Note 18 - California First National Bancorp (Parent Only) Financial Information: (Detail) - Condensed Statements of Cash Flows of California First National Bancorp: (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jun. 30, 2012	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 8,903	$ 8,903	$ 10,907	$ 10,907	$ 11,127	$ 11,127
Adjustments to reconcile net earnings to cash flows:
Deferred income taxes		65		7,913		3,804
Other, net		(107)		(1,466)		999
Net cash (used for) provided by operating activities		9,937		15,643		7,012
CASH FLOWS FROM INVESTING ACTIVITIES:
Net cash provided by investing activities		(7,573)		(52,521)		67,507
CASH FLOWS FROM FINANCING ACTIVITIES:
Dividends paid		11,462		10,288		6,112
Net cash used for financing activities		(42,745)		60,192		(55,748)
NET CHANGE IN CASH AND CASH EQUIVALENTS		(40,381)		23,314		18,771
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD		97,302		73,988		55,217
CASH AND CASH EQUIVALENTS AT END OF PERIOD	56,921	56,921	97,302	97,302	73,988	73,988
Parent Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income		8,903		10,907
Adjustments to reconcile net earnings to cash flows:
Amortization of premiums or discounts on securities, net		1		32
Net (gain) loss recognized on investment securities				(55)
Deferred income taxes		(290)		(1,098)
Equity in undistributed earnings of subsidiaries		(9,424)		(10,810)
Net change in other liabilities		134		153
Net change in other assets		318		2,509
Other, net		(157)		16
Net cash (used for) provided by operating activities		(515)		1,654
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sale of investment securities		2,270		6,971
Payments for investments in and (advances to) subsidiaries		9,345		(784)
Net cash provided by investing activities		11,615		6,187
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock		195		1,627
Dividends paid		(11,462)		(10,288)
Net cash used for financing activities		(11,267)		(8,661)
NET CHANGE IN CASH AND CASH EQUIVALENTS		(167)		(820)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD		6,414		7,234
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 6,247	$ 6,247	$ 6,414	$ 6,414