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Income taxes - Narrative (Details) (Internal Revenue Service (IRS), USD $)
In Millions, unless otherwise specified |
Dec. 31, 2014
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| Operating Loss Carryforwards [Line Items] | |
| Operating Loss Carryforwards | $ 16.0us-gaap_OperatingLossCarryforwards |
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Subsidiary
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| Operating Loss Carryforwards [Line Items] | |
| Operating Loss Carryforwards |
$ 3.3us-gaap_OperatingLossCarryforwards / us-gaap_IncomeTaxAuthorityAxis = us-gaap_InternalRevenueServiceIRSMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
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- Definition
Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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