Loans and Leases (Details 8) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	$ 135,037	$ 132,139	$ 132,472
Charge-offs	(6,501)	(3,308)	(27,603)
Recoveries	2,016	1,589	11,683
Allowance for Loan and Lease Losses, Net charge-offs	(4,485)	(1,719)	(15,920)
Provision	8,000	11,500	22,000
Balance, end of period	138,552	141,920	138,552	$ 141,920
The ending balance of the loan and lease portfolio is composed of loans and leases:
Ending balance of loans and leases	18,735,543		18,735,543		$ 17,957,713
Non Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	135,037	132,139	132,472	139,456
Charge-offs	(6,501)	(3,308)	(27,603)	(33,696)
Recoveries	2,016	1,589	11,683	9,886
Allowance for Loan and Lease Losses, Net charge-offs				(23,810)
Provision	8,000	11,500	22,000	26,274
Balance, end of period	138,552	141,920	138,552	141,920
Amount of the allowance applicable to loans and leases:
Individually evaluated for impairment	9,330	20,859	9,330	20,859
Collectively evaluated for impairment	129,222	121,061	129,222	121,061
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated for impairment	110,620	130,011	110,620	130,011
Collectively evaluated for impairment	18,624,923	17,100,135	18,624,923	17,100,135
Ending balance of loans and leases	18,735,543	17,230,146	18,735,543	17,230,146	17,957,713
Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period				6,400
Real Estate Mortgage
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for Loan and Lease Losses, Net charge-offs	(25)	(504)	(372)	(6,072)
The ending balance of the loan and lease portfolio is composed of loans and leases:
Ending balance of loans and leases	7,896,924		7,896,924		7,918,141
Real Estate Mortgage \| Non Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	46,826	45,467	46,021	40,051
Charge-offs	(120)	(726)	(850)	(8,071)
Recoveries	95	222	478	1,999
Provision	(1,655)	1,394	(503)	12,378
Balance, end of period	45,146	46,357	45,146	46,357
Amount of the allowance applicable to loans and leases:
Individually evaluated for impairment	248	496	248	496
Collectively evaluated for impairment	44,898	45,861	44,898	45,861
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated for impairment	29,808	44,985	29,808	44,985
Collectively evaluated for impairment	7,867,116	7,633,675	7,867,116	7,633,675
Ending balance of loans and leases	7,896,924	7,678,660	7,896,924	7,678,660	7,918,141
Real Estate Construction and Land
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for Loan and Lease Losses, Net charge-offs	0	23	0	49
The ending balance of the loan and lease portfolio is composed of loans and leases:
Ending balance of loans and leases	2,551,474		2,551,474		2,233,656
Real Estate Construction and Land \| Non Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	26,378	26,210	28,209	13,055
Charge-offs	0	0	0	0
Recoveries	0	23	0	49
Provision	683	(47)	(1,148)	13,082
Balance, end of period	27,061	26,186	27,061	26,186
Amount of the allowance applicable to loans and leases:
Individually evaluated for impairment	0	0	0	0
Collectively evaluated for impairment	27,061	26,186	27,061	26,186
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated for impairment	5,357	5,533	5,357	5,533
Collectively evaluated for impairment	2,546,117	1,995,424	2,546,117	1,995,424
Ending balance of loans and leases	2,551,474	2,000,957	2,551,474	2,000,957	2,233,656
Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for Loan and Lease Losses, Net charge-offs	(4,123)	(1,069)	(14,867)	(17,619)
The ending balance of the loan and lease portfolio is composed of loans and leases:
Ending balance of loans and leases	7,878,557		7,878,557		7,404,595
Commercial \| Non Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	59,401	58,806	56,360	84,022
Charge-offs	(6,021)	(2,372)	(25,951)	(25,321)
Recoveries	1,898	1,303	11,084	7,702
Provision	8,907	9,907	22,692	1,241
Balance, end of period	64,185	67,644	64,185	67,644
Amount of the allowance applicable to loans and leases:
Individually evaluated for impairment	9,082	20,363	9,082	20,363
Collectively evaluated for impairment	55,103	47,281	55,103	47,281
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated for impairment	75,455	79,493	75,455	79,493
Collectively evaluated for impairment	7,803,102	7,072,565	7,803,102	7,072,565
Ending balance of loans and leases	7,878,557	7,152,058	7,878,557	7,152,058	7,404,595
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for Loan and Lease Losses, Net charge-offs	(337)	(169)	(681)	(168)
The ending balance of the loan and lease portfolio is composed of loans and leases:
Ending balance of loans and leases					401,321
Consumer \| Non Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	2,432	1,656	1,882	2,328
Charge-offs	(360)	(210)	(802)	(304)
Recoveries	23	41	121	136
Provision	65	246	959	(427)
Balance, end of period	2,160	1,733	2,160	1,733
Amount of the allowance applicable to loans and leases:
Individually evaluated for impairment	0	0	0	0
Collectively evaluated for impairment	2,160	1,733	2,160	1,733
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated for impairment	0	0	0	0
Collectively evaluated for impairment	408,588	398,471	408,588	398,471
Ending balance of loans and leases	408,588	398,471	408,588	398,471	$ 401,321
Non Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for Loan and Lease Losses, Net charge-offs	$ (4,485)	$ (1,719)	$ (15,920)	$ (23,810)

Financing Receivable, Allowance for Credit Loss, Additional Information, Portfolio Composition [Abstract]

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Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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