CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets
Accounts receivable, reserve	$ 306	$ 411
Inventories, obsolescence reserve	$ 520	$ 1,484
Class A Common Stock [Member]
Telos stockholders' deficit
Common stock, par value (in dollars per share)	$ 0
Common stock, shares authorized (in shares)	50,000,000
Common stock, shares issued (in shares)	45,158,460	45,213,461
Class B Common Stock [Member]
Telos stockholders' deficit
Common stock, par value (in dollars per share)	$ 0
Common stock, shares authorized (in shares)	5,000,000
Common stock, shares issued (in shares)	4,037,628