Segment Information - Information About Reported Segments (Details)	3 Months Ended
	Mar. 31, 2019 USD ($) Segments	Mar. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | Segments	3
Net revenue	$ 265,400,000	$ 189,300,000
Intercompany net revenues	0	0
Comprehensive income	11,600,000	182,400,000
Foreign currency translation, net of tax	0	(600,000)
Change in pension benefits, net of tax	0	(200,000)
Net income	11,600,000	182,000,000.0
Loss (income) from discontinued operations, net of tax	300,000	(167,900,000)
Income from continuing operations, net of tax	11,900,000	14,100,000
Depreciation and amortization	20,800,000	13,800,000
Interest expense	13,700,000	9,600,000
Income tax provision	6,500,000	2,600,000
EBITDA	52,900,000	40,100,000
Stock-based compensation expense	4,700,000	2,800,000
Other charges	(500,000)	0
Pre-opening expense	1,300,000	600,000
Interest, depreciation and amortization expense related to equity investments	3,500,000	4,300,000
Recapitalization costs related to Midwest Gaming	8,200,000	0
Transaction expense, net	3,500,000	1,400,000
Total adjustments to EBITDA	21,700,000	9,100,000
Adjusted EBITDA	74,600,000	49,200,000
Churchill Downs
Segment Reporting Information [Line Items]
Net revenue	21,400,000	2,300,000
Adjusted Segment EBITDA	1,400,000	(6,000,000.0)
Online Wagering
Segment Reporting Information [Line Items]
Net revenue	63,400,000	63,600,000
Adjusted Segment EBITDA	16,900,000	17,900,000
Gaming
Segment Reporting Information [Line Items]
Net revenue	170,100,000	112,500,000
Adjusted Segment EBITDA	64,800,000	46,400,000
Operating Segments
Segment Reporting Information [Line Items]
Net revenue	265,400,000	189,300,000
Adjusted Segment EBITDA	83,100,000	58,300,000
Operating Segments | Churchill Downs
Segment Reporting Information [Line Items]
Net revenue	21,000,000.0	2,000,000.0
Intercompany net revenues	400,000	300,000
Adjusted Segment EBITDA	1,400,000	(6,000,000.0)
Operating Segments | Churchill Downs | Churchill Downs Racetrack
Segment Reporting Information [Line Items]
Net revenue	2,300,000	2,000,000.0
Operating Segments | Churchill Downs | Derby City Gaming
Segment Reporting Information [Line Items]
Net revenue	18,700,000	0
Operating Segments | Online Wagering
Segment Reporting Information [Line Items]
Net revenue	63,100,000	63,200,000
Intercompany net revenues	300,000	400,000
Adjusted Segment EBITDA	16,900,000	17,900,000
Operating Segments | Online Wagering | TwinSpires
Segment Reporting Information [Line Items]
Net revenue	63,000,000.0	63,200,000
Operating Segments | Online Wagering | Online Sports Betting and iGaming
Segment Reporting Information [Line Items]
Net revenue	100,000	0
Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue	168,800,000	111,500,000
Intercompany net revenues	1,300,000	1,000,000.0
Adjusted Segment EBITDA	64,800,000	46,400,000
Operating Segments | Gaming | Oxford
Segment Reporting Information [Line Items]
Net revenue	23,900,000	24,200,000
Operating Segments | Gaming | Calder
Segment Reporting Information [Line Items]
Net revenue	25,400,000	24,900,000
Operating Segments | Gaming | Riverwalk
Segment Reporting Information [Line Items]
Net revenue	16,300,000	14,400,000
Operating Segments | Gaming | Harlow’s
Segment Reporting Information [Line Items]
Net revenue	15,300,000	13,300,000
Operating Segments | Gaming | Fair Grounds and VSI
Segment Reporting Information [Line Items]
Net revenue	37,500,000	34,400,000
Operating Segments | Gaming | Ocean Downs
Segment Reporting Information [Line Items]
Net revenue	18,400,000	0
Operating Segments | Gaming | Presque Isle
Segment Reporting Information [Line Items]
Net revenue	29,700,000	0
Operating Segments | Gaming | Lady Luck Nemacolin
Segment Reporting Information [Line Items]
Net revenue	2,300,000	0
Operating Segments | Gaming | Saratoga
Segment Reporting Information [Line Items]
Net revenue	0	300,000
Segment Reconciling Items | All Other
Segment Reporting Information [Line Items]
Net revenue	12,500,000	12,600,000
Intercompany net revenues	2,200,000	2,400,000
Adjusted Segment EBITDA	(8,500,000)	(9,100,000)
Eliminations
Segment Reporting Information [Line Items]
Intercompany net revenues	$ (4,200,000)	$ (4,100,000)