Loan and lease acquired with deteriorated credit quality [Abstract]

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The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and other-than-temporary impairments), for loans accounted for as debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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A valuation allowance for financing receivables that are expected to be uncollectible.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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Amount of direct write-downs of financing receivables charged against the allowance.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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No definition available.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

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Allowance for Loan and Lease Losses (Summary of Activity In Allowance for Loan and Lease Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans and Leases Evaluated for Impairment [Abstract]
Net Loans and Leases				$ 25,299,564	$ 23,374,932
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
ALLL for loans and leases acquired with deteriorated credit quality				223,712	221,893
PCI Loans				606,576	762,998	$ 809,169	$ 950,516
Commercial
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
PCI Loans				296,672	393,419
Non-PCI Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 211,867	$ 205,026	$ 189,904
Provisions	29,232	29,139	34,870
Charge-offs	(39,554)	(36,386)	(29,587)
Recoveries	13,023	14,088	9,839
Ending balance	214,568	211,867	205,026
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment				9,827	9,728
ALLL for loans and leases collectively evaluated for impairment				204,741	202,139
Total allowance for loan and lease losses	211,867	205,026	189,904	214,568	211,867	205,026	189,904
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment				146,430	155,646
Loans and leases collectively evaluated for impairment				24,770,270	22,678,181
Net Loans and Leases				24,916,700	22,833,827
Non-PCI Loans \| Commercial \| Construction and land development
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	24,470	28,877	16,288
Provisions	10,533	(4,329)	12,871
Charge-offs	(44)	(599)	(680)
Recoveries	311	521	398
Ending balance	35,270	24,470	28,877
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment				490	185
ALLL for loans and leases collectively evaluated for impairment				34,780	24,285
Total allowance for loan and lease losses	24,470	28,877	16,288	35,270	24,470	28,877	16,288
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment				2,175	788
Loans and leases collectively evaluated for impairment				755,679	668,427
Net Loans and Leases				757,854	669,215
Non-PCI Loans \| Commercial \| Mortgage
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	45,005	48,278	69,896
Provisions	(1,490)	(5,694)	(21,912)
Charge-offs	(1,140)	(421)	(987)
Recoveries	1,076	2,842	1,281
Ending balance	43,451	45,005	48,278
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment				2,671	3,648
ALLL for loans and leases collectively evaluated for impairment				40,780	41,357
Total allowance for loan and lease losses	45,005	48,278	69,896	43,451	45,005	48,278	69,896
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment				55,447	73,655
Loans and leases collectively evaluated for impairment				10,661,787	9,655,367
Net Loans and Leases				10,717,234	9,729,022
Non-PCI Loans \| Commercial \| Other commercial real estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	4,571	3,269	2,168
Provisions	(2,171)	1,280	925
Charge-offs	(69)	(5)	0
Recoveries	150	27	176
Ending balance	2,481	4,571	3,269
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment				42	209
ALLL for loans and leases collectively evaluated for impairment				2,439	4,362
Total allowance for loan and lease losses	4,571	3,269	2,168	2,481	4,571	3,269	2,168
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment				860	1,857
Loans and leases collectively evaluated for impairment				426,125	471,576
Net Loans and Leases				426,985	473,433
Non-PCI Loans \| Commercial \| Commercial and industrial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	59,824	56,132	48,640
Provisions	2,511	11,624	15,218
Charge-offs	(10,211)	(11,921)	(9,455)
Recoveries	3,496	3,989	1,729
Ending balance	55,620	59,824	56,132
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment				1,137	1,062
ALLL for loans and leases collectively evaluated for impairment				54,483	58,762
Total allowance for loan and lease losses	59,824	56,132	48,640	55,620	59,824	56,132	48,640
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment				9,868	9,888
Loans and leases collectively evaluated for impairment				3,928,862	3,615,320
Net Loans and Leases				3,938,730	3,625,208
Non-PCI Loans \| Commercial \| Other
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	4,689	3,127	1,855
Provisions	(2,827)	2,189	877
Charge-offs	(130)	(912)	(144)
Recoveries	489	285	539
Ending balance	2,221	4,689	3,127
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment				105	0
ALLL for loans and leases collectively evaluated for impairment				2,116	4,689
Total allowance for loan and lease losses	4,689	3,127	1,855	2,221	4,689	3,127	1,855
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment				291	521
Loans and leases collectively evaluated for impairment				296,133	301,655
Net Loans and Leases				296,424	302,176
Non-PCI Loans \| Noncommercial \| Construction and land development
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,962	1,596	1,485
Provisions	(1,520)	2,366	45
Charge-offs	(219)	0	0
Recoveries	127	0	66
Ending balance	2,350	3,962	1,596
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment				81	68
ALLL for loans and leases collectively evaluated for impairment				2,269	3,894
Total allowance for loan and lease losses	3,962	1,596	1,485	2,350	3,962	1,596	1,485
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment				3,749	4,551
Loans and leases collectively evaluated for impairment				253,281	243,738
Net Loans and Leases				257,030	248,289
Non-PCI Loans \| Noncommercial \| Mortgage
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	15,706	14,447	14,105
Provisions	897	2,096	801
Charge-offs	(1,689)	(1,376)	(926)
Recoveries	558	539	467
Ending balance	15,472	15,706	14,447
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment				1,901	2,733
ALLL for loans and leases collectively evaluated for impairment				13,571	12,973
Total allowance for loan and lease losses	15,706	14,447	14,105	15,472	15,706	14,447	14,105
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment				42,168	37,842
Loans and leases collectively evaluated for impairment				4,223,519	3,485,944
Net Loans and Leases				4,265,687	3,523,786
Non-PCI Loans \| Noncommercial \| Revolving mortgage
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	22,436	21,013	15,971
Provisions	1,112	2,509	7,413
Charge-offs	(3,235)	(2,368)	(3,287)
Recoveries	1,549	1,282	916
Ending balance	21,862	22,436	21,013
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment				2,515	1,085
ALLL for loans and leases collectively evaluated for impairment				19,347	21,351
Total allowance for loan and lease losses	22,436	21,013	15,971	21,862	22,436	21,013	15,971
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment				28,852	23,770
Loans and leases collectively evaluated for impairment				2,514,123	2,677,755
Net Loans and Leases				2,542,975	2,701,525
Non-PCI Loans \| Noncommercial \| Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	31,204	28,287	19,496
Provisions	22,187	17,098	18,632
Charge-offs	(22,817)	(18,784)	(14,108)
Recoveries	5,267	4,603	4,267
Ending balance	35,841	31,204	28,287
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment				885	738
ALLL for loans and leases collectively evaluated for impairment				34,956	30,466
Total allowance for loan and lease losses	31,204	28,287	19,496	35,841	31,204	28,287	19,496
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment				3,020	2,774
Loans and leases collectively evaluated for impairment				1,710,761	1,558,399
Net Loans and Leases				1,713,781	1,561,173
PCI Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	10,026	13,769	16,312
Provisions	(765)	(3,447)	(1,929)
Charge-offs	(117)	(296)	(614)
Recoveries	0	0	0
Ending balance	9,144	10,026	13,769
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
Total allowance for loan and lease losses	$ 10,026	$ 13,769	$ 16,312	$ 9,144	$ 10,026	$ 13,769	$ 16,312