Represents the number of warrants exercised as of balance sheet date.

No definition available.

Name:	ewbc_WarrantsExercised
Namespace Prefix:	ewbc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e637-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e681-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669686-108580

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 31
-Article 5

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

STOCKHOLDERS' EQUITY AND EARNINGS PER SHARE (Details) - USD ($)		1 Months Ended	3 Months Ended														12 Months Ended
	May. 01, 2013	Apr. 30, 2008	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jan. 17, 2014	Jan. 16, 2014	Jul. 17, 2013	Jan. 23, 2013	Dec. 31, 2012
Class of Stock
Accumulated other comprehensive (loss) income (“AOCI”), net of tax			$ (14,941,000)				$ 4,237,000										$ (14,941,000)	$ 4,237,000	$ (30,459,000)					$ 4,669,000
Purchase of treasury stock pursuant to the Stock Repurchase Program, shares																			8,026,807
Weighted average price of shares repurchased (in dollars per share)																			$ 24.89
Total cost of repurchase of treasury shares																	$ 0	$ 0	$ 199,992,000
Quarterly Dividends
Dividend per share (in dollars per share)			$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.18	$ 0.18	$ 0.18	$ 0.18							$ 0.80	$ 0.72	$ 0.60
MetroCorp
Class of Stock
Warrants converted into the right to acquire shares																				230,282	771,429
Number of warrants exercised			0														0
Series A Non-Cumulative Perpetual Convertible Preferred Stock
Class of Stock
Number of shares issued during the period		200,000
Preferred stock dividend rate (as a percent)		8.00%
Preferred stock liquidation preference (in dollars per share)		$ 1,000
Proceeds from issuance of convertible preferred stock		$ 194,100,000
Preferred shares converted	85,710
Common stock issued on conversion of convertible preferred stock	5,594,080
Quarterly Dividends
Preferred stock dividend per share (in dollars per share)																			$ 20.00
Preferred stock cash dividends paid																			$ 3,400,000
Common Stock
Class of Stock
Amount of stock repurchase approved by the Board of Directors																						$ 100,000,000	$ 200,000,000
Quarterly Dividends
Dividend per share (in dollars per share)				$ 0.2	$ 0.2	$ 0.2					$ 0.18	$ 0.18	$ 0.18	$ 0.15	$ 0.15	$ 0.15	$ 0.2	$ 0.18	$ 0.15
Common stock cash dividends paid																	$ 116,200,000	$ 104,000,000	$ 83,300,000