Loans Held for Investment (Details 5) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 item	Dec. 31, 2012	Mar. 31, 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	$ 945,991	$ 986,194	$ 695,749
Business loans: Commercial and industrial
Credit Risk Grades
Total Gross Loans	140,592	115,354	83,947
Business loans: Commercial owner occupied
Credit Risk Grades
Total Gross Loans	166,571	150,934	146,904
Business loans: SBA
Credit Risk Grades
Total Gross Loans	5,116	6,882	3,948
Business loans: Warehouse facilities
Credit Risk Grades
Total Gross Loans	138,935	195,761	44,246
Real estate loans: Commercial non-owner occupied
Credit Risk Grades
Total Gross Loans	256,015	253,409	168,672
Real estate loans: Multi-family
Credit Risk Grades
Total Gross Loans	139,100	156,424	185,367
Real estate loans: One-to-four family
Credit Risk Grades
Total Gross Loans	87,109	97,463	52,280
Real estate loans: Land
Credit Risk Grades
Total Gross Loans	7,863	8,774	7,246
Other loans
Credit Risk Grades
Total Gross Loans	4,690	1,193	3,139
Pass
Credit Risk Grades
Total Gross Loans	913,266	940,393	661,285
Pass | Business loans: Commercial and industrial
Credit Risk Grades
Total Gross Loans	136,947	111,895	82,070
Pass | Business loans: Commercial owner occupied
Credit Risk Grades
Total Gross Loans	149,787	136,330	134,326
Pass | Business loans: SBA
Credit Risk Grades
Total Gross Loans	5,063	6,819	3,747
Pass | Business loans: Warehouse facilities
Credit Risk Grades
Total Gross Loans	138,935	195,761	44,246
Pass | Real estate loans: Commercial non-owner occupied
Credit Risk Grades
Total Gross Loans	247,140	240,585	165,237
Pass | Real estate loans: Multi-family
Credit Risk Grades
Total Gross Loans	137,014	143,003	170,714
Pass | Real estate loans: One-to-four family
Credit Risk Grades
Total Gross Loans	85,849	96,061	50,580
Pass | Real estate loans: Land
Credit Risk Grades
Total Gross Loans	7,853	8,762	7,246
Pass | Other loans
Credit Risk Grades
Total Gross Loans	4,678	1,177	3,119
Special Mention
Credit Risk Grades
Total Gross Loans	3,765	15,036	15,246
Special Mention | Business loans: Commercial and industrial
Credit Risk Grades
Total Gross Loans	96	92	864
Special Mention | Business loans: Commercial owner occupied
Credit Risk Grades
Total Gross Loans	2,792	2,674	3,778
Special Mention | Real estate loans: Commercial non-owner occupied
Credit Risk Grades
Total Gross Loans	360	687	672
Special Mention | Real estate loans: Multi-family
Credit Risk Grades
Total Gross Loans	517	11,583	9,932
Substandard
Credit Risk Grades
Total Gross Loans	28,960	30,765	19,218
Substandard | Business loans: Commercial and industrial
Credit Risk Grades
Total Gross Loans	3,549	3,367	1,013
Substandard | Business loans: Commercial owner occupied
Credit Risk Grades
Total Gross Loans	13,992	11,930	8,800
Substandard | Business loans: SBA
Credit Risk Grades
Total Gross Loans	53	63	201
Substandard | Real estate loans: Commercial non-owner occupied
Credit Risk Grades
Total Gross Loans	8,515	12,137	2,763
Substandard | Real estate loans: Multi-family
Credit Risk Grades
Total Gross Loans	1,569	1,838	4,721
Substandard | Real estate loans: One-to-four family
Credit Risk Grades
Total Gross Loans	1,260	1,402	1,700
Substandard | Real estate loans: Land
Credit Risk Grades
Total Gross Loans	10	12
Substandard | Other loans
Credit Risk Grades
Total Gross Loans	$ 12	$ 16	$ 20