Summary Of Significant Accounting Policies (Accounting Changes To Consolidated Statements Of Income) (Details) - USD ($) $ / shares in Units, $ 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]
Revenue	$ 3,422		$ 76,009		$ 52,650	$ 137,501
Operating income (loss)	(22,195)		5,730		(29,235)	4,370
Income (loss) before income taxes	(24,454)		3,924		(33,423)	727
Income tax (expense) benefit	1,567		(1,630)		4,580	(573)
Net income (loss)	(22,887)	$ (5,956)	2,294	$ (2,140)	(28,843)	154
Net income (loss) attributable to Reading International, Inc. common shareholders	$ (22,702)		$ 2,331		$ (28,577)	$ 207
Basic earnings (loss) per share	$ (1.04)		$ 0.10		$ (1.31)	$ 0.01
Diluted earnings (loss) per share	$ (1.04)		$ 0.10		$ (1.31)	$ 0.01
Cinema [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	$ 1,217		$ 72,296		$ 47,527	$ 130,223
Tax Year 2019 [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue			76,009			137,501
Operating income (loss)			5,730			4,370
Income (loss) before income taxes			3,924			727
Income tax (expense) benefit			(1,630)			(573)
Net income (loss)			2,294			154
Net income (loss) attributable to Reading International, Inc. common shareholders			$ 2,331			$ 207
Basic earnings (loss) per share			$ 0.10			$ 0.01
Diluted earnings (loss) per share			$ 0.10			$ 0.01
Tax Year 2019 [Member] | Cinema [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue			$ 72,296			$ 130,223
Tax Year 2019 [Member] | As Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue			76,096			137,646
Operating income (loss)			5,817			4,515
Income (loss) before income taxes			4,011			872
Income tax (expense) benefit			(1,654)			(612)
Net income (loss)			2,357			260
Net income (loss) attributable to Reading International, Inc. common shareholders			$ 2,394			$ 313
Basic earnings (loss) per share			$ 0.10			$ 0.01
Diluted earnings (loss) per share			$ 0.10			$ 0.01
Tax Year 2019 [Member] | As Reported [Member] | Cinema [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue			$ 72,383			$ 130,368
Tax Year 2019 [Member] | Adjustments [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue			(87)			(145)
Operating income (loss)			(87)			(145)
Income (loss) before income taxes			(87)			(145)
Income tax (expense) benefit			24			39
Net income (loss)			(63)			(106)
Net income (loss) attributable to Reading International, Inc. common shareholders			$ (63)			$ (106)
Basic earnings (loss) per share			$ 0.00			$ 0.00
Diluted earnings (loss) per share			$ 0.00			$ 0.00
Tax Year 2019 [Member] | Adjustments [Member] | Cinema [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue			$ (87)			$ (145)