Condensed Consolidating Statement of Cash Flow (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Net Cash Provided By Used In Operating Activities Abstract
Net Income (Loss) Attributable to Parent	$ 161,335	$ 148,350
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Equity in undistributed earnings of subsidiaries	0	0
Provision for loan losses	326,130	395,912
Amortization of intangibles	7,605	6,973
Depreciation, Nonproduction	34,953	34,864
Net (accretion of discounts) amortization of premiums and deferred fees	(22,118)	(97,668)
Impairment Losses On Net Assets To Be Disposed Of	0	6,085
Impaiment losses on long-lives assets	0	0
Fair value adjustments of mortgage servicing rights	7,217	26,373
Fair value change in equity appreciation instrument	0	(8,323)
FDIC loss share (income) expense	19,387	(49,344)
Amortization Of Prepaid F D I C Assesment	30,157	68,640
Adjustments (expense) to indemnity reserves on loans sold	17,990	29,587
Losses (earnings) from investments under equity method	9,788	11,250
Earnings from changes in fair value related to instruments measured at fair value pursuant to the fair value option	0	0
Stock Option Plan Expense	0	0
Deferred income tax expense (benefit)	(150,201)	44,608
Loss Gain [Abstract]
Disposition of premises and equipment	(8,253)	(2,019)
Early extinguishment of debt	24,950	0
Sale and valuation adjustments of investment securities	285	(8,044)
Sale of loans, including valuation adjustments on loans held-for-sale	(18,569)	(14,756)
Sale of equity method investment	0	(16,907)
Sale of processing and technology business, net of transaction costs	0	0
Gains (Losses) on Sales of Other Assets	(2,545)	0
Acquisitions of loans held-for-sale	(288,844)	(253,401)
Proceeds from sale of loans held-for-sale	242,088	101,549
Net disbursements on loans held-for-sale	(860,804)	(617,591)
Increase (Decrease) in Operating Assets [Abstract]
Trading securities	849,304	492,882
Accrued income receivable	(8,735)	14,924
Other assets	65,944	(25,576)
Increase (Decrease) in Accounts Payable and Accrued Liabilities [Abstract]
Interest payable	(7,553)	(7,344)
Pension and other postretirement benefit obligations	24,156	(128,802)
Other liabilities	(48,062)	(109,155)
Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities	244,270	(105,283)
Net Cash Provided By Used In Operating Activities	405,605	43,067
Net Cash Provided By Used In Investing Activities Abstract
Change In Money Market Investments	450,511	(289,844)
Payments To Acquire Investments Abstract
Available-for-sale	(1,284,834)	(1,198,613)
Held-to-maturity	(250)	(65,358)
Other	(152,607)	(116,582)
Proceeds From Sale Maturity And Collections Of Investments Abstract
Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities	1,166,618	979,868
Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities	4,398	54,617
Other	119,098	104,231
Proceeds from sale of investment securities available for sale	8,031	35,099
Proceeds From Sale Of Other Investments	0	2,294
Net repayments on loans	687,582	1,013,103
Proceeds From Sale Of Loans Receivable	51,677	290,119
Acquisition of loan portfolios	(1,051,588)	(985,675)
F D I C Indemnification Asset Cash Payments Received	327,739	561,111
Cash received from acquisitions	0	(500)
Proceeds From Sale Of Equity Method Investments	0	31,503
Net proceeds from sale of processing and technology business	0	0
Capital Contribution Subsidiaries		0
Mortgage servicing rights purchased	(1,620)	(1,251)
Acquisition of premises and equipment	(34,336)	(37,868)
Proceeds from sale of: [Abstract]
Premises and equipment	20,612	12,314
Proceeds from Sale of Other Productive Assets	1,026	0
Foreclosed assets	142,019	133,017
Net Cash Provided By Used In Investing Activities	454,076	521,585
Net Increase Decrease In [Abstract]
Deposits	(1,624,634)	1,192,652
Federal funds purchased and assets sold under agreements to repurchase	(196,533)	189,056
Other short-term borrowings	910,000	(198,022)
Payments of notes payable	(72,815)	(2,055,254)
Proceeds From Notes Payable	61,331	419,500
Proceeds from issuance of common stock	7,788	5,394
Net proceeds from issuance of depository shares	0	0
