Contingencies (Details)	1 Months Ended	12 Months Ended
Jan. 31, 2012	Jan. 31, 2009 Amendments	Mar. 31, 2013 Company
Contingencies (Textual) [Abstract]
Companies named as Potentially Responsible Parties			100
Amendments approved to consent decree		2
Percent of contribution to the total waste	0.50%

The number of claims settled and dismissed during the period.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 9, 10, 11, 12

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

Name:	us-gaap_LossContingencyClaimsSettledAndDismissedNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration