The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Goodwill and Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill acquired			$ 93,900
Goodwill	$ 211,251		211,251		$ 117,345
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets			3,993	$ 1,908
Core deposit
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 1,600	$ 600	$ 4,000	$ 1,900
Finite-lived intangible assets useful life			10 years