Shareholders' equity, net (Tables)

12 Months Ended

Dec. 31, 2018

Disclosure of Shareholders' equity, net [Line Items]

Disclosure of detailed information about dividends declared and paid [Text Block]

The table below presents the dividends declared and paid in 2018, 2017 and 2016:

Meetings	Date	Dividends declared and paid			Dividend per share
		US$(000)			US$

2018 Dividends
Mandatory Annual Shareholders’ Meeting	March 27		8,269			0.03
Less - Dividends of treasury shares			(648	)
			7,621

Board of Directors’ Meeting	October 25		16,538			0.06
Less - Dividends of treasury shares			(1,299	)
			15,239
			22,860

2017 Dividends
Mandatory Annual Shareholders’ Meeting	March 28		15,711			0.056
Less - Dividends of treasury shares			(1,232	)
			14,479

Board of Directors’ Meeting	October 27		8,269			0.030
Less - Dividends of treasury shares			(649	)
			7,620
			22,099

2016 Dividends
Board of Directors’ Meeting	October 27		8,269			0.03
Less - Dividends of treasury shares			(648	)
			7,621

Disclosure of detailed information about equity share capital [Text Block]

As of December 31, 2018, the Company’s capital stock structure is as follows:

Percentage of individual interest in capital	Number of shareholders		Total percentage interest

Up to 1.00		2,811		4.37
From 1.01 to 20.00		2		21.07
From 20.01 to 30.00		1		21.00
From 30.01 to 60.00		1		53.56

		2,815		100.00

Disclosure Of Earning Per Share [Text Block]

The calculation of profit (loss) per share attributable to the equity holders of the parent is presented below:

	2018			2017		2016

Profit (loss) net (numerator) - US$		(13,445,000	)		60,823,000		(323,492,000	)
Total common and investment shares (denominator)		253,986,867			253,986,867		253,986,867

Profit (loss) net per basic share and diluted - US$		(0.05	)		0.24		(1.27	)

The calculation of profit (loss) per share from continuing operations attributable to the equity holders of the Parent is presented below:

	2018			2017		2016

Profit (loss) net (numerator) - US$		(6,242,000	)		70,921,000		(304,419,000	)
Total common and investment shares (denominator)		253,986,867			253,986,867		253,986,867

Profit (loss) net per basic share and diluted - US$		(0.02	)		0.28		(1.20	)

capital stock [Member]

Disclosure of Shareholders' equity, net [Line Items]

Disclosure of classes of share capital [text block]

The Group’s share capital is stated in Soles and consists of common shares with voting rights, with a nominal amount of S/10.00 per share. The table below presents the composition of the capital stock as of December 31, 2018 and 2017:

	Number of shares			Capital stock			Capital stock
				S/(000)			US$(000)

Common shares		274,889,924			2,748,899			813,162
Treasury shares		(21,174,734	)		(211,747	)		(62,665	)

		253,715,190			2,537,152			750,497

investment shares [Member]

Disclosure of Shareholders' equity, net [Line Items]

Disclosure of classes of share capital [text block]

The table below presents the composition of the investment shares as of December 31, 2018 and 2017:

	Number of shares			Investment shares			Investment shares
				S/(000)			US$(000)

Investment shares		744,640			7,447			2,161
Treasury investment shares		(472,963	)		(4,730	)		(1,370	)

		271,677			2,717			791