Loans Held for Investment - Purchased Credit Impaired Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Loans Held for Investment
Total purchase credit impaired	$ 9,721	$ 4,559
Commercial and industrial
Loans Held for Investment
Total purchase credit impaired	3,679	2,586
Commercial owner occupied
Loans Held for Investment
Total purchase credit impaired	3,208	491
SBA
Loans Held for Investment
Total purchase credit impaired	361	0
Commercial non-owner occupied
Loans Held for Investment
Total purchase credit impaired	1,151	1,088
Multi-family
Loans Held for Investment
Total purchase credit impaired	237	0
One-to-four family
Loans Held for Investment
Total purchase credit impaired	262	1
Construction
Loans Held for Investment
Total purchase credit impaired	549	0
Other loans
Loans Held for Investment
Total purchase credit impaired	$ 274	$ 393