Investments and Acquisition Activities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended				3 Months Ended		6 Months Ended		3 Months Ended		3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Jun. 30, 2013 Commercial Paper	Jun. 30, 2013 Debt Securities	Dec. 31, 2012 ACDL [Member]	Jun. 30, 2013 ACDL [Member]	Jun. 30, 2013 Farmworks	Jun. 30, 2013 Retama Partners	Sep. 30, 2012 Federated Sports and Gaming	Jun. 30, 2013 Retama Partners	Jun. 30, 2013 Retama Partners	Jun. 30, 2012 Retama Partners
Schedule of Equity Method Investments
Equity Method Investment, Other than Temporary Impairment							$ 25.0	$ 92.2
Long-term Purchase Commitment, Amount									2.0
Long Term Purchase Commitment, Invested Amount									1.5
Business Acquisition, Contratual rights														50.00%
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred														7.8
Business Acquisition, Cost of Acquired Entity, Cash Paid												16.7
Capital Funding, Future Commitment													2.0
Promissory Notes		9.0		4.0
Purchase price											4.6
Held-to-maturity Securities					3.4
Impairment of assets	0	1.3	0			1.1
Held-to-maturity, Corporate Bonds		11.4
Goodwill, Acquired During Period										3.3
Intangible Asset, Acquired During Period										$ 5.0