Commitments and Contingencies, Guarantees and Indemnifications (Details) (Payment or Performance Guarantee, Customer Loans for Farm Rewiring Program, USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Payment or Performance Guarantee \| Customer Loans for Farm Rewiring Program
Guarantees [Abstract]
Guarantee issued and outstanding	$ 1.0	$ 1.0
Current exposure under the guarantee	$ 0.4	$ 0.4

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 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