Real Estate and Accumulated Depreciation (Detail) (USD $) In Millions, unless otherwise specified			12 Months Ended																																																																	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Atlanta Marriott Marquis	Dec. 31, 2012 Atlanta Marriott Perimeter Center	Dec. 31, 2012 Atlanta Marriott Suites Midtown	Dec. 31, 2012 Boston Marriott Copley Place	Dec. 31, 2012 Calgary Marriott	Dec. 31, 2012 Chicago Marriott O Hare	Dec. 31, 2012 Chicago Marriott Suites Downers Grove	Dec. 31, 2012 Chicago Marriott Suites O Hare	Dec. 31, 2012 Coronado Island Marriott Resort & Spa	Dec. 31, 2012 Costa Mesa Marriott	Dec. 31, 2012 Courtyard Chicago Downtown River North	Dec. 31, 2012 Courtyard Nashua	Dec. 31, 2012 Dallas/Addison Marriott Quorum by the Galleria	Dec. 31, 2012 Dayton Marriott	Dec. 31, 2012 Delta Meadowvale Hotel & Conference Center	Dec. 31, 2012 Denver Marriott Tech Center Hotel	Dec. 31, 2012 Denver Marriott West	Dec. 31, 2012 Embassy Suites Chicago - Downtown/Lakefront	Dec. 31, 2012 Four Seasons Hotel Atlanta	Dec. 31, 2012 Four Seasons Hotel Philadelphia	Dec. 31, 2012 Gaithersburg Marriott Washingtonian Center	Dec. 31, 2012 Grand Hyatt Atlanta In Buckhead	Dec. 31, 2012 Grand Hyatt Washington	Dec. 31, 2012 Greensboro Highpoint Marriott Airport	Dec. 31, 2012 Harbor Beach Marriott Resort & Spa	Dec. 31, 2012 Hilton Melbourne South Wharf	Dec. 31, 2012 Hilton Singer Island Oceanfront Resort	Dec. 31, 2012 Houston Airport Marriott at George Bush Intercontinental	Dec. 31, 2012 Houston Marriott at the Texas Medical Center	Dec. 31, 2012 Hyatt Regency Cambridge, Overlooking Boston	Dec. 31, 2012 Hyatt Regency Maui Resort & Spa	Dec. 31, 2012 Hyatt Regency Reston	Dec. 31, 2012 Hyatt Regency San Francisco Airport	Dec. 31, 2012 Hyatt Regency Washington on Capitol Hill	Dec. 31, 2012 JW Marriott Atlanta Buckhead	Dec. 31, 2012 JW Marriott Desert Springs Resort & Spa	Dec. 31, 2012 JW Marriott Hotel Rio de Janeiro	Dec. 31, 2012 JW Marriott Houston	Dec. 31, 2012 JW Marriott Mexico City	Dec. 31, 2012 JW Marriott Washington, D.C.	Dec. 31, 2012 Kansas City Airport Marriott	Dec. 31, 2012 Key Bridge Marriott	Dec. 31, 2012 Manchester Grand Hyatt San Diego	Dec. 31, 2012 Manhattan Beach Marriott	Dec. 31, 2012 Marina Del Rey Marriott	Dec. 31, 2012 Marriott At Metro Center	Dec. 31, 2012 Memphis Marriott Downtown	Dec. 31, 2012 Miami Marriott Biscayne Bay	Dec. 31, 2012 Minneapolis Marriott City Center	Dec. 31, 2012 New Orleans Marriott	Dec. 31, 2012 New York Marriott Downtown	Dec. 31, 2012 New York Marriott Marquis	Dec. 31, 2012 Newark Liberty International Airport Marriott	Dec. 31, 2012 Newport Beach Marriott Bayview	Dec. 31, 2012 Newport Beach Marriott Hotel Spa	Dec. 31, 2012 New Zealand Hotel Portfolio	Dec. 31, 2012 Orlando World Center Marriott	Dec. 31, 2012 Park Ridge Marriott	Dec. 31, 2012 Philadelphia Airport Marriott	Dec. 31, 2012 Philadelphia Marriott Downtown	Dec. 31, 2012 Portland Marriott Downtown Waterfront	Dec. 31, 2012 Residence Inn Arlington Pentagon City	Dec. 31, 2012 San Antonio Marriott Rivercenter	Dec. 31, 2012 San Antonio Marriott