Cash Dividends Paid To Parent Company		0
Dividends paid	(2,482)	(2,792)
Treasury stock acquired	(276)	(418)
Proceeds From Contributed Capital		0
Proceeds From Contributions From Parent		0
Net Cash Provided By Used In Financing Activities	(917,621)	(449,884)
Cash And Cash Equivalents Period Increase Decrease	(57,940)	114,768
Cash and due from banks at beginning of period	535,282	452,373
Cash and due from banks at end of period	477,342	567,141
Parent Company [Member]
Net Cash Provided By Used In Operating Activities Abstract
Net Income (Loss) Attributable to Parent	161,335	148,350
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Equity in undistributed earnings of subsidiaries	(207,370)	(193,660)
Provision for loan losses	267	0
Amortization of intangibles	0	0
Depreciation, Nonproduction	484	582
Net (accretion of discounts) amortization of premiums and deferred fees	21,624	18,397
Impairment Losses On Net Assets To Be Disposed Of	0	0
Fair value adjustments of mortgage servicing rights	0	0
Fair value change in equity appreciation instrument	0	0
FDIC loss share (income) expense	0	0
Amortization Of Prepaid F D I C Assesment	0	0
Adjustments (expense) to indemnity reserves on loans sold	0	0
Losses (earnings) from investments under equity method	(3,079)	(11,271)
Deferred income tax expense (benefit)	(14,755)	3,555
Loss Gain [Abstract]
Disposition of premises and equipment	1	7
Early extinguishment of debt	0	0
Sale and valuation adjustments of investment securities	0	0
Sale of loans, including valuation adjustments on loans held-for-sale	0	0
Sale of equity method investment	0	(5,493)
Sale of processing and technology business, net of transaction costs		0
Gains (Losses) on Sales of Other Assets	0
Acquisitions of loans held-for-sale	0	0
Proceeds from sale of loans held-for-sale	0	0
Net disbursements on loans held-for-sale	0	0
Increase (Decrease) in Operating Assets [Abstract]
Trading securities	0	0
Accrued income receivable	(1,168)	(686)
Other assets	134,437	4,134
Increase (Decrease) in Accounts Payable and Accrued Liabilities [Abstract]
Interest payable	0	(3,467)
Pension and other postretirement benefit obligations	0	0
Other liabilities	(1,347)	(72,709)
Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities	(70,906)	(260,611)
Net Cash Provided By Used In Operating Activities	90,429	(112,261)
Net Cash Provided By Used In Investing Activities Abstract
Change In Money Market Investments	24,008	(5,921)
Payments To Acquire Investments Abstract
Available-for-sale	0	0
Held-to-maturity	0	(37,093)
Other	0	0
Proceeds From Sale Maturity And Collections Of Investments Abstract
Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities	0	0
Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities	0	50,613
Other	0	0
Proceeds from sale of investment securities available for sale	0	0
Proceeds From Sale Of Other Investments	0	0
Net repayments on loans	(71,042)	211,975
Proceeds From Sale Of Loans Receivable	0	0
Acquisition of loan portfolios	0	0
F D I C Indemnification Asset Cash Payments Received	0	0
Cash received from acquisitions	0	0
Proceeds From Sale Of Equity Method Investments	0	(10,690)
Net proceeds from sale of processing and technology business		0
Capital Contribution Subsidiaries	(50,000)	0
Mortgage servicing rights purchased	0	0
Acquisition of premises and equipment	(637)	(500)
Proceeds from sale of: [Abstract]
Premises and equipment	24	19
Proceeds from Sale of Other Productive Assets	0
Foreclosed assets	0	0
Net Cash Provided By Used In Investing Activities	(97,647)	208,403
Net Increase Decrease In [Abstract]
Deposits	0	0
Federal funds purchased and assets sold under agreements to repurchase	0	0
Other short-term borrowings	0	0
Prepayment penalties paid on cancellation of debt		0
Payments of notes payable	0	(100,000)
Proceeds From Notes Payable	0	0
Proceeds from issuance of common stock	7,788	5,394
Net proceeds from issuance of depository shares	0	0
Cash Dividends Paid To Parent Company	0	0
Dividends paid	(2,482)	(2,792)
Treasury stock acquired	(276)	(418)
Proceeds From Contributed Capital	0	1,514
Proceeds From Contributions From Parent	0	0
