Noncontrolling Interests (Summary Of Changes In Controlling And Non-controlling Stockholders’ Equity) (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Balance		$ (39,737,000)			$ (39,737,000)
Balance	$ 117,399,000	139,616,000	$ 179,335,000	$ 179,979,000	139,616,000	$ 179,979,000
Net income (loss)	(22,887,000)	(5,956,000)	2,294,000	(2,140,000)	(28,843,000)	154,000
Other comprehensive income, net	10,716,000	(15,897,000)	(2,347,000)	1,511,000
Share-based compensation expense	369,000	336,000	400,000	280,000
Share repurchase plan	0	(671,000)	(2,622,000)	(9,000)
Class A common stock issued for share-based bonuses and options exercised				(185,000)
Restricted Stock Units	(11,000)	(30,000)	(31,000)	(74,000)
Contributions from noncontrolling stockholders			9,000	18,000
Distributions to noncontrolling stockholders			(15,000)	(27,000)
Balance	105,586,000	117,399,000	177,023,000	179,335,000	105,586,000	177,023,000
Balance	(40,407,000)				(40,407,000)
Additional Paid-In Capital [Member]
Balance	148,908,000	148,602,000	147,472,000	147,452,000	148,602,000	147,452,000
Share-based compensation expense	369,000	336,000	400,000	280,000
Class A common stock issued for share-based bonuses and options exercised				(185,000)
Restricted Stock Units	(11,000)	(30,000)	(31,000)	(75,000)
Balance	149,266,000	148,908,000	147,841,000	147,472,000	149,266,000	147,841,000
Retained Earnings (Accumulated Deficit) [Member]
Balance	14,772,000	20,647,000	44,952,000	47,048,000	20,647,000	47,048,000
Net income (loss)	(22,702,000)	(5,875,000)	2,331,000	(2,124,000)
Balance	(7,930,000)	14,772,000	47,283,000	44,952,000	(7,930,000)	47,283,000
Treasury Shares [Member]
Balance	(40,407,000)	(39,737,000)	(25,231)	$ (25,222)	(39,737,000)	(25,222)
Share repurchase plan	0	(670,000)	(2,622)
Share repurchase plan, shares				(9)
Balance	(40,407,000)	(40,407,000)	(27,853)	$ (25,231)	(40,407,000)	(27,853)
Accumulated Other Comprehensive Income/(Loss) [Member]
Balance	(10,290,000)	5,589,000	7,625,000	6,115,000	5,589,000	6,115,000
Other comprehensive income, net	10,707,000	(15,879,000)	(2,346,000)	1,510,000
Balance	417,000	(10,290,000)	5,279,000	7,625,000	417,000	5,279,000
Reading International Inc. Stockholders' Equity [Member]
Balance	113,231,000	135,349,000	175,068,000	175,642,000	135,349,000	175,642,000
Net income (loss)	(22,702,000)	(5,875,000)	2,331,000	(2,124,000)
Other comprehensive income, net	10,707,000	(15,879,000)	(2,346,000)	1,510,000
Share-based compensation expense	369,000	336,000	400,000	280,000
Share repurchase plan	0	(670,000)	(2,622,000)	(9,000)
Class A common stock issued for share-based bonuses and options exercised				(185,000)
Restricted Stock Units	(11,000)	(30,000)	(31,000)	(74,000)
Balance	101,594,000	113,231,000	172,800,000	175,068,000	101,594,000	172,800,000
Noncontrolling Stockholders' Equity [Member]
Balance	4,168,000	4,267,000	4,267,000	4,337,000	4,267,000	4,337,000
Net income (loss)	(185,000)	(81,000)	(37,000)	(16,000)
Other comprehensive income, net	9,000	(18,000)	(1,000)	1,000
Contributions from noncontrolling stockholders			9,000	18,000
Distributions to noncontrolling stockholders			(15,000)	(27,000)
Balance	$ 3,992,000	$ 4,168,000	4,223,000	4,267,000	$ 3,992,000	4,223,000
Accounting Standards Update 2016-02 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Balance			(18,000)
Balance				(18,000)
Accounting Standards Update 2016-02 [Member] | Retained Earnings (Accumulated Deficit) [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Balance			28,000
Balance				28,000
Accounting Standards Update 2016-02 [Member] | Reading International Inc. Stockholders' Equity [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Balance			28,000
Balance				28,000
Accounting Standards Update 2016-02 [Member] | Noncontrolling Stockholders' Equity [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Balance			(46,000)
Balance				(46,000)
Class A [Member]
Balance, shares		20,102,535			20,102,535
Balance, shares	20,067,635				20,067,635
Class A [Member] | Common Stock Shares Outstanding [Member]
Balance	$ 231,000	$ 231,000	$ 233,000	$ 232,000	$ 231,000	$ 232,000
Balance, shares	20,047	20,103	21,235	21,195	20,103	21,195
Share repurchase plan, shares		(75)	(197)
Restricted Stock Units				$ 1,000
Restricted Stock Units, shares	21	19	33	40
Balance	$ 231,000	$ 231,000	$ 233,000	$ 233,000	$ 231,000	$ 233,000
Balance, shares	20,068	20,047	21,071	21,235	20,068	21,071
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