Loan and Lease Finance Receivables and Allowance for Credit Losses (Details 6) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans	$ 4
Troubled debt restructurings, pre-modification outstanding recorded investment	3,354
Troubled debt restructurings, post-modifications outstanding recorded investment	3,354
Troubled debt restructurings, outstanding recorded investment	3,349
Covered Loans [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans
Troubled debt restructurings, pre-modification outstanding recorded investment
Troubled debt restructurings, post-modifications outstanding recorded investment
Troubled debt restructurings, outstanding recorded investment
Non-Covered Loans [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans	4
Troubled debt restructurings, pre-modification outstanding recorded investment	3,354
Troubled debt restructurings, post-modifications outstanding recorded investment	3,354
Troubled debt restructurings, outstanding recorded investment	3,349
Commercial and Industrial [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans	2
Troubled debt restructurings, pre-modification outstanding recorded investment	2,534
Troubled debt restructurings, post-modifications outstanding recorded investment	2,534
Troubled debt restructurings, outstanding recorded investment	2,532
Construction - Speculative [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans
Troubled debt restructurings, pre-modification outstanding recorded investment
Troubled debt restructurings, post-modifications outstanding recorded investment
Troubled debt restructurings, outstanding recorded investment
Construction - Non-Speculative [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans
Troubled debt restructurings, pre-modification outstanding recorded investment
Troubled debt restructurings, post-modifications outstanding recorded investment
Troubled debt restructurings, outstanding recorded investment
Commercial Real Estate - Owner-Occupied [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans	1
Troubled debt restructurings, pre-modification outstanding recorded investment	307
Troubled debt restructurings, post-modifications outstanding recorded investment	307
Troubled debt restructurings, outstanding recorded investment	304
Commercial Real Estate - Non-Owner-Occupied [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans	1
Troubled debt restructurings, pre-modification outstanding recorded investment	513
Troubled debt restructurings, post-modifications outstanding recorded investment	513
Troubled debt restructurings, outstanding recorded investment	513
Residential Real Estate (SFR 1-4) [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans
Troubled debt restructurings, pre-modification outstanding recorded investment
Troubled debt restructurings, post-modifications outstanding recorded investment
Troubled debt restructurings, outstanding recorded investment
Dairy and Livestock [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans
Troubled debt restructurings, pre-modification outstanding recorded investment
Troubled debt restructurings, post-modifications outstanding recorded investment
Troubled debt restructurings, outstanding recorded investment
Agribusiness [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans
Troubled debt restructurings, pre-modification outstanding recorded investment
Troubled debt restructurings, post-modifications outstanding recorded investment
Troubled debt restructurings, outstanding recorded investment
Municipal Lease Finance Receivables [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans
Troubled debt restructurings, pre-modification outstanding recorded investment
Troubled debt restructurings, post-modifications outstanding recorded investment
Troubled debt restructurings, outstanding recorded investment
Consumer [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans
Troubled debt restructurings, pre-modification outstanding recorded investment
Troubled debt restructurings, post-modifications outstanding recorded investment
Troubled debt restructurings, outstanding recorded investment
Auto and Equipment Leases [Member]
Loans modified as troubled debt restructuring
Troubled debt restructurings, number of loans
Troubled debt restructurings, pre-modification outstanding recorded investment
Troubled debt restructurings, post-modifications outstanding recorded investment
Troubled debt restructurings, outstanding recorded investment