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Cash flow information (Details 1) - USD ($) | 9 Months Ended
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Sep. 30, 2017 | Sep. 30, 2016
Interest, net of amount capitalized and AFUDC - borrowed of $676 and $842 in 2017 and 2016, respectively |  | $ 58,119,000 | $ 66,281,000
Income taxes paid (refunded), net | [1] | 46,430,000 | 73,771,000
Property, plant and equipment additions in accounts payable |  | 16,914,000 | 22,560,000
Capitalized interest and AFUDC borrowed |  | 676,000 | 842,000
Continuing and discontinued operations [Member] |  |  |
Income taxes paid (refunded), net |  | $ 1,400,000 | $ (144,000)
[1] | Income taxes paid (refunded), net of discontinued operations, were $1.4 million and $(144,000) for the nine months ended September 30, 2017 and 2016, respectively.

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- Definition The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4297-108586 + Details
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