Financing Liability for Construction in Progress (Details) (USD $) In Millions	9 Months Ended	12 Months Ended
Sep. 30, 2011	Dec. 31, 2010	Dec. 31, 2009
Financing Liability for Construction in Progress (Textual) [Abstract]
Structural leasehold improvement costs incurred during construction		$ 18.9
Construction costs reimbursed by the landlord	18.8
Fair value of the building capitalized			6.9
Increased liability due to additional structural leasehold improvements		18.9
Increased liability due to land lease expense		0.2
Increased liability due to capitalized interest expense		$ 0.2

Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software, net of accumulated depreciation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 33

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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