Organization (Details)	Dec. 31, 2014 state building property
Organization
Number of properties owned	370us-gaap_NumberOfRealEstateProperties
Number of buildings owned	397snh_NumberOfBuildings
Number of states in which properties are located	38

The number of states the entity operates in as of the balance sheet date.

No definition available.

Name:	us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant