PARENT COMPANY FINANCIAL STATEMENTS (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
STATEMENTS OF INCOME
Gain on sales of investment securities available-for-sale									$ 757	$ 9,700	$ 31,200
Interest expense	31,577	32,254	33,205	35,132	39,830	44,959	47,132	45,501	132,168	177,422	201,117
Compensation and net occupancy reimbursement to subsidiary									55,475	50,082	52,073
Other expense									59,731	60,383	67,879
Income before income taxes and equity in undistributed income of subsidiaries	108,200	105,203	104,394	107,795	103,339	97,685	95,730	86,580	425,592	383,334	255,909
Income tax benefit	(36,300)	(34,093)	(33,837)	(39,712)	(37,133)	(35,253)	(35,205)	(30,509)	(143,942)	(138,100)	(91,345)
NET INCOME	71,900	71,110	70,557	68,083	66,206	62,432	60,525	56,071	281,650	245,234	164,564
East West Bancorp, Inc.
STATEMENTS OF INCOME
Dividends from subsidiaries									324,094	72,129	85,158
Interest income											1,095
Gain on sales of investment securities available-for-sale											556
Other income									2	372	3
Total income									324,096	72,501	86,812
Interest expense									3,092	4,734	5,302
Compensation and net occupancy reimbursement to subsidiary									2,573	2,537	2,921
Other expense									1,309	2,339	2,132
Total expense									6,974	9,610	10,355
Income before income taxes and equity in undistributed income of subsidiaries									317,122	62,891	76,457
Income tax benefit									2,892	3,830	3,592
Equity in undistributed (loss) income of subsidiaries									(38,364)	178,513	84,515
NET INCOME									$ 281,650	$ 245,234	$ 164,564