Goodwill and intangible assets Goodwill and intangible assets - Goodwill activity (Details) - USD ($)	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 137,190,000
Addition from acquisition of Atlantic Capital branches	31,396,000
Impairment due to sale of third party origination (TPO) mortgage delivery channel	(100,000)	$ 0
Goodwill, ending balance	$ 168,486,000	$ 137,190,000

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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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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- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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