Loans and Allowance for Credit Losses Non-Performing Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Receivables [Abstract]
Non-accrual loans and leases	$ 127,141	$ 128,572
Loans and leases 90 days or more past due and still accruing	11,540	11,106
Total non-performing loans and leases	138,681	139,678
Other real estate owned (OREO)	9,012	10,518
Total non-performing assets	$ 147,693	$ 150,196