Condensed Consolidated Statements of Cash Flows Supplemental Information - Write-downs (Parenthetical) (Details) $ in Thousands, ¥ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($)		Jun. 30, 2022 CNY (¥)	Jun. 30, 2021 USD ($)
Supplemental Cash Flow Elements [Line Items]
Other assets write downs on impairment			$ 4,500	[1]	¥ 30.0
Theater system components written off in Costs and expenses			200			300
Write-downs for excess inventory	$ 300	$ 100	278	[2]		$ 200	[2]
Film assets write downs on impairment loss			$ 500

[1] In the six months ended June 30, 2022, the Company recognized a full impairment of its RMB 30.0 million ($4.5 million) investment in the film Mozart from Space (2021 — $nil) based on projected box office results and distribution costs. (See Note 16(e).)

[2] In the six months ended June 30, 2022, the Company recorded write-downs of $0.3 million in Costs and Expenses Applicable to Technology Sales principally to reduce the carrying value of service parts held in Russia. In the six months ended June 30, 2021, the Company recorded write-downs of $0.2 million in Costs and Expenses Applicable to Technology Sales to reduce the carrying value of excess inventory.