Note 6 - Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Detail) - Allowance for Credit Losses (Continued) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Balance at beginning of period	$ 118,764	$ 145,003	$ 121,962	$ 145,072
Balance at end of period	118,682	139,831	118,682	139,831
Loans charged-off	(23,681)	(27,748)	(46,367)	(49,317)
Recoveries of loans previously charged-off	1,141	3,813	2,419	5,821
Net loans charged-off	(22,540)	(23,935)	(43,948)	(43,496)
Provision for loan losses	22,458	18,763	40,668	38,255
Commercial, Industrial, And Agricultural [Member]
Balance at beginning of period			46,017	49,545
Balance at end of period	43,410	48,534	43,410	48,534
Loans charged-off			(14,613)	(11,877)
Recoveries of loans previously charged-off			1,251	2,356
Net loans charged-off			(13,362)	(9,521)
Provision for loan losses			10,755	8,510
Office Retail And Industrial [Member]
Balance at beginning of period			16,012	20,758
Balance at end of period	18,353	16,862	18,353	16,862
Loans charged-off			(5,237)	(1,846)
Recoveries of loans previously charged-off			309	54
Net loans charged-off			(4,928)	(1,792)
Provision for loan losses			7,269	(2,104)
Multi-Family [Member]
Balance at beginning of period			5,067	3,996
Balance at end of period	4,789	8,875	4,789	8,875
Loans charged-off			(484)	(7,201)
Recoveries of loans previously charged-off			162
Net loans charged-off			(322)	(7,201)
Provision for loan losses			44	12,080
Residential Construction [Member]
Balance at beginning of period			14,563	27,933
Balance at end of period	12,872	24,327	12,872	24,327
Loans charged-off			(4,281)	(9,083)
Recoveries of loans previously charged-off			220	2,766
Net loans charged-off			(4,061)	(6,317)
Provision for loan losses			2,370	2,711
Other Commerical Real Estate [Member]
Balance at beginning of period			24,471	29,869
Balance at end of period	24,830	27,435	24,830	27,435
Loans charged-off			(13,922)	(8,331)
Recoveries of loans previously charged-off			25	472
Net loans charged-off			(13,897)	(7,859)
Provision for loan losses			14,256	5,425
Consumer [Member]
Balance at beginning of period			14,843	12,971
Balance at end of period	13,446	13,798	13,446	13,798
Loans charged-off			(5,122)	(5,779)
Recoveries of loans previously charged-off			452	173
Net loans charged-off			(4,670)	(5,606)
Provision for loan losses			3,273	6,433
Covered Loans [Member]
Balance at beginning of period			989
Balance at end of period	982		982
Loans charged-off			(2,708)	(5,200)
Net loans charged-off			(2,708)	(5,200)
Provision for loan losses			2,701	5,200
Total Allowance [Member]
Balance at beginning of period			121,962	145,072
Balance at end of period	118,682	139,831	118,682	139,831
Loans charged-off			(46,367)	(49,317)
Recoveries of loans previously charged-off			2,419	5,821
Net loans charged-off			(43,948)	(43,496)
Provision for loan losses			$ 40,668	$ 38,255