Income Taxes (Narrative) (Details)	3 Months Ended
Mar. 31, 2013
Minimum [Member]
Open Tax Year	2009
Maximum [Member]
Open Tax Year	2012

Tax year that remains open to examination under enacted tax laws, in CCYY format.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

Name:	us-gaap_OpenTaxYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration