Condensed Consolidating Statement of Condition (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010
Assets
Cash And Due From Banks	$ 472,806	$ 535,282	$ 464,555	$ 452,373
Money market investments	1,304,263	1,376,174	961,565
Trading Securities	404,293	436,331	634,799
Available For Sale Securities	5,138,616	5,009,823	5,686,341
Investment securities held-to-maturity, at amortized cost	124,372	125,383	142,106
Other investment securities, at lower of cost or realizable value	195,708	179,880	174,930
Loans held-for-sale, at lower of cost or fair value	361,596	363,093	569,678
Loans held-in-portfolio:
Less- Unearned Income	99,321	100,596	104,760
Allowance for loan losses	803,264	815,308	736,505
Total loans held-in-portfolio, net	23,897,198	24,135,991	24,669,834
FDIC loss share asset	1,880,357	1,915,128	2,426,305	2,410,219
Premises and equipment, net	533,545	538,486	543,577
Interest Receivable	126,568	125,209	147,670
Servicing Asset At Fair Value Amount	156,331	151,323	167,416	166,907
Other Assets	1,439,532	1,462,393	1,314,739
Goodwill	647,911	648,350	647,387	647,387
Intangible Assets Net Excluding Goodwill	61,798	63,954	56,441
Total assets	37,049,221	37,348,432	38,829,793
Deposits Abstract
Noninterest Bearing Deposit Liabilities	5,366,420	5,655,474	4,913,009
Interest Bearing Deposit Liabilities	21,831,316	22,286,653	22,283,665
Total deposits	27,197,736	27,942,127	27,196,674
Securities Sold under Agreements to Repurchase	2,113,557	2,141,097	2,642,800
Other short-term borrowings	751,200	296,200	290,302
Notes Payable	1,843,754	1,856,372	3,794,655
Other liabilities	1,175,903	1,193,883	1,100,456
Liabilities	33,082,150	33,429,679	35,024,887
Stockholders Equity Abstract
Preferred stock	50,160	50,160	50,160
Common stock	10,276	10,263	10,236
Surplus	4,116,710	4,114,661	4,096,245
Accumulated deficit	(165,249)	(212,726)	(338,126)
Treasury stock	(1,041)	(1,057)	(607)
Accumulated other comprehensive (loss) income, net of tax	(43,785)	(42,548)	(13,002)
Total stockholders' equity	3,967,071	3,918,753	3,804,906	3,800,531
Liabilities And Stockholders Equity	37,049,221	37,348,432	38,829,793
Non Covered Under Loss Sharing Agreements With F D I C [Member]
Loans held-in-portfolio:
Loans held-in-portfolio	20,577,995	20,703,192	20,781,549
Real Estate Acquired Through Foreclosure	193,768	172,497	156,888
Covered Under Loss Sharing Agreements With F D I C [Member]
Loans held-in-portfolio:
Loans held-in-portfolio	4,221,788	4,348,703	4,729,550
Real Estate Acquired Through Foreclosure	110,559	109,135	65,562
Parent Company [Member]
Assets
Cash And Due From Banks	4,460	6,365	1,836	1,638
Money market investments	18,298	42,239	2
Trading Securities	0	0	0
Available For Sale Securities	41,798	35,700	37,363
Investment securities held-to-maturity, at amortized cost	185,000	185,000	209,734
Other investment securities, at lower of cost or realizable value	10,850	10,850	10,850
Investment in subsidiaries	4,081,525	3,987,287	3,846,966
Loans held-for-sale, at lower of cost or fair value	0	0	0
Loans held-in-portfolio:
Less- Unearned Income	0	0	0
Allowance for loan losses	148	8	60
Total loans held-in-portfolio, net	212,454	249,607	330,148
FDIC loss share asset	0	0	0
Premises and equipment, net	2,563	2,533	2,818
Interest Receivable	2,156	1,512	2,347
Servicing Asset At Fair Value Amount	0	0	0
Other Assets	232,648	217,877	257,598
