Federal Home Loan Bank Advances - Summary of Contractual Maturities of FHLB Advances (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract]
Due in 2021	$ 95,000
Due in 2022	29,000
Due in 2023	160
Due in 2024	75,000
Due in 2025	550,000
Thereafter	1,250,000
Fair value hedge basis adjustments and unamortized prepayment fees	(7,725)	$ 22,183
Federal Home Loan Bank advances	$ 1,991,435	$ 1,822,847

Accumulated Fair Value Hedge Basis Adjustments And Unamortized Prepayment Fees

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- Definition

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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Amount of advance from Federal Home Loan Bank (FHLBank) maturing after 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).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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Amount of advance from Federal Home Loan Bank (FHLBank) maturing in 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).

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Amount of advance from Federal Home Loan Bank (FHLBank) maturing in second 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).

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Amount of advance from Federal Home Loan Bank (FHLBank) maturing in fourth 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).

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- Definition

Amount of advance from Federal Home Loan Bank (FHLBank) maturing in third 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).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-SubTopic 470
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-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

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- Definition

Amount of advance from Federal Home Loan Bank (FHLBank) 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).

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