Loans Held for Investment (Details 5) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Other information concerning the credit quality
Current	$ 1,465,048	$ 1,241,140	$ 1,057,635
30-59 Days Past Due	236	969	669
60-89 Days Past Due	994		580
90+ Days Past Due	72	1,143	1,073
Total	1,466,350	1,243,252	1,059,957
Non-Accruing	1,941	2,251	2,032
Business loans: Commercial and industrial
Other information concerning the credit quality
Current	319,418	187,035	146,000
30-59 Days Past Due			7
60-89 Days Past Due	99		233
90+ Days Past Due	24
Total	319,541	187,035	146,240
Non-Accruing	24		96
Business loans: Commercial owner occupied
Other information concerning the credit quality
Current	216,367	219,875	201,162
30-59 Days Past Due		768	640
60-89 Days Past Due	417
90+ Days Past Due		446
Total	216,784	221,089	201,802
Non-Accruing	549	747
Business loans: SBA
Other information concerning the credit quality
Current	15,115	10,645	5,795
60-89 Days Past Due			25
90+ Days Past Due		14
Total	15,115	10,659	5,820
Non-Accruing		14
Business loans: Warehouse facilities
Other information concerning the credit quality
Current	114,032	87,517	135,317
Total	114,032	87,517	135,317
Real estate loans: Commercial non-owner occupied
Other information concerning the credit quality
Current	360,288	332,984	295,767
90+ Days Past Due		560
Total	360,288	333,544	295,767
Non-Accruing	910	983	450
Real estate loans: Multi-family
Other information concerning the credit quality
Current	251,512	233,689	171,762
90+ Days Past Due			1,035
Total	251,512	233,689	172,797
Non-Accruing			1,035
Real estate loans: One-to-four family
Other information concerning the credit quality
Current	131,258	145,041	84,290
30-59 Days Past Due	236	71	22
60-89 Days Past Due	478		322
90+ Days Past Due	48	123	38
Total	132,020	145,235	84,672
Non-Accruing	458	507	451
Real estate loans: Construction
Other information concerning the credit quality
Current	47,034	13,040	2,135
Total	47,034	13,040	2,135
Real estate loans: Land
Other information concerning the credit quality
Current	6,271	7,605	10,438
Total	6,271	7,605	10,438
Other loans
Other information concerning the credit quality
Current	3,753	3,709	4,969
30-59 Days Past Due		130
Total	$ 3,753	$ 3,839	$ 4,969