Long-Term Contracts (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Oct. 31, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Deferred revenue, classified within other currrent liabilities			$ 10,000		$ 10,000		$ 10,000
Display-Only
Upfront payment received	$ 5,000	$ 5,000
Deferred Revenue, Description					In May 2018, we signed a five-year license agreement with a customer granting them exclusive license to our LBS technology for display-only applications. As part of the agreement, we received a first payment of $5.0 million in June 2018 and the second payment of $5.0 million in October 2018. The contract includes requirements that must be met in order to maintain exclusivity. If this licensee acquires a customer, the agreement requires the licensee to buy any needed components from us. During the year ended December 31, 2018 we completed the performance obligations required by the contract. As a result, we recognized $10.0 million in license and royalty revenue during the year ended December 31, 2018.
LBS Display System
Contract revenue from development fees			$ 47	$ 1,500	$ 2,900	$ 5,600
Deferred Revenue, Description					In April 2017, we signed a contract with a major technology company to develop an LBS display system. Under the agreement, we received an upfront payment of $10.0 million in 2017 and, as of September 30, 2019, have also received $15.0 million, net of early payment discounts, representing all payment due for development work. The original contract was for $14.0 million in fees for development work, but we and our customer agreed to add $1.1 million in additional work to total $15.1 million. After applying early payment discounts, we recognized revenue of $15.0 million in development fees over time based on the proportion of total cost expended (under Topic 606, the "input method") to the total cost expected to complete the contract performance obligation. For the three and nine months ended September 30, 2019, we recognized $47,000 and $2.9 million, respectively, of contract revenue from development fees on this agreement compared to $1.5 million and $5.6 million, respectively, during the three and nine months ended September 30, 2018. The $10.0 million upfront payment will be recognized as revenue at the point in time future component sales are transferred to the customer. Based on current pricing and cost estimates, the amount of the per unit upfront payment would be greater than our estimated per unit gross profit. We have an amount equal to the $10.0 million upfront payment classified as a contract liability on the balance sheet. We have received initial purchase orders from our customer under the product supply agreement signed in April 2017. We expect to apply $877,000 of the upfront payment over the two quarters ended December 31, 2019 and March 31, 2020. To the extent that the component purchases do not fully expend the $10.0 million upfront payment, there is no repayment provision to the customer.