Loans and Allowance for Credit Losses Troubled Debt Restructurings (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	$ 61,605	$ 66,379
Non-accrual TDRs	28,659	29,051
Total TDRs	90,264	95,430
Residential Mortgage
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	24,102	26,016
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	15,685	13,959
Commercial - secured
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	5,143	10,820
Real estate – home equity
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	16,665	15,558
Consumer - direct
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	$ 10	$ 26