Consolidated income tax provision (benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Summary of consolidated income tax provision (benefit)
Current income taxes	$ (86)	$ (1,954)
Deferred income taxes	1,014	0
Income tax provision (benefit)	$ 928	$ (1,954)

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

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Name:	us-gaap_DeferredIncomeTaxExpenseBenefit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration