Borrowings and Subordinated Debt - Subordinated Debentures (Details) $ in Thousands, € in Millions		3 Months Ended
		Mar. 31, 2026 USD ($) Rate		Dec. 31, 2025 USD ($)	Mar. 31, 2026 EUR (€)
Subordinated Borrowing [Line Items]
Subordinated Debentures, Gross		$ 1,015,970		$ 1,016,327
Subordinated debt		$ 954,072		$ 952,740
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		4.33%		4.47%	4.33%
Debt Issuance Costs, Gross		$ (3,100)		$ (3,300)
Subordinated Debt Trust V Due September 2033
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		3.10%
Subordinated Debt Trust VI Due September 2033
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		3.05%
Subordinated Debt Trust CII Due September 2033
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		2.95%
Subordinated Debt Trust VII Due April 2034
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		2.75%
Subordinated Debt Trust CIII Due September 2035
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		1.69%
Subordinated Debt Trust FCCI Due March 2037
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		1.60%
Subordinated Debt Trust FCBI Due December 2035
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		1.55%
Trust Preferred Securities Two Thousand Five Series One
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		1.95%
Trust Preferred Securities Two Thousand Five Series Two
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		1.95%
Two Thousand Six One Term Debt Securitization
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		1.95%
Two Thousand Six Two Term Debt Securitization
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		1.95%
Trust Preferred Securities Two Thousand Six Series Three
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		2.05%
Denomination value | €					€ 25.8
Trust Preferred Securities Two Thousand Six Series Four
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		1.95%
Trust Preferred Securities Two Thousand Six Series Five
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		1.95%
Two Thousand Seven One Term Debt Securitization
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		1.95%
PMB Statutory Trust III
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		3.40%
PMB CapitalTrust III
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		2.00%
Subordinated Notes
Subordinated Borrowing [Line Items]
Rate Index (Quarterly Reset)		4.195%		437.50%
Subordinated Debentures
Subordinated Borrowing [Line Items]
Unamortized discount	[1]	$ (61,898)		$ (63,587)
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		5.24%	[2]	5.35%	5.24%	[2]
Subordinated Debentures | Subordinated Debt Trust V Due September 2033
Subordinated Borrowing [Line Items]
Balance		$ 10,310		$ 10,310
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		7.04%	[2]	7.07%	7.04%	[2]
Subordinated Debentures | Subordinated Debt Trust VI Due September 2033
Subordinated Borrowing [Line Items]
Balance		$ 10,310		$ 10,310
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		6.99%	[2]	7.03%	6.99%	[2]
Subordinated Debentures | Subordinated Debt Trust CII Due September 2033
Subordinated Borrowing [Line Items]
Balance		$ 5,155		$ 5,155
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		6.89%	[2]	6.92%	6.89%	[2]
Subordinated Debentures | Subordinated Debt Trust VII Due April 2034
Subordinated Borrowing [Line Items]
Balance		$ 61,856		$ 61,856
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		6.68%	[2]	6.85%	6.68%	[2]
Subordinated Debentures | Subordinated Debt Trust CIII Due September 2035
Subordinated Borrowing [Line Items]
Balance		$ 20,619		$ 20,619
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		5.63%	[2]	5.67%	5.63%	[2]
Subordinated Debentures | Subordinated Debt Trust FCCI Due March 2037
Subordinated Borrowing [Line Items]
Balance		$ 16,495		$ 16,495
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		5.54%	[2]	5.58%	5.54%	[2]
Subordinated Debentures | Subordinated Debt Trust FCBI Due December 2035
Subordinated Borrowing [Line Items]
Balance		$ 10,310		$ 10,310
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		5.49%	[2]	5.53%	5.49%	[2]
Subordinated Debentures | Trust Preferred Securities Two Thousand Five Series One
Subordinated Borrowing [Line Items]
Balance		$ 82,475		$ 82,475
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		5.89%	[2]	5.93%	5.89%	[2]
Subordinated Debentures | Trust Preferred Securities Two Thousand Five Series Two
Subordinated Borrowing [Line Items]
Balance		$ 128,866		$ 128,866
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		5.88%	[2]	6.05%	5.88%	[2]
Subordinated Debentures | Two Thousand Six One Term Debt Securitization
Subordinated Borrowing [Line Items]
Balance		$ 51,545		$ 51,545
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		8.70%	[2]	9.20%	8.70%	[2]
Subordinated Debentures | Two Thousand Six Two Term Debt Securitization
Subordinated Borrowing [Line Items]
Balance		$ 51,550		$ 51,550
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		5.88%	[2]	6.05%	5.88%	[2]
Subordinated Debentures | Trust Preferred Securities Two Thousand Six Series Three
Subordinated Borrowing [Line Items]
Balance	[3]	$ 29,778		$ 30,275
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		4.08%	[2]	4.12%	4.08%	[2]
Subordinated Debentures | Trust Preferred Securities Two Thousand Six Series Four
Subordinated Borrowing [Line Items]
Balance		$ 16,470		$ 16,470
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		8.70%	[2]	9.20%	8.70%	[2]
Subordinated Debentures | Trust Preferred Securities Two Thousand Six Series Five
Subordinated Borrowing [Line Items]
Balance		$ 6,650		$ 6,650
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		5.88%	[2]	6.05%	5.88%	[2]
Subordinated Debentures | Two Thousand Seven One Term Debt Securitization
Subordinated Borrowing [Line Items]
Balance		$ 39,177		$ 39,177
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		5.88%	[2]	6.05%	5.88%	[2]
Subordinated Debentures | Subordinated notes due May 2031
Subordinated Borrowing [Line Items]
Balance	[4]	$ 381,877		$ 381,737
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate	[2],[5]	3.25%		3.25%	3.25%
Subordinated Debentures | Subordinated Notes Due October 30, 2030
Subordinated Borrowing [Line Items]
Balance		$ 75,000		$ 75,000
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate	[2],[6]	7.86%		8.05%	7.86%
Rate Index (Quarterly Reset) | Rate		4.195%
Subordinated Debentures | PMB Statutory Trust III
Subordinated Borrowing [Line Items]
Balance		$ 7,217		$ 7,217
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		7.37%		7.35%	7.37%
Subordinated Debentures | PMB CapitalTrust III
Subordinated Borrowing [Line Items]
Balance		$ 10,310		$ 10,310
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate		5.93%	[2]	6.15%	5.93%	[2]

[1] Amount represents the fair value adjustment on subordinated debt assumed in acquisitions.

[2] Rates do not include the effects of discounts and issuance costs.

[3] Denomination is in Euros with a value of €25.8 million

[4] Net of unamortized issuance costs of $3.1 million at March 31, 2026 and $3.3 million at December 31, 2025.

[5] The subordinated notes, which were issued at the Bank level rather than the holding company level, carried a fixed interest rate until May 1, 2026. On that date, the Company redeemed the outstanding principal amount of $385 million. The balance reflected in the table above differs from the redemption amount due to the carrying value of the subordinated notes, which includes the impact of unamortized debt issuance discount at the reporting date. For more information see “Note 17. Subsequent Events” in Item 1 of this Form 10‑Q.

[6] Interest rate was fixed at 4.375% until October 30, 2025, when it changed to a floating rate equal to 3-month Term SOFR, plus a spread of 419.5 basis points.