Condensed Consolidated Statements of Cash Flows Supplemental Information - Write-downs, Net of Recoveries (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Write-downs, net of recoveries
Accounts receivable		$ 1,957	$ 1,567
Joint revenue sharing arrangements	[1]	748	354
Film assets	[2]	179	0
Property, plant and equipment	[1]	78	482
Other intangible assets		22	38
Financing receivables		0	100
Write-downs, net of recoveries		$ 2,984	$ 2,541

[1] The Company recognized asset impairment charges of $0.1 million (2018 — $0.8 million) reflecting property, plant and equipment that were no longer in use. In the nine months ended September 30, 2019, the Company recorded a charge of $0.2 million in cost of sales applicable to Equipment and product sales and $0.1 million in revenue applicable to Equipment and product sales upon the upgrade of xenon-based digital systems under joint revenue sharing arrangements to laser-based digital systems. No such charge was recorded in the nine months ended September 30, 2018.

[2] The Company discontinued production of a certain film asset in 2019, resulting in a write down of costs incurred totalling $0.2 million (2018 —$nil).