Fair value measurement (Tables)

12 Months Ended

Dec. 31, 2019

Disclosure of financial liabilities [abstract]

Schedule of assets and liabilities measured at fair value

	December 31, 2019
		Quoted prices in active markets	Significant observable inputs	Significant unobservable inputs
	Total	(Level 1)	(Level 2)	(Level 3)
	US$'000	US$'000	US$'000	US$'000
Other financial assets (Note 10):
Listed equity securities	5,544	5,544	—	—
Other financial liabilities (Note 19):
Derivative financial instruments - cross currency swap	(9,600)	—	(9,600)	—
Derivative financial instruments - interest rate swaps	—	—	—	—
Other liabilities (Note 21)
Contingent consideration in a business combinations	(21,965)	—	—	(21,965)

	December 31, 2018
		Quoted prices in active markets	Significant observable inputs	Significant unobservable inputs
	Total	(Level 1)	(Level 2)	(Level 3)
	US$'000	US$'000	US$'000	US$'000
Other assets (Note 12):
Biological assets	7,790	—	—	7,790
Other financial assets (Note 10):
Debt investments	67,079	—	—	67,079
Listed equity securities	2,523	2,523	—	—
Other financial liabilities (Note 19):
Derivative financial instruments - cross currency swap	(20,384)	—	(20,384)	—
Derivative financial instruments - interest rate swaps	(3,079)	—	(3,079)	—
Other liabilities (Note 21)
Contingent consideration in a business combinations	(26,222)	—	—	(26,222)

Schedule of changes fair value of biological assets classified at level 3 in the hierarchy

	Level 3
	US$'000
January 1, 2018	27,279
Loss recognised in profit or loss (Note 25.5)	(7,615)
Disposal of biological assets	(12,168)
Translation differences	294
December 31, 2018	7,790
Loss recognised in profit or loss (Note 25.5)	(530)
Disposal of biological assets	(7,365)
Translation differences	105
December 31, 2019	—