Earnings per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Basic EPS:
Net income attributable to City National Corporation	$ 51,523	[1]	$ 46,265	[1]
Less: Dividends on preferred stock	2,406
Net income available to common shareholders	49,117		46,265
Less: Earnings allocated to participating securities	637		738
Earnings allocated to common shareholders	48,480		45,527
Weighted average common shares outstanding	53,731,000		52,741,000
Basic earnings per common share (in dollars per share)	$ 0.90		$ 0.86
Diluted EPS:
Earnings allocated to common shareholders	$ 48,484		$ 45,530
Weighted average common shares outstanding	53,731,000		52,741,000
Dilutive effect of equity awards (in shares)	337,000		280,000
Weighted average diluted common shares outstanding	54,068,000		53,021,000
Diluted earnings per common share (in dollars per share)	$ 0.90		$ 0.86
Average outstanding stock options
Antidilutive securities not included in calculation of diluted EPS:
Antidilutive securities not included in calculation of diluted EPS (in shares)	2,000,000		3,000,000

[1] Net income excludes net income attributable to redeemable noncontrolling interest of $585 and $243 for the three month periods ended March 31, 2013 and 2012, respectively. Redeemable noncontrolling interest is reflected in the mezzanine section of the consolidated balance sheets. See Note 17 of the Notes to the Unaudited Consolidated Financial Statements.