Mergers and Acquisitions - Narrative (Details) $ in Thousands	Feb. 12, 2024 USD ($) loan	Jan. 24, 2024 USD ($)	Jan. 11, 2023 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jan. 31, 2022
Business Acquisition [Line Items]
Depositary share, interest in a share of preferred stock							0.025
Goodwill				$ 2,868,068	$ 2,631,465	$ 2,514,104
Loans held for sale ($323 and $2,610 valued under fair value option)				239,763	$ 6,541
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Mortgage Servicing Portfolio
Business Acquisition [Line Items]
Proceeds from Divestiture of Businesses	$ 18,400
Mortgage Loans, Derecognition Of Mortgage Servicing Rights	$ 6,700
Number Of Mortgage Loans | loan	9,184
Mortgage Loans, Unpaid Principal Balance	$ 1,400,000
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 11,700
Disposal Group, Held-for-Sale, Not Discontinued Operations | Commercial Services Business
Business Acquisition [Line Items]
Loans held for sale ($323 and $2,610 valued under fair value option)				49,700
Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Costs, Related Assets And Liabilities To Be Sold				$ 220,200
interLINK
Business Acquisition [Line Items]
Equity interests acquired			100.00%
Goodwill			$ 143,200
Cash consideration			158,600
Business Combination, Consideration Transferred			174,600
Contingent consideration			16,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Acquired Including Goodwill			31,400
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Royalty Liabilities			15,900
interLINK | Broker Dealer Relationship
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles			36,000
interLINK | Non Competition Agreement
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles			4,000
interLINK | Developed Technology Rights
Business Acquisition [Line Items]
Intangible assets acquired			$ 6,000
Ametros
Business Acquisition [Line Items]
Equity interests acquired		99.40%
Goodwill		$ 228,185
Cash consideration		359,700
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		152,439
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue		20,391
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Members Funds		288,167
Business Combinations, Recognized Identifiable Assets Acquired And Liabilities Assumed, Operating Lease Liabilities		838
Business Combinations, Recognized Identifiable Assets Acquired And Liabilities Assumed, Accrued Expenses		$ 4,270