Borrowings and Subordinated Debentures Borrowings and Subordinated Debentures (Details 1) $ in Thousands, € in Millions		12 Months Ended
		Dec. 31, 2018 USD ($)	Dec. 31, 2018 EUR (€)	Dec. 31, 2017 USD ($)
Subordinated Borrowing [Line Items]
Long-term Debt, Gross		$ 541,344		$ 555,146
Debt Instrument, Unamortized Discount	[1]	(87,498)		(92,709)
Subordinated debentures		$ 453,846		$ 462,437
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		2.56%	2.56%	1.39%
Debt Instrument Date Issued		Jun. 30, 2006
Debt Instrument, Maturity Date		Sep. 18, 2036
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 1.85
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		5.89%	5.89%	4.70%
Debt Instrument Date Issued		Aug. 15, 2003
Debt Instrument, Maturity Date		Sep. 17, 2033
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 3.10
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		5.84%	5.84%	4.64%
Debt Instrument Date Issued		Sep. 03, 2003
Debt Instrument, Maturity Date		Sep. 15, 2033
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 3.05
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		5.74%	5.74%	4.55%
Debt Instrument Date Issued		Sep. 17, 2003
Debt Instrument, Maturity Date		Sep. 17, 2033
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 2.95
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		5.27%	5.27%	4.13%
Debt Instrument Date Issued		Feb. 05, 2004
Debt Instrument, Maturity Date		Apr. 23, 2034
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 2.75
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		4.48%	4.48%	3.28%
Debt Instrument Date Issued		Aug. 15, 2005
Debt Instrument, Maturity Date		Sep. 15, 2035
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 1.69
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		4.39%	4.39%	3.19%
Debt Instrument Date Issued		Jan. 25, 2007
Debt Instrument, Maturity Date		Mar. 15, 2037
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 1.60
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		4.34%	4.34%	3.14%
Debt Instrument Date Issued		Sep. 30, 2005
Debt Instrument, Maturity Date		Dec. 15, 2035
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 1.55
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		4.74%	4.74%	3.54%
Debt Instrument Date Issued		Nov. 21, 2005
Debt Instrument, Maturity Date		Dec. 15, 2035
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 1.95
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		4.47%	4.47%	3.33%
Debt Instrument Date Issued		Dec. 14, 2005
Debt Instrument, Maturity Date		Jan. 30, 2036
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 1.95
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		4.47%	4.47%	3.33%
Debt Instrument Date Issued		Feb. 22, 2006
Debt Instrument, Maturity Date		Apr. 30, 2036
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 1.95
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		4.47%	4.47%	3.33%
Debt Instrument Date Issued		Sep. 27, 2006
Debt Instrument, Maturity Date		Oct. 30, 2036
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 1.95
Trust Preferred Securities Two Thousand Six Series Three [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross	[2]	$ 29,556		$ 30,986
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		1.73%	1.73%	1.72%
Debt Instrument Date Issued		Sep. 29, 2006
Debt Instrument, Maturity Date		Oct. 30, 2036
Debt Instrument, Basis Spread on Variable Rate		3-month EURIBOR + 2.05
Liability, Reporting Currency Denominated, Value | €			€ 25.8
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		4.47%	4.47%	3.33%
Debt Instrument Date Issued		Dec. 05, 2006
Debt Instrument, Maturity Date		Jan. 30, 2037
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 1.95
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		4.47%	4.47%	3.33%
Debt Instrument Date Issued		Dec. 19, 2006
Debt Instrument, Maturity Date		Jan. 30, 2037
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 1.95
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		4.47%	4.47%	3.33%
Debt Instrument Date Issued		Jun. 13, 2007
Debt Instrument, Maturity Date		Jul. 30, 2037
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 1.95
Subordinated Debentures Trust I Due March 2035 [Domain]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross	[3]	$ 0		$ 6,186
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate				3.64%
Debt Instrument Date Issued		Dec. 10, 2004
Debt Instrument, Maturity Date		Mar. 15, 2035
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 2.05
Subordinated Debentures Trust II Due March 2036 [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross	[3]	$ 0		$ 3,093
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate				3.34%
Debt Instrument Date Issued		Dec. 23, 2005
Debt Instrument, Maturity Date		Mar. 15, 2036
Debt Instrument, Basis Spread on Variable Rate		3-month LIBOR + 1.75
Subordinated Debentures Trust III Due September 2036 [Member]
Subordinated Borrowing [Line Items]
Long-term Debt, Gross	[3]	$ 0		$ 3,093
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate				3.44%
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%
London Interbank Offered Rate (LIBOR) [Member] | Subordinated Debentures Trust I Due March 2035 [Domain]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		2.05%
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		0.00%	0.00%
London Interbank Offered Rate (LIBOR) [Member] | Subordinated Debentures Trust II Due March 2036 [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.75%
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		0.00%	0.00%
London Interbank Offered Rate (LIBOR) [Member] | Subordinated Debentures Trust III Due September 2036 [Member]
Subordinated Borrowing [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.85%
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		0.00%	0.00%
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%

[1] Amount represents the fair value adjustment on trust preferred securities assumed in acquisitions.

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

[3] Amount represents the fair value adjustment on trust preferred securities assumed in acquisitions.