Net Cash Provided By Used In Financing Activities	5,030	(96,302)
Cash And Cash Equivalents Period Increase Decrease	(2,188)	(160)
Cash and due from banks at beginning of period	6,365	1,638
Cash and due from banks at end of period	4,177	1,478
Guarantor Subsidiaries Member
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Amortization Of Prepaid F D I C Assesment	0	0
Non Guarantor Subsidiaries Member
Net Cash Provided By Used In Operating Activities Abstract
Net Income (Loss) Attributable to Parent	(5,645)	3,095
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Equity in undistributed earnings of subsidiaries	(18,417)	(25,868)
Provision for loan losses	0	0
Amortization of intangibles	0	0
Depreciation, Nonproduction	2	2
Net (accretion of discounts) amortization of premiums and deferred fees	84	149
Impairment Losses On Net Assets To Be Disposed Of	0	0
Fair value adjustments of mortgage servicing rights	0	0
Fair value change in equity appreciation instrument	0	0
FDIC loss share (income) expense	0	0
Adjustments (expense) to indemnity reserves on loans sold	0	0
Losses (earnings) from investments under equity method	(379)	(1,082)
Deferred income tax expense (benefit)	0	(264)
Loss Gain [Abstract]
Disposition of premises and equipment	0	0
Early extinguishment of debt	0	0
Sale and valuation adjustments of investment securities	0	0
Sale of loans, including valuation adjustments on loans held-for-sale	0	0
Sale of equity method investment	0	0
Sale of processing and technology business, net of transaction costs		0
Gains (Losses) on Sales of Other Assets	0
Acquisitions of loans held-for-sale	0	0
Proceeds from sale of loans held-for-sale	0	0
Net disbursements on loans held-for-sale	0	0
Increase (Decrease) in Operating Assets [Abstract]
Trading securities	0	0
Accrued income receivable	81	80
Other assets	1,049	1,406
Increase (Decrease) in Accounts Payable and Accrued Liabilities [Abstract]
Interest payable	2,527	3,048
Pension and other postretirement benefit obligations	0	0
Other liabilities	(20)	(2,349)
Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities	(15,073)	(24,878)
Net Cash Provided By Used In Operating Activities	(20,718)	(21,783)
Net Cash Provided By Used In Investing Activities Abstract
Change In Money Market Investments	(88)	(22)
Payments To Acquire Investments Abstract
Available-for-sale	0	0
Held-to-maturity	0	0
Other	0	0
Proceeds From Sale Maturity And Collections Of Investments Abstract
Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities	0	0
Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities	0	0
Other	0	0
Proceeds from sale of investment securities available for sale	0	0
Proceeds From Sale Of Other Investments	0	0
Net repayments on loans	0	0
Proceeds From Sale Of Loans Receivable	0	0
Acquisition of loan portfolios	0	0
F D I C Indemnification Asset Cash Payments Received	0	0
Cash received from acquisitions	0	0
Proceeds From Sale Of Equity Method Investments	0	0
Net proceeds from sale of processing and technology business		0
Capital Contribution Subsidiaries	0	0
Mortgage servicing rights purchased	0	0
Acquisition of premises and equipment	0	0
Proceeds from sale of: [Abstract]
Premises and equipment	0	0
Proceeds from Sale of Other Productive Assets	0
Foreclosed assets	0	0
Net Cash Provided By Used In Investing Activities	(88)	(22)
Net Increase Decrease In [Abstract]
Deposits	0	0
Federal funds purchased and assets sold under agreements to repurchase	0	0
Other short-term borrowings	(29,500)	(13,500)
Prepayment penalties paid on cancellation of debt		0
Payments of notes payable	0	(3,000)
Proceeds From Notes Payable	0	0
Proceeds from issuance of common stock	0	0
Net proceeds from issuance of depository shares	0	0
Cash Dividends Paid To Parent Company	0	0
Dividends paid	0	0
Treasury stock acquired	0	0
Proceeds From Contributed Capital	0	0
Proceeds From Contributions From Parent	50,000	37,000
Net Cash Provided By Used In Financing Activities	20,500	20,500
Cash And Cash Equivalents Period Increase Decrease	(306)	(1,305)
Cash and due from banks at beginning of period	932	1,576
Cash and due from banks at end of period	626	271
