Impact of COVID-19 Pandemic And Liquidity (Narrative) (Details) $ in Millions					3 Months Ended				12 Months Ended
	May 07, 2021 USD ($)	May 07, 2021 NZD ($)	Mar. 26, 2021 USD ($)	Mar. 06, 2020 USD ($)	Mar. 31, 2021 USD ($) item country		Mar. 31, 2021 NZD ($) item	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Impact Of Covid [Line Items]
Impairment of property					$ 0				$ 217,000
Working capital					$ (13,000,000.0)				(64,100,000)
Number of cinemas closed | item					6		6
Number of cinemas opened | item					56		56
Number of cinemas | item					61
Contractual Facility					$ 248,072,000				300,449,000
Number of countries in which entity operates | country					3
Number of business plans | item					2
Proceeds from sale of assets					$ 65,569,000
Repayment of long-term borrowings					$ 42,552,000			$ 22,733,000
Shadow View Land And Farming, LLC [Member]
Impact Of Covid [Line Items]
Ownership percentage by noncontrolling interest					50.00%
Bank Of America Credit Facility [Member]
Impact Of Covid [Line Items]
Contractual Facility				$ 55,000,000.0	$ 55,000,000				55,000,000
44 Union Square [Member]
Impact Of Covid [Line Items]
Repayment of notes payable			$ 40,600,000
Secured debt					0
Westpac Bank Corporate Credit Facility [Member]
Impact Of Covid [Line Items]
Contractual Facility					$ 22,365,000	[1]	$ 32.0		$ 23,021,000	[2]
United States [Member]
Impact Of Covid [Line Items]
Number of cinemas closed | item					4		4
Number of cinemas opened | item					19		19
Number of cinemas | item					24
Manukau, New Zealand And Coachella, California [Member]
Impact Of Covid [Line Items]
Proceeds from sale of assets					$ 60,000,000.0
Subsequent Event [Member] | 44 Union Square [Member]
Impact Of Covid [Line Items]
Contractual Facility	$ 43,000,000.0
Subsequent Event [Member] | Westpac Bank Corporate Credit Facility [Member]
Impact Of Covid [Line Items]
Repayment of long-term borrowings	$ 11,200,000	$ 16.0

[1] The contractual facilities and outstanding balances of the foreign currency denominated borrowings were translated into U.S. dollars based on the applicable exchange rates as of March 31, 2021.

[2] The contractual facilities and outstanding balances of the foreign currency denominated borrowings were translated into U.S. dollars based on the applicable exchange rates as of December 31, 2020.