Financial Data Resulting from Transactions with Related Parties, Income Statement Data (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended												12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014		Dec. 31, 2013		Dec. 28, 2012
Related Party Transaction [Line Items]
Base management fees													$ 672	[1]	$ 621	[1]	$ 581	[1]
Incentive management fees													302	[1]	256	[1]	232	[1]
Cost reimbursements													11,055	[1]	10,291	[1]	9,405	[1]
Revenues	3,559	3,460	3,484	3,293	3,219	[2]	3,160	[2]	3,263	[2]	3,142	[2],[3]	13,796		12,784	[2]	11,814
Reimbursed costs													(11,055)	[1]	(10,291)	[1]	(9,405)	[1]
Depreciation, amortization and other													(148)	[1]	(127)	[1]	(102)	[1]
General, administrative, and other													(659)	[1]	(649)	[1]	(582)	[1]
Related Party Transactions
Related Party Transaction [Line Items]
Base management fees													17		17		26
Incentive management fees													6		1		5
Owned, leased, and other revenue													1		1		3
Cost reimbursements													226		236		315
Revenues													250		255		349
Reimbursed costs													(226)		(236)		(315)
Depreciation, amortization and other													(2)		(2)		(2)
General, administrative, and other													(2)		(3)		2
Gains and other income													0		0		43
Interest expense													0		0		1
Interest income													5		4		3
Equity in earnings (losses)													$ 6		$ (5)		$ (13)

[1] See Footnote No. 17, “Related Party Transactions,” to our Consolidated Financial Statements for disclosure of related party amounts.

[2] The sum of the earnings per share for the four quarters differs from annual earnings per share due to the required method of computing the weighted average shares in interim periods.

[3] Beginning in 2013, we changed our financial reporting cycle to a calendar year-end reporting cycle and an end-of-month quarterly reporting cycle. Accordingly, our 2013 first quarter included the period from December 29, 2012 through March 31, 2013.