Calder Exit Costs - Additional Information (Details) - USD ($) $ in Millions		12 Months Ended
	Nov. 08, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Calder exit costs		$ 2.5	$ 13.9	$ 2.3
Gain (loss) on sale of land		$ 23.7	0.0	$ 0.0
Land
Restructuring Cost and Reserve [Line Items]
Gain (loss) on sale of land	$ 23.7
Calder Grandstand
Restructuring Cost and Reserve [Line Items]
Long-lived asset impairment			$ 12.7