Borrowings and Subordinated Debentures (Details 2) $ in Thousands, € in Millions		12 Months Ended
	Apr. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 EUR (€)	Dec. 31, 2020 USD ($)
Subordinated Borrowing [Line Items]
Subordinated debt		$ 863,283		$ 465,812
Subordinated debentures		$ 863,300
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		0.00%	0.00%	0.00%
Subordinated Debentures, Gross		$ 935,728		$ 543,275
Debt Issuance Costs, Gross		$ 5,400
Trust Preferred Securities Two Thousand Six Series Three [Member]
Subordinated Borrowing [Line Items]
Liability, Reporting Currency Denominated, Value | €			€ 25.8
Subordinated notes due May 2031
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		2.52%
April 30, 2021 Issuance
Subordinated Borrowing [Line Items]
Subordinated debentures	$ 400,000
Subordinated Borrowing, Interest Rate	3.25%
London Interbank Offered Rate (LIBOR) [Member] | Subordinated Debt Trust V Due September 2033 [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		3.10%
London Interbank Offered Rate (LIBOR) [Member] | Subordinated Debt Trust VI Due September 2033 [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		3.05%
London Interbank Offered Rate (LIBOR) [Member] | Subordinated Debt Trust CII Due September 2033 [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		2.95%
London Interbank Offered Rate (LIBOR) [Member] | Subordinated Debt Trust VII Due April 2034 [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		2.75%
London Interbank Offered Rate (LIBOR) [Member] | Subordinated Debt Trust CIII Due September 2035 [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.69%
London Interbank Offered Rate (LIBOR) [Member] | Subordinated Debt Trust FCCI Due March 2037 [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.60%
London Interbank Offered Rate (LIBOR) [Member] | Subordinated Debt Trust FCBI Due December 2035 [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.55%
London Interbank Offered Rate (LIBOR) [Member] | Trust Preferred Securities Two Thousand Five Series One [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.95%
London Interbank Offered Rate (LIBOR) [Member] | Trust Preferred Securities Two Thousand Five Series Two [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.95%
London Interbank Offered Rate (LIBOR) [Member] | Two Thousand Six One Term Debt Securitization [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.95%
London Interbank Offered Rate (LIBOR) [Member] | Two Thousand Six Two Term Debt Securitization [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.95%
London Interbank Offered Rate (LIBOR) [Member] | Trust Preferred Securities Two Thousand Six Series Four [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.95%
London Interbank Offered Rate (LIBOR) [Member] | Trust Preferred Securities Two Thousand Six Series Five [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.95%
London Interbank Offered Rate (LIBOR) [Member] | Two Thousand Seven One Term Debt Securitization [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.95%
Euribor Rate [Member] | Trust Preferred Securities Two Thousand Six Series Three [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		2.05%
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate | April 30, 2021 Issuance
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.52%
Subordinated Debt
Subordinated Borrowing [Line Items]
Debt Instrument, Unamortized Discount		$ (72,445)		$ (77,463)
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		2.64%	2.64%	2.24%
Subordinated Debt | Subordinated Debt Trust V Due September 2033 [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 10,310		$ 10,310
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		3.32%	3.32%	3.33%
Subordinated Debt | Subordinated Debt Trust VI Due September 2033 [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 10,310		$ 10,310
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		3.25%	3.25%	3.27%
Subordinated Debt | Subordinated Debt Trust CII Due September 2033 [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 5,155		$ 5,155
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		3.17%	3.17%	3.18%
Subordinated Debt | Subordinated Debt Trust VII Due April 2034 [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 61,856		$ 61,856
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		2.88%	2.88%	2.96%
Subordinated Debt | Subordinated Debt Trust CIII Due September 2035 [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 20,619		$ 20,619
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		1.89%	1.89%	1.91%
Subordinated Debt | Subordinated Debt Trust FCCI Due March 2037 [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 16,495		$ 16,495
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		1.80%	1.80%	1.82%
Subordinated Debt | Subordinated Debt Trust FCBI Due December 2035 [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 10,310		$ 10,310
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		1.75%	1.75%	1.77%
Subordinated Debt | Trust Preferred Securities Two Thousand Five Series One [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 82,475		$ 82,475
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		2.15%	2.15%	2.17%
Subordinated Debt | Trust Preferred Securities Two Thousand Five Series Two [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 128,866		$ 128,866
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		2.08%	2.08%	2.16%
Subordinated Debt | Two Thousand Six One Term Debt Securitization [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 51,545		$ 51,545
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		2.08%	2.08%	2.16%
Subordinated Debt | Two Thousand Six Two Term Debt Securitization [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 51,550		$ 51,550
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		2.08%	2.08%	2.16%
Subordinated Debt | Trust Preferred Securities Two Thousand Six Series Three [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 29,306		$ 31,487
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		1.49%	1.49%	1.54%
Subordinated Debt | Trust Preferred Securities Two Thousand Six Series Four [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 16,470		$ 16,470
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		2.08%	2.08%	2.16%
Subordinated Debt | Trust Preferred Securities Two Thousand Six Series Five [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 6,650		$ 6,650
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		2.08%	2.08%	2.16%
Subordinated Debt | Two Thousand Seven One Term Debt Securitization [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 39,177		$ 39,177
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		2.08%	2.08%	2.16%
Subordinated Debt | Subordinated notes due May 2031
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 394,634		$ 0
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		3.25%	3.25%	0.00%