Loans, Allowance for Loan and Lease Losses, and Reserve for Off-Balance Sheet Credit Commitments (Details) (USD $)	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009
Accounts notes and loans receivable
Loans and leases, excluding covered loans	$ 11,663,123,000		$ 11,386,628,000	$ 11,483,044,000
Less: Allowance for loan and lease losses	(265,933,000)	(263,356,000)	(257,007,000)	(290,492,000)	(292,799,000)	(288,493,000)
Loans and leases, excluding covered loans, net	11,397,190,000		11,129,621,000	11,192,552,000
Covered loans	1,724,633,000		1,857,522,000	2,080,846,000
Less: Allowance for loan losses	(67,629,000)	(82,016,000)	(67,389,000)	(46,255,000)
Covered loans, net	1,657,004,000		1,790,133,000	2,034,591,000
Total loans and leases	13,387,756,000		13,244,150,000	13,563,890,000
Net loans and leases	13,054,194,000		12,919,754,000	13,227,143,000
Unamortized fees, net of deferred costs	4,500,000		7,000,000	5,200,000
Number of states with largest concentration	5
Commercial
Accounts notes and loans receivable
Loans and leases, excluding covered loans	4,420,899,000		4,136,874,000	3,935,544,000
Covered loans	41,135,000		55,082,000	85,638,000
Commercial real estate mortgages
Accounts notes and loans receivable
Loans and leases, excluding covered loans	1,930,269,000		1,958,317,000	2,078,003,000
Less: Allowance for loan and lease losses	(49,060,000)	(47,519,000)	(52,516,000)
Covered loans	1,482,186,000		1,569,739,000	1,710,159,000
Residential mortgage
Accounts notes and loans receivable
Loans and leases, excluding covered loans	3,710,765,000		3,552,312,000	3,577,894,000
Less: Allowance for loan and lease losses	(12,873,000)	(13,527,000)	(16,753,000)
Covered loans	19,494,000		18,380,000	21,680,000
Real estate construction
Accounts notes and loans receivable
Loans and leases, excluding covered loans	355,014,000		467,785,000	629,902,000
Less: Allowance for loan and lease losses	(29,455,000)	(36,693,000)	(40,824,000)
Covered loans	173,263,000		204,945,000	250,162,000
Equity lines of credit
Accounts notes and loans receivable
Loans and leases, excluding covered loans	735,899,000		733,741,000	742,071,000
Less: Allowance for loan and lease losses	(6,668,000)	(6,445,000)	(7,229,000)
Covered loans	5,791,000		6,919,000	9,780,000
Installment loan
Accounts notes and loans receivable
Loans and leases, excluding covered loans	130,924,000		160,144,000	169,070,000
Less: Allowance for loan and lease losses	(1,951,000)	(5,445,000)	(3,931,000)
Covered loans	2,764,000		2,457,000	3,427,000
Lease financing
Accounts notes and loans receivable
Loans and leases, excluding covered loans	$ 379,353,000		$ 377,455,000	$ 350,560,000
California
Accounts notes and loans receivable
Percent of total loans excluding covered loans outstanding (as a percent)	85.00%
Percent of total covered loans (as a percent)	39.00%
Nevada
Accounts notes and loans receivable
Percent of total loans excluding covered loans outstanding (as a percent)	6.00%
Percent of total covered loans (as a percent)	9.00%
New York
Accounts notes and loans receivable
Percent of total loans excluding covered loans outstanding (as a percent)	2.00%
Percent of total covered loans (as a percent)	5.00%
Texas
Accounts notes and loans receivable
Percent of total covered loans (as a percent)	12.00%
Arizona
Accounts notes and loans receivable
Percent of total covered loans (as a percent)	4.00%
Other states
Accounts notes and loans receivable
Percent of total loans excluding covered loans outstanding (as a percent)	7.00%
Percent of total covered loans (as a percent)	31.00%