Other Intangible Assets Other Intangible Assets (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 17, 2013
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	$ 238,865,000	$ 76,002,000
Accumulated amortization	(47,236,000)	(36,196,000)
Net carrying amount	191,629,000	39,806,000
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Net carrying amount	549,972,000	198,149,000
Amortization expense	13,300,000	12,200,000	11,200,000
Annual license fees paid	2,300,000
Oxford Acquisition [Member]
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles				3,800,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets				60,900,000
Calder
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Annual license fees paid	2,300,000	2,300,000
Slots gaming rights
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Net carrying amount	128,890,000	128,890,000
Trademarks
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Net carrying amount	225,729,000	25,729,000
Illinois Horseracing Equity Trust
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Net carrying amount	3,307,000	3,307,000
Other
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Net carrying amount	417,000	417,000
Favorable contracts
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	11,000,000	11,000,000
Accumulated amortization	(4,907,000)	(4,260,000)
Net carrying amount	6,093,000	6,740,000
Customer Relationships [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	89,203,000	56,540,000
Accumulated amortization	(39,399,000)	(30,464,000)
Net carrying amount	49,804,000	26,076,000
Slot gaming license
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	2,250,000	2,250,000
Accumulated amortization	(1,125,000)	(1,125,000)
Net carrying amount	1,125,000	1,125,000
Table Games License [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	2,493,000
Accumulated amortization	(180,000)
Technology-Based Intangible Assets [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	87,000,000	0
Accumulated amortization	(931,000)	0
Net carrying amount	86,069,000	0
In Process Research and Development [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	12,700,000	0
Accumulated amortization	(105,000)	0
Net carrying amount	12,595,000	0
Other
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	3,719,000	3,719,000
Accumulated amortization	(326,000)	(297,000)
Net carrying amount	3,393,000	3,422,000
Strategic Developer Relationships [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	30,500,000	0
Accumulated amortization	(263,000)	0
Net carrying amount	30,237,000	0
Oxford Acquisition [Member] | Table Games License [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	400,000
Harlows Casino [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	2,800,000
Harlows Casino [Member] | Other
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	400,000
Big Fish Games [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	162,900,000
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Net carrying amount	$ 200,000,000