Brookdale Lease Amendments and Terminations and the Formation of Two RIDEA Joint Ventures ("Brookdale Transaction") - RIDEA Subsidiaries (Details) $ in Thousands		8 Months Ended	12 Months Ended
	Aug. 29, 2014 USD ($) property	Aug. 29, 2014 USD ($) property	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2016 property
Lease Amendments And Terminations And Joint Venture Formations.
Joint Venture Ownership Percentage	49.00%	49.00%
Lease Terminations Considerations Received Abstract
Net termination fee revenue			$ 1,103	$ 38,001
RIDEA JV
Lease Terminations Considerations Received Abstract
Net termination fee revenue		$ 38,000
Net Gain Recognized on Lease Terminations
Gain based on fair value of net consideration received for lease terminations		108,000
Charges related to lease termination write-offs		$ 70,000
CCRC JV
Lease Amendments And Terminations And Joint Venture Formations.
Joint Venture Ownership Percentage	14.00%	14.00%
Brookdale Senior Living
Lease Amendments And Terminations And Joint Venture Formations.
Joint Venture Ownership Percentage	20.00%	20.00%
Brookdale Senior Living | RIDEA JV
Lease Amendments And Terminations And Joint Venture Formations.
Number of facilities for which existing lease agreement is terminated | property	49
Number of properties with purchase options cancelled on termination | property	19	19
Lease Terminations Considerations Received Abstract
Consideration received - Short-term receivable	$ 34,000	$ 34,000
Consideration received - Note receivable	68,000	68,000
Effective offset for net consideration paid	53,000	$ 53,000
Number of Real Estate Properties | property					49
Consideration received for terminated leases	$ 47,000
Brookdale Senior Living | CCRC JV
Lease Amendments And Terminations And Joint Venture Formations.
Joint Venture Ownership Percentage	51.00%	51.00%