Loans and Leases - Remaining commitments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Loans and leases
Loan and lease commitments	$ 5,907,690	$ 5,549,591
Commercial and Industrial
Loans and leases
Loan and lease commitments	2,451,362	2,484,857
Commercial real estate | Real estate
Loans and leases
Loan and lease commitments	130,597	114,186
Construction | Real estate
Loans and leases
Loan and lease commitments	718,121	526,938
Residential | Real estate
Loans and leases
Loan and lease commitments	1,053,581	913,757
Consumer
Loans and leases
Loan and lease commitments	1,554,029	1,509,853
Residential mortgage | Residential | Real estate
Loans and leases
Loan and lease commitments	842	121
Home equity | Home equity Line | Real estate
Loans and leases
Loan and lease commitments	$ 1,052,739	$ 913,636