Regulatory Requirements And Capital Ratios (Schedule Of Capital Amounts And Ratios) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Parent Company
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
CET1 capital	$ 532,640	$ 492,526
CET1 ratio	16.00%	15.10%
CET1 capital, minimum capital required basel III phase in schedule		$ 208,294
CET1 ratio, minimum capital required basel III phase in schedule		6.375%
CET1 capital, minimum capital required basel III fully phased in	$ 232,358	$ 228,715
CET1 ratio, minimum capital required basel III fully phased in	7.00%	7.00%
CET1 capital, required to be well-capitalized	$ 215,761	$ 212,378
CET1 ratio, required to be well capitalized	6.50%	6.50%
Tier I capital	$ 536,640	$ 496,526
Tier I capital, ratio	16.20%	15.20%
Tier 1, capital, minimum capital required basel III phase in schedule		$ 257,304
Tier 1, ratio, minimum capital required basel III phase in schedule		7.875%
Tier 1, capital, minimum capital required basel III fully phased in	$ 282,150	$ 277,725
Tier 1, ratio, minimum capital required basel III fully phased in	8.50%	8.50%
Tier 1, capital, required to be well-capitalized	$ 265,552	$ 261,389
Tier 1, ratio, required to be well-capitalized	8.00%	8.00%
Total capital	$ 548,291	$ 512,801
Total capital, ratio	16.50%	15.70%
Total capital, minimum capital required basel III phase in schedule		$ 322,651
Total capital, ratio, minimum capital required basel iIII phase in schedule		9.875%
Total capital, minimum capital required basel III fully phased in	$ 348,538	$ 343,072
Total capital, ratio, minimum capital required basel III fully phased in	10.50%	10.50%
Total capital, required to be well-capitalized	$ 331,941	$ 326,736
Total capital, ratio, required to be well-capitalized	10.00%	10.00%
Tier 1 Leverage Capital, Average Assets	$ 536,640	$ 496,526
Tier I Leverage Ratio, Average Assets	11.00%	11.40%
Tier 1 Leverage Capital, minimum capital required basel III phase in schedule		$ 174,833
Tier 1 Leverage Ratio, minimum capital required basel III phase in schedule		4.00%
Tier 1 Leverage Capital, minimum capital required basel III fully phased in	$ 195,558	$ 174,833
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	$ 244,448	$ 218,542
Tier 1 Leverage Capital, Average Assets, Well Capitalized Ratio	5.00%	5.00%
City National
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
CET1 capital	$ 459,006	$ 423,099
CET1 ratio	13.90%	13.10%
CET1 capital, minimum capital required basel III phase in schedule		$ 206,676
CET1 ratio, minimum capital required basel III phase in schedule		6.375%
CET1 capital, minimum capital required basel III fully phased in	$ 230,808	$ 226,938
CET1 ratio, minimum capital required basel III fully phased in	7.00%	7.00%
CET1 capital, required to be well-capitalized	$ 214,322	$ 210,728
CET1 ratio, required to be well capitalized	6.50%	6.50%
Tier I capital	$ 459,006	$ 423,099
Tier I capital, ratio	13.90%	13.10%
Tier 1, capital, minimum capital required basel III phase in schedule		$ 255,306
Tier 1, ratio, minimum capital required basel III phase in schedule		7.875%
Tier 1, capital, minimum capital required basel III fully phased in	$ 280,267	$ 275,568
Tier 1, ratio, minimum capital required basel III fully phased in	8.50%	8.50%
Tier 1, capital, required to be well-capitalized	$ 263,781	$ 259,358
Tier 1, ratio, required to be well-capitalized	8.00%	8.00%
Total capital	$ 470,656	$ 439,374
Total capital, ratio	14.30%	13.60%
Total capital, minimum capital required basel III phase in schedule		$ 320,145
Total capital, ratio, minimum capital required basel iIII phase in schedule		9.875%
Total capital, minimum capital required basel III fully phased in	$ 346,213	$ 340,408
Total capital, ratio, minimum capital required basel III fully phased in	10.50%	10.50%
Total capital, required to be well-capitalized	$ 329,726	$ 324,198
Total capital, ratio, required to be well-capitalized	10.00%	10.00%
Tier 1 Leverage Capital, Average Assets	$ 459,006	$ 423,099
Tier I Leverage Ratio, Average Assets	9.50%	9.80%
Tier 1 Leverage Capital, minimum capital required basel III phase in schedule		$ 172,594
Tier 1 Leverage Ratio, minimum capital required basel III phase in schedule		4.00%
Tier 1 Leverage Capital, minimum capital required basel III fully phased in	$ 193,074	$ 172,594
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	$ 241,342	$ 215,742
Tier 1 Leverage Capital, Average Assets, Well Capitalized Ratio	5.00%	5.00%