Loan and Lease Finance Receivables and Allowance for Credit Losses (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Summary of the components of loan and lease finance receivables
Commercial and Industrial	$ 523,950	$ 499,986
Real Estate:
Construction	94,831	223,478
Commercial Real Estate	2,171,399	2,272,270
SFR Mortgage	179,731	224,325
Consumer	59,789	67,371
Municipal lease finance receivables	113,629	129,128
Auto and equipment leases, net of unearned discount	17,370	17,982
Dairy and Livestock	343,549	376,143
Agribusiness	28,523	57,304
Gross Loans	3,532,771	3,867,987
Less: Purchase accounting discount	(50,780)	(114,763)
Less: Deferred loan fees, net	(5,395)	(5,484)
Gross loans, net of deferred loan fees	3,476,596	3,747,740
Allowance for credit losses	(93,964)	(105,259)	(108,924)
Net Loans	3,382,632	3,642,481
Non-Covered Loans [Member]
Summary of the components of loan and lease finance receivables
Commercial and Industrial	494,299	460,399
Real Estate:
Construction	76,146	138,980
Commercial Real Estate	1,948,292	1,980,256
SFR Mortgage	176,442	218,467
Consumer	51,436	56,747
Municipal lease finance receivables	113,460	128,552
Auto and equipment leases, net of unearned discount	17,370	17,982
Dairy and Livestock	343,350	376,143
Agribusiness	4,327	1,686
Gross Loans	3,225,122	3,379,212
Less: Purchase accounting discount	0	0
Less: Deferred loan fees, net	(5,395)	(5,484)
Gross loans, net of deferred loan fees	3,219,727	3,373,728
Allowance for credit losses	(93,964)	(105,259)
Net Loans	3,125,763	3,268,469
Covered Loans [Member]
Summary of the components of loan and lease finance receivables
Commercial and Industrial	29,651	39,587
Real Estate:
Construction	18,685	84,498
Commercial Real Estate	223,107	292,014
SFR Mortgage	3,289	5,858
Consumer	8,353	10,624
Municipal lease finance receivables	169	576
Auto and equipment leases, net of unearned discount	0	0
Dairy and Livestock	199	0
Agribusiness	24,196	55,618
Gross Loans	307,649	488,775
Less: Purchase accounting discount	(50,780)	(114,763)
Less: Deferred loan fees, net	0	0
Gross loans, net of deferred loan fees	256,869	374,012
Allowance for credit losses	0	0	0
Net Loans	$ 256,869	$ 374,012