BUSINESS COMBINATION - Estimated Fair Value of Net Assets Acquired (Detail) $ in Thousands	Sep. 01, 2020 USD ($)
Fair Value Disclosure Item Amounts [Domain] \| Measurment Period Adjustments [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 2,798
Fair Value Disclosure Item Amounts [Domain] \| Fair Value as Originally Recorded
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	1,277,626
Fair Value Disclosure Item Amounts [Domain] \| Fair Value as Remeasured
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	1,280,424
BSPR \| Fair Value Disclosure Item Amounts [Domain] \| Measurment Period Adjustments [Member]
Fair value of assets acquired:
Cash and cash equivalents	0
Investment securities	0
Loans, net	(216)
Premises and equipment, net	0
Intangibles	0
Other assets	(352)
Total assets and identifiable intangible assets acquired	(568)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]
Deposits	0
Other liabilities	865
Total liabilities assumed	865
Fair value of net assets and identifiable intangible assets	(1,433)
Goodwill	4,231
BSPR \| Fair Value Disclosure Item Amounts [Domain] \| Measurment Period Adjustments [Member] \| Residential Portfolio Segment [Member]
Fair value of assets acquired:
Loans, net	(216)
BSPR \| Fair Value Disclosure Item Amounts [Domain] \| Measurment Period Adjustments [Member] \| Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member]
Fair value of assets acquired:
Loans, net	0
BSPR \| Fair Value Disclosure Item Amounts [Domain] \| Measurment Period Adjustments [Member] \| Commercial Portfolio Segment [Member] \| Commercial And Industrial Sector [Member]
Fair value of assets acquired:
Loans, net	0
BSPR \| Fair Value Disclosure Item Amounts [Domain] \| Measurment Period Adjustments [Member] \| Consumer Portfolio Segment [Member]
Fair value of assets acquired:
Loans, net	0
BSPR \| Fair Value Estimated [Member]
Fair value of assets acquired:
Cash and cash equivalents	1,684,252
Investment securities	1,167,225
Loans, net	2,514,916
Premises and equipment, net	12,499
Intangibles	39,232
Other assets	144,008
Total assets and identifiable intangible assets acquired	5,562,132
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]
Deposits	4,194,940
Other liabilities	95,869
Total liabilities assumed	4,290,809
Fair value of net assets and identifiable intangible assets	1,271,323
Goodwill	6,303
BSPR \| Fair Value Estimated [Member] \| Residential Portfolio Segment [Member]
Fair value of assets acquired:
Loans, net	807,637
BSPR \| Fair Value Estimated [Member] \| Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member]
Fair value of assets acquired:
Loans, net	740,919
BSPR \| Fair Value Estimated [Member] \| Commercial Portfolio Segment [Member] \| Commercial And Industrial Sector [Member]
Fair value of assets acquired:
Loans, net	752,154
BSPR \| Fair Value Estimated [Member] \| Consumer Portfolio Segment [Member]
Fair value of assets acquired:
Loans, net	214,206
BSPR \| Fair Value As Remeasured [Member]
Fair value of assets acquired:
Cash and cash equivalents	1,684,252
Investment securities	1,167,225
Loans, net	2,514,700
Premises and equipment, net	12,499
Intangibles	39,232
Other assets	143,656
Total assets and identifiable intangible assets acquired	5,561,564
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]
Deposits	4,194,940
Other liabilities	96,734
Total liabilities assumed	4,291,674
Fair value of net assets and identifiable intangible assets	1,269,890
Goodwill	10,534
BSPR \| Fair Value As Remeasured [Member] \| Residential Portfolio Segment [Member]
Fair value of assets acquired:
Loans, net	807,421
BSPR \| Fair Value As Remeasured [Member] \| Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member]
Fair value of assets acquired:
Loans, net	740,919
BSPR \| Fair Value As Remeasured [Member] \| Commercial Portfolio Segment [Member] \| Commercial And Industrial Sector [Member]
Fair value of assets acquired:
Loans, net	752,154
BSPR \| Fair Value As Remeasured [Member] \| Consumer Portfolio Segment [Member]
Fair value of assets acquired:
Loans, net	$ 214,206

Amount of financing receivables after allowance for credit losses acquired during a business combination.

No definition available.

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The amount of deposits assumed (as defined) which have been recognized as of the acquisition date.

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Amount of assets acquired at the acquisition date.

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Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount of investments in debt and equity securities, including, but not limited to, held-to-maturity, trading and available-for-sale expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer, acquired at the acquisition date.

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The amount of identifiable intangible assets recognized as of the acquisition date.

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Amount of liabilities assumed at the acquisition date.

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Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed.

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Amount of other liabilities due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of other assets expected to be realized or consumed after one year or the normal operating cycle, if longer, acquired at the acquisition date.

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The amount of property, plant, and equipment recognized as of the acquisition date.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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