MORTGAGE SERVICING RIGHTS - Schedule of Activity Related to MSRs (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Mortgage Servicing Rights
Beginning balance	$ 862,813
Ending balance	953,845	$ 862,813
Servicing portfolio loans unpaid principal balance	115,700,564	107,211,972	$ 93,225,169
MSRs
Mortgage Servicing Rights
Beginning balance	862,813	718,799
Additions, following the sale of loan	313,376	321,225
Amortization	(176,428)	(149,888)
Pre-payments and write-offs	(45,916)	(27,323)
Ending balance	$ 953,845	$ 862,813

This is the sum of principal amount outstanding for both securitized and unsecuritized loans of all types.

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Amount of other-than-temporary impairment (OTTI) applied to contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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Amortized amount of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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