Financial Risk and Fair Value Disclosures (Tables)

12 Months Ended

Dec. 31, 2019

Statement [Line Items]

Categories of Financial Instruments

(1) Categories of financial instruments

	As of December 31,
Financial Assets	2018		2019
	NT$		NT$
	(In Thousands)		(In Thousands)
Financial assets at fair value through profit or loss	$	12,084,297	$	14,021,473
Financial assets at fair value through other comprehensive income		11,585,477		14,723,232
Financial assets measured at amortized cost
Cash and cash equivalents (excludes cash on hand)		83,655,648		95,486,403
Receivables		24,583,451		26,459,392
Refundable deposits		2,757,399		2,600,733
Other financial assets		2,320,037		2,353,066
Total	$	136,986,309	$	155,644,299

	As of December 31,
Financial Liabilities	2018		2019
	NT$		NT$
	(In Thousands)		(In Thousands)
Financial liabilities measured at amortized cost
Short-term loans	$	13,103,808	$	12,015,206
Payables		23,559,548		27,433,065
Guarantee deposits (current portion included)		665,793		296,694
Bonds payable (current portion included)		41,378,182		38,781,416
Long-term loans (current portion included)		30,826,215		33,902,074
Lease liabilities (Note)		—		6,031,025
Other financial liabilities		20,523,099		20,093,441
Total	$	130,056,645	$	138,552,921

Maturity Profile of Financial Liabilities Based on Contractual Undiscounted Payments and Contractual Maturity

The table below summarizes the maturity profile of the Company’s financial liabilities based on the contractual undiscounted payments and contractual maturity:

	As of December 31, 2018
	Less than 1 year		2 to 3 years		4 to 5 years		> 5 years		Total
	NT$		NT$		NT$		NT$		NT$
	(In Thousands)		(In Thousands)		(In Thousands)		(In Thousands)		(In Thousands)
Non-derivative financial liabilities
Short-term loans	$	13,171,811	$	—	$	—	$	—	$	13,171,811
Payables		23,088,071		199,788		—		—		23,287,859
Guarantee deposits		52,890		154,787		15,385		442,731		665,793
Bonds payable		3,000,855		23,187,913		8,484,393		8,563,021		43,236,182
Long-term loans		4,036,260		10,997,829		17,209,849		4,765,719		37,009,657
Other financial liabilities		112,744		—		17,477,984		4,369,730		21,960,458
Total	$	43,462,631	$	34,540,317	$	43,187,611	$	18,141,201	$	139,331,760

	As of December 31, 2019
	Less than 1 year		2 to 3 years		4 to 5 years		> 5 years		Total
	NT$		NT$		NT$		NT$		NT$
	(In Thousands)		(In Thousands)		(In Thousands)		(In Thousands)		(In Thousands)
Non-derivative financial liabilities
Short-term loans	$	12,211,621	$	—	$	—	$	—	$	12,211,621
Payables		26,998,325		198,862		—		—		27,197,187
Guarantee deposits		100,584		97,108		—		99,002		296,694
Bonds payable		20,659,607		10,590,265		8,689,971		—		39,939,843
Long-term loans		6,104,795		19,631,931		13,097,986		12,000		38,846,712
Lease liabilities		740,939		1,413,978		1,180,955		3,792,192		7,128,064
Other financial liabilities		—		12,668,287		8,445,826		—		21,114,113
Total	$	66,815,871	$	44,600,431	$	31,414,738	$	3,903,194	$	146,734,234

Details of Forward Exchange Contracts

The details of forward exchange contracts entered into by UMC are summarized as follows:

As of December 31, 2018

Type	Notional Amount	Contract Period
Forward exchange contracts	Sell USD 28 million	December 10, 2018~ January 7, 2019

Reconciliations for Fair Value Measurement in Level 3 Fair Value Hierarchy

Reconciliations for fair value measurement in Level 3 fair value hierarchy were as follows:

	Financial assets at fair value through profit or loss														Financial assets at fair value through other comprehensive income
	Common stock			Preferred stock			Funds		Option			Total			Common stock			Preferred stock			Total
	NT$			NT$			NT$		NT$			NT$			NT$			NT$			NT$
	(In Thousands)			(In Thousands)			(In Thousands)		(In Thousands)			(In Thousands)			(In Thousands)			(In Thousands)			(In Thousands)
As of January 1, 2018	$	3,832,537		$	2,994,294		$	1,183,940	$	31,605		$	8,042,376		$	3,350,694		$	233,326		$	3,584,020
Recognized in profit (loss)		(3,356	)		(394,931	)		69,827		(31,605	)		(360,065	)		—			—			—
Recognized in other comprehensive loss		—			—			—		—			—			(115,520	)		(49,300	)		(164,820	)
Acquisition		140,338			630,626			577,347		—			1,348,311			—			—			—
Disposal		(468,337	)		(310,025	)		—		—			(778,362	)		—			—			—
Return of capital		(22,954	)		—			—		—			(22,954	)		—			—			—
Transfer to Level 3		22,050			—			—		—			22,050			—			—			—
Transfer out of Level 3		(442,138	)		—			—		—			(442,138	)		—			—			—
Exchange effect		19,551			51,564			18,674		—			89,789			—			—			—
As of December 31, 2018	$	3,077,691		$	2,971,528		$	1,849,788	$	—		$	7,899,007		$	3,235,174		$	184,026		$	3,419,200