Goodwill	0	0	0
Intangible Assets Net Excluding Goodwill	554	554	554
Total assets	4,792,306	4,739,524	4,700,216
Deposits Abstract
Noninterest Bearing Deposit Liabilities	0	0	0
Interest Bearing Deposit Liabilities	0	0	0
Total deposits	0	0	0
Securities Sold under Agreements to Repurchase	0	0	0
Other short-term borrowings	0	0	0
Notes Payable	767,769	760,849	741,684
Subordinated Debt	0	0	0
Other liabilities	57,466	59,922	153,626
Liabilities	825,235	820,771	895,310
Stockholders Equity Abstract
Preferred stock	50,160	50,160	50,160
Common stock	10,276	10,263	10,236
Surplus	4,108,183	4,106,134	4,087,718
Accumulated deficit	(156,721)	(204,199)	(329,599)
Treasury stock	(1,041)	(1,057)	(607)
Accumulated other comprehensive (loss) income, net of tax	(43,786)	(42,548)	(13,002)
Total stockholders' equity	3,967,071	3,918,753	3,804,906
Liabilities And Stockholders Equity	4,792,306	4,739,524	4,700,216
Parent Company [Member] | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Loans held-in-portfolio:
Loans held-in-portfolio	212,602	249,615	330,208
Real Estate Acquired Through Foreclosure	0	0	0
Parent Company [Member] | Covered Under Loss Sharing Agreements With F D I C [Member]
Loans held-in-portfolio:
Loans held-in-portfolio	0	0	0
Real Estate Acquired Through Foreclosure	0	0	0
Guarantor Subsidiaries Member
Assets
Cash And Due From Banks	936	391	40,583	618
Money market investments	16,100	15,456	7,266
Trading Securities	0	0	0
Available For Sale Securities	0	3,370	3,898
Investment securities held-to-maturity, at amortized cost	1,000	1,000	1,000
Other investment securities, at lower of cost or realizable value	1	1	1
Investment in subsidiaries	944	1,147,617	1,104,183
Loans held-for-sale, at lower of cost or fair value	0	0	0
Loans held-in-portfolio:
Less- Unearned Income	0	0	0
Allowance for loan losses	0	0	0
Total loans held-in-portfolio, net	0	0	0
FDIC loss share asset	0	0	0
Premises and equipment, net	0	0	0
Interest Receivable	6	15	14
Servicing Asset At Fair Value Amount	0	0	0
Other Assets	71,068	78,221	73,935
Goodwill	0	0	0
Intangible Assets Net Excluding Goodwill	0	0	0
Total assets	90,055	1,246,071	1,230,880
Deposits Abstract
Noninterest Bearing Deposit Liabilities	0	0	0
Interest Bearing Deposit Liabilities	0	0	0
Total deposits	0	0	0
Securities Sold under Agreements to Repurchase	0	0	0
Other short-term borrowings	0	0	0
Notes Payable	0	0	0
Subordinated Debt	0	0	0
Other liabilities	4,707	4,901	7,636
Liabilities	4,707	4,901	7,636
Stockholders Equity Abstract
Preferred stock	0	0	0
Common stock	4,066	4,066	4,066
Surplus	2,929,370	4,092,743	4,092,743
Accumulated deficit	(2,819,171)	(2,883,705)	(2,869,853)
Treasury stock	0	0	0
Accumulated other comprehensive (loss) income, net of tax	(28,917)	28,066	(3,712)
Total stockholders' equity	85,348	1,241,170	1,223,244
Liabilities And Stockholders Equity	90,055	1,246,071	1,230,880
Guarantor Subsidiaries Member | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Loans held-in-portfolio:
Loans held-in-portfolio	0	0	0
Real Estate Acquired Through Foreclosure	0	0	0
Guarantor Subsidiaries Member | Covered Under Loss Sharing Agreements With F D I C [Member]
Loans held-in-portfolio:
Loans held-in-portfolio	0	0	0
Real Estate Acquired Through Foreclosure	0	0	0
Non Guarantor Subsidiaries Member
Assets
Cash And Due From Banks	930	932	675	1,576
