Segment Results (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 segment		Mar. 31, 2012
Segment Results
Number of reportable segments	3
Earnings Summary:
Net interest income	$ 201,073		$ 200,713
Provision for losses on covered loans	9,892		7,466
Noninterest income	93,528		75,700
Depreciation and amortization	10,104		9,314
Noninterest expense	201,236		191,406
Income before income taxes	73,369		68,227
Provision (benefit) for income taxes	21,261		21,719
Net income	52,108		46,508
Less: Net income attributable to noncontrolling interest	585		243
Net income attributable to City National Corporation	51,523	[1]	46,265	[1]
Selected Average Balances:
Loans and leases, excluding covered loans	14,809,341		12,432,292
Covered loans	989,452		1,438,714
Total assets	27,709,159		23,644,899
Deposits	22,410,953		20,217,395
Goodwill	642,622		486,682
Customer-relationship intangibles, net	47,310		35,500
Commercial and Private Banking
Earnings Summary:
Net interest income	183,562		171,815
Provision for losses on covered loans	9,892		7,466
Noninterest income	50,263		47,245
Depreciation and amortization	3,618		3,582
Noninterest expense	170,860		171,524
Income before income taxes	49,455		36,488
Provision (benefit) for income taxes	20,771		15,325
Net income	28,684		21,163
Net income attributable to City National Corporation	28,684		21,163
Selected Average Balances:
Loans and leases, excluding covered loans	14,754,689		12,379,023
Covered loans	989,452		1,438,714
Total assets	15,985,918		14,137,481
Deposits	21,840,183		19,721,998
Goodwill	393,177		324,761
Customer-relationship intangibles, net	5,916		9,007
Wealth Management
Earnings Summary:
Net interest income	314		615
Noninterest income	55,452		39,371
Depreciation and amortization	1,900		1,446
Noninterest expense	47,117		36,053
Income before income taxes	6,749		2,487
Provision (benefit) for income taxes	2,589		943
Net income	4,160		1,544
Less: Net income attributable to noncontrolling interest	585		243
Net income attributable to City National Corporation	3,575		1,301
Selected Average Balances:
Total assets	644,338		537,732
Deposits	106,345		99,035
Goodwill	249,445		161,921
Customer-relationship intangibles, net	41,394		26,493
Other
Earnings Summary:
Net interest income	17,197		28,283
Noninterest income	(12,187)		(10,916)
Depreciation and amortization	4,586		4,286
Noninterest expense	(16,741)		(16,171)
Income before income taxes	17,165		29,252
Provision (benefit) for income taxes	(2,099)		5,451
Net income	19,264		23,801
Net income attributable to City National Corporation	19,264		23,801
Selected Average Balances:
Loans and leases, excluding covered loans	54,652		53,269
Total assets	11,078,903		8,969,686
Deposits	$ 464,425		$ 396,362

[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.