| a. | Other operating income and expenses, net |
| For the Year Ended December 31 | ||||||||||||||||
| 2015 | 2016 | 2017 | ||||||||||||||
| NT$ | NT$ | NT$ | US$ (Note 4) | |||||||||||||
| Rental income | $ | 60,230 | $ | 51,607 | $ | 131,570 | $ | 4,439 | ||||||||
| Gain (loss) on disposal of property, plant and equipment and other assets | (127,111 | ) | (127,159 | ) | 367,110 | 12,386 | ||||||||||
| Impairment loss on property, plant and equipment and goodwill | (258,129 | ) | (888,231 | ) | (714,675 | ) | (24,112 | ) | ||||||||
| Loss on damages and claims | (116,445 | ) | (12,778 | ) | (85,585 | ) | (2,888 | ) | ||||||||
| Others | 189,926 | 176,281 | 410,136 | 13,837 | ||||||||||||
| $ | (251,529 | ) | $ | (800,280 | ) | $ | 108,556 | $ | 3,662 | |||||||