Note 6 - Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Detail) - Impaired Loans Individually Evaluated by Class (Continued) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011
Commercial And Industrial [Member]
Average Recorded Investment Balance	$ 50,777		$ 48,982
Interest Income Recognized	94	[1]	51	[1]
Agricultural [Member]
Average Recorded Investment Balance	1,117		1,463
Interest Income Recognized		[1]		[1]
Office Retail And Industrial [Member]
Average Recorded Investment Balance	35,874		30,423
Interest Income Recognized	2	[1]	30	[1]
Multi-Family [Member]
Average Recorded Investment Balance	7,680		12,226
Interest Income Recognized		[1]	6	[1]
Residential Construction [Member]
Average Recorded Investment Balance	17,658		34,828
Interest Income Recognized	1	[1]	27	[1]
Commercial Construction [Member]
Average Recorded Investment Balance	21,397		23,818
Interest Income Recognized		[1]		[1]
Other Commerical Real Estate [Member]
Average Recorded Investment Balance	41,085		26,143
Interest Income Recognized	38	[1]	23	[1]
Total Commercial Real Estate [Member]
Average Recorded Investment Balance	123,694		127,438
Interest Income Recognized	41	[1]	86	[1]
Total Impaired Loans Individually Evaluated For Impairment [Member]
Average Recorded Investment Balance	175,588		177,883
Interest Income Recognized	$ 135	[1]	$ 137	[1]

[1] Recorded using the cash basis of accounting.