Commitments and Contingencies (Details Numeric) (USD $)	1 Months Ended	6 Months Ended
	Jun. 30, 2010	Jun. 01, 2012 buildings	Dec. 02, 2011		Jun. 01, 2012 East and West Towers [Member]	Jun. 01, 2012 Almaden Tower [Member]	Jun. 30, 2009 East and West Towers and Almaden Tower [Domain]
Property Subject to or Available for Operating Lease [Line Items]
Number of Corporate Headquarter Office Buildings		3
Standby letter of credit							$ 16,500,000
Lease Receivable Purchased		207,239,000	207,239,000	[1]	126,800,000	80,400,000
Option to Purchase Buildings					143,200,000	103,600,000
Residual Value Guarantees					126,800,000	89,400,000
Sale-leaseback agreement classified as a capital lease	$ 32,200,000	$ 15,100,000
Sale-leaseback agreement period	43 months

[1] The Condensed Consolidated Balance Sheet as of December 2, 2011 has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements.