Loans and Leases - Commitments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Loans and leases
Loan and lease commitments	$ 5,814,078	$ 5,549,591
Real estate
Loans and leases
Loan and lease commitments	1,045,782	913,757
Commercial and Industrial
Loans and leases
Loan and lease commitments	2,452,918	2,484,857
Commercial real estate | Real estate
Loans and leases
Loan and lease commitments	126,033	114,186
Construction | Real estate
Loans and leases
Loan and lease commitments	627,675	526,938
Residential mortgage | Real estate
Loans and leases
Loan and lease commitments	327	121
Home equity line | Real estate
Loans and leases
Loan and lease commitments	1,045,455	913,636
Consumer
Loans and leases
Loan and lease commitments	$ 1,561,670	$ 1,509,853