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Income Taxes (Details Textual) (USD $) In Millions, unless otherwise specified | 3 Months Ended | 6 Months Ended |  | 1 Months Ended
--- | --- | --- | --- | ---
Jun. 30, 2014 | Jun. 30, 2013 | Jun. 30, 2014 | Jun. 30, 2013 | Mar. 31, 2013 | Oct. 31, 2011 Tax Year 2007 | Oct. 31, 2011 Tax Year 2008 | Oct. 31, 2011 Tax Year 2009
Income Tax Contingency [Line Items] |  |  |  |  |  |  |  |
Effective tax rate | 27.00% | 24.40% | 26.90% | 19.60% |  |  |  |
Net benefit for a previously unrecognized position |  |  |  |  | $ 49.8 |  |  |
Expense for non-income based state taxes |  |  |  |  | 10.3 |  |  |
Proposed deduction disallowance by tax authorities |  |  |  |  |  | $ 130.0 | $ 130.0 | $ 130.0

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