Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 item	Jun. 30, 2012	Dec. 31, 2012
Segment Reporting
Number of operating segments			4
Number of reportable segments			3
Number of rehabilitation hospitals			2
Revenues:
Rental income	$ 112,297	$ 108,407	$ 224,150	$ 215,435
Residents fees and services	74,631	35,986	149,687	71,554
Total revenues	186,928	144,393	373,837	286,989
Expenses:
Property operating expenses	74,484	39,818	148,163	78,304
Depreciation	38,296	34,624	75,999	67,397
General and administrative	8,168	8,068	16,816	15,753
Acquisition related costs	292	1,829	2,187	2,694
Impairment of assets	4,371		5,675	3,071
Total expenses	125,611	84,339	248,840	167,219
Operating income	61,317	60,054	124,997	119,770
Interest and other income	397	227	570	709
Interest expense	(29,567)	(28,120)	(59,131)	(57,009)
Loss on early extinguishment of debt	(105)		(105)
Equity in earnings of an investee	79	76	155	121
Income before income tax expense	32,121	32,237	66,486	63,591
Income tax expense	(140)	(43)	(280)	(247)
Income from continuing operations	31,981	32,194	66,206	63,344
Discontinued operations:
Income from discontinued operations	1,513	1,057	2,523	2,259
Impairment of assets from discontinued operations	(27,896)		(27,896)
Net income	5,598	33,251	40,833	65,603
Total assets	4,748,631		4,748,631		4,748,002
Triple Net Senior Living Communities
Revenues:
Rental income	56,957	59,643	113,723	118,467
Total revenues	56,957	59,643	113,723	118,467
Expenses:
Depreciation	17,019	17,191	33,936	34,383
Impairment of assets	4,371		4,371
Total expenses	21,390	17,191	38,307	34,383
Operating income	35,567	42,452	75,416	84,084
Interest expense	(6,596)	(10,163)	(13,060)	(20,287)
Income before income tax expense	28,971	32,289	62,356	63,797
Income from continuing operations	28,971	32,289	62,356	63,797
Discontinued operations:
Net income	28,971	32,289	62,356	63,797
Total assets	1,829,372	1,756,892	1,829,372	1,756,892
Managed Senior Living Communities
Revenues:
Residents fees and services	74,631	35,986	149,687	71,554
Total revenues	74,631	35,986	149,687	71,554
Expenses:
Property operating expenses	58,231	26,244	116,135	51,743
Depreciation	7,028	3,874	13,877	7,580
Total expenses	65,259	30,118	130,012	59,323
Operating income	9,372	5,868	19,675	12,231
Interest expense	(3,073)	(2,813)	(6,141)	(5,866)
Income before income tax expense	6,299	3,055	13,534	6,365
Income from continuing operations	6,299	3,055	13,534	6,365
Discontinued operations:
Net income	6,299	3,055	13,534	6,365
Total assets	964,610	623,653	964,610	623,653
MOBs
Revenues:
Rental income	50,899	44,306	101,582	88,090
Total revenues	50,899	44,306	101,582	88,090
Expenses:
Property operating expenses	16,253	13,574	32,028	26,561
Depreciation	13,301	12,611	26,290	23,538
Impairment of assets			1,304	3,071
Total expenses	29,554	26,185	59,622	53,170
Operating income	21,345	18,121	41,960	34,920
Interest expense	(1,387)	(381)	(2,734)	(793)
Income before income tax expense	19,958	17,740	39,226	34,127
Income from continuing operations	19,958	17,740	39,226	34,127
Discontinued operations:
Income from discontinued operations	1,513	1,057	2,523	2,259
Impairment of assets from discontinued operations	(27,896)		(27,896)
Net income	(6,425)	18,797	13,853	36,386
Total assets	1,742,120	1,885,994	1,742,120	1,885,994
All Other Operations
Revenues:
Rental income	4,441	4,458	8,845	8,878
Total revenues	4,441	4,458	8,845	8,878
Expenses:
Depreciation	948	948	1,896	1,896
General and administrative	8,168	8,068	16,816	15,753
Acquisition related costs	292	1,829	2,187	2,694
Total expenses	9,408	10,845	20,899	20,343
Operating income	(4,967)	(6,387)	(12,054)	(11,465)
Interest and other income	397	227	570	709
Interest expense	(18,511)	(14,763)	(37,196)	(30,063)
Loss on early extinguishment of debt	(105)		(105)
Equity in earnings of an investee	79	76	155	121
Income before income tax expense	(23,107)	(20,847)	(48,630)	(40,698)
Income tax expense	(140)	(43)	(280)	(247)
Income from continuing operations	(23,247)	(20,890)	(48,910)	(40,945)
Discontinued operations:
Net income	(23,247)	(20,890)	(48,910)	(40,945)
Total assets	212,529	200,013	212,529	200,013
Consolidated
Revenues:
Rental income	112,297	108,407	224,150	215,435
Residents fees and services	74,631	35,986	149,687	71,554
Total revenues	186,928	144,393	373,837	286,989
Expenses:
Property operating expenses	74,484	39,818	148,163	78,304
Depreciation	38,296	34,624	75,999	67,397
General and administrative	8,168	8,068	16,816	15,753
Acquisition related costs	292	1,829	2,187	2,694
Impairment of assets	4,371		5,675	3,071
Total expenses	125,611	84,339	248,840	167,219
Operating income	61,317	60,054	124,997	119,770
Interest and other income	397	227	570	709
Interest expense	(29,567)	(28,120)	(59,131)	(57,009)
Loss on early extinguishment of debt	(105)		(105)
Equity in earnings of an investee	79	76	155	121
Income before income tax expense	32,121	32,237	66,486	63,591
Income tax expense	(140)	(43)	(280)	(247)
Income from continuing operations	31,981	32,194	66,206	63,344
Discontinued operations:
Income from discontinued operations	1,513	1,057	2,523	2,259
Impairment of assets from discontinued operations	(27,896)		(27,896)
Net income	5,598	33,251	40,833	65,603
Total assets	$ 4,748,631	$ 4,466,552	$ 4,748,631	$ 4,466,552