XML 236 R217.htm IDEA: XBRL DOCUMENT v3.19.1
Significant Subsequent Events - Additional Information (Detail)
$ / shares in Units, $ / shares in Units, $ in Thousands, $ in Thousands
 12 Months Ended
Mar. 28, 2019
USD ($)
$ / shares
Mar. 28, 2019
TWD ($)
$ / shares
Dec. 31, 2017
TWD ($)
Dec. 31, 2016
TWD ($)
Disclosure of non-adjusting events after reporting period [line items]        
Proceeds from issue of ordinary shares     $ 10,290,000  
Proceeds from issue of bonds     $ 8,000,000 $ 9,000,000
Ordinary shares [member]        
Disclosure of non-adjusting events after reporting period [line items]        
Par value of ordinary shares | (per share) $ 0.3 $ 10.0    
Ordinary shares [member] | Top of range [member]        
Disclosure of non-adjusting events after reporting period [line items]        
Proceeds from issue of ordinary shares $ 98,007 $ 3,000,000    
Unsecured domestic bonds [member]        
Disclosure of non-adjusting events after reporting period [line items]        
Maturity term Five and seven year Five and seven year    
Unsecured domestic bonds [member] | Unsecured domestic bond annual interest rates of 0.9% with maturity of 5 years [member]        
Disclosure of non-adjusting events after reporting period [line items]        
Proceeds from issue of bonds $ 212,349 $ 6,500,000    
Interest rate 0.90% 0.90%    
Maturity term 5 years 5 years    
Unsecured domestic bonds [member] | Unsecured domestic bond annual interest rates of 1.03% with maturity of 7 years [member]        
Disclosure of non-adjusting events after reporting period [line items]        
Proceeds from issue of bonds $ 114,342 $ 3,500,000    
Interest rate 1.03% 1.03%    
Maturity term 7 years 7 years