Loans Held for Investment (Details 4) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014 item	Dec. 31, 2013	Sep. 30, 2013
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	$ 1,547,911	$ 1,243,252	$ 1,142,015
Business loans: Commercial and industrial
Credit Risk Grades
Total Gross Loans	360,700	187,035	173,720
Business loans: Commercial owner occupied
Credit Risk Grades
Total Gross Loans	237,996	221,089	222,162
Business loans: SBA
Credit Risk Grades
Total Gross Loans	20,482	10,659	6,455
Business loans: Warehouse facilities
Credit Risk Grades
Total Gross Loans	108,093	87,517	49,104
Real estate loans: Commercial non-owner occupied
Credit Risk Grades
Total Gross Loans	355,984	333,544	304,979
Real estate loans: Multi-family
Credit Risk Grades
Total Gross Loans	262,588	233,689	218,929
Real estate loans: One-to-four family
Credit Risk Grades
Total Gross Loans	125,326	145,235	152,667
Real estate loans: Construction
Credit Risk Grades
Total Gross Loans	67,118	13,040	2,835
Real estate loans: Land
Credit Risk Grades
Total Gross Loans	6,103	7,605	7,371
Other loans
Credit Risk Grades
Total Gross Loans	3,521	3,839	3,793
Pass
Credit Risk Grades
Total Gross Loans	1,529,964	1,221,125	1,117,312
Pass | Business loans: Commercial and industrial
Credit Risk Grades
Total Gross Loans	358,922	184,247	170,840
Pass | Business loans: Commercial owner occupied
Credit Risk Grades
Total Gross Loans	228,154	207,872	207,519
Pass | Business loans: SBA
Credit Risk Grades
Total Gross Loans	20,482	10,659	6,455
Pass | Business loans: Warehouse facilities
Credit Risk Grades
Total Gross Loans	108,093	87,517	49,104
Pass | Real estate loans: Commercial non-owner occupied
Credit Risk Grades
Total Gross Loans	351,614	329,538	299,940
Pass | Real estate loans: Multi-family
Credit Risk Grades
Total Gross Loans	261,574	232,661	217,897
Pass | Real estate loans: One-to-four family
Credit Risk Grades
Total Gross Loans	124,383	144,152	151,564
Pass | Real estate loans: Construction
Credit Risk Grades
Total Gross Loans	67,118	13,040	2,835
Pass | Real estate loans: Land
Credit Risk Grades
Total Gross Loans	6,103	7,605	7,371
Pass | Other loans
Credit Risk Grades
Total Gross Loans	3,521	3,834	3,787
Special Mention
Credit Risk Grades
Total Gross Loans	891	2,092	3,568
Special Mention | Business loans: Commercial and industrial
Credit Risk Grades
Total Gross Loans		12	68
Special Mention | Business loans: Commercial owner occupied
Credit Risk Grades
Total Gross Loans	387	1,217	2,632
Special Mention | Real estate loans: Commercial non-owner occupied
Credit Risk Grades
Total Gross Loans		352	355
Special Mention | Real estate loans: Multi-family
Credit Risk Grades
Total Gross Loans	504	511	513
Substandard
Credit Risk Grades
Total Gross Loans	17,056	20,035	21,135
Substandard | Business loans: Commercial and industrial
Credit Risk Grades
Total Gross Loans	1,778	2,776	2,812
Substandard | Business loans: Commercial owner occupied
Credit Risk Grades
Total Gross Loans	9,455	12,000	12,011
Substandard | Real estate loans: Commercial non-owner occupied
Credit Risk Grades
Total Gross Loans	4,370	3,654	4,684
Substandard | Real estate loans: Multi-family
Credit Risk Grades
Total Gross Loans	510	517	519
Substandard | Real estate loans: One-to-four family
Credit Risk Grades
Total Gross Loans	943	1,083	1,103
Substandard | Other loans
Credit Risk Grades
Total Gross Loans		$ 5	$ 6