Investment Securities - Narrative (Details)		3 Months Ended
	Mar. 13, 2023 USD ($)	Mar. 31, 2023 USD ($) Investments	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($) Investments	Dec. 31, 2021 USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Transfer, Amount	$ 23,000,000
Debt Securities, Held-To-Maturity, After Allowance For Credit Loss, Transfer, Amount	13,200,000
Allowance for Credit Losses	$ 800,000			$ 0
Debt Securities, Held-to-maturity, Allowance for Credit Loss		$ 700,000	$ 1,600,000	1,900,000	$ 0
Interest Receivable		113,700,000		118,300,000
Debt Securities, Available-for-sale, Realized Gain		0	0
Debt Securities, Available-for-sale, Realized Loss		(23,400,000)	$ 0
Securities Sold under Agreements to Repurchase, Fair Value of Collateral		3,607,300,000		4,998,900,000
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure		$ 3,228,500,000		$ 4,432,000,000
Investment securities in an unrealized loss position (securities) | Investments		1,023		1,222
Callable Within One Year
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost of investment securities callable after one year but within five years		$ 1,525,900,000
Fair value of investment securities callable after one year but within five years		1,446,900,000
Callable structured notes amortized costs		$ 0