Shareholders' Equity - Additional Information (Details) - USD ($)		3 Months Ended	12 Months Ended
	Jun. 09, 2017	Feb. 12, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Oct. 30, 2018	Oct. 29, 2018	Nov. 29, 2017	Apr. 25, 2017	Feb. 29, 2016	Feb. 24, 2016	Dec. 31, 2015
Distribution Made to Limited Partner [Line Items]
Authorized stock repurchase amount									$ 250,000,000.0	$ 150,000,000.0	$ 150,000,000.0	$ 150,000,000.0
Remaining unused authorization for stock repurchase program					$ 122,400,000		$ 78,300,000			$ 114,600,000		$ 11,900,000
Stock repurchased during period (in shares)					635,370
Stock repurchased and retired during period, value					$ 27,600,000
Repurchase aggregate cost			$ 549,500,000	$ 190,900,000	$ 39,000,000
Common stock, shares authorized (in shares)			150,000,000	150,000,000		150,000,000	50,000,000
The Duchossois Group
Distribution Made to Limited Partner [Line Items]
Stock repurchased during period (in shares)	3,000,000			3,000,000
Stock repurchased and retired during period, value	$ 158,800,000
Repurchase price (in dollars per share)	$ 52.93
April 2017 Stock Repurchase Program
Distribution Made to Limited Partner [Line Items]
Remaining unused authorization for stock repurchase program				$ 78,300,000
Stock repurchased during period (in shares)				3,231,087
Stock repurchased and retired during period, value				$ 171,700,000
Tender Offer
Distribution Made to Limited Partner [Line Items]
Authorized stock repurchase amount								$ 500,000,000.0
Stock repurchased during period (in shares)		5,660,376
Repurchase price (in dollars per share)		$ 88.33
Repurchase aggregate cost		$ 500,000,000
October 2018 Stock Repurchase Program
Distribution Made to Limited Partner [Line Items]
Authorized stock repurchase amount						$ 300,000,000.0
Remaining unused authorization for stock repurchase program			$ 268,000,000
Stock repurchased during period (in shares)			372,282
Repurchase aggregate cost			$ 32,000,000