Summary of Significant Accounting Policies - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Investment Securities - Held to Maturity	$ 2,446,589	$ 2,487,440
Net book balance	1,000	1,000
Liability recorded for expected credit losses on unfunded commitments	53,200
Other Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accrued interest receivable for investment securities	25,800	26,500
Other Liabilities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability recorded for expected credit losses on unfunded commitments	$ 53,200	$ 56,300