Organization (Details)	Mar. 31, 2013 property
Office Properties [Member]
Business Acquisition [Line Items]
Number of real estate properties	19
Media and Entertainment Properties [Member]
Business Acquisition [Line Items]
Number of real estate properties	2

The number of real estate properties owned as of the balance sheet date.

No definition available.

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