Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 30, 2019
Goodwill [Line Items]
Goodwill acquired	[1]	$ 84,175	$ 0
Goodwill, written off related to sale of business unit		0	4,224
Core deposits and other intangible assets		10,900
Finite-lived intangible assets acquired	[2]	9,154	80
Amortization expense on finite-lived intangible assets		800	$ 900	$ 1,200
DNB
Goodwill [Line Items]
Goodwill acquired		84,200
Core Deposits
Goodwill [Line Items]
Finite-lived intangible assets acquired		7,300
Core Deposits | DNB
Goodwill [Line Items]
Core deposits and other intangible assets					$ 7,288
Wealth Management
Goodwill [Line Items]
Finite-lived intangible assets acquired		$ 1,900
Wealth Management | DNB
Goodwill [Line Items]
Core deposits and other intangible assets					$ 1,772

[1] Management is continuing to evaluate the purchase accounting fair value adjustments for the DNB merger. Any changes in preliminary estimates will be adjusted in goodwill in subsequent periods, but not extending beyond one year from the date of acquisition.

[2] Management is still evaluating the intangible asset valuation due to the final independent valuation report not being complete. Any changes in preliminary estimates will be adjusted in goodwill in subsequent periods, but not extending beyond one year from the date of acquisition.