Borrowings and Subordinated Debentures Borrowings and Subordinated Debentures (Details 1) $ in Thousands, € in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Dec. 31, 2019 USD ($)
Subordinated Borrowing [Line Items]
Subordinated Debentures	$ 465,812		$ 458,209
Subordinated debentures	$ 465,800
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	0.00%	0.00%	1.64%
Subordinated Debentures, Gross	$ 543,275		$ 540,690
Trust Preferred Securities Two Thousand Six Series Three [Member]
Subordinated Borrowing [Line Items]
Liability, Reporting Currency Denominated, Value | €		€ 25.8
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%
Subordinated Debt
Subordinated Borrowing [Line Items]
Debt Instrument, Unamortized Discount	$ (77,463)		$ (82,481)
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	2.24%	2.24%	3.87%
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	3.33%	3.33%	5.00%
Debt Instrument Date Issued	Aug. 15, 2003
Debt Instrument, Maturity Date	Sep. 17, 2033
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	3.27%	3.27%	4.94%
Debt Instrument Date Issued	Sep. 03, 2003
Debt Instrument, Maturity Date	Sep. 15, 2033
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +
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	3.18%	3.18%	4.85%
Debt Instrument Date Issued	Sep. 17, 2003
Debt Instrument, Maturity Date	Sep. 17, 2033
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +
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	2.96%	2.96%	4.69%
Debt Instrument Date Issued	Feb. 05, 2004
Debt Instrument, Maturity Date	Apr. 23, 2034
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +
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	1.91%	1.91%	3.58%
Debt Instrument Date Issued	Aug. 15, 2005
Debt Instrument, Maturity Date	Sep. 15, 2035
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +
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	1.82%	1.82%	3.49%
Debt Instrument Date Issued	Jan. 25, 2007
Debt Instrument, Maturity Date	Mar. 15, 2037
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +
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	1.77%	1.77%	3.44%
Debt Instrument Date Issued	Sep. 30, 2005
Debt Instrument, Maturity Date	Dec. 15, 2035
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +
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	2.17%	2.17%	3.85%
Debt Instrument Date Issued	Nov. 21, 2005
Debt Instrument, Maturity Date	Dec. 15, 2035
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +
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	2.16%	2.16%	3.89%
Debt Instrument Date Issued	Dec. 14, 2005
Debt Instrument, Maturity Date	Jan. 30, 2036
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +
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	2.16%	2.16%	3.89%
Debt Instrument Date Issued	Feb. 22, 2006
Debt Instrument, Maturity Date	Apr. 30, 2036
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +
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	2.16%	2.16%	3.89%
Debt Instrument Date Issued	Sep. 27, 2006
Debt Instrument, Maturity Date	Oct. 30, 2036
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +
Subordinated Debt | Trust Preferred Securities Two Thousand Six Series Three [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross	$ 31,487		$ 28,902
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	1.54%	1.54%	1.64%
Debt Instrument Date Issued	Sep. 29, 2006
Debt Instrument, Maturity Date	Oct. 30, 2036
Debt Instrument, Basis Spread on Variable Rate	3-month EURIBOR +
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	2.16%	2.16%	3.89%
Debt Instrument Date Issued	Dec. 05, 2006
Debt Instrument, Maturity Date	Jan. 30, 2037
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +
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	2.16%	2.16%	3.89%
Debt Instrument Date Issued	Dec. 19, 2006
Debt Instrument, Maturity Date	Jan. 30, 2037
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +
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	2.16%	2.16%	3.89%
Debt Instrument Date Issued	Jun. 13, 2007
Debt Instrument, Maturity Date	Jul. 30, 2037
Debt Instrument, Basis Spread on Variable Rate	3-month LIBOR +