Restructuring Programs and Other Separation Costs - Additional Information (Detail) $ in Millions		3 Months Ended	6 Months Ended
	Feb. 27, 2018 USD ($)	Sep. 30, 2018 USD ($) Position	Jun. 30, 2018 USD ($) Position	Dec. 31, 2017 USD ($)
Restructuring Cost And Reserve [Line Items]
Severance costs	$ 6.7
Other Executives [Member]
Restructuring Cost And Reserve [Line Items]
Severance costs			$ 3.8
2018 Restructuring Program [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring costs, description			involves the elimination of approximately 125 positions during the third quarter of 2018 across the Company’s theme parks and its corporate headquarters.
Restructuring and other related costs incurred to date			$ 1.8
2018 Restructuring Program [Member] | Scenario, Forecast [Member]
Restructuring Cost And Reserve [Line Items]
Number of positions eliminated | Position		125
Additional expected restructuring charges related to severance and other termination benefits		$ 4.0
2017 Restructuring Program [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring costs, description			involved the elimination of approximately 350 positions across all of the Company’s theme parks and corporate headquarters.
Number of positions eliminated | Position			350
Restructuring and other related costs incurred to date				$ 5.2