Loans Held for Investment - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) area grade	Dec. 31, 2015 USD ($)	Mar. 31, 2015 USD ($)
Receivables [Abstract]
Secured loans limit to one borrower	$ 125,200
Unsecured loans limit to one borrower	75,000
Aggregate outstanding balance of loans to one borrower of secured credit	26,400
Total purchase credit impaired	9,595
Purchased credit impaired loans, nonaccrual status	1,800
Nonaccruing loans	$ 3,054	$ 2,736	$ 2,742
Number of areas where the entity's credit quality is maintained and credit risk managed | area	2
Number of Pass scale grades | grade	6