Condensed Consolidating Information (Details 1) (USD $) In Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2011	Mar. 31, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Revenues:
Rental income	$ 269,877		$ 140,723	$ 556,603	$ 398,871
Resident fees and services	276,364		113,182	593,348	331,535
Medical office building and other services revenues	9,271		6,711	26,050	6,711
Income from loans and investments	10,072		4,014	24,548	11,336
Interest and other income	373		35	529	420
Total revenues	565,957		264,665	1,201,078	748,873
Expenses:
Interest	73,756		45,519	170,046	133,449
Depreciation and amortization	161,027		52,104	293,541	154,458
Property-level operating expenses	209,161		82,007	440,965	236,069
Medical office building services costs	6,347		4,633	19,837	4,633
General, administrative and professional fees	20,624		15,278	51,010	35,819
Loss on extinguishment of debt	8,685	16,500		25,211	6,549
Litigation proceeds, net	(85,327)			(85,327)
Merger-related expenses and deal costs	69,350		5,142	131,606	11,668
Other	14,436		(419)	6,664	(404)
Total expenses	478,059		204,264	1,053,553	582,241
Income before income (loss) from unconsolidated entities, income taxes, discontinued operations and noncontrolling interest	87,898		60,401	147,525	166,632
Income (loss) from unconsolidated entities	182		(392)	(71)	(392)
Income tax benefit (expense)	13,904		(1,657)	23,310	(2,352)
Income from continuing operations	101,984		58,352	170,764	163,888
Discontinued operations			542		7,139
Net income	101,984		58,894	170,764	171,027	249,729
Net income (loss) attributable to noncontrolling interest, net of tax	(901)		996	(781)	2,443
Net income attributable to common stockholders	102,885		57,898	171,545	168,584
Parent Company [Member]
Revenues:
Rental income	623		607	1,848	1,802
Income from loans and investments	1,124		1,406	5,070	4,247
Equity earnings in affiliates	52,119		61,077	160,275	176,659
Interest and other income	6		18	96	310
Total revenues	53,872		63,108	167,289	183,018
Expenses:
Interest	392		820	(474)	1,096
Depreciation and amortization	440		412	1,273	1,219
General, administrative and professional fees	1,194		203	(5,840)	323
Litigation proceeds, net				(85,327)
Merger-related expenses and deal costs	47,309		3,573	108,509	10,041
Other	883		(477)	913	(435)
Total expenses	(35,109)		4,531	19,054	12,244
Income before income (loss) from unconsolidated entities, income taxes, discontinued operations and noncontrolling interest	88,981		58,577	148,235	170,774
Income tax benefit (expense)	13,904		(679)	23,310	(2,190)
Income from continuing operations			57,898		168,584
Net income	102,885		57,898	171,545	168,584
Net income attributable to common stockholders	102,885		57,898	171,545	168,584
Wholly Owned Subsidiary Guarantors [Member]
Revenues:
Rental income	55,453		52,463	165,454	141,317
Resident fees and services	100,885		65,252	252,803	190,801
Medical office building and other services revenues	8,162		6,711	24,941	6,711
Income from loans and investments	428		755	2,495	1,635
Equity earnings in affiliates	258		439	1,102	1,307
Interest and other income	7		4	19	40
Total revenues	165,193		125,624	446,814	341,811
Expenses:
Interest	14,241		18,386	45,409	56,371
Depreciation and amortization	34,908		28,889	95,651	84,084
Property-level operating expenses	78,415		46,908	192,137	132,036
Medical office building services costs	6,347		4,633	19,837	4,633
General, administrative and professional fees	9,074		8,311	28,101	16,870
Loss on extinguishment of debt				16,526	102
Merger-related expenses and deal costs	674		1,569	1,730	1,617
Other	1,863		60	2,950	31
Total expenses	145,522		108,756	402,341	295,744
Income before income (loss) from unconsolidated entities, income taxes, discontinued operations and noncontrolling interest	19,671		16,868	44,473	46,067
Income tax benefit (expense)			(978)		(162)
Income from continuing operations			15,890		45,905
Discontinued operations			422		1,132
Net income	19,671		16,312	44,473	47,037
Net income (loss) attributable to noncontrolling interest, net of tax			352		1,134
Net income attributable to common stockholders	19,671		15,960	44,473	45,903
Ventas Issuers [Member]
Revenues:
Rental income	71,611		70,534	212,653	209,879
Income from loans and investments	103		1,853	8,566	5,454
Interest and other income	10		21	52	63
Total revenues	71,724		72,408	221,271	215,396
Expenses:
Interest	21,952		13,261	53,457	39,658
Depreciation and amortization	8,795		9,296	26,706	28,429
Property-level operating expenses	115		134	414	398
General, administrative and professional fees	6,427		5,575	21,625	15,414
Loss on extinguishment of debt	8,685			8,685	6,447
Total expenses	45,974		28,266	110,887	90,346
Income before income (loss) from unconsolidated entities, income taxes, discontinued operations and noncontrolling interest	25,750		44,142	110,384	125,050
Income (loss) from unconsolidated entities	61		(392)	(192)	(392)
Income from continuing operations			43,750		124,658
Discontinued operations			120		6,007
Net income	25,811		43,870	110,192	130,665
Net income attributable to common stockholders	25,811		43,870	110,192	130,665
Non-Guarantor Subsidiaries [Member]
Revenues:
Rental income	142,190		17,119	176,648	45,873
Resident fees and services	175,479		47,930	340,545	140,734
Medical office building and other services revenues	1,109			1,109
Income from loans and investments	8,417			8,417
Interest and other income	350		(8)	362	7
Total revenues	327,545		65,041	527,081	186,614
Expenses:
Interest	37,171		13,052	71,654	36,324
Depreciation and amortization	116,884		13,507	169,911	40,726
Property-level operating expenses	130,631		34,965	248,414	103,635
General, administrative and professional fees	3,929		1,189	7,124	3,212
Merger-related expenses and deal costs	21,367			21,367	10
Other	11,690		(2)	2,801
Total expenses	321,672		62,711	521,271	183,907
Income before income (loss) from unconsolidated entities, income taxes, discontinued operations and noncontrolling interest	5,873		2,330	5,810	2,707
Income (loss) from unconsolidated entities	121			121
Income from continuing operations			2,330		2,707
Net income	5,994		2,330	5,931	2,707
Net income (loss) attributable to noncontrolling interest, net of tax	(901)		644	(781)	1,309
Net income attributable to common stockholders	6,895		1,686	6,712	1,398
Consolidated Eliminations [Member]
Revenues:
Equity earnings in affiliates	(52,377)		(61,516)	(161,377)	(177,966)
Total revenues	(52,377)		(61,516)	(161,377)	(177,966)
Expenses:
Income before income (loss) from unconsolidated entities, income taxes, discontinued operations and noncontrolling interest	(52,377)		(61,516)	(161,377)	(177,966)
Income from continuing operations			(61,516)		(177,966)
Net income	(52,377)		(61,516)	(161,377)	(177,966)
Net income attributable to common stockholders	$ (52,377)		$ (61,516)	$ (161,377)	$ (177,966)