Components of Special Charges (Detail) - Entity [Domain] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Operating:
Severance and benefits	$ 25	$ 38	$ 75	$ 52
Integration-related costs	14	17	32	51
Costs associated with permanently grounding Embraer ERJ 135 aircraft		66		66
(Gains) losses on sale of assets and other special charges	16	48	12	52
Special charges	55	169	119	221
Nonoperating:
Loss on extinguishment of debt and other, net	128		134	21
Income tax benefit				(1)
Total operating and nonoperating special charges, net of income taxes	$ 183	$ 169	$ 253	$ 241