Segment Results (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 segment		Jun. 30, 2012
Segment Results
Number of reportable segments			3
Earnings Summary:
Net interest income	$ 202,919	$ 216,479	$ 403,992		$ 417,192
Provision for credit losses on loans and leases, excluding covered loans		1,000			1,000
Provision for losses on covered loans	(11,927)	13,293	(2,035)		20,759
Noninterest income	82,209	74,768	175,737		150,468
Depreciation and amortization	10,180	9,531	20,284		18,845
Noninterest expense	201,249	184,985	402,485		376,391
Income before income taxes	85,626	82,438	158,995		150,665
Provision for income taxes	25,422	27,271	46,683		48,990
Net income	60,204	55,167	112,312		101,675
Less: Net income attributable to noncontrolling interest	463	409	1,048		652
Net income attributable to City National Corporation	59,741	54,758	111,264	[1]	101,023	[1]
Selected Average Balances:
Loans and leases, excluding covered loans	15,434,102	13,125,867	15,123,447		12,779,080
Covered loans	909,728	1,341,041	949,370		1,389,877
Total assets	27,469,581	24,362,546	27,588,708		24,003,722
Deposits	23,118,818	20,948,246	22,766,840		20,582,821
Goodwill	642,622	533,146	642,622		509,914
Customer-relationship intangibles, net	45,375	33,843	46,337		34,671
Commercial and Private Banking
Earnings Summary:
Net interest income	185,024	184,758	368,980		356,572
Provision for credit losses on loans and leases, excluding covered loans		1,000			1,000
Provision for losses on covered loans	(11,927)	13,293	(2,035)		20,759
Noninterest income	30,555	50,089	80,818		96,974
Depreciation and amortization	3,624	3,414	7,243		6,997
Noninterest expense	171,289	165,635	342,286		336,785
Income before income taxes	52,593	51,505	102,304		88,005
Provision for income taxes	15,699	17,123	30,237		28,740
Net income	36,894	34,382	72,067		59,265
Net income attributable to City National Corporation	36,894	34,382	72,067		59,265
Selected Average Balances:
Loans and leases, excluding covered loans	15,379,372	13,073,029	15,068,756		12,726,026
Covered loans	909,728	1,341,041	949,370		1,389,877
Total assets	16,505,989	14,728,913	16,247,389		14,433,156
Deposits	22,409,159	20,379,604	22,126,242		20,050,801
Goodwill	393,177	370,333	393,177		347,547
Customer-relationship intangibles, net	5,176	8,129	5,543		8,568
Wealth Management
Earnings Summary:
Net interest income	247	648	565		1,264
Noninterest income	58,472	39,966	113,925		79,337
Depreciation and amortization	1,876	1,538	3,776		2,984
Noninterest expense	48,684	36,123	95,664		72,262
Income before income taxes	8,159	2,953	15,050		5,355
Provision for income taxes	2,298	846	4,138		1,536
Net income	5,861	2,107	10,912		3,819
Less: Net income attributable to noncontrolling interest	463	409	1,048		652
Net income attributable to City National Corporation	5,398	1,698	9,864		3,167
Selected Average Balances:
Total assets	652,737	530,179	648,561		533,956
Deposits	120,702	96,839	113,563		97,937
Goodwill	249,445	162,813	249,445		162,367
Customer-relationship intangibles, net	40,199	25,714	40,794		26,103
Other
Earnings Summary:
Net interest income	17,648	31,073	34,447		59,356
Noninterest income	(6,818)	(15,287)	(19,006)		(25,843)
Depreciation and amortization	4,680	4,579	9,265		8,864
Noninterest expense	(18,724)	(16,773)	(35,465)		(32,656)
Income before income taxes	24,874	27,980	41,641		57,305
Provision for income taxes	7,425	9,302	12,308		18,714
Net income	17,449	18,678	29,333		38,591
Net income attributable to City National Corporation	17,449	18,678	29,333		38,591
Selected Average Balances:
Loans and leases, excluding covered loans	54,730	52,838	54,691		53,054
Total assets	10,310,855	9,103,454	10,692,758		9,036,610
Deposits	$ 588,957	$ 471,803	$ 527,035		$ 434,083

[1] Net income excludes net income attributable to redeemable noncontrolling interest of $1,048 and $652 for the six month periods ended June 30, 2013 and 2012, respectively. Redeemable noncontrolling interest is reflected in the mezzanine section of the consolidated balance sheets. See Note 18 of the Notes to the Unaudited Consolidated Financial Statements.