Loans and Leases - Commitments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Loans and leases
Loan and lease commitments	$ 5,791,088	$ 5,549,591
Real estate
Loans and leases
Loan and lease commitments	863,426	913,757
Commercial and Industrial
Loans and leases
Loan and lease commitments	2,559,014	2,484,857
Commercial Real Estate | Real estate
Loans and leases
Loan and lease commitments	134,523	114,186
Construction | Real estate
Loans and leases
Loan and lease commitments	687,925	526,938
Residential mortgage | Real estate
Loans and leases
Loan and lease commitments	329	121
Home Equity Line | Real estate
Loans and leases
Loan and lease commitments	863,097	913,636
Consumer
Loans and leases
Loan and lease commitments	$ 1,546,200	$ 1,509,853