Other Accrued Liabilities (Components Of Other Accrued Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Other Accrued Liabilities [Abstract]
Pension	$ 120	$ 120
Postretirement benefit obligation	71	71
Deferred revenue	327	327
Self-fitting software liability	238	285
Technology access liability	989	1,236
Other	729	830
Total	$ 2,474	$ 2,869