Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 45

-Paragraph 13

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

Name:	us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Commitments And Contingencies (Details) (USD $)	0 Months Ended	1 Months Ended	9 Months Ended
Commitments And Contingencies (Details) (USD $)	Apr. 08, 2011	Jul. 31, 2010	Sep. 30, 2011	Sep. 30, 2010	Jul. 31, 2011	Jul. 20, 2011
Commitments And Contingencies
Settled to legal proceedings				$ 7,000,000
Increase in net earnings				2,751,000
Increase in earnings per diluted share				$ 0.06
Payment obligation of affiliate		12,400,000
Guarantee of affiliate's obligations	6,200,000					24,000,000
Term of equipment leasing agreements (in years)	5
Prior guarantee obligations maximum exposure					$ 20,000,000
Line of credit maturity period			July 2013