Brookdale Lease Amendments and Terminations and the Formation of Two RIDEA Joint Ventures (“Brookdale Transaction”) - Compents of Brookdale Transaction and NNN Lease Restructing (Details) $ in Millions	Aug. 29, 2014 USD ($) item property
Lease Amendments And Terminations And Joint Venture Formations [Line Items]
Number Of Properties Contributed To Joint Venture | item	48
Brookdale Senior Living
Lease Amendments And Terminations And Joint Venture Formations [Line Items]
Annualized base rent reductions, first year	$ 6.5
Annualized base rent reductions, subsequent years	$ 7.5
Number of communities sold in purchase option | item	9
Proceeds from communities sold in purchase option	$ 60.0
Brookdale Senior Living | NNN-leased Portfolio
Lease Amendments And Terminations And Joint Venture Formations [Line Items]
Number of facilities for which existing lease agreement is amended | property	153
Number of properties with purchase options cancelled on amendment | property	30
Average initial lease term	15 years
Number of extension options | item	2
Term of lease extension options	10 years
Business Combination, Consideration Transferred [Abstract]
Consideration paid to terminate purchase options	$ 129.0
Rent concessions	76.0
Net consideration paid	$ 53.0