Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Impact of Modifications Classified as Troubled Debt Restructurings (Details) - Troubled Debt Restructurings [Member] $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) Contract	Mar. 31, 2016 USD ($) Contract
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	8	2
Pre-Modification Outstanding Recorded Investment	$ 675	$ 71
Post-Modification Outstanding Recorded Investment	$ 663	$ 71
Secured by 1-4 Family Residential Properties [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	7	2
Pre-Modification Outstanding Recorded Investment	$ 334	$ 71
Post-Modification Outstanding Recorded Investment	$ 338	$ 71
Construction, Land Development and Other Land Loans [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	1
Pre-Modification Outstanding Recorded Investment	$ 341
Post-Modification Outstanding Recorded Investment	$ 325