Money market investments	14,526	552	1,323
Trading Securities	0	0	0
Available For Sale Securities	0	0	0
Investment securities held-to-maturity, at amortized cost	0	0	0
Other investment securities, at lower of cost or realizable value	4,492	4,492	4,492
Investment in subsidiaries	1,633,640	1,627,313	1,595,118
Loans held-for-sale, at lower of cost or fair value	0	0	0
Loans held-in-portfolio:
Less- Unearned Income	0	0	0
Allowance for loan losses	0	0	0
Total loans held-in-portfolio, net	0	0	0
FDIC loss share asset	0	0	0
Premises and equipment, net	118	118	121
Interest Receivable	37	113	31
Servicing Asset At Fair Value Amount	0	0	0
Other Assets	12,954	13,222	15,669
Goodwill	0	0	0
Intangible Assets Net Excluding Goodwill	0	0	0
Total assets	1,666,697	1,646,742	1,617,429
Deposits Abstract
Noninterest Bearing Deposit Liabilities	0	0	0
Interest Bearing Deposit Liabilities	0	0	0
Total deposits	0	0	0
Securities Sold under Agreements to Repurchase	0	0	0
Other short-term borrowings	0	30,500	42,400
Notes Payable	427,325	427,297	427,189
Subordinated Debt	0	0	0
Other liabilities	44,784	42,269	44,345
Liabilities	472,109	500,066	513,934
Stockholders Equity Abstract
Preferred stock	0	0	0
Common stock	2	2	2
Surplus	4,153,208	4,103,208	4,066,208
Accumulated deficit	(3,015,889)	(3,013,481)	(2,985,273)
Treasury stock	0	0	0
Accumulated other comprehensive (loss) income, net of tax	57,267	56,947	22,558
Total stockholders' equity	1,194,588	1,146,676	1,103,495
Liabilities And Stockholders Equity	1,666,697	1,646,742	1,617,429
Non Guarantor Subsidiaries Member | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Loans held-in-portfolio:
Loans held-in-portfolio	0	0	0
Real Estate Acquired Through Foreclosure	0	0	0
Non Guarantor Subsidiaries Member | Covered Under Loss Sharing Agreements With F D I C [Member]
Loans held-in-portfolio:
Loans held-in-portfolio	0	0	0
Real Estate Acquired Through Foreclosure	0	0	0
Other Subsidiaries [Member]
Assets
Cash And Due From Banks	473,020	534,796	464,790	451,723
Money market investments	1,285,964	1,357,890	961,497
Trading Securities	404,293	436,331	634,799
Available For Sale Securities	5,114,293	4,988,390	5,663,205
Investment securities held-to-maturity, at amortized cost	123,372	124,383	116,372
Other investment securities, at lower of cost or realizable value	180,365	164,537	159,587
Investment in subsidiaries	0	0	0
Loans held-for-sale, at lower of cost or fair value	361,596	363,093	569,678
Loans held-in-portfolio:
Less- Unearned Income	99,321	100,596	104,760
Allowance for loan losses	803,116	815,300	736,445
Total loans held-in-portfolio, net	23,867,664	24,106,359	24,634,841
FDIC loss share asset	1,880,357	1,915,128	2,426,305
Premises and equipment, net	530,864	535,835	540,638
Interest Receivable	124,471	123,858	145,365
Servicing Asset At Fair Value Amount	156,331	151,323	167,416
Other Assets	1,163,764	1,183,103	993,319
Goodwill	647,912	648,350	647,387
Intangible Assets Net Excluding Goodwill	61,244	63,400	55,887
Total assets	36,679,837	36,978,408	38,403,536
Deposits Abstract
Noninterest Bearing Deposit Liabilities	5,374,587	5,689,034	4,981,103
Interest Bearing Deposit Liabilities	21,899,143	22,302,798	22,292,338
Total deposits	27,273,730	27,991,832	27,273,441
Securities Sold under Agreements to Repurchase	2,113,557	2,165,157	2,642,800
Other short-term borrowings	908,000	459,600	514,902
