Leases (Balance Sheet Classification) (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease assets	$ 104,289
Total lease assets	112,488
Operating lease liabilities	112,843
Finance lease liabilities	5,533
Total lease liabilities	118,376
Operating lease right-of use assets
Lessee, Lease, Description [Line Items]
Operating lease assets	104,289
Premises and equipment
Lessee, Lease, Description [Line Items]
Finance lease assets	8,199
Operating lease liabilities
Lessee, Lease, Description [Line Items]
Operating lease liabilities	112,843
Long-term debt and finance lease liabilities
Lessee, Lease, Description [Line Items]
Finance lease liabilities	$ 5,533