XML 168 R154.htm IDEA: XBRL DOCUMENT v3.8.0.1
Equity - Unrealized Gain (Loss) on Available-for-sale Financial Assets (Detail)
$ in Millions, $ in Millions
 12 Months Ended
Dec. 31, 2017
TWD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
TWD ($)
Dec. 31, 2015
TWD ($)
Beginning balance $ 366,928   $ 369,339 $ 365,712
Unrealized gain (loss) on available-for-sale financial assets 605   (721) (671)
Income tax relating to unrealized gain and loss on available-for-sale financial assets (3)   (2) 2
Ending balance 369,410 $ 12,463 366,928 369,339
Unrealized gain (loss) on available-for-sale financial assets [Member]        
Beginning balance (51)   91 740
Unrealized gain (loss) on available-for-sale financial assets 607   (721) (670)
Income tax relating to unrealized gain and loss on available-for-sale financial assets 2   2 (2)
Amount reclassified from equity to profit or loss on disposal of available-for-sale financial assets 0   0 0
Amount reclassified from equity to profit or loss on impairment of available-for-sale financial assets 0   577 23
Ending balance $ 558 $ 19 $ (51) $ 91