Goodwill and other intangibles - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2018	Jun. 30, 2018
Business Acquisition [Line Items]
Increase in goodwill		$ 11,308
Intangibles recorded in connection with acquisitions		$ 3,600
Acquired software
Business Acquisition [Line Items]
Acquired intangibles, amortization period		3 years
Title
Business Acquisition [Line Items]
Increase in goodwill	$ 11,300	$ 11,308

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The amount of identifiable intangible assets recognized as of the acquisition date.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 55
-Paragraph 37
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- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

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