Loans and Leases (Details 7 - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Financing Receivable, Modifications [Line Items]
Allowance for loan and lease losses	$ 143,289		$ 143,289			$ 115,111
Loans and Leases Receivable, Net of Deferred Income	14,641,460		14,641,460			14,478,254
Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Modifications [Line Items]
Allowance for loan and lease losses	132,000	$ 85,047	132,000	$ 85,047	$ 120,807	105,534	$ 79,680	$ 70,456
Allowance for Loan and Lease Losses, Write-offs	(1,712)	(623)	(7,085)	(10,534)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	1,280	1,990	2,761	4,521
Provision for Loan and Lease Losses	11,625	4,000	30,790	20,604
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	29,056	15,008	29,056	15,008
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	102,944	70,039	102,944	70,039
Financing Receivable, Individually Evaluated for Impairment	198,423	166,767	198,423	166,767
Financing Receivable, Collectively Evaluated for Impairment	14,306,157	11,644,784	14,306,157	11,644,784
Loans and Leases Receivable, Net of Deferred Income	14,504,580	11,811,551	14,504,580	11,811,551		14,289,209
Purchased Credit Impaired Loans and Leases
Financing Receivable, Modifications [Line Items]
Allowance for loan and lease losses	11,289		11,289			9,577
Loans and Leases Receivable, Allowance, PCI	11,289	14,328	11,289	14,328	9,554	9,577	12,698	13,999
Allowance for Loan and Lease Losses, Write-offs	168	0	(331)	(579)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	0	101	0	112
Provision for Loan and Lease Losses	1,903	1,529	2,043	796
Receivables Acquired With Deteriorated Credit Quality, Allowance For Credit Losses	11,289	14,328	11,289	14,328
Receivables Acquired with Deteriorated Credit Quality	136,880	222,638	136,880	222,638
Loans and Leases Receivable, Net of Deferred Income	136,880	222,638	136,880	222,638		189,045
NonPCI and PCI Loans
Financing Receivable, Modifications [Line Items]
Loans and Leases Receivable Allowance NonPCi and PCI	143,289	99,375	143,289	99,375	130,361	115,111	92,378	84,455
Allowance for Loan and Lease Losses, Write-offs	(1,880)	(623)	(7,416)	(11,113)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	1,280	2,091	2,761	4,633
Provision for Loan and Lease Losses	13,528	5,529	32,833	21,400
Loans and Leases Receivable Net Of Deferred Income NonPCI and PCI	14,641,460	12,034,189	14,641,460	12,034,189
Mortgage Loans on Real Estate | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Modifications [Line Items]
Allowance for loan and lease losses	29,331	29,908	29,331	29,908	29,099	36,654	30,911	25,097
Allowance for Loan and Lease Losses, Write-offs	(866)	(62)	(1,603)	(1,515)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	939	200	1,938	1,495
Provision for Loan and Lease Losses	159	(1,141)	(7,658)	4,831
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	1,230	1,461	1,230	1,461
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	28,101	28,447	28,101	28,447
Financing Receivable, Individually Evaluated for Impairment	92,284	56,297	92,284	56,297
Financing Receivable, Collectively Evaluated for Impairment	5,471,096	5,354,134	5,471,096	5,354,134
Loans and Leases Receivable, Net of Deferred Income	5,563,380	5,410,431	5,563,380	5,410,431		5,688,063
Real Estate Construction | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Modifications [Line Items]
Allowance for loan and lease losses	7,853	3,908	7,853	3,908	6,876	7,137	2,173	4,248
Allowance for Loan and Lease Losses, Write-offs	0	0	0	0
Allowance for Loan and Lease Loss, Recovery of Bad Debts	6	12	158	644
Provision for Loan and Lease Losses	971	1,723	558	(984)
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	16	49	16	49
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	7,837	3,859	7,837	3,859
Financing Receivable, Individually Evaluated for Impairment	7,498	8,118	7,498	8,118
Financing Receivable, Collectively Evaluated for Impairment	688,735	340,621	688,735	340,621
Loans and Leases Receivable, Net of Deferred Income	696,233	348,739	696,233	348,739		527,720
Commercial Portfolio Segment | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Modifications [Line Items]
Allowance for loan and lease losses	93,404	50,531	93,404	50,531	83,957	61,082	45,794	39,858
Allowance for Loan and Lease Losses, Write-offs	(655)	(534)	(4,700)	(8,929)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	312	1,744	626	2,154
Provision for Loan and Lease Losses	9,790	3,527	36,396	17,448
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	27,624	13,305	27,624	13,305
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	65,780	37,226	65,780	37,226
Financing Receivable, Individually Evaluated for Impairment	98,247	98,767	98,247	98,767
Financing Receivable, Collectively Evaluated for Impairment	7,934,086	5,867,335	7,934,086	5,867,335
Loans and Leases Receivable, Net of Deferred Income	8,032,333	5,966,102	8,032,333	5,966,102		7,952,577
Consumer Portfolio Segment | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Modifications [Line Items]
Allowance for loan and lease losses	1,412	700	1,412	700	$ 875	661	$ 802	$ 1,253
Allowance for Loan and Lease Losses, Write-offs	(191)	(27)	(782)	(90)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	23	34	39	228
Provision for Loan and Lease Losses	705	(109)	1,494	(691)
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	186	193	186	193
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	1,226	507	1,226	507
Financing Receivable, Individually Evaluated for Impairment	394	3,585	394	3,585
Financing Receivable, Collectively Evaluated for Impairment	212,240	82,694	212,240	82,694
Loans and Leases Receivable, Net of Deferred Income	$ 212,634	$ 86,279	$ 212,634	$ 86,279		$ 120,849