Other Subsidiaries [Member]
Net Cash Provided By Used In Operating Activities Abstract
Net Income (Loss) Attributable to Parent	235,576	215,392
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Equity in undistributed earnings of subsidiaries	0	0
Provision for loan losses	325,863	395,912
Amortization of intangibles	7,605	6,973
Depreciation, Nonproduction	34,467	34,280
Net (accretion of discounts) amortization of premiums and deferred fees	(43,339)	(115,727)
Impairment Losses On Net Assets To Be Disposed Of	0	6,085
Fair value adjustments of mortgage servicing rights	7,217	26,373
Fair value change in equity appreciation instrument	0	(8,323)
FDIC loss share (income) expense	19,387	(49,344)
Amortization Of Prepaid F D I C Assesment	30,157	68,640
Adjustments (expense) to indemnity reserves on loans sold	17,990	29,587
Losses (earnings) from investments under equity method	(25,821)	(14,699)
Deferred income tax expense (benefit)	(135,709)	40,692
Loss Gain [Abstract]
Disposition of premises and equipment	(8,254)	(2,026)
Early extinguishment of debt	24,950	0
Sale and valuation adjustments of investment securities	285	(8,044)
Sale of loans, including valuation adjustments on loans held-for-sale	(18,569)	(14,756)
Sale of equity method investment	0	(11,414)
Sale of processing and technology business, net of transaction costs		0
Gains (Losses) on Sales of Other Assets	(2,545)
Acquisitions of loans held-for-sale	(288,844)	(253,401)
Proceeds from sale of loans held-for-sale	242,088	101,549
Net disbursements on loans held-for-sale	(860,804)	(617,591)
Increase (Decrease) in Operating Assets [Abstract]
Trading securities	849,304	492,882
Accrued income receivable	(7,728)	15,467
Other assets	(23,830)	(1,089)
Increase (Decrease) in Accounts Payable and Accrued Liabilities [Abstract]
Interest payable	(10,114)	(6,969)
Pension and other postretirement benefit obligations	24,156	(128,802)
Other liabilities	(47,787)	(36,398)
Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities	110,125	(50,143)
Net Cash Provided By Used In Operating Activities	345,701	165,249
Net Cash Provided By Used In Investing Activities Abstract
Change In Money Market Investments	450,564	(283,923)
Payments To Acquire Investments Abstract
Available-for-sale	(1,284,834)	(1,198,613)
Held-to-maturity	(250)	(28,265)
Other	(152,607)	(116,582)
Proceeds From Sale Maturity And Collections Of Investments Abstract
Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities	1,166,618	979,868
Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities	4,398	4,004
Other	119,098	104,231
Proceeds from sale of investment securities available for sale	8,031	35,099
Proceeds From Sale Of Other Investments	0	2,294
Net repayments on loans	687,866	1,008,880
Proceeds From Sale Of Loans Receivable	51,677	290,119
Acquisition of loan portfolios	(1,051,588)	(985,675)
F D I C Indemnification Asset Cash Payments Received	327,739	561,111
Cash received from acquisitions	0	(500)
Proceeds From Sale Of Equity Method Investments	0	42,193
Net proceeds from sale of processing and technology business		0
Capital Contribution Subsidiaries	0	(37,000)
Mortgage servicing rights purchased	(1,620)	(1,251)
Acquisition of premises and equipment	(33,699)	(37,368)
Proceeds from sale of: [Abstract]
Premises and equipment	20,588	12,295
Proceeds from Sale of Other Productive Assets	1,026
Foreclosed assets	142,019	133,017
Net Cash Provided By Used In Investing Activities	455,026	483,934
Net Increase Decrease In [Abstract]
Deposits	(1,631,309)	1,201,464
Federal funds purchased and assets sold under agreements to repurchase	(220,593)	189,056
Other short-term borrowings	1,010,400	(389,822)
Prepayment penalties paid on cancellation of debt		0
Payments of notes payable	(72,815)	(1,952,254)
Proceeds From Notes Payable	61,331	419,500
Proceeds from issuance of common stock	0	0
Net proceeds from issuance of depository shares	0	0
Cash Dividends Paid To Parent Company	(5,000)	0
Dividends paid	0	0
Treasury stock acquired	0	0
Proceeds From Contributed Capital	0	(1,514)
Proceeds From Contributions From Parent	0	0
