Loans and Leases (Details 8) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	$ 139,456
Reserve for Unfunded Loan Commitments, Balance, beginning of period	28,635		$ 17,523
Allowance for Credit Losses, Balance, beginning of period	168,091		174,761
Allowance for Loan and Lease Losses, Charge-offs	12,153
Reserve for Unfunded Loan Commitments, Charge-offs	0		0
Allowance for Credit Losses, Charge-offs	(12,153)		(23,158)
Allowance for Loan and Lease Loss, Recoveries	7,198
Reserve for Unfunded Loan Commitments, Recoveries	0		0
Allowance for Credit Losses, Recoveries	7,198		2,739
Allowance for Loan and Lease Losses, Net charge-offs	(4,955)
Reserve for Unfunded Loan Commitments, Net charge-offs	0		0
Allowance For Credit Losses, Net charge-offs	(4,955)		(20,419)
Allowance for Loan and Lease Losses, Provision (negative provision)	(226)
Reserve for Unfunded Commitments, Provision (negative provision)	(4,226)		(240)
Allowance for Credit Losses, Provision (negative provision)	4,000	$ 6,406	24,728
Balance, end of period	134,275	139,456
Reserve for Unfunded Loan Commitments, Balance, end of period	32,861	28,635	17,763
Allowance for Credit Losses, Balance, end of period	167,136	168,091	179,070
Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	133,012		143,755
Allowance for Credit Losses, Balance, beginning of period			161,278
Allowance for Loan and Lease Losses, Charge-offs			20,928
Allowance for Credit Losses, Charge-offs			(20,928)
Allowance for Loan and Lease Loss, Recoveries			2,739
Allowance for Credit Losses, Recoveries			2,739
Allowance for Loan and Lease Losses, Net charge-offs			(18,189)
Allowance For Credit Losses, Net charge-offs			(18,189)
Allowance for Loan and Lease Losses, Provision (negative provision)			24,260
Allowance for Credit Losses, Provision (negative provision)			24,500
Balance, end of period		133,012	149,826
Allowance for Credit Losses, Balance, end of period			167,589
Purchased Credit Impaired Loans and Leases
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	$ 6,444
Balance, beginning of period			13,483
Allowance for Loan and Lease Losses, Charge-offs			2,230
Allowance for Loan and Lease Loss, Recoveries			0
Allowance for Loan and Lease Losses, Net charge-offs			(2,230)
Allowance for Loan and Lease Losses, Provision (negative provision)			228
Balance, end of period		$ 6,444
Balance, end of period			$ 11,481