Summary of Significant Accounting Policies (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Revenue Recognition [Abstract]
Term of residency agreements- minimum (in days)			30
Term of residency agreements - maximum (in years)			1
Refund of resident's entrance fee under certain conditions (in months)			12
Consolidated Balance Sheets [Abstract]
Refundable entrance fees and deferred revenue	$ 370,142,000		$ 370,142,000		$ 370,755,000
Deferred tax liability	96,187,000		96,187,000		96,187,000
Accumulated deficit	(957,069,000)		(957,069,000)		(955,427,000)
Consolidated Statements of Operations [Abstract]
Resident fees	620,938,000	602,050,000	1,245,308,000	1,198,599,000	2,412,936,000	2,290,322,000
Total revenue	716,468,000	690,473,000	1,428,734,000	1,373,181,000	2,768,738,000	2,456,483,000
Loss before income taxes	(4,036,000)	(18,133,000)	670,000	(27,747,000)	(64,948,000)	(67,270,000)
Provision for income taxes	(1,164,000)	(882,000)	(2,312,000)	(1,812,000)	(1,519,000)	(1,780,000)
Net loss	(5,200,000)	(19,015,000)	(1,642,000)	(29,559,000)	(66,467,000)	(69,050,000)
Basic and diluted net loss per share	$ (0.04)	$ (0.16)	$ (0.01)	$ (0.24)	$ (0.54)	$ (0.57)
Consolidated Statements of Cash Flows [Abstract]
Net loss	(5,200,000)	(19,015,000)	(1,642,000)	(29,559,000)	(66,467,000)	(69,050,000)
Amortization of entrance fees			(14,165,000)	(12,376,000)	(25,362,000)	(23,966,000)
Deferred income tax (benefit) provision			0	(304,000)	(525,000)	383,000
As Reported [Member]
Consolidated Balance Sheets [Abstract]
Refundable entrance fees and deferred revenue					361,360,000
Deferred tax liability					99,851,000
Accumulated deficit					(949,696,000)
Consolidated Statements of Operations [Abstract]
Resident fees		602,387,000		1,199,273,000	2,414,283,000	2,291,757,000
Total revenue		690,810,000		1,373,855,000	2,770,085,000	2,457,918,000
Loss before income taxes		(17,796,000)		(27,073,000)	(63,601,000)	(65,835,000)
Provision for income taxes		(1,014,000)		(2,075,000)	(2,044,000)	(2,340,000)
Net loss		(18,810,000)		(29,148,000)	(65,645,000)	(68,175,000)
Basic and diluted net loss per share		$ (0.15)		$ (0.24)	$ (0.54)	$ (0.56)
Consolidated Statements of Cash Flows [Abstract]
Net loss		(18,810,000)		(29,148,000)	(65,645,000)	(68,175,000)
Amortization of entrance fees				(13,050,000)	(26,709,000)	(25,401,000)
Deferred income tax (benefit) provision				(41,000)	0	943,000
Adjustment [Member]
Consolidated Balance Sheets [Abstract]
Refundable entrance fees and deferred revenue					9,395,000
Deferred tax liability					(3,664,000)
Accumulated deficit					(5,731,000)
Consolidated Statements of Operations [Abstract]
Resident fees		(337,000)		(674,000)	(1,347,000)	(1,435,000)
Total revenue		(337,000)		(674,000)	(1,347,000)	(1,435,000)
Loss before income taxes		(337,000)		(674,000)	(1,347,000)	(1,435,000)
Provision for income taxes		132,000		263,000	525,000	560,000
Net loss		(205,000)		(411,000)	(822,000)	(875,000)
Basic and diluted net loss per share		$ (0.01)		$ 0	$ 0	$ (0.01)
Consolidated Statements of Cash Flows [Abstract]
Net loss		(205,000)		(411,000)	(822,000)	(875,000)
Amortization of entrance fees				674,000	1,347,000	1,435,000
Deferred income tax (benefit) provision				(263,000)	(525,000)	(560,000)
Carrying Value, Fair Value Disclosure [Member]
Fair Value of Financial Instruments [Line Items]
Long-term Debt, Fair Value	2,600,000,000		2,600,000,000		2,700,000,000
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value of Financial Instruments [Line Items]
Long-term Debt, Fair Value	$ 2,600,000,000		$ 2,600,000,000		$ 2,700,000,000