Securities - Contractual Maturity Information for Securities Held to Maturity (Detail) - USD ($) $ in Thousands |
Jun. 30, 2026 |
Dec. 31, 2025 |
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| Investments, Debt and Equity Securities [Abstract] | ||
| Due in 1 year or less, Amortized Cost | $ 89,562 | |
| Due after 1 year through 5 years, Amortized Cost | 556,314 | |
| Due after 5 years through 10 years, Amortized Cost | 797,227 | |
| Due after 10 years, Amortized Cost | 1,867,338 | |
| Total, Amortized cost | 3,310,441 | |
| Mortgage-backed securities, Amortized cost | 2,405,985 | |
| Amortized Cost | 5,716,426 | $ 5,724,227 |
| Due in 1 year or less, Fair Value | 89,149 | |
| Due after 1 year through 5 years, Fair Value | 548,106 | |
| Due after 5 years through 10 years, Fair Value | 767,036 | |
| Due after 10 years, Fair Value | 1,748,622 | |
| Total, Fair value | 3,152,913 | |
| Mortgage-backed securities, Fair value | 2,086,534 | |
| Total securities held to maturity, Fair value | $ 5,239,447 | $ 5,250,465 |
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- Definition Mortgage backed securities held to maturity amortized cost. No definition available.
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- Definition Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
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- Definition Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
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- Definition Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing after tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
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| X | ||||||||||
- Definition Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date, maturing after tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date. Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
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- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
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- Definition Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- References No definition available.
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- Definition Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as held-to-maturity. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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