Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue Recognition [Abstract]
Term of residency agreements- minimum			30 days
Term of residency agreements - maximum			1 year
Self Insurance Liability Accruals [Abstract]
Decrease in facility operating expense	$ (1,800)	$ (3,700)	$ (9,300)	$ (9,300)
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Decrease in net cash used in investing activities			13,027	523,378
Increase in net cash provided by operating activities			170,508	294,323
Decrease in net cash used in financing activities			239,929	(310,552)
Revenue	840,179		$ 2,642,414
Trade names | Minimum
Finite-Lived Intangible Assets, Net [Abstract]
Useful lives of definite lived assets			2 years
Trade names | Maximum
Finite-Lived Intangible Assets, Net [Abstract]
Useful lives of definite lived assets			5 years
Management contracts | Minimum
Finite-Lived Intangible Assets, Net [Abstract]
Useful lives of definite lived assets			3 years
Management contracts | Maximum
Finite-Lived Intangible Assets, Net [Abstract]
Useful lives of definite lived assets			9 years
ASU 2016-18
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Decrease in net cash used in investing activities		4,600		6,300
ASU 2016-15
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Increase in net cash provided by operating activities		10,600		11,200
Decrease in net cash used in financing activities		10,600		11,200
ASU 2014-09
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Decrease in resident fee revenue and facility operating expenses	2,100		$ 5,200
Increase in revenue	11,200		34,900
Resident fees
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Revenue	840,179	922,892	2,642,414	2,873,889
Facility operating expense
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Costs of services	607,076	650,654	1,866,477	1,967,601
Reimbursed costs incurred on behalf of managed communities
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Revenue	261,355	236,958	765,802	650,863
Costs of services	$ 261,355	$ 236,958	$ 765,802	$ 650,863