ALLOWANCE FOR LOAN AND LEASE LOSSES - Changes in Allowance for Loan and Lease Losses (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013		Dec. 31, 2012
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	$ 285,858	$ 435,414
Charge-offs	(200,316)	(216,410)
Charge-off related to bulk sale		(196,491)
Recoveries	27,323	19,594
Provision (release)	109,530	243,751
Reclassification		0	[1]
Ending balance	222,395	285,858
Balance at end of period	55,205	102,601		221,749
Ending balance: general allowance	167,190	183,257
Ending balance	9,262,436	9,636,170
Ending balance: impaired loans	945,407	919,112		1,465,294
Ending balance: purchased credit-impaired loans	102,604	4,791
Ending balance: loans with general allowance	8,214,425	8,712,267
Purchased Credit Impaired [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Ending balance: purchased credit-impaired loans	0	0
Ending balance: impaired loans	945,407
Ending balance: purchased credit-impaired loans	102,604	4,791
Residential Mortgage [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	33,110	68,354
Charge-offs	(24,345)	(30,192)
Charge-off related to bulk sale		(98,972)
Recoveries	1,049	1,165
Provision (release)	17,487	92,755
Reclassification		0	[1]
Ending balance	27,301	33,110
Balance at end of period	10,854	18,125
Ending balance: general allowance	16,447	14,985
Ending balance	3,011,187	2,549,008
Ending balance: impaired loans	424,244	410,994
Ending balance: loans with general allowance	2,488,449	2,138,014
Residential Mortgage [Member] | Purchased Credit Impaired [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Ending balance: purchased credit-impaired loans	0	0
Ending balance: purchased credit-impaired loans	98,494	0
Commercial Mortgage Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	73,138	97,692
Charge-offs	(25,807)	(27,400)
Charge-off related to bulk sale		(40,057)
Recoveries	10,639	4,855
Provision (release)	(7,076)	27,357
Reclassification		10,691	[1]
Ending balance	50,894	73,138
Balance at end of period	14,289	32,189
Ending balance: general allowance	36,605	40,949
Ending balance	1,665,787	1,823,608
Ending balance: impaired loans	210,738	219,372
Ending balance: loans with general allowance	1,451,656	1,604,236
Commercial Mortgage Loans [Member] | Purchased Credit Impaired [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Ending balance: purchased credit-impaired loans	0	0
Ending balance: purchased credit-impaired loans	3,393	0
Commercial And Industrial Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	85,295	146,900
Charge-offs	(61,935)	(65,171)
Charge-off related to bulk sale		(44,678)
Recoveries	3,680	4,636
Provision (release)	36,681	53,048
Reclassification		(9,440)	[1]
Ending balance	63,721	85,295
Balance at end of period	21,314	26,686
Ending balance: general allowance	42,407	58,609
Ending balance	2,479,437	3,028,322
Ending balance: impaired loans	236,371	187,104
Ending balance: loans with general allowance	2,243,066	2,841,218
Commercial And Industrial Loans [Member] | Purchased Credit Impaired [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Ending balance: purchased credit-impaired loans	0	0
Ending balance: purchased credit-impaired loans	0	0
Construction Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	35,814	61,600
Charge-offs	(11,533)	(30,539)
Charge-off related to bulk sale		(12,784)
Recoveries	6,049	2,076
Provision (release)	(17,508)	16,712
Reclassification		(1,251)	[1]
Ending balance	12,822	35,814
Balance at end of period	2,577	22,144
Ending balance: general allowance	10,245	13,670
Ending balance	123,480	168,713
Ending balance: impaired loans		72,717
Ending balance: loans with general allowance	84,013	95,996
Construction Loans [Member] | Purchased Credit Impaired [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Ending balance: purchased credit-impaired loans	0	0
Ending balance: impaired loans	39,467
Ending balance: purchased credit-impaired loans	0	0
Consumer Loan [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	58,501	60,868
Charge-offs	(76,696)	(63,108)
Charge-off related to bulk sale		0
Recoveries	5,906	6,862
Provision (release)	79,946	53,879
Reclassification		0	[1]
Ending balance	67,657	58,501
Balance at end of period	6,171	3,457
Ending balance: general allowance	61,486	55,044
Ending balance	1,982,545	2,066,519
Ending balance: impaired loans		28,925
Ending balance: loans with general allowance	1,947,241	2,032,803
Consumer Loan [Member] | Purchased Credit Impaired [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Ending balance: purchased credit-impaired loans	0	0
Ending balance: impaired loans	34,587
Ending balance: purchased credit-impaired loans	$ 717	$ 4,791

[1] During the second quarter of 2013, after a comprehensive review of substantially all of the loans in our commercial portfolios, the classification of certain loans was revised to more accurately depict the nature of the underlying loans. This reclassification resulted in a net increase of $269.0 million in commercial mortgage loans, since the principal source of repayment for such loans is derived primarily from the operation of the underlying real estate, with a corresponding decrease of $246.8 million in commercial and industrial loans and a $22.2 million decrease in construction loans. The Corporation evaluated the impact of this reclassification on the provision for loan losses and determined that the effect of this adjustment was not material to any previously reported results.