15	18
Income taxes	4	4
SUPPLEMENTAL DISCLOSURE OF NONCASH TRANSACTIONS
Flight equipment under finance leases	1	14
Assets constructed for others	$ 21	$ 40