Loans Held for Investment (Details 6) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Other information concerning the credit quality
Current	$ 1,057,635	$ 985,303	$ 791,645
30-59 Days Past Due	669	106	399
60-89 Days Past Due	580	303	2,885
90+ Days Past Due	1,073	482	3,423
Total	1,059,957	986,194	798,352
Non-Accruing	2,032	2,206	8,426
Business loans: Commercial and industrial
Other information concerning the credit quality
Current	146,000	115,078	84,141
30-59 Days Past Due	7
60-89 Days Past Due	233	58	50
90+ Days Past Due		218
Total	146,240	115,354	84,191
Non-Accruing	96	347	9
Business loans: Commercial owner occupied
Other information concerning the credit quality
Current	201,162	150,689	148,900
30-59 Days Past Due	640
60-89 Days Past Due		245
90+ Days Past Due			1,528
Total	201,802	150,934	150,428
Non-Accruing		14	1,528
Business loans: SBA
Other information concerning the credit quality
Current	5,795	6,697	3,475
30-59 Days Past Due			46
60-89 Days Past Due	25
90+ Days Past Due		185	474
Total	5,820	6,882	3,995
Non-Accruing		260	503
Business loans: Warehouse facilities
Other information concerning the credit quality
Current	135,317	195,761	61,111
Total	135,317	195,761	61,111
Real estate loans: Commercial non-owner occupied
Other information concerning the credit quality
Current	295,767	253,409	241,290
30-59 Days Past Due			259
90+ Days Past Due			1,151
Total	295,767	253,409	242,700
Non-Accruing	450	670	2,094
Real estate loans: Multi-family
Other information concerning the credit quality
Current	171,762	156,424	180,907
60-89 Days Past Due			2,835
90+ Days Past Due	1,035
Total	172,797	156,424	183,742
Non-Accruing	1,035	266	3,115
Real estate loans: One-to-four family
Other information concerning the credit quality
Current	84,290	97,283	56,588
30-59 Days Past Due	22	101	93
60-89 Days Past Due	322
90+ Days Past Due	38	79	13
Total	84,672	97,463	56,694
Non-Accruing	451	522	486
Real estate loans: Construction
Other information concerning the credit quality
Current			281
Total	2,135		281
Real estate loans: Land
Other information concerning the credit quality
Current	10,438	8,774	10,934
90+ Days Past Due			257
Total	10,438	8,774	11,191
Non-Accruing		127	691
Other loans
Other information concerning the credit quality
Current	4,969	1,188	4,018
30-59 Days Past Due		5	1
Total	$ 4,969	$ 1,193	$ 4,019