	Financial assets at fair value through profit or loss															Financial assets at fair value through other comprehensive income
	Common stock			Preferred stock			Funds			Convertible bonds			Total			Common stock			Preferred stock			Total
	NT$			NT$			NT$			NT$			NT$			NT$			NT$			NT$
	(In Thousands)			(In Thousands)			(In Thousands)			(In Thousands)			(In Thousands)			(In Thousands)			(In Thousands)			(In Thousands)
As of January 1, 2019	$	3,077,691		$	2,971,528		$	1,849,788		$	—		$	7,899,007		$	3,235,174		$	184,026		$	3,419,200
Recognized in profit (loss)		(272,299	)		273,047			(14,024	)		6,145			(7,131	)		—			—			—
Recognized in other comprehensive income (loss)		—			—			—			—			—			199,244			(8,532	)		190,712
Acquisition		159,476			396,890			204,082			51,956			812,404			—			—			—
Disposal		(1,475	)		(328,371	)		—			—			(329,846	)		(2,303,988	)		—			(2,303,988	)
Return of capital		(14,954	)		—			—			—			(14,954	)		—			—			—
Transfer to Level 3		—			—			—			49,706			49,706			—			—			—
Transfer out of Level 3		(53,300	)		—			—			—			(53,300	)		—			—			—
Exchange effect		(14,451	)		(33,800	)		(28,821	)		(3,099	)		(80,171	)		—			—			—
As of December 31, 2019	$	2,880,688		$	3,279,294		$	2,011,025		$	104,708		$	8,275,715		$	1,130,430		$	175,494		$	1,305,924

Summary of Significant Unobservable Inputs of Fair Value Measurement in Level 3 Fair Value Hierarchy

Significant unobservable inputs of fair value measurement in Level 3 fair value hierarchy were as follow:

As of December 31, 2018
Category of equity securities	Valuation technique	Significant unobservable inputs	Quantitative information	Interrelationship between inputs and fair value	Sensitivity analysis of interrelationship between inputs and fair value
Unlisted stock	Market Approach	Discount for lack of marketability	15%~50%	The greater degree of lack of marketability, the lower the estimated fair value is determined.	A change of 5% in the discount for lack of marketability of the aforementioned fair values of unlisted stocks could decrease/increase the Company’s profit (loss) and other comprehensive income (loss) for the year ended December 31, 2018 by NT$309 million and by NT$241 million, respectively.

As of December 31, 2019
Category of equity securities	Valuation technique	Significant unobservable inputs	Quantitative information	Interrelationship between inputs and fair value	Sensitivity analysis of interrelationship between inputs and fair value
Unlisted stock	Market Approach	Discount for lack of marketability	0%~50%	The greater degree of lack of marketability, the lower the estimated fair value is determined.	A change of 5% in the discount for lack of marketability of the aforementioned fair values of unlisted stocks could decrease/increase the Company’s profit (loss) for the year ended December 31, 2019 by NT$267 million and NT$191 million, respectively, and decrease/increase the Company’s other comprehensive income (loss) for the year ended December 31, 2019 by NT$87 million.

Recurring fair value measurement [member]

Statement [Line Items]

Assets and Liabilities Measured and Recorded at Fair Value

a. Assets and liabilities measured and recorded at fair value on a recurring basis:

	As of December 31, 2018
	Level 1		Level 2		Level 3		Total
	NT$		NT$		NT$		NT$
	(In Thousands)		(In Thousands)		(In Thousands)		(In Thousands)
Financial assets:
Financial assets at fair value through profit or loss, current	$	493,481	$	34,969	$	—	$	528,450
Financial assets at fair value through profit or loss, noncurrent		3,612,243		44,597		7,899,007		11,555,847
Financial assets at fair value through other comprehensive income, noncurrent		8,166,277		—		3,419,200		11,585,477

	As of December 31, 2019
	Level 1		Level 2		Level 3		Total
	NT$		NT$		NT$		NT$
	(In Thousands)		(In Thousands)		(In Thousands)		(In Thousands)
Financial assets:
Financial assets at fair value through profit or loss, current	$	668,476	$	—	$	54,318	$	722,794
Financial assets at fair value through profit or loss, noncurrent		4,737,027		340,255		8,221,397		13,298,679
Financial assets at fair value through other comprehensive income, noncurrent		13,417,308		—		1,305,924		14,723,232

Not measured at fair value in statement of financial position but for which fair value is disclosed [member]

Statement [Line Items]

Assets and Liabilities Measured and Recorded at Fair Value

The fair values of the Company’s short-term financial instruments including cash and cash equivalents, receivables, refundable deposits, other financial assets-current, short-term loans, payables and guarantee deposits approximate their carrying amount due to their maturities within one year.

As of December 31, 2018

			Fair value measurements during reporting period using
Items	Fair value		Level 1		Level 2		Level 3		Carrying amount
	NT$		NT$		NT$		NT$		NT$
	(In Thousands)		(In Thousands)		(In Thousands)		(In Thousands)		(In Thousands)
Bonds payables (current portion included)	$	41,714,368	$	23,929,019	$	17,785,349	$	—	$	41,378,182
Long-term loans (current portion included)		30,826,215		—		30,826,215		—		30,826,215

As of December 31, 2019

			Fair value measurements during reporting period using
Items	Fair value		Level 1		Level 2		Level 3		Carrying amount
	NT$		NT$		NT$		NT$		NT$
	(In Thousands)		(In Thousands)		(In Thousands)		(In Thousands)		(In Thousands)
Bonds payables (current portion included)	$	39,571,920	$	21,347,047	$	18,224,873	$	—	$	38,781,416
Long-term loans (current portion included)		33,902,074		—		33,902,074		—		33,902,074