Income Taxes Income Taxes (Details)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Examination [Line Items]
Income Tax Examination, Year under Examination	2012	2011	2010

Tax year being audited in the income tax examination, in CCYY format.

No definition available.

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