Earnings per Common Share (Details) (USD $) In Thousands, except Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Basic EPS:
Net income attributable to City National Corporation	$ 47,471	$ 41,318	$ 87,163	$ 57,016
Less: Dividends and accretion on preferred stock				5,702
Net income available to common shareholders	47,471	41,318	87,163	51,314
Less: Earnings allocated to participating securities	759	535	1,333	635
Earnings allocated to common shareholders	46,712	40,783	85,830	50,679
Weighted average common shares outstanding (in shares)	52,462,000	52,012,000	52,392,000	51,852,000
Basic earnings per common share (in dollars per share)	$ 0.89	$ 0.78	$ 1.64	$ 0.98
Diluted EPS:
Earnings allocated to common shareholders	$ 46,718	$ 40,787	$ 85,841	$ 50,684
Weighted average common shares outstanding (in shares)	52,462,000	52,012,000	52,392,000	51,852,000
Dilutive effect of equity awards (in shares)	515,000	530,000	539,000	484,000
Weighted average diluted common shares outstanding (in shares)	52,977,000	52,542,000	52,931,000	52,336,000
Diluted earnings per common share (in dollars per share)	$ 0.88	$ 0.78	$ 1.62	$ 0.97
Average outstanding stock options
Antidilutive securities not included in calculation of basic or diluted EPS:
Antidilutive securities not included in calculation of basic or diluted EPS (in shares)	2,000,000	1,500,000	1,800,000	2,200,000
Common stock warrant
Antidilutive securities not included in calculation of basic or diluted EPS:
Antidilutive securities not included in calculation of basic or diluted EPS (in shares)		100,000		600,000