Riverwalk	Dec. 31, 2012 San Cristobal Tower, Santiago	Dec. 31, 2012 San Diego Marriott Hotel Marina	Dec. 31, 2012 San Diego Marriott Mission Valley	Dec. 31, 2012 San Francisco Marriott Fisherman Wharf	Dec. 31, 2012 San Francisco Marriott Marquis	Dec. 31, 2012 San Ramon Marriott	Dec. 31, 2012 Santa Clara Marriott	Dec. 31, 2012 Scottsdale Marriott At McDowell Mountains	Dec. 31, 2012 Scottsdale Marriott Suites Old Town	Dec. 31, 2012 Seattle Airport Marriott	Dec. 31, 2012 Sheraton Boston Hotel	Dec. 31, 2012 Sheraton Indianapolis Hotel Suites	Dec. 31, 2012 Sheraton Needham Hotel	Dec. 31, 2012 Sheraton New York Times Square Hotel	Dec. 31, 2012 Sheraton Parsippany Hotel	Dec. 31, 2012 Sheraton San Diego Hotel Marina	Dec. 31, 2012 Sheraton Santiago Hotel Convention Center	Dec. 31, 2012 Swissotel Chicago	Dec. 31, 2012 Tampa Airport Marriott	Dec. 31, 2012 Tampa Marriott Waterside Hotel Marina	Dec. 31, 2012 The Fairmont Kea Lani, Maui	Dec. 31, 2012 The Ritz Carlton, Amelia Island	Dec. 31, 2012 The Ritz Carlton, Buckhead	Dec. 31, 2012 The Ritz Carlton, Marina Del Rey	Dec. 31, 2012 The Ritz Carlton, Naples	Dec. 31, 2012 The Ritz Carlton, Naples Golf Resort	Dec. 31, 2012 The Ritz Carlton, Phoenix	Dec. 31, 2012 The Ritz Carlton, San Francisco	Dec. 31, 2012 The Ritz Carlton, Tysons Corner	Dec. 31, 2012 The St. Regis, Houston	Dec. 31, 2012 The Westin Buckhead Atlanta	Dec. 31, 2012 The Westin Chicago River North	Dec. 31, 2012 The Westin Cincinnati	Dec. 31, 2012 The Westin Denver Downtown	Dec. 31, 2012 The Westin Georgetown, Washington, DC	Dec. 31, 2012 The Westin Indianapolis	Dec. 31, 2012 The Westin Kierland Resort & Spa	Dec. 31, 2012 The Westin Los Angeles Airport	Dec. 31, 2012 The Westin Mission Hills Resort Spa	Dec. 31, 2012 The Westin New York Grand Central	Dec. 31, 2012 The Westin Seattle	Dec. 31, 2012 The Westin South Coast Plaza, Costa Mesa	Dec. 31, 2012 The Westin Waltham Boston	Dec. 31, 2012 Toronto Marriott Downtown Eaton Centre Hotel	Dec. 31, 2012 W New York	Dec. 31, 2012 W New York Union Square	Dec. 31, 2012 W Seattle	Dec. 31, 2012 Washington Dulles Airport Marriott	Dec. 31, 2012 Westfields Marriott Washington Dulles	Dec. 31, 2012 Total Hotels	Dec. 31, 2012 Other Properties
Real Estate and Accumulated Depreciation [Line Items]
Debt	$ 993	$ 1,006																									$ 134	$ 85						$ 100																							$ 103	$ 87	$ 246																																$ 205									$ 33																$ 993
Initial Costs, Land	1,963		13				5	4	2	5		3	7	3	14	2	4	6			5	26	7	8	154				2			18	92	11	16	40	16	13	13	4	11	26				7		20				16	19			6	11	34	18			3	6	6			7		4	6				8	3	3	42	3	5	346	8		19	29			55	25	14		19	6	10	31		6	5	33			16	12	100		40	156	39		9		138	48	11		7	1,939	24
Initial Costs, Buildings & Improvements	9,571		184	7	26	203	18	26	14	36	53	18	27	14	27	30	20	26	12	86	48	60	22	88	247	19	62	136	10	10	19	84	212	78	119	230	21	143	29	26	35	98	8	38	548	29	13	24	16	27	27	96	79	552	30	14	13	105	157	20	42	144	40	29	86	45	15	202	23	20	278	22	39	48	20	42	262	51	27	409	30	328	11	132	9		294	115	81	52	126		63	123	89	33	84	116	54	89	80	100	280	102	47	152	175	46	59	27	102	145	125	3	32	9,567	4
