Summary Of Significant Accounting Policies (Accounting Changes To Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance	$ 117,399	$ 139,616	$ 179,335	$ 179,979	$ 139,616	$ 179,979
Net income (loss) attributable to Reading International, Inc. common shareholders	(22,887)	(5,956)	2,294	(2,140)	(28,843)	154
Balance	105,586	117,399	177,023	179,335	105,586	177,023
Reading International Inc. Stockholders' Equity [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance	113,231	135,349	175,068	175,642	135,349	175,642
Net income (loss) attributable to Reading International, Inc. common shareholders	(22,702)	(5,875)	2,331	(2,124)
Balance	$ 101,594	$ 113,231	172,800	175,068	$ 101,594	172,800
Tax Year 2019 [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance				179,979		179,979
Net income (loss) attributable to Reading International, Inc. common shareholders			2,294			154
Balance			177,023			177,023
Tax Year 2019 [Member] | As Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance				180,547		180,547
Net income (loss) attributable to Reading International, Inc. common shareholders			2,357			260
Balance			177,697			177,697
Tax Year 2019 [Member] | Adjustments [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance				$ (568)		(568)
Net income (loss) attributable to Reading International, Inc. common shareholders			(63)			(106)
Balance			$ (674)			$ (674)