Operating Segments Information - Additional Information (Detail) $ in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2017 TWD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 TWD ($)	Dec. 31, 2015 TWD ($)
Disclosure of operating segments [line items]
Operating revenue	$ 290,441,208	$ 9,798,961	$ 274,884,107	$ 283,302,536
Packaging and EMS segments [member] \| Customer One [member]
Disclosure of operating segments [line items]
Operating revenue	$ 83,873,393	$ 2,829,737	$ 66,554,659	$ 88,311,697

The income arising in the course of an entity's ordinary activities. Income is increases in economic benefits during the accounting period in the form of inflows or enhancements of assets or decreases of liabilities that result in an increase in equity, other than those relating to contributions from equity participants.

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+ Details