Discontinued Operations (Narrative) (Details) (USD $) In Millions, unless otherwise specified	5 Months Ended
Jun. 01, 2010 sqft
Discontinued Operations
Aggregate square feet of the property	150,050
Gain recorded on disposal of office property	$ 4.4

The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 28
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

Name:	us-gaap_GainLossOnSaleOfProperties
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration