Summary Of Significant Accounting And Reporting Policies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) branch	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Condensed Financial Statements, Captions [Line Items]
Document Period End Date	Dec. 31, 2019
Number of Reportable Segments	1
DiscontinuationofInterestThresholdDays	90 days
Past Due Threshold in Days	30 days
Other real estate, foreclosed assets, and repossessed assets	$ 4,700	$ 4,600
Amortization Method Qualified Affordable Housing Project Investments	10,100	5,400
Cash paid for interest	37,000	24,800	$ 16,400
Income taxes paid	14,900	$ 20,800	$ 22,600
Qualified Affordable Housing Project Investments, Commitment	$ 3,200
City National
Condensed Financial Statements, Captions [Line Items]
Number of offices | branch	95
Residential real estate
Condensed Financial Statements, Captions [Line Items]
Threshold period past due for write-off of financing receivable	120 days
Commercial Industrial Loans And Commercial Real Estate
Condensed Financial Statements, Captions [Line Items]
Threshold period past due for write-off of financing receivable	120 days
Consumer Loan
Condensed Financial Statements, Captions [Line Items]
Threshold period past due for write-off of financing receivable	120 days