Subsequent Costs Capitalized	4,127		160	46	9	62	16	51	6	8	26	6	12	7	22	8	24	29	11	7	19	20	8	22	2	12	100	(4)	18	38	18	6	24	19	49	28	24	127	(6)	22	7	43	25	31	15	19	24	21	35	30	39	112	36	172	4	8	113	(8)	334	11	9	109	25	10	80	17	4	276	11	20	92	20	54	7	9	19	46	12	11	163	17	25	10	81	22	108	26	68	62	25	98	92	8	24	16	18	22	1	11	9	13	7	19	15	(43)	66	20	9	9	18	41	6	3	37	16	4,100	27
Land	1,996		16	15			5	4	2	5		3	7	3	14	2	4	6			6	27	7	8	154				2			19	81	12	20	40	16	13	11	6	10	26						20				16	19			6	11	34	29			11	6	6			8		4	6				8	3	3	42	3	5	346	8		20	30		11	55	25	15		21	22	10	31		6	6	33			16	12	100		13	156	39		9		138	48	11		7	1,972	24
Buildings & Improvements	13,665		341	38	35	265	34	77	20	44	79	24	39	21	49	38	44	55	23	93	66	79	30	110	249	31	162	132	28	48	37	89	247	96	164	258	45	270	25	46	43	141	33	69	563	55	37	45	51	57	66	208	115	724	34	22	126	97	480	31	51	245	65	39	166	62	18	478	34	40	370	42	93	55	29	61	308	63	38	572	47	353	20	212	31	97	320	183	142	77	222	76	71	147	105	51	105	117	65	98	93	107	299	117	31	218	195	55	68	45	143	151	128	40	48	13,634	31
Total	15,661		357	53	35	265	39	81	22	49	79	27	46	24	63	40	48	61	23	93	72	106	37	118	403	31	162	132	30	48	37	108	328	108	184	298	61	283	36	52	53	167	33	69	563	55	37	65	51	57	66	224	134	724	34	28	137	131	509	31	51	256	71	45	166	62	26	478	38	46	370	42	93	63	32	64	350	66	43	918	55	353	40	242	31	108	375	208	157	77	243	98	81	178	105	57	111	150	65	98	109	119	399	117	44	374	234	55	77	45	281	199	139	40	55	15,606	55
Accumulated Depreciation	$ 4,768		$ 114	$ 22	$ 16	$ 86	$ 19	$ 45	$ 10	$ 18	$ 36	$ 12	$ 20	$ 13	$ 25	$ 15	$ 24	$ 27	$ 15	$ 22	$ 26	$ 34	$ 15	$ 42	$ 4	$ 16	$ 79	$ 8	$ 15	$ 40	$ 21	$ 41	$ 65	$ 38	$ 64	$ 52	$ 26	$ 110	$ 1	$ 28	$ 33	$ 58	$ 28	$ 59	$ 33	$ 26	$ 18	$ 23	$ 24	$ 30	$ 45	$ 107	$ 55	$ 463	$ 26	$ 11	$ 69	$ 5	$ 184	$ 13	$ 22	$ 98	$ 31	$ 17	$ 70	$ 30	$ 3	$ 177	$ 17	$ 22	$ 203	$ 18	$ 71	$ 12	$ 13	$ 35	$ 59	$ 11	$ 7	$ 106	$ 10	$ 64	$ 5	$ 66	$ 23	$ 34	$ 73	$ 68	$ 66	$ 39	$ 113	$ 20	$ 29	$ 59	$ 43	$ 12	$ 40	$ 7	$ 14	$ 19	$ 19	$ 20	$ 48	$ 23	$ 14	$ 15	$ 32	$ 22	$ 14	$ 23	$ 34	$ 9	$ 22	$ 32	$ 25	$ 4,752	$ 16
Date of Completion of Construction																																																																																						2000						2002
Date Acquired			1998	1976	1996	2002	1996	1998	1989	1997	1997	1996	1992	1989	1994	1998	1996	1994	1983	2004	1998	1998	1993	1998	2012	1983	1997	2011	1986	1984	1998	1998	2003	1998	1998	2006	1990	1997	2010	1994	1996	2003	1993	1997	2011	1997	1995	1994	1998	1998	1986	1996	1997	1986	1984	1975	1975	2011	1997	1987	1995	1995	1994	1996	1996	1995	2006	1996	1998	1994	1989	1996	1989	2004	1988	1998	2006	2006	1986	2006	2006	2006	2006	1998	2000		2003	1998	1996	1997	1996		1998	1998	1998	2006	1998	2010	2006	2006	2006	2006	2006	2006	2006	2011	2006	2006	2006	1995	2006	2010	2006	1970	1994		various
Depreciation Life			40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	33 years	40 years	40 years	31 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	35 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	35 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years	40 years		40 years