Loans - Carrying Amount of Purchased Credit Impaired Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accounts Notes And Loans Receivable [Line Items]
Net loans	$ 5,108,683	$ 4,526,833
Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans	6,137	8,173
Unaccreted discount on purchased credit impaired loans		(3,657)
Net loans	6,137	4,516
Residential Properties | Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Net loans	291
Commercial Real Estate | Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Net loans	5,529	3,327
Commercial and Industrial Loans | Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans	317	603
Net loans	317	408
Land | Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Net loans		781
Real Estate Loans | Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans	5,820	7,570
Real Estate Loans | Residential Properties | Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans	291	366
Real Estate Loans | Commercial Real Estate | Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans	$ 5,529	6,146
Real Estate Loans | Land | Receivables Acquired with Deteriorated Credit Quality
Accounts Notes And Loans Receivable [Line Items]
Total impaired loans		$ 1,058