Loans and Leases (Details 7) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2017		Jun. 30, 2016	Jun. 30, 2017		Jun. 30, 2016	Dec. 31, 2016
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period				$ 157,238
Balance, end of period	$ 145,958			145,958
The ending balance of the loan and lease portfolio is composed of loans and leases:
Ending balance of loans and leases	15,543,457			15,543,457			$ 15,455,954
Non Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	149,826		$ 120,807	143,755		$ 105,534
Charge-offs	(22,951)		(1,712)	(43,879)		(7,085)
Recoveries	2,004		1,280	4,743		2,761
Provision	10,000		11,625	34,260		30,790
Balance, end of period	138,879		132,000	138,879		132,000
Amount of the allowance applicable to loans and leases:
impairment	13,312		29,056	13,312		29,056
impairment	125,567		102,944	125,567		102,944
The ending balance of the loan and lease portfolio is composed of loans and leases:
impairment	227,774		198,423	227,774		198,423
impairment	15,243,257		14,306,157	15,243,257		14,306,157
Ending balance of loans and leases	15,471,031	[1],[2]	14,504,580	15,471,031	[1],[2]	14,504,580	15,347,530
Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period				13,483
Balance, beginning of period	11,481		9,554	13,483		9,577
Charge-offs	(3,459)		(168)	(5,689)		(331)
Recoveries	58		0	58		0
Provision	(1,001)		1,903	(773)		2,043
Balance, end of period	7,079			7,079
Balance, end of period	7,079		11,289	7,079		11,289
Amount of the allowance applicable to loans and leases:
deteriorated credit quality	7,079		11,289	7,079		11,289
The ending balance of the loan and lease portfolio is composed of loans and leases:
deteriorated credit quality	72,426		136,880	72,426		136,880
Ending balance of loans and leases	72,426		136,880	72,426		136,880	108,424
NonPCI and PCI Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	161,307		130,361	157,238		115,111
Charge-offs	(26,410)		(1,880)	(49,568)		(7,416)
Recoveries	2,062		1,280	4,801		2,761
Provision	8,999		13,528	33,487		32,833
Balance, end of period	145,958		143,289	145,958		143,289
The ending balance of the loan and lease portfolio is composed of loans and leases:
Total loans and leases	15,543,457		14,641,460	15,543,457		14,641,460
Real Estate Mortgage | Non Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	35,368		29,099	37,765		36,654
Charge-offs	(142)		(866)	(1,686)		(1,603)
Recoveries	20		939	250		1,938
Provision	1,876		159	793		(7,658)
Balance, end of period	37,122		29,331	37,122		29,331
Amount of the allowance applicable to loans and leases:
impairment	1,415		1,230	1,415		1,230
impairment	35,707		28,101	35,707		28,101
The ending balance of the loan and lease portfolio is composed of loans and leases:
impairment	117,441		92,284	117,441		92,284
impairment	5,954,357		5,471,096	5,954,357		5,471,096
Ending balance of loans and leases	6,071,798	[1],[2]	5,563,380	6,071,798	[1],[2]	5,563,380	5,617,956
Real Estate Construction and Land | Non Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	10,476		6,876	10,045		7,137
Charge-offs	0		0	0		0
Recoveries	9		6	17		158
Provision	833		971	1,256		558
Balance, end of period	11,318		7,853	11,318		7,853
Amount of the allowance applicable to loans and leases:
impairment	0		16	0		16
impairment	11,318		7,837	11,318		7,837
The ending balance of the loan and lease portfolio is composed of loans and leases:
impairment	5,840		7,498	5,840		7,498
impairment	1,157,500		688,735	1,157,500		688,735
Ending balance of loans and leases	1,163,340	[1],[2]	696,233	1,163,340	[1],[2]	696,233	962,839
Commercial | Non Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	102,134		83,957	93,853		61,082
Charge-offs	(22,696)		(655)	(41,981)		(4,700)
Recoveries	1,953		312	4,401		626
Provision	6,973		9,790	32,091		36,396
Balance, end of period	88,364		93,404	88,364		93,404
Amount of the allowance applicable to loans and leases:
impairment	11,564		27,624	11,564		27,624
impairment	76,800		65,780	76,800		65,780
The ending balance of the loan and lease portfolio is composed of loans and leases:
impairment	104,008		98,247	104,008		98,247
impairment	7,733,659		7,934,086	7,733,659		7,934,086
Ending balance of loans and leases	7,837,667	[1],[2]	8,032,333	7,837,667	[1],[2]	8,032,333	8,391,560
Consumer | Non Purchased Credit Impaired Loans and Leases
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	1,848		875	2,092		661
Charge-offs	(113)		(191)	(212)		(782)
Recoveries	22		23	75		39
Provision	318		705	120		1,494
Balance, end of period	2,075		1,412	2,075		1,412
Amount of the allowance applicable to loans and leases:
impairment	333		186	333		186
impairment	1,742		1,226	1,742		1,226
The ending balance of the loan and lease portfolio is composed of loans and leases:
impairment	485		394	485		394
impairment	397,741		212,240	397,741		212,240
Ending balance of loans and leases	$ 398,226	[1]	$ 212,634	$ 398,226	[1]	$ 212,634	$ 375,175

[1] Excludes loans held for sale carried at lower of cost or fair value.

[2] Excludes loans held for sale carried at lower of cost or fair value.