Notes Payable	648,660	668,226	2,625,782
Subordinated Debt	185,000	185,000	185,000
Other liabilities	1,114,857	1,133,815	941,449
Liabilities	32,243,804	32,603,630	34,183,374
Stockholders Equity Abstract
Preferred stock	0	0	0
Common stock	51,564	51,564	51,564
Surplus	5,870,137	5,870,287	5,857,287
Accumulated deficit	(1,467,930)	(1,532,810)	(1,699,949)
Treasury stock	0	0	0
Accumulated other comprehensive (loss) income, net of tax	(17,738)	(14,263)	11,260
Total stockholders' equity	4,436,033	4,374,778	4,220,162
Liabilities And Stockholders Equity	36,679,837	36,978,408	38,403,536
Other Subsidiaries [Member] | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Loans held-in-portfolio:
Loans held-in-portfolio	20,548,313	20,673,552	20,746,496
Real Estate Acquired Through Foreclosure	193,768	172,497	156,888
Other Subsidiaries [Member] | Covered Under Loss Sharing Agreements With F D I C [Member]
Loans held-in-portfolio:
Loans held-in-portfolio	4,221,788	4,348,703	4,729,550
Real Estate Acquired Through Foreclosure	110,559	109,135	65,562
Consolidation Eliminations Member
Assets
Cash And Due From Banks	(6,540)	(7,202)	(43,329)	(3,182)
Money market investments	(30,625)	(39,963)	(8,523)
Trading Securities	0	0	0
Available For Sale Securities	(17,475)	(17,637)	(18,125)
Investment securities held-to-maturity, at amortized cost	(185,000)	(185,000)	(185,000)
Other investment securities, at lower of cost or realizable value	0	0	0
Investment in subsidiaries	(5,716,109)	(6,762,217)	(6,546,267)
Loans held-for-sale, at lower of cost or fair value	0	0	0
Loans held-in-portfolio:
Less- Unearned Income	0	0	0
Allowance for loan losses	0	0	0
Total loans held-in-portfolio, net	(182,920)	(219,975)	(295,155)
FDIC loss share asset	0	0	0
Premises and equipment, net	0	0	0
Interest Receivable	(102)	(289)	(87)
Servicing Asset At Fair Value Amount	0	0	0
Other Assets	(40,902)	(30,030)	(25,782)
Goodwill	(1)	0	0
Intangible Assets Net Excluding Goodwill	0	0	0
Total assets	(6,179,674)	(7,262,313)	(7,122,268)
Deposits Abstract
Noninterest Bearing Deposit Liabilities	(8,167)	(33,560)	(68,094)
Interest Bearing Deposit Liabilities	(67,827)	(16,145)	(8,673)
Total deposits	(75,994)	(49,705)	(76,767)
Securities Sold under Agreements to Repurchase	0	(24,060)	0
Other short-term borrowings	(156,800)	(193,900)	(267,000)
Notes Payable	0	0	0
Subordinated Debt	(185,000)	(185,000)	(185,000)
Other liabilities	(45,911)	(47,024)	(46,600)
Liabilities	(463,705)	(499,689)	(575,367)
Stockholders Equity Abstract
Preferred stock	0	0	0
Common stock	(55,632)	(55,632)	(55,632)
Surplus	(12,944,188)	(14,057,711)	(14,007,711)
Accumulated deficit	7,294,462	7,421,469	7,546,548
Treasury stock	0	0	0
Accumulated other comprehensive (loss) income, net of tax	(10,611)	(70,750)	(30,106)
Total stockholders' equity	(5,715,969)	(6,762,624)	(6,546,901)
Liabilities And Stockholders Equity	(6,179,674)	(7,262,313)	(7,122,268)
Consolidation Eliminations Member | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Loans held-in-portfolio:
Loans held-in-portfolio	(182,920)	(219,975)	(295,155)
Real Estate Acquired Through Foreclosure	0	0	0
Consolidation Eliminations Member | Covered Under Loss Sharing Agreements With F D I C [Member]
Loans held-in-portfolio:
Loans held-in-portfolio	0	0	0
Real Estate Acquired Through Foreclosure	$ 0	$ 0	$ 0