Loans and Leases (Details 8) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	$ 134,275	$ 139,456		$ 139,456
Reserve for Unfunded Loan Commitments, Balance, beginning of period	32,861	28,635	$ 17,763	28,635	$ 17,523
Allowance for Credit Losses, Balance, beginning of period	167,136	168,091	179,070	168,091	174,761
Allowance for Loan and Lease Losses, Charge-offs	(18,235)			(30,388)
Reserve for Unfunded Loan Commitments, Charge-offs	0		0	0	0
Allowance for Credit Losses, Charge-offs	(18,235)		(26,410)	(30,388)	(49,568)
Allowance for Loan and Lease Loss, Recoveries	1,099			8,297
Reserve for Unfunded Loan Commitments, Recoveries	0		0	0	0
Allowance for Credit Losses, Recoveries	1,099		2,062	8,297	4,801
Allowance for Loan and Lease Losses, Net charge-offs	(17,136)		(24,348)	(22,091)	(44,767)
Reserve for Unfunded Loan Commitments, Net charge-offs	0		0	0	0
Allowance For Credit Losses, Net charge-offs	(17,136)		(24,348)	(22,091)	(44,767)
Allowance for Loan and Lease Losses, Provision (negative provision)	15,000			14,774
Reserve for Unfunded Commitments, Provision (negative provision)	(2,500)		(2,500)	(6,726)	(2,740)
Allowance for Credit Losses, Provision (negative provision)	17,500	4,000	11,499	21,500	36,227
Balance, end of period	132,139	134,275		132,139
Reserve for Unfunded Loan Commitments, Balance, end of period	35,361	32,861	20,263	35,361	20,263
Allowance for Credit Losses, Balance, end of period	167,500	167,136	166,221	167,500	166,221
Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period		133,012	149,826	133,012	143,755
Allowance for Credit Losses, Balance, beginning of period			167,589		161,278
Allowance for Loan and Lease Losses, Charge-offs			(22,951)		(43,879)
Allowance for Credit Losses, Charge-offs			(22,951)		(43,879)
Allowance for Loan and Lease Loss, Recoveries			2,004		4,743
Allowance for Credit Losses, Recoveries			2,004		4,743
Allowance for Loan and Lease Losses, Net charge-offs			(20,947)		(39,136)
Allowance For Credit Losses, Net charge-offs			(20,947)		(39,136)
Allowance for Loan and Lease Losses, Provision (negative provision)			10,000		34,260
Allowance for Credit Losses, Provision (negative provision)			12,500		37,000
Balance, end of period	138,879		138,879	138,879	138,879
Allowance for Credit Losses, Balance, end of period			159,142		159,142
Purchased Credit Impaired Loans and Leases
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period		$ 6,444		6,444
Balance, beginning of period			11,481		13,483
Allowance for Loan and Lease Losses, Charge-offs			(3,459)		(5,689)
Allowance for Loan and Lease Loss, Recoveries			58		58
Allowance for Loan and Lease Losses, Net charge-offs			(3,401)		(5,631)
Allowance for Loan and Lease Losses, Provision (negative provision)			(1,001)		(773)
Balance, end of period	$ 7,079		$ 7,079	$ 7,079	$ 7,079