Summary Of Significant Accounting Policies (Accounting Changes To Consolidated Statements Of Income) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	$ 49,228	$ 61,492
Operating income (loss)	(7,039)	(1,360)
Income (loss) before income taxes	(8,968)	(3,198)
Income tax benefit (expense)	3,013	1,057
Net income (loss)	(5,955)	(2,141)
Net income (loss) attributable to Reading International, Inc. common shareholders	$ (5,875)	$ (2,125)
Basic earnings (loss) per share	$ (0.27)	$ (0.09)
Diluted earnings (loss) per share	$ (0.27)	$ (0.09)
Cinema [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	$ 46,310	$ 57,927
Tax Year 2019 [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		61,492
Operating income (loss)		(1,360)
Income (loss) before income taxes		(3,198)
Income tax benefit (expense)		1,057
Net income (loss)		(2,141)
Net income (loss) attributable to Reading International, Inc. common shareholders		$ (2,125)
Basic earnings (loss) per share		$ (0.09)
Diluted earnings (loss) per share		$ (0.09)
Tax Year 2019 [Member] | Cinema [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		$ 57,927
Tax Year 2019 [Member] | As Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		61,551
Operating income (loss)		(1,301)
Income (loss) before income taxes		(3,139)
Income tax benefit (expense)		1,042
Net income (loss)		(2,097)
Net income (loss) attributable to Reading International, Inc. common shareholders		$ (2,081)
Basic earnings (loss) per share		$ (0.09)
Diluted earnings (loss) per share		$ (0.09)
Tax Year 2019 [Member] | As Reported [Member] | Cinema [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		$ 57,986
Tax Year 2019 [Member] | Adjustments [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		(59)
Operating income (loss)		(59)
Income (loss) before income taxes		(59)
Income tax benefit (expense)		15
Net income (loss)		(44)
Net income (loss) attributable to Reading International, Inc. common shareholders		$ (44)
Basic earnings (loss) per share		$ 0.00
Diluted earnings (loss) per share		$ 0.00
Tax Year 2019 [Member] | Adjustments [Member] | Cinema [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		$ (59)