Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Troubled Debt Restructuring Subsequently Defaulted (Details) - Troubled Debt Restructurings that Subsequently Defaulted [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($) Contract	Sep. 30, 2016 USD ($) Contract
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	6	1
Recorded Investment | $	$ 64	$ 101
Commercial and Industrial [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	2	0
Recorded Investment | $	$ 0	$ 0
Secured by 1-4 Family Residential Properties [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	4	1
Recorded Investment | $	$ 64	$ 101