Estimated Useful Lives of Assets (Detail)	12 Months Ended
	Dec. 31, 2020
Buildings On Owned Land
Property, Plant and Equipment [Line Items]
Estimated useful life of assets	40 years
Buildings On Leased Land
Property, Plant and Equipment [Line Items]
Estimated useful life of assets	Lesser of lease term or useful life
Land And Buildings Under Finance Leases
Property, Plant and Equipment [Line Items]
Estimated useful life of assets	Lesser of lease term or useful life
Theatre furniture and equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of assets	3 years
Theatre furniture and equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of assets	15 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Estimated useful life of assets	Lesser of lease term or useful life