Note 18 - California First National Bancorp (Parent Only) Financial Information: (Details) - Condensed Balance Sheets of California First National Bancorp: (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 75,469	$ 56,921	$ 97,302	$ 73,988
Other assets	857	1,162
	558,903	486,171	524,415
Accrued liabilities	2,156	2,799
	378,024	289,732
Preferred stock; 2,500,000 shares authorized; none issued	0	0
Common stock, $.01 par value; 20,000,000 shares authorized; 10,447,227 (2013) and 10,433,684 (2012) issued and outstanding	104	104
Additional paid in capital	3,213	3,044
Retained earnings	176,972	192,603
Other comprehensive income, net of tax	590	688
	180,879	196,439	199,622	198,548
	558,903	486,171
Parent Company [Member] | Investment in Banking Subsidiary [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Investment in Subsidiaries	98,155	83,192
Parent Company [Member] | Investment in Nonbanking Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Investment in Subsidiaries	74,450	71,734
Parent Company [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	4,584	6,247	6,414	7,234
Intercompany receivable	106	150
Intercompany note receivable	3,682	35,864
Other assets	1,203	851
Premises and other fixed assets	193	168
	182,373	198,206
Accrued liabilities	421	1,218
Intercompany payable	137	171
Income taxes payable- deferred	936	378
	1,494	1,767
Preferred stock; 2,500,000 shares authorized; none issued	0	0
Common stock, $.01 par value; 20,000,000 shares authorized; 10,447,227 (2013) and 10,433,684 (2012) issued and outstanding	104	104
Additional paid in capital	3,213	3,044
Retained earnings	176,972	192,603
Other comprehensive income, net of tax	590	688
	180,879	196,439
	$ 182,373	$ 198,206