Acquisitions (Details) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Feb. 28, 2015 USD ($) Community	Mar. 31, 2016 USD ($) Community	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) Community
Schedule of Acquisitions and Disposals [Line Items]
Number of communities purchased or sold | Community		7
Aggregate selling price		$ 46,700
Gain on Sale of Communities		2,700
Asset impairment		3,375	$ 0
Assets Held-for-sale		65,906		$ 110,620
Loss on facility lease termination		0	$ 76,143
February 2015 acquisition of 15 communities [Member]
Schedule of Acquisitions and Disposals [Line Items]
Number of communities purchased or sold | Community	15
Aggregate purchase price	$ 268,600
Fair Value of Assets Acquired	187,200
Reversal of deferred lease liability	5,300
Loss on facility lease termination	$ 76,100
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Schedule of Acquisitions and Disposals [Line Items]
Number of communities purchased or sold | Community				17
Asset impairment		2,600		$ 15,200
Disposal Group, Including Discontinued Operation, Liabilities		$ 60,800