Loans and Leases - Commitments (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Loans and leases
Loan and lease commitments	$ 5,179,570	$ 5,192,874
Real estate
Loans and leases
Loan and lease commitments	1,519,886	1,481,722
Commercial and Industrial
Loans and leases
Loan and lease commitments	2,194,182	2,262,712
Commercial Real Estate | Real estate
Loans and leases
Loan and lease commitments	74,193	46,812
Construction | Real estate
Loans and leases
Loan and lease commitments	495,320	480,926
Residential | Real estate
Loans and leases
Loan and lease commitments	950,373	953,984
Consumer
Loans and leases
Loan and lease commitments	1,465,486	1,448,336
Lease Financing
Loans and leases
Loan and lease commitments	$ 16	$ 104