The charge for the use of long-lived depreciable capital leased assets for the period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6455314&loc=d3e45031-112735

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 840

-Section 55

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6501752&loc=d3e56872-110439

Name:	us-gaap_CapitalLeasesIncomeStatementAmortizationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Property and Equipment (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Property and Equipment (Textual) [Abstract]
Amortization of assets held under capital leases	$ 7.1	$ 5.2	$ 13.4	$ 10.2
Maximum [Member]
Property, Plant and Equipment [Line Items]
Lease Obligation Period			5 years