Schedule of Share-Based Compensation Plan Cost (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Integration and merger related costs	$ 408	$ 60	$ 137	$ 134	$ 170	$ 123	$ 145	$ 79	$ 739		$ 517		$ 171
Compensation cost									57	[1],[2]	54	[1],[2]	117	[1],[2]
Share-Based Awards Converted To Cash Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Integration and merger related costs									9		17		70
Compensation cost									6	[1],[2],[3]	19	[1],[2],[3]	84	[1],[2],[3]
United Air Lines Inc
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Integration and merger related costs									569		360		138
Compensation cost									32		28		63
United Air Lines Inc | Share-Based Awards Converted To Cash Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Integration and merger related costs									5		7		24
Continental Airlines Inc | Successor
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Integration and merger related costs									170		157		33
Compensation cost									25		26		54
Continental Airlines Inc | Successor | Share-Based Awards Converted To Cash Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Integration and merger related costs									$ 4		$ 10		$ 46

[1] All compensation cost is recorded to Salaries and related costs, with the exception of $9 million, $17 million and $70 million in 2012, 2011 and 2010, respectively, that was recorded in integration and Merger-related costs as a component of special charges, respectively.

[2] United recorded $32 million, $28 million and $63 million of compensation cost related to UAL's share-based plans during 2012, 2011 and 2010, respectively. These amounts included $5 million, $7 million and $24 million that were classified as integration and Merger-related costs as a component of special charges during 2012, 2011 and 2010, respectively. Continental Successor recorded $25 million, $26 million and $54 million of compensation cost related to UAL's share-based plans during 2012, 2011 and 2010, respectively. These amounts included $4 million, $10 million and $46 million that were classified as integration and Merger-related costs as a component of special charges during 2012, 2011 and 2010, respectively.

[3] As described below, in connection with the Merger, certain awards were converted into fixed cash equivalents.