Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, Recognition of Outside Basis Difference, Amount	$ 2.3
Effective Income Tax Rate Reconciliation, Percent	20.30%	5.80%	30.00%	19.70%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			35.00%	35.00%
Proceeds from sale of other property and equipment		11.8
Effective Income Tax Rate Reconciliation, Deduction, Other, Amount		$ 17.8