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BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES - Transition Adjustment Impact of ASC 326 (Detail) - USD ($) $ in Thousands			3 Months Ended
	Jan. 01, 2020	Dec. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt Securities, Held-to-maturity, Allowance for Credit Loss		$ 0	$ 9,268
Financing Receivable, Allowance for Credit Loss		155,139	292,774	$ 183,732	$ 196,362
Off-Balance Sheet, Credit Loss, Liability		0	5,741	0	412
Pre-tax effect in beginning retained eaarnings		155,139
ASC 326
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt Securities, Held-to-maturity, Allowance for Credit Loss	$ 8,134
Financing Receivable, Allowance for Credit Loss	236,304
Off-Balance Sheet, Credit Loss, Liability	3,922
Pre-tax effect in beginning retained eaarnings	248,360
ASC 326 \| Cumulative Effect Period Of Adoption Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt Securities, Held-to-maturity, Allowance for Credit Loss	8,134
Financing Receivable, Allowance for Credit Loss	81,165
Off-Balance Sheet, Credit Loss, Liability	3,922
Pre-tax effect in beginning retained eaarnings	93,221
Tax effect	31,333
After-tax effect in beginning retained earnings	62,322
PCD loans [Member] \| ASC 326 \| Cumulative Effect Period Of Adoption Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Balance sheet reclassification			434
Residential Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss		44,806	107,082	51,886	50,794
Residential Portfolio Segment [Member] \| ASC 326
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	94,643
Residential Portfolio Segment [Member] \| ASC 326 \| Cumulative Effect Period Of Adoption Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	49,837
Commercial Portfolio Segment [Member] \| Commercial And Industrial Sector [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss		15,198	38,310	22,321	32,546
Commercial Portfolio Segment [Member] \| Commercial And Industrial Sector [Member] \| ASC 326
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	29,929
Commercial Portfolio Segment [Member] \| Commercial And Industrial Sector [Member] \| ASC 326 \| Cumulative Effect Period Of Adoption Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	14,731
Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss		39,194	33,971	53,430	55,581
Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member] \| ASC 326
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	19,888
Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member] \| ASC 326 \| Cumulative Effect Period Of Adoption Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	(19,306)
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss		2,370	5,253	3,331	3,592
Commercial Portfolio Segment [Member] \| Construction Loans [Member] \| ASC 326
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	3,167
Commercial Portfolio Segment [Member] \| Construction Loans [Member] \| ASC 326 \| Cumulative Effect Period Of Adoption Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	797
Consumer Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss		$ 53,571	$ 108,158	$ 52,764	$ 53,849
Consumer Portfolio Segment [Member] \| ASC 326
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	88,677
Consumer Portfolio Segment [Member] \| ASC 326 \| Cumulative Effect Period Of Adoption Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 35,106