Loans Held for Investment - Purchased Credit Impaired Loans (Details) $ in Thousands	Mar. 31, 2016 USD ($)
Loans Held for Investment
Total purchase credit impaired	$ 9,595
Commercial and industrial
Loans Held for Investment
Total purchase credit impaired	4,802
Commercial owner occupied
Loans Held for Investment
Total purchase credit impaired	1,993
Commercial non-owner occupied
Loans Held for Investment
Total purchase credit impaired	1,542
One-to-four family
Loans Held for Investment
Total purchase credit impaired	817
Other loans
Loans Held for Investment
Total purchase credit impaired	441
Canyon National
Loans Held for Investment
Total purchase credit impaired	1,506
Canyon National | Commercial and industrial
Loans Held for Investment
Total purchase credit impaired	89
Canyon National | Commercial owner occupied
Loans Held for Investment
Total purchase credit impaired	523
Canyon National | Commercial non-owner occupied
Loans Held for Investment
Total purchase credit impaired	894
Canyon National | One-to-four family
Loans Held for Investment
Total purchase credit impaired	0
Canyon National | Other loans
Loans Held for Investment
Total purchase credit impaired	0
IDPK
Loans Held for Investment
Total purchase credit impaired	1,163
IDPK | Commercial and industrial
Loans Held for Investment
Total purchase credit impaired	183
IDPK | Commercial owner occupied
Loans Held for Investment
Total purchase credit impaired	332
IDPK | Commercial non-owner occupied
Loans Held for Investment
Total purchase credit impaired	648
IDPK | One-to-four family
Loans Held for Investment
Total purchase credit impaired	0
IDPK | Other loans
Loans Held for Investment
Total purchase credit impaired	0
SCAF
Loans Held for Investment
Total purchase credit impaired	6,926
SCAF | Commercial and industrial
Loans Held for Investment
Total purchase credit impaired	4,530
SCAF | Commercial owner occupied
Loans Held for Investment
Total purchase credit impaired	1,138
SCAF | Commercial non-owner occupied
Loans Held for Investment
Total purchase credit impaired	0
SCAF | One-to-four family
Loans Held for Investment
Total purchase credit impaired	817
SCAF | Other loans
Loans Held for Investment
Total purchase credit impaired	$ 441