Net Cash Provided By Used In Financing Activities	(857,986)	(533,570)
Cash And Cash Equivalents Period Increase Decrease	(57,259)	115,613
Cash and due from banks at beginning of period	534,796	451,723
Cash and due from banks at end of period	477,537	567,336
Consolidation Eliminations Member
Net Cash Provided By Used In Operating Activities Abstract
Net Income (Loss) Attributable to Parent	(229,931)	(218,487)
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Equity in undistributed earnings of subsidiaries	225,787	219,528
Provision for loan losses	0	0
Amortization of intangibles	0	0
Depreciation, Nonproduction	0	0
Net (accretion of discounts) amortization of premiums and deferred fees	(487)	(487)
Impairment Losses On Net Assets To Be Disposed Of	0	0
Fair value adjustments of mortgage servicing rights	0	0
Fair value change in equity appreciation instrument	0	0
FDIC loss share (income) expense	0	0
Amortization Of Prepaid F D I C Assesment	0	0
Adjustments (expense) to indemnity reserves on loans sold	0	0
Losses (earnings) from investments under equity method	39,067	38,302
Deferred income tax expense (benefit)	263	625
Loss Gain [Abstract]
Disposition of premises and equipment	0	0
Early extinguishment of debt	0	0
Sale and valuation adjustments of investment securities	0	0
Sale of loans, including valuation adjustments on loans held-for-sale	0	0
Sale of equity method investment	0	0
Sale of processing and technology business, net of transaction costs		0
Gains (Losses) on Sales of Other Assets	0
Acquisitions of loans held-for-sale	0	0
Proceeds from sale of loans held-for-sale	0	0
Net disbursements on loans held-for-sale	0	0
Increase (Decrease) in Operating Assets [Abstract]
Trading securities	0	0
Accrued income receivable	80	63
Other assets	(45,712)	(30,027)
Increase (Decrease) in Accounts Payable and Accrued Liabilities [Abstract]
Interest payable	34	44
Pension and other postretirement benefit obligations	0	0
Other liabilities	1,092	2,301
Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities	220,124	230,349
Net Cash Provided By Used In Operating Activities	(9,807)	11,862
Net Cash Provided By Used In Investing Activities Abstract
Change In Money Market Investments	(23,973)	22
Payments To Acquire Investments Abstract
Available-for-sale	0	0
Held-to-maturity	0	0
Other	0	0
Proceeds From Sale Maturity And Collections Of Investments Abstract
Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities	0	0
Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities	0	0
Other	0	0
Proceeds from sale of investment securities available for sale	0	0
Proceeds From Sale Of Other Investments	0	0
Net repayments on loans	70,758	(207,752)
Proceeds From Sale Of Loans Receivable	0	0
Acquisition of loan portfolios	0	0
F D I C Indemnification Asset Cash Payments Received	0	0
Cash received from acquisitions	0	0
Proceeds From Sale Of Equity Method Investments	0	0
Net proceeds from sale of processing and technology business		0
Capital Contribution Subsidiaries	50,000	37,000
Mortgage servicing rights purchased	0	0
Acquisition of premises and equipment	0	0
Proceeds from sale of: [Abstract]
Premises and equipment	0	0
Proceeds from Sale of Other Productive Assets	0
Foreclosed assets	0	0
Net Cash Provided By Used In Investing Activities	96,785	(170,730)
Net Increase Decrease In [Abstract]
Deposits	6,675	(8,812)
Federal funds purchased and assets sold under agreements to repurchase	24,060	0
Other short-term borrowings	(70,900)	205,300
Prepayment penalties paid on cancellation of debt		0
Payments of notes payable	0	0
Proceeds From Notes Payable	0	0
Proceeds from issuance of common stock	0	0
Net proceeds from issuance of depository shares	0	0
Cash Dividends Paid To Parent Company	5,000	0
Dividends paid	0	0
Treasury stock acquired	0	0
Proceeds From Contributed Capital	0	0
Proceeds From Contributions From Parent	(50,000)	(37,000)
Net Cash Provided By Used In Financing Activities	(85,165)	159,488
Cash And Cash Equivalents Period Increase Decrease	1,813	620
Cash and due from banks at beginning of period	(6,811)	(2,564)
Cash and due from banks at end of period	$ (4,998)	$ (1,944)