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Fair Values of Assets and Liabilities (Summary of Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Detail) - USD ($) $ in Thousands | 3 Months Ended
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Mar. 31, 2022 | Mar. 31, 2021
Loans held-for- investment |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning balance | $ 15,891 | $ 10,280
Net income | (772) | (530)
Other comprehensive income (loss) | 0 | 0
Purchases | 0 | 0
Issuances | 0 | 0
Sales | 0 | 0
Settlements | (1,667) | (3,918)
Net transfers into/(out of) Level 3 | 31,012 | 576
Ending balance | 44,464 | 6,408
Mortgage servicing rights |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning balance | 147,571 | 92,081
Net income | 51,575 | 32,235
Other comprehensive income (loss) | 0 | 0
Purchases | 0 | 0
Issuances | 0 | 0
Sales | 0 | 0
Settlements | 0 | 0
Net transfers into/(out of) Level 3 | 0 | 0
Ending balance | 199,146 | 124,316
Derivative assets |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning balance | 10,560 | 48,091
Net income | (7,113) | (22,457)
Other comprehensive income (loss) | 0 | 0
Purchases | 0 | 0
Issuances | 0 | 0
Sales | 0 | 0
Settlements | 0 | 0
Net transfers into/(out of) Level 3 | 0 | 0
Ending balance | 3,447 | 25,634
Municipal Securities |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning balance | 105,687 | 109,876
Net income | 0 | 0
Other comprehensive income (loss) | (5,449) | (2,068)
Purchases | 1,246 | 0
Issuances | 0 | 0
Sales | 0 | 0
Settlements | (1,083) | (6,060)
Net transfers into/(out of) Level 3 | 0 | 0
Ending balance | 100,401 | 101,748
U.S. Government agencies |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning balance | 0 | 1,966
Net income | 0 | 0
Other comprehensive income (loss) | 0 | (24)
Purchases | 0 | 0
Issuances | 0 | 0
Sales | 0 | 0
Settlements | 0 | (158)
Net transfers into/(out of) Level 3 | 0 | 0
Ending balance | $ 0 | $ 1,784

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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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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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