Deposits and Borrowed Funds (Details 2) (USD $) In Thousands, unless otherwise specified										12 Months Ended					12 Months Ended				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 City National Corporation	Dec. 31, 2012 City National Corporation	Dec. 31, 2013 5.125% Senior Notes Due February 2013 City National Corporation	Dec. 31, 2012 5.125% Senior Notes Due February 2013 City National Corporation	Dec. 31, 2013 5.25% Senior Notes Due September 2020 City National Corporation	Dec. 31, 2012 5.25% Senior Notes Due September 2020 City National Corporation	Dec. 31, 2013 9.00% Subordinated Notes Due July 2019 Prime rate	Dec. 31, 2013 9.00% Subordinated Notes Due July 2019 City National Bank	Dec. 31, 2012 9.00% Subordinated Notes Due July 2019 City National Bank	Dec. 31, 2013 9.00% Subordinated Notes Due August 2019 City National Bank	Dec. 31, 2012 9.00% Subordinated Notes Due August 2019 City National Bank	Dec. 31, 2013 Fixed and Floating Subordinated Notes due August 2019 City National Bank	Dec. 31, 2012 Fixed and Floating Subordinated Notes due August 2019 City National Bank	Dec. 31, 2013 5.375% Subordinated Notes Due July 2022 City National Bank	Dec. 31, 2012 5.375% Subordinated Notes Due July 2022 City National Bank	Dec. 31, 2013 Floating Rate Securities Due November 2034 Business Bancorp Capital Trust I	Dec. 31, 2012 Floating Rate Securities Due November 2034 Business Bancorp Capital Trust I	Dec. 31, 2013 Nonrecourse debt	Dec. 31, 2012 Nonrecourse debt	Dec. 31, 2013 Other long-term debt
Short-term borrowings
Current portion of senior notes							$ 206,581
Federal funds purchased		1,214,200
Total short-term borrowings	3,889	1,423,798			206,581																3,889	3,017
Long-term debt
Long-term debt	$ 735,968	$ 706,051		$ 304,618	$ 302,765			$ 299,463	$ 297,613		$ 50,000	$ 49,755	$ 75,000	$ 74,876	$ 55,000	$ 54,909	$ 149,994	$ 148,642	$ 5,155	$ 5,152	$ 91,388	$ 75,104	$ 9,968
Fixed interest rate (as a percent)						5.125%	5.125%	5.25%	5.25%		9.00%	9.00%	9.00%	9.00%			5.375%	5.375%					5.64%
Average interest rate (as a percent)	0.18%	0.09%	0.06%																		3.83%
Variable rate basis										Prime rate	LIBOR				three-month LIBOR				three-month LIBOR
Frequency to reset interest rate															Quarterly
Interest rate cap (as a percent)															10.00%
Interest rate for initial period (as a percent)											9.00%				9.00%
Initial interest rate period											5 years				5 years
Basis spread after initial period (as a percent)										5.00%	6.00%				6.00%
Basis spread (as a percent)																			1.965%
Interest rate as of reporting date (as a percent)																			2.20%