Loans and Leases (Details 4) - USD ($) $ in Thousands	Dec. 31, 2017		Dec. 31, 2016
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 155,784		$ 170,599
Impaired Financing Receivable Performing Restructured Loans	56,838		64,952
Impaired Financing Receivable, Recorded Investment	212,622		235,551
Non Purchased Credit Impaired Loans and Leases [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	155,784		170,599
Impaired Financing Receivable, Recorded Investment	212,622	[1]	235,551
Non Purchased Credit Impaired Loans and Leases [Member] | Mortgages [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	68,913		69,335
Impaired Financing Receivable Performing Restructured Loans	47,560		54,750
Impaired Financing Receivable, Recorded Investment	116,473	[1]	124,085
Non Purchased Credit Impaired Loans and Leases [Member] | Real Estate Construction [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	0		364
Impaired Financing Receivable Performing Restructured Loans	5,690		6,893
Impaired Financing Receivable, Recorded Investment	5,690	[1]	7,257
Non Purchased Credit Impaired Loans and Leases [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	86,851		100,561
Impaired Financing Receivable Performing Restructured Loans	3,488		3,157
Impaired Financing Receivable, Recorded Investment	90,339	[1]	103,718
Non Purchased Credit Impaired Loans and Leases [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	20		339
Impaired Financing Receivable Performing Restructured Loans	100		152
Impaired Financing Receivable, Recorded Investment	$ 120	[1]	$ 491

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