Organization (Details)	Dec. 31, 2016 state building property
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of properties owned \| property	433
Number of buildings \| building	459
Number of states in which properties are located \| state	42

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