SEGMENT INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Revenues:
Rental income	$ 274,205	$ 140,810
Resident fees and services	285,795	114,502
Medical office building and other services revenue	5,608	6,957
Income from loans and investments	8,036	6,085
Interest and other income	50	78
Total revenues	573,694	268,432
Less:
Interest and other income	50	78
Property-level operating expenses	216,756	86,787
Medical office building services costs	2,988	5,536
Segment NOI	353,900	176,031
Income (loss) from unconsolidated entities	317	(170)
Segment profit	354,217	175,861
Interest and other income	50	78
Interest expense	(70,668)	(41,740)
Depreciation and amortization	(163,197)	(51,314)
General, administrative and professional fees	(22,200)	(14,832)
Loss on extinguishment of debt	(29,544)	(16,520)
Merger-related expenses and deal costs	(7,981)	(6,449)
Other	(1,576)	(1)
Income tax (expense) benefit	(11,338)	3,197
Discontinued operations	42,329	766
Net income	90,092	49,046	363,261
Triple-Net Leased Properties
Revenues:
Rental income	209,509	116,574
Medical office building and other services revenue	1,109	0
Total revenues	210,618	116,574
Less:
Segment NOI	210,618	116,574
Income (loss) from unconsolidated entities	266	0
Segment profit	210,884	116,574
Senior Living Operations
Revenues:
Resident fees and services	285,795	114,502
Total revenues	285,795	114,502
Less:
Property-level operating expenses	195,666	78,111
Segment NOI	90,129	36,391
Segment profit	90,129	36,391
MOB Operations
Revenues:
Rental income	64,696	24,236
Medical office building and other services revenue	4,499	6,957
Total revenues	69,195	31,193
Less:
Property-level operating expenses	21,090	8,676
Medical office building services costs	2,988	5,536
Segment NOI	45,117	16,981
Income (loss) from unconsolidated entities	51	(170)
Segment profit	45,168	16,811
All Other
Revenues:
Income from loans and investments	8,036	6,085
Interest and other income	50	78
Total revenues	8,086	6,163
Less:
Interest and other income	50	78
Segment NOI	8,036	6,085
Segment profit	8,036	6,085
Interest and other income	$ 50	$ 78