Loans and Leases - Commitments (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Loans and leases
Loan and lease commitments	$ 5,121,811	$ 5,192,874
Real estate
Loans and leases
Loan and lease commitments	1,476,518	1,481,722
Commercial and Industrial
Loans and leases
Loan and lease commitments	2,185,810	2,262,712
Commercial Real Estate | Real estate
Loans and leases
Loan and lease commitments	88,331	46,812
Construction | Real estate
Loans and leases
Loan and lease commitments	434,406	480,926
Residential | Real estate
Loans and leases
Loan and lease commitments	953,781	953,984
Consumer
Loans and leases
Loan and lease commitments	1,459,467	1,448,336
Lease Financing
Loans and leases
Loan and lease commitments	$ 16	$ 104