Summary Of Significant Accounting Policies (Accounting Changes To Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2020		Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019		Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance					$ 139,616					$ 179,979	$ 139,616	$ 179,979	$ 181,382
Net income (loss) attributable to Reading International, Inc. common shareholders	$ (17,663)	[1]	$ (19,352)	$ (22,887)	(5,955)	$ (27,458)	[1]	$ 801	$ 2,294	(2,140)	(65,857)	(26,503)	14,166
Balance	81,173					139,616					81,173	139,616	179,979
Reading International Inc. Stockholders' Equity [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance					135,349					175,642	135,349	175,642	177,051
Net income (loss) attributable to Reading International, Inc. common shareholders											(65,200)	(26,429)	14,034
Balance	77,769					135,349					$ 77,769	135,349	175,642
As Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss) attributable to Reading International, Inc. common shareholders	$ (17,663)	[1]	$ (19,352)	$ (22,887)	$ (5,955)	$ (27,458)	[1]	852	2,357	(2,097)
Adjustments [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss) attributable to Reading International, Inc. common shareholders								$ (51)	$ (63)	(43)
Tax Year 2018 [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss) attributable to Reading International, Inc. common shareholders													14,166
Tax Year 2018 [Member] | As Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss) attributable to Reading International, Inc. common shareholders													14,498
Tax Year 2018 [Member] | Adjustments [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss) attributable to Reading International, Inc. common shareholders													(332)
Tax Year 2019 [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance										179,979		179,979	181,382
Net income (loss) attributable to Reading International, Inc. common shareholders													14,166
Balance													179,979
Tax Year 2019 [Member] | As Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance										180,547		180,547	181,618
Net income (loss) attributable to Reading International, Inc. common shareholders													14,498
Balance													180,547
Tax Year 2019 [Member] | Adjustments [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance										$ (568)		$ (568)	(236)
Net income (loss) attributable to Reading International, Inc. common shareholders													(332)
Balance													$ (568)

[1] Since previously published financial statements have been corrected, there is no impact on the fourth quarter results for 2019 or for the full year of 2020 and so no data is displayed here.