Loans and Leases - Commitments (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Loans and leases
Loan and lease commitments	$ 5,468,976	$ 5,549,591
Real estate
Loans and leases
Loan and lease commitments	894,641	913,757
Commercial and Industrial
Loans and leases
Loan and lease commitments	2,384,738	2,484,857
Commercial Real Estate | Real estate
Loans and leases
Loan and lease commitments	132,701	114,186
Construction | Real estate
Loans and leases
Loan and lease commitments	529,679	526,938
Residential | Real estate
Loans and leases
Loan and lease commitments	479	121
Home Equity Line | Real estate
Loans and leases
Loan and lease commitments	894,162	913,636
Consumer
Loans and leases
Loan and lease commitments	$ 1,527,217	$ 1,509,853