Three Months Ended March 31, | Year Ended December 31, | ||||||||||||||||||||||
2018 | 2017 | 2016 | 2015 | 2014 | 2013 | ||||||||||||||||||
Fixed charges: | |||||||||||||||||||||||
Interest expense | $2 | $44 | $29 | $75 | $125 | $29 | |||||||||||||||||
Interest portion of rental expense | 62 | 249 | 263 | 312 | 398 | 486 | |||||||||||||||||
Total fixed charges | $64 | $293 | $292 | $387 | $523 | $515 | |||||||||||||||||
Earnings: | |||||||||||||||||||||||
Loss from continuing operations before income taxes | $ | (3,948 | ) | $ | (20,361 | ) | $ | (7,547 | ) | $ | (15,186 | ) | $ | (19,306 | ) | $ | (15,487 | ) | |||||
Fixed charges per above | 64 | 293 | 292 | 387 | 526 | 515 | |||||||||||||||||
Deficiency of earnings available to cover fixed charges | $ | (3,884 | ) | $ | (20,068 | ) | $ | (7,255 | ) | $ | (14,799 | ) | $ | (18,783 | ) | $ | (14,972 | ) | |||||
Ratio of earnings to fixed charges | — | — | — | — | — | — | |||||||||||||||||