Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Receivables, allowance for doubtful accounts	$ 15	$ 13
Aircraft fuel, spare parts and supplies, obsolescence allowance	181	162
Intangibles, accumulated amortization	987	933
Common stock, par value	$ 0.01	$ 0.01
Common shares, authorized	1,000,000,000	1,000,000,000
Common shares, outstanding	373,569,662	362,283,555
United Airlines, Inc.
Receivables, allowance for doubtful accounts	15	13
Aircraft fuel, spare parts and supplies, obsolescence allowance	181	162
Intangibles, accumulated amortization	$ 987	$ 933
Common stock, par value	$ 0.01	$ 0.01
Common shares, authorized	1,000	1,000
Common shares, issued	1,000	1,000
Common shares, outstanding	1,000	1,000