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FAIR VALUE MEASUREMENT - Schedule of Fair Value Changes and Activity for Level 3 (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020
Interest Rate Lock and Loan Purchase Commitments |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning balance, net | $ 17,392 | $ 2,223
Payoffs/Sales | (26,796) | (40,742)
Total realized/unrealized gains | 11,888 | 55,911
Ending balance, net | 2,484 | 17,392
Investment securities AFS |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning balance, net | 2,710 | 1,952
Additions | 0 | 985
Transfers | 0 | 0
Payoffs/Sales | (192) | (435)
Total realized/unrealized gains | (36) | 208
Ending balance, net | 2,482 | 2,710
Single family LHFI |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning balance, net | 7,108 | 3,468
Additions | 4,051 | 6,088
Transfers | 0 | 0
Payoffs/Sales | (4,279) | (2,409)
Total realized/unrealized gains | 407 | (39)
Ending balance, net | $ 7,287 | $ 7,108

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- Definition Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 + Details
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