Acquisitions Schedule of Consideration Paid, Assets Acquired and Liabilities Assumed in Acquisition of CFS (Details) - USD ($) $ in Thousands	Jan. 01, 2020	Dec. 31, 2019
As Recorded By Summit [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 29,691
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Cash and Cash Equivalents	0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	60,210
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Securities Available for Sale	(47)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities	90,107
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Purchased Performing Loans	188
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Purchased Performing Loans	38,153
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Purchased Credit Impaired Loans	(569)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Purchased Credit Impaired Loans	1,308
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Allowance For Loan Losses	312
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Assets, Allowance For Loan Losses	0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Property, Plant, And Equipment	(142)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	665
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Property Held-For-Sale	0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property Held-For-Sale	10
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Intangibles	717
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	717
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Other Assets	(474)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	3,864
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Assets	(15)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	195,034
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Deposits	239
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits	173,269
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Other Liabilities	(407)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	2,896
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Liabilities	(168)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	176,165
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Fair Value Adjustment, Assets (Liabilities), Net	153
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	18,869
Goodwill	10,822
Cornerstone Financial Services Inc. [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	60,210
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities	90,154
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Purchased Performing Loans	37,965
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Purchased Credit Impaired Loans	1,877
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Assets, Allowance For Loan Losses	(312)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	807
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property Held-For-Sale	10
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	4,338
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	195,049	$ 195,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits	173,030
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	3,303
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	176,333	$ 176,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	18,716
Goodwill	10,820
Cash Consideration [Member] | As Recorded By Summit [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	14,250
Cash Consideration [Member] | Cornerstone Financial Services Inc. [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	14,300
Stock Consideration [Member] | As Recorded By Summit [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	15,441
Stock Consideration [Member] | Cornerstone Financial Services Inc. [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 15,400