Segment Information - Total Asset Information For Segments (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 2,360,274	$ 1,352,261
Capital expenditures	54,486	48,771	41,298
Racing Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	518,517	513,345
Capital expenditures	35,637	20,184	14,027
Casino Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	621,240	622,038
Capital expenditures	7,715	13,643	14,524
TwinSpires [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	182,322	186,621
Capital expenditures	5,778	5,908	4,427
Big Fish Games [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,007,438	0
Capital expenditures	116	0	0
Other Investments
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	30,757	30,257
Capital expenditures	$ 5,240	$ 9,036	$ 8,320