Loans and Leases - Commitments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans and leases
Loan and lease commitments	$ 5,549,591	$ 5,401,763
Real estate
Loans and leases
Loan and lease commitments	913,757	980,792
Commercial and Industrial
Loans and leases
Loan and lease commitments	2,484,857	2,406,261
Commercial Real Estate | Real estate
Loans and leases
Loan and lease commitments	114,186	78,266
Construction | Real estate
Loans and leases
Loan and lease commitments	526,938	450,856
Residential | Real estate
Loans and leases
Loan and lease commitments	121	22
Home Equity Line | Real estate
Loans and leases
Loan and lease commitments	913,636	980,770
Consumer
Loans and leases
Loan and lease commitments	$ 1,509,853	$ 1,485,588