Acquisitions and Dispositions - 2014 Acquisitions Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Nov. 21, 2014
Furniture, fixtures, and other property, plant and equipment | Minimum
Business Acquisition [Line Items]
Remaining useful life range (in years)	5 years
Furniture, fixtures, and other property, plant and equipment | Maximum
Business Acquisition [Line Items]
Remaining useful life range (in years)	10 years
Bally Acquisition
Business Acquisition [Line Items]
Property and equipment total		$ 335.3
Intangible asset total		1,800.3
Weighted-average remaining useful life (in years)	9 years 5 months
Bally Acquisition | Brand names
Business Acquisition [Line Items]
Intangible asset total		225.0
Bally Acquisition | Brand names
Business Acquisition [Line Items]
Intangible asset total		90.7
Weighted-average remaining useful life (in years)	9 years 2 months
Bally Acquisition | Core technology and content
Business Acquisition [Line Items]
Intangible asset total		734.7
Weighted-average remaining useful life (in years)	7 years 2 months
Bally Acquisition | Customer relationships
Business Acquisition [Line Items]
Intangible asset total		726.0
Weighted-average remaining useful life (in years)	15 years 1 month 6 days
Bally Acquisition | Long-term licenses
Business Acquisition [Line Items]
Intangible asset total		23.9
Weighted-average remaining useful life (in years)	3 years
Bally Acquisition | Land and land improvements
Business Acquisition [Line Items]
Land and land improvements		18.1
Bally Acquisition | Buildings and leasehold improvements
Business Acquisition [Line Items]
Buildings and leasehold improvements		36.3
Bally Acquisition | Buildings and leasehold improvements | Minimum
Business Acquisition [Line Items]
Remaining useful life range (in years)	2 years
Bally Acquisition | Buildings and leasehold improvements | Maximum
Business Acquisition [Line Items]
Remaining useful life range (in years)	40 years
Bally Acquisition | Furniture, fixtures, and other property, plant and equipment
Business Acquisition [Line Items]
Furniture, fixtures, and other property, plant and equipment		33.6
Bally Acquisition | Furniture, fixtures, and other property, plant and equipment | Minimum
Business Acquisition [Line Items]
Remaining useful life range (in years)	2 years
Bally Acquisition | Furniture, fixtures, and other property, plant and equipment | Maximum
Business Acquisition [Line Items]
Remaining useful life range (in years)	15 years
Bally Acquisition | Gaming equipment
Business Acquisition [Line Items]
Furniture, fixtures, and other property, plant and equipment		$ 247.3
Bally Acquisition | Gaming equipment | Minimum
Business Acquisition [Line Items]
Remaining useful life range (in years)	1 year
Bally Acquisition | Gaming equipment | Maximum
Business Acquisition [Line Items]
Remaining useful life range (in years)	3 years