LHFI and Allowance for Loan Losses, LHFI - Troubled Debt Restructuring Subsequently Defaulted (Details) - Troubled Debt Restructurings that Subsequently Defaulted [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) Contract	Dec. 31, 2016 USD ($) Contract	Dec. 31, 2015 USD ($) Contract
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	7	3	5
Recorded Investment | $	$ 9,604	$ 2,154	$ 260
Commercial and Industrial [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	3	2
Recorded Investment | $	$ 9,526	$ 2,154
Secured by 1-4 Family Residential Properties [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	4	1	5
Recorded Investment | $	$ 78		$ 260