Regulatory Requirements And Capital Ratios (Schedule Of Capital Amounts And Ratios) (Details) $ in Thousands	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Parent Company
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
CET1 capital	$ 557,641	$ 532,640
CET1 ratio	0.162	0.160
CET1 capital, minimum capital required basel III fully phased in	$ 241,221	$ 232,358
CET1 ratio, minimum capital required basel III fully phased in	7.00%	7.00%
CET1 capital, required to be well-capitalized	$ 223,991	$ 215,761
CET1 ratio, required to be well capitalized	6.50%	6.50%
Tier I capital	$ 557,641	$ 536,640
Tier I capital, ratio	0.162	0.162
Tier 1, capital, minimum capital required basel III fully phased in	$ 292,911	$ 282,150
Tier 1, ratio, minimum capital required basel III fully phased in	8.50%	8.50%
Tier 1, capital, required to be well-capitalized	$ 275,681	$ 265,552
Tier 1, ratio, required to be well-capitalized	0.080	0.080
Total capital	$ 577,292	$ 548,291
Total capital, ratio	0.168	0.165
Total capital, minimum capital required basel III fully phased in	$ 361,831	$ 348,538
Total capital, ratio, minimum capital required basel III fully phased in	10.50%	10.50%
Total capital, required to be well-capitalized	$ 344,601	$ 331,941
Total capital, ratio, required to be well-capitalized	0.100	0.100
Tier 1 Leverage Capital, Average Assets	$ 557,641	$ 536,640
Tier I Leverage Ratio, Average Assets	0.102	0.110
Tier 1 Leverage Capital, minimum capital required basel III fully phased in	$ 218,163	$ 195,558
Tier 1 Leverage Ratio, minimum capital required basel III fully phased in	4.00%	4.00%
Tier 1 Leverage Capital Required to be Well Capitalized	$ 272,704	$ 244,448
Tier 1 Leverage Capital, Average Assets, Well Capitalized Ratio	0.050	0.050
City National
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
CET1 capital	$ 482,754	$ 459,006
CET1 ratio	0.141	0.139
CET1 capital, minimum capital required basel III fully phased in	$ 239,569	$ 230,808
CET1 ratio, minimum capital required basel III fully phased in	7.00%	7.00%
CET1 capital, required to be well-capitalized	$ 222,457	$ 214,322
CET1 ratio, required to be well capitalized	6.50%	6.50%
Tier I capital	$ 482,754	$ 459,006
Tier I capital, ratio	0.141	0.139
Tier 1, capital, minimum capital required basel III fully phased in	$ 290,906	$ 280,267
Tier 1, ratio, minimum capital required basel III fully phased in	8.50%	8.50%
Tier 1, capital, required to be well-capitalized	$ 273,793	$ 263,781
Tier 1, ratio, required to be well-capitalized	0.080	0.080
Total capital	$ 502,405	$ 470,656
Total capital, ratio	0.147	0.143
Total capital, minimum capital required basel III fully phased in	$ 359,354	$ 346,213
Total capital, ratio, minimum capital required basel III fully phased in	10.50%	10.50%
Total capital, required to be well-capitalized	$ 342,242	$ 329,726
Total capital, ratio, required to be well-capitalized	0.100	0.100
Tier 1 Leverage Capital, Average Assets	$ 482,754	$ 459,006
Tier I Leverage Ratio, Average Assets	0.090	0.095
Tier 1 Leverage Capital, minimum capital required basel III fully phased in	$ 215,277	$ 193,074
Tier 1 Leverage Ratio, minimum capital required basel III fully phased in	4.00%	4.00%
Tier 1 Leverage Capital Required to be Well Capitalized	$ 269,097	$ 241,342
Tier 1 Leverage Capital, Average Assets, Well Capitalized Ratio	0.050	0.050