Consolidated Statements of Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Interest Income
Loans	$ 2,303	$ 2,266	$ 2,320
Securities	538	547	455
Other	8	13	15
Total interest income	2,849	2,826	2,790
Interest Expense
Deposits	216	290	408
Commercial paper and other short-term borrowings	6	4	22
Long-term debt	149	108	111
Total interest expense	371	402	541
Net Interest Income	2,478	2,424	2,249
(Reversal of) provision for loan losses	(202)	182	1,114
Net interest income after (reversal of) provision for loan losses	2,680	2,242	1,135
Noninterest Income
Service charges on deposit accounts	228	250	291
Trust and investment management fees	132	133	135
Trading account activities	126	111	74
Merchant banking fees	97	83	65
Securities gains, net	58	105	24
Brokerage commissions and fees	47	40	34
Card processing fees, net	37	41	32
Other	91	160	72
Total noninterest income	816	923	727
Noninterest Expense
Salaries and employee benefits	1,385	1,230	972
Net occupancy and equipment	267	252	233
Professional and outside services	209	199	159
Intangible asset amortization	106	124	162
Regulatory assessments	69	116	134
(Reversal of) provision for losses on off-balance sheet commitments	(29)	(14)	51
Other	408	465	377
Total noninterest expense	2,415	2,372	2,088
Income (loss) before income taxes and including noncontrolling interests	1,081	793	(226)
Income tax expense (benefit)	318	239	(161)
Net Income (Loss) including Noncontrolling Interests	763	554	(65)
Deduct: Net loss from noncontrolling interests	15	19	0
Net Income (Loss) attributable to UnionBanCal Corporation (UNBC)	$ 778	$ 573	$ (65)