Regulatory Ratios and Capital - Schedule of Compliance With Regulatory Capital Requirements (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	0.0600
Capital Required to be Well Capitalized to Risk Weighted Assets	0.1000
CET1, actual amount	$ 3,419,546	$ 3,251,979
Tier One Risk Based Capital	3,829,546	3,661,979
Capital	4,534,636	4,390,656
Tier One Leverage Capital	$ 3,829,546	$ 3,661,979
CET1, actual ratio	12.14%	11.38%
Tier One Risk Based Capital to Risk Weighted Assets	0.1360	0.1282
Capital to Risk Weighted Assets	0.1610	0.1537
Tier One Leverage Capital to Average Assets	0.1188	0.1133
Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
CET1 to be well capitalized under prompt corrective action provisions, ratio	6.50%
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	0.0800
Capital Required to be Well Capitalized to Risk Weighted Assets	0.1000
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	0.0500
CET1, actual amount	$ 3,509,504	$ 3,611,714
Tier One Risk Based Capital	3,509,504	3,611,714
Capital	3,842,043	3,968,168
Tier One Leverage Capital	$ 3,509,504	$ 3,611,714
CET1, actual ratio	12.53%	12.75%
Tier One Risk Based Capital to Risk Weighted Assets	0.1253	0.1275
Capital to Risk Weighted Assets	0.1372	0.1400
Tier One Leverage Capital to Average Assets	0.1099	0.1127
Basel III, Phase-In Schedule
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
CET1 for capital adequacy purposes, ratio	7.00%
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	0.0850
Capital Required for Capital Adequacy to Risk Weighted Assets	0.1050
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	0.0400
Basel III, Phase-In Schedule \| Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
CET1 for capital adequacy purposes, ratio	7.00%
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	0.0850
Capital Required for Capital Adequacy to Risk Weighted Assets	0.1050
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	0.0400

Common Equity Tier 1 Capital

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Common Equity Tier 1, Capital Required for Capital Adequacy to Risk Weighted Assets

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Common Equity Tier 1, Capital to Risk Weighted Assets

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Amount of total capital as defined by regulatory framework.

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Ratio of minimum total risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477270/942-505-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477270/942-505-50-1B

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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477270/942-505-50-1

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Amount of Tier 1 leverage capital as defined by regulatory framework.

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