Note 6 - Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Detail) - Allowance for Credit Losses (Continued) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Balance	$ 121,962	$ 145,072	$ 144,808	$ 93,869
Loans charged-off	(111,576)	(155,330)	(168,038)
Recoveries of loans previously charged-off	7,884	8,245	3,305
Net loans charged-off	(103,692)	(147,085)	(164,733)
Provision for loan losses	80,582	147,349	215,672
Commercial, Industrial, And Agricultural [Member] | Period Start [Member]
Balance			22,189
Loans charged-off			(57,083)
Recoveries of loans previously charged-off			1,899
Net loans charged-off			(55,184)
Provision for loan losses			87,447
Commercial, Industrial, And Agricultural [Member] | Second Period Start [Member]
Balance			54,452
Loans charged-off		(37,130)
Recoveries of loans previously charged-off		5,227
Net loans charged-off		(31,903)
Provision for loan losses		26,996
Commercial, Industrial, And Agricultural [Member] | Third Period Start [Member]
Balance		49,545
Loans charged-off	(32,750)
Recoveries of loans previously charged-off	3,493
Net loans charged-off	(29,257)
Provision for loan losses	25,729
Commercial, Industrial, And Agricultural [Member] | Period End [Member]
Balance	46,017
Office Retail And Industrial [Member] | Period Start [Member]
Balance			22,048
Loans charged-off			(7,869)
Recoveries of loans previously charged-off			13
Net loans charged-off			(7,856)
Provision for loan losses			5,972
Office Retail And Industrial [Member] | Second Period Start [Member]
Balance			20,164
Loans charged-off		(10,322)
Recoveries of loans previously charged-off		612
Net loans charged-off		(9,710)
Provision for loan losses		10,304
Office Retail And Industrial [Member] | Third Period Start [Member]
Balance		20,758
Loans charged-off	(8,193)
Recoveries of loans previously charged-off	79
Net loans charged-off	(8,114)
Provision for loan losses	3,368
Office Retail And Industrial [Member] | Period End [Member]
Balance	16,012
Multi-Family [Member] | Period Start [Member]
Balance			2,680
Loans charged-off			(3,485)
Recoveries of loans previously charged-off			2
Net loans charged-off			(3,483)
Provision for loan losses			5,358
Multi-Family [Member] | Second Period Start [Member]
Balance			4,555
Loans charged-off		(2,788)
Recoveries of loans previously charged-off		363
Net loans charged-off		(2,425)
Provision for loan losses		1,866
Multi-Family [Member] | Third Period Start [Member]
Balance		3,996
Loans charged-off	(14,584)
Recoveries of loans previously charged-off	410
Net loans charged-off	(14,174)
Provision for loan losses	15,245
Multi-Family [Member] | Period End [Member]
Balance	5,067
Residential Construction [Member] | Period Start [Member]
Balance			32,910
Loans charged-off			(63,045)
Recoveries of loans previously charged-off			403
Net loans charged-off			(62,642)
Provision for loan losses			62,810
Residential Construction [Member] | Second Period Start [Member]
Balance			33,078
Loans charged-off		(55,611)
Recoveries of loans previously charged-off		770
Net loans charged-off		(54,841)
Provision for loan losses		49,696
Residential Construction [Member] | Third Period Start [Member]
Balance		27,933
Loans charged-off	(13,895)
Recoveries of loans previously charged-off	2,830
Net loans charged-off	(11,065)
Provision for loan losses	(2,305)
Residential Construction [Member] | Period End [Member]
Balance	14,563
Other Commerical Real Estate [Member] | Period Start [Member]
Balance			7,927
Loans charged-off			(22,033)
Recoveries of loans previously charged-off			516
Net loans charged-off			(21,517)
Provision for loan losses			34,674
Other Commerical Real Estate [Member] | Second Period Start [Member]
Balance			21,084
Loans charged-off		(37,225)
Recoveries of loans previously charged-off		494
Net loans charged-off		(36,731)
Provision for loan losses		45,516
Other Commerical Real Estate [Member] | Third Period Start [Member]
Balance		29,869
Loans charged-off	(21,712)
Recoveries of loans previously charged-off	642
Net loans charged-off	(21,070)
Provision for loan losses	15,672
Other Commerical Real Estate [Member] | Period End [Member]
Balance	24,471
Consumer [Member] | Period Start [Member]
Balance			6,115
Loans charged-off			(14,523)
Recoveries of loans previously charged-off			472
Net loans charged-off			(14,051)
Provision for loan losses			19,411
Consumer [Member] | Second Period Start [Member]
Balance			11,475
Loans charged-off		(10,640)
Recoveries of loans previously charged-off		740
Net loans charged-off		(9,900)
Provision for loan losses		11,396
Consumer [Member] | Third Period Start [Member]
Balance		12,971
Loans charged-off	(10,531)
Recoveries of loans previously charged-off	430
Net loans charged-off	(10,101)
Provision for loan losses	11,973
Consumer [Member] | Period End [Member]
Balance	14,843
Covered Loans [Member] | Period Start [Member]
Balance			0
Loans charged-off			0
Recoveries of loans previously charged-off			0
Net loans charged-off			0
Provision for loan losses			0
Covered Loans [Member] | Second Period Start [Member]
Balance			0
Loans charged-off		(1,614)
Recoveries of loans previously charged-off		39
Net loans charged-off		(1,575)
Provision for loan losses		1,575
Covered Loans [Member] | Third Period Start [Member]
Balance		0
Loans charged-off	(9,911)
Recoveries of loans previously charged-off	0
Net loans charged-off	(9,911)
Provision for loan losses	10,900
Covered Loans [Member] | Period End [Member]
Balance	989
Total Allowance [Member] | Period Start [Member]
Balance			93,869
Loans charged-off			(168,038)
Recoveries of loans previously charged-off			3,305
Net loans charged-off			(164,733)
Provision for loan losses			215,672
Total Allowance [Member] | Second Period Start [Member]
Balance			144,808
Loans charged-off		(155,330)
Recoveries of loans previously charged-off		8,245
Net loans charged-off		(147,085)
Provision for loan losses		147,349
Total Allowance [Member] | Third Period Start [Member]
Balance		145,072
Loans charged-off	(111,576)
Recoveries of loans previously charged-off	7,884
Net loans charged-off	(103,692)
Provision for loan losses	80,582
Total Allowance [Member] | Period End [Member]
Balance	$ 121,962