Non-controlling Interests (Summary Of Changes In Controlling And Non-controlling Stockholders’ Equity) (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Balance		$ (40,407,000)			$ (40,407,000)
Balance	$ 95,749,000	81,173,000	$ 117,400,000	$ 139,616,000	81,173,000	$ 139,616,000
Net income (loss)	22,594,000	22,067,000	(22,887,000)	(5,955,000)	44,661,000	(28,843,000)
Other comprehensive income, net	(1,592,000)	(2,545,000)	10,716,000	(15,897,000)
Share-based compensation expense	450,000	464,000	369,000	336,000
Share repurchase plan				(671,000)
Restricted Stock Units	(2,000)	(110,000)	(11,000)	(30,000)
Distributions to noncontrolling stockholders		(5,300,000)
Balance	117,199,000	95,749,000	105,587,000	117,400,000	117,199,000	105,587,000
Balance	(40,407,000)				(40,407,000)
Additional Paid-In Capital [Member]
Balance	150,332,000	149,979,000	148,908,000	148,602,000	149,979,000	148,602,000
Share-based compensation expense	450,000	464,000	369,000	336,000
Restricted Stock Units	(2,000)	(111,000)	(11,000)	(30,000)
Balance	150,780,000	150,332,000	149,266,000	148,908,000	150,780,000	149,266,000
Retained Earnings (Accumulated Deficit) [Member]
Balance	(25,588,000)	(44,553,000)	14,772,000	20,647,000	(44,553,000)	20,647,000
Net income (loss)	22,702,000	18,965,000	(22,702,000)	(5,875,000)
Balance	(2,886,000)	(25,588,000)	(7,930,000)	14,772,000	(2,886,000)	(7,930,000)
Treasury Shares [Member]
Balance	(40,407,000)	(40,407,000)	(40,407)	(39,737)	(40,407,000)	(39,737)
Share repurchase plan				(670)
Balance	(40,407,000)	(40,407,000)	(40,407)	(40,407)	(40,407,000)	(40,407)
Accumulated Other Comprehensive Income (Loss) [Member]
Balance	9,957,000	12,502,000	(10,290,000)	5,589,000	12,502,000	5,589,000
Other comprehensive income, net	(1,592,000)	(2,545,000)	10,707,000	(15,879,000)
Balance	8,365,000	9,957,000	417,000	(10,290,000)	8,365,000	417,000
Reading International Inc. Stockholders' Equity [Member]
Balance	94,543,000	77,769,000	113,231,000	135,349,000	77,769,000	135,349,000
Net income (loss)	22,702,000	18,965,000	(22,702,000)	(5,875,000)
Other comprehensive income, net	(1,592,000)	(2,545,000)	10,707,000	(15,879,000)
Share-based compensation expense	450,000	464,000	369,000	336,000
Share repurchase plan				(671,000)
Restricted Stock Units	(2,000)	(110,000)	(11,000)	(30,000)
Balance	116,101,000	94,543,000	101,594,000	113,231,000	116,101,000	101,594,000
Noncontrolling Interests [Member]
Balance	1,206,000	3,404,000	4,169,000	4,267,000	3,404,000	4,267,000
Net income (loss)	(108,000)	3,102,000	(185,000)	(80,000)
Other comprehensive income, net			9,000	(18,000)
Distributions to noncontrolling stockholders		(5,300,000)
Balance	$ 1,098,000	$ 1,206,000	3,993,000	4,169,000	$ 1,098,000	3,993,000
Class A [Member]
Balance, shares		20,068,607			20,068,607
Balance, shares	20,128,815				20,128,815
Class A [Member] | Common Stock Shares Outstanding [Member]
Balance	$ 232,000	$ 231,000	$ 231,000	$ 231,000	$ 231,000	$ 231,000
Balance, shares	20,121	20,069	20,047	20,103	20,069	20,103
Share repurchase plan, shares				(75)
Restricted Stock Units		$ 1,000
Restricted Stock Units, shares	4	52	21	19
Balance	$ 232,000	$ 232,000	$ 231,000	$ 231,000	$ 232,000	$ 231,000
Balance, shares	20,125	20,121	20,068	20,047	20,125	20,068
Class B [Member]
Balance, shares		1,680,590			1,680,590
Balance, shares	1,680,590				1,680,590
Class B [Member] | Common Stock Shares Outstanding [Member]
Balance	$ 17,000	$ 17,000	$ 17,000	$ 17,000	$ 17,000	$ 17,000
Balance, shares	1,680	1,680	1,680	1,680	1,680	1,680
Balance	$ 17,000	$ 17,000	$ 17,000	$ 17,000	$ 17,000	$ 17,000
Balance, shares	1,680	1,680	1,680	1,680	1,680	1,680