Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Interest and Dividend Income
Loans receivable, including loan fees	$ 100,151	$ 90,838	$ 290,337	$ 267,557
Investment securities- taxable	5,105	10,868	19,389	34,986
Investment securities- nontaxable				995
Federal Home Loan Bank stock	508	449	1,379	1,041
Deposits with banks	571	307	1,499	796
Total interest and dividend income	106,335	102,462	312,604	305,375
Interest Expense
Time deposits of $100,000 or more	7,107	6,887	20,519	20,466
Other deposits	5,005	3,485	13,462	9,244
Securities sold under agreements to repurchase	5,858	8,402	19,731	29,778
Advances from Federal Home Loan Bank	153	150	849	375
Long-term debt	1,456	930	3,012	2,778
Short-term borrowings	1		1
Total interest expense	19,580	19,854	57,574	62,641
Net interest income before provision for credit losses	86,755	82,608	255,030	242,734
Credit for loan losses	(5,100)	(3,000)	(8,800)	(3,000)
Net interest income after credit for loan losses	91,855	85,608	263,830	245,734
Non-Interest Income
Securities gains, net	361	8,688	6,827	27,157
Letters of credit commissions	1,559	1,698	4,547	4,608
Depository service fees	1,330	1,371	3,999	4,330
Other operating income	5,724	4,963	17,181	15,867
Total non-interest income	8,974	16,720	32,554	51,962
Non-Interest Expense
Salaries and employee benefits	22,630	22,751	69,472	67,192
Occupancy expense	3,934	3,812	11,692	10,966
Computer and equipment expense	2,471	2,446	7,307	7,488
Professional services expense	5,991	5,813	16,410	18,484
FDIC and State assessments	2,261	1,712	6,692	5,431
Marketing expense	639	1,097	2,722	2,703
Other real estate owned (income)/expense	(1,011)	527	(629)	886
Operations of affordable housing investments, net	1,672	1,234	5,126	4,952
Amortization of core deposit intangibles	214	1,363	510	4,097
Costs associated with debt redemption	527	6,861	3,348	22,557
Other operating expense	3,279	3,054	10,538	8,758
Total non-interest expense	42,607	50,670	133,188	153,514
Income before income tax expense	58,222	51,658	163,196	144,182
Income tax expense	22,313	19,029	60,944	52,489
Net income	35,909	32,629	102,252	91,693
Less: net income attributable to noncontrolling interest		151		452
Net income attributable to Cathay General Bancorp	35,909	32,478	102,252	91,241
Dividends on preferred stock and noncash charge from repayment		(2,434)		(9,685)
Net income attributable to common stockholders	35,909	30,044	102,252	81,556
Other comprehensive income/(loss), net of tax
Unrealized holding gain/(loss) on securities available-for-sale	170	(1,074)	25,014	(5,908)
Less: reclassification adjustments included in net income	209	5,036	3,957	15,740
Unrealized holding gain/(loss) on cash flow hedge derivatives	100		(163)
Less: reclassification adjustments included in net income	0	0	0	0
Total other comprehensive gain/(loss), net of tax	61	(6,110)	20,894	(21,648)
Total comprehensive income	$ 35,970	$ 26,368	$ 123,146	$ 69,593
Net income per common share:
Basic (in Dollars per share)	$ 0.45	$ 0.38	$ 1.28	$ 1.03
Diluted (in Dollars per share)	$ 0.45	$ 0.38	$ 1.28	$ 1.03
Cash dividends paid per common share (in Dollars per share)	$ 0.07	$ 0.01	$ 0.19	$ 0.03
Average common shares outstanding
Basic (in Shares)	79,677,952	78,894,262	79,639,202	78,853,333
Diluted (in Shares)	80,176,100	79,114,122	80,087,819	78,944,152