Loans Held for Investment (Details 5) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013 item	Dec. 31, 2012	Jun. 30, 2012
Loans Held for Investment
Number of areas where the entity's credit quality is maintained and credit risk managed	2
Number of Pass scale grades	6
Credit Risk Grades
Total Gross Loans	$ 1,059,957	$ 986,194	$ 798,352
Business loans: Commercial and industrial
Credit Risk Grades
Total Gross Loans	146,240	115,354	84,191
Business loans: Commercial owner occupied
Credit Risk Grades
Total Gross Loans	201,802	150,934	150,428
Business loans: SBA
Credit Risk Grades
Total Gross Loans	5,820	6,882	3,995
Business loans: Warehouse facilities
Credit Risk Grades
Total Gross Loans	135,317	195,761	61,111
Real estate loans: Commercial non-owner occupied
Credit Risk Grades
Total Gross Loans	295,767	253,409	242,700
Real estate loans: Multi-family
Credit Risk Grades
Total Gross Loans	172,797	156,424	183,742
Real estate loans: One-to-four family
Credit Risk Grades
Total Gross Loans	84,672	97,463	56,694
Real estate loans: Construction
Credit Risk Grades
Total Gross Loans	2,135		281
Real estate loans: Land
Credit Risk Grades
Total Gross Loans	10,438	8,774	11,191
Other loans
Credit Risk Grades
Total Gross Loans	4,969	1,193	4,019
Pass
Credit Risk Grades
Total Gross Loans	1,031,298	940,393	752,138
Pass | Business loans: Commercial and industrial
Credit Risk Grades
Total Gross Loans	143,034	111,895	81,359
Pass | Business loans: Commercial owner occupied
Credit Risk Grades
Total Gross Loans	186,271	136,330	134,749
Pass | Business loans: SBA
Credit Risk Grades
Total Gross Loans	5,820	6,819	3,858
Pass | Business loans: Warehouse facilities
Credit Risk Grades
Total Gross Loans	135,317	195,761	61,111
Pass | Real estate loans: Commercial non-owner occupied
Credit Risk Grades
Total Gross Loans	289,210	240,585	236,685
Pass | Real estate loans: Multi-family
Credit Risk Grades
Total Gross Loans	170,726	143,003	166,309
Pass | Real estate loans: One-to-four family
Credit Risk Grades
Total Gross Loans	83,395	96,061	55,303
Pass | Real estate loans: Construction
Credit Risk Grades
Total Gross Loans	2,135		281
Pass | Real estate loans: Land
Credit Risk Grades
Total Gross Loans	10,430	8,762	8,591
Pass | Other loans
Credit Risk Grades
Total Gross Loans	4,960	1,177	3,892
Special Mention
Credit Risk Grades
Total Gross Loans	3,257	15,036	16,355
Special Mention | Business loans: Commercial and industrial
Credit Risk Grades
Total Gross Loans	88	92	1,753
Special Mention | Business loans: Commercial owner occupied
Credit Risk Grades
Total Gross Loans	2,298	2,674	4,036
Special Mention | Real estate loans: Commercial non-owner occupied
Credit Risk Grades
Total Gross Loans	356	687	668
Special Mention | Real estate loans: Multi-family
Credit Risk Grades
Total Gross Loans	515	11,583	9,898
Substandard
Credit Risk Grades
Total Gross Loans	25,402	30,765	29,859
Substandard | Business loans: Commercial and industrial
Credit Risk Grades
Total Gross Loans	3,118	3,367	1,079
Substandard | Business loans: Commercial owner occupied
Credit Risk Grades
Total Gross Loans	13,233	11,930	11,643
Substandard | Business loans: SBA
Credit Risk Grades
Total Gross Loans		63	137
Substandard | Real estate loans: Commercial non-owner occupied
Credit Risk Grades
Total Gross Loans	6,201	12,137	5,347
Substandard | Real estate loans: Multi-family
Credit Risk Grades
Total Gross Loans	1,556	1,838	7,535
Substandard | Real estate loans: One-to-four family
Credit Risk Grades
Total Gross Loans	1,277	1,402	1,391
Substandard | Real estate loans: Land
Credit Risk Grades
Total Gross Loans	8	12	2,600
Substandard | Other loans
Credit Risk Grades
Total Gross Loans	$ 9	$ 16	$ 127