Income Taxes (Details)	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2011	Jun. 30, 2011	Dec. 31, 2010
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Effective tax rate	27.00%	29.00%	32.00%

A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 47

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph h
-Subparagraph 2
-Article 4

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Namespace Prefix:	us-gaap
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration