Summary of Significant Accounting Policies - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Held-to-maturity Securities	$ 2,806,465	$ 1,819,901
Threshold Net Book Balance, Individually Evaluated Loans	1,000
Liability Recorded for Expected Credit Losses on Unfunded Commitments	32,500
Other Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accrued interest receivable for investment securities	27,600	19,200
Interest Receivable	82,100	70,600
Other Liabilities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability Recorded for Expected Credit Losses on Unfunded Commitments	$ 32,500	$ 30,500