Brookdale Lease Amendments and Terminations and the Formation of Two RIDEA Joint Ventures (“Brookdale Transaction”) - Continuing Care Retirement Communities Joint Venture (Details) $ in Thousands		12 Months Ended
	Aug. 29, 2014 USD ($) item	Dec. 31, 2015 USD ($)
Lease Amendments And Terminations And Joint Venture Formations [Line Items]
Joint Venture Ownership Percentage	49.00%
Joint Venture Disclosures [Abstract]
Cash contributed | $		$ 770,325
Brookdale Senior Living
Lease Amendments And Terminations And Joint Venture Formations [Line Items]
Joint Venture Ownership Percentage	20.00%
CCRC JV
Lease Amendments And Terminations And Joint Venture Formations [Line Items]
Number of retirement communities	14
Joint Venture Disclosures [Abstract]
Number of retirement communities contributed to joint venture	2
Fair value of retirement communities or properties contributed | $	$ 162,000
Carrying value of properties contributed | $	92,000
Cash contributed | $	370,000
Debt related to retirement communities or properties contributed | $	$ 569,000
CCRC JV | Brookdale Senior Living
Lease Amendments And Terminations And Joint Venture Formations [Line Items]
Joint Venture Ownership Percentage	51.00%
Joint Venture Disclosures [Abstract]
Number of retirement communities contributed to joint venture	8
Number of properties intended to be acquired in future	4
CCRC JV | CCRCJV Prop Co | Brookdale Senior Living
Lease Amendments And Terminations And Joint Venture Formations [Line Items]
Number of properties to be leased	8
CCRC JV | CCRCJV Op Co | Brookdale Senior Living
Lease Amendments And Terminations And Joint Venture Formations [Line Items]
Number of properties to be owned directly	6