Loans Held for Investment (Details 5) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Other information concerning the credit quality
Current	$ 1,323,892	$ 1,241,140	$ 942,975
30-59 Days Past Due	118	969	58
60-89 Days Past Due	32		1,077
90+ Days Past Due	1,427	1,143	1,881
Total	1,325,469	1,243,252	945,991
Non-Accruing	2,674	2,251	3,102
Business loans: Commercial and industrial
Other information concerning the credit quality
Current	271,845	187,035	140,365
30-59 Days Past Due			9
60-89 Days Past Due	32
90+ Days Past Due			218
Total	271,877	187,035	140,592
Non-Accruing	31		333
Business loans: Commercial owner occupied
Other information concerning the credit quality
Current	223,402	219,875	166,326
30-59 Days Past Due		768
90+ Days Past Due	446	446	245
Total	223,848	221,089	166,571
Non-Accruing	864	747	245
Business loans: SBA
Other information concerning the credit quality
Current	10,985	10,645	5,044
30-59 Days Past Due	46
90+ Days Past Due	14	14	72
Total	11,045	10,659	5,116
Non-Accruing	14	14	121
Business loans: Warehouse facilities
Other information concerning the credit quality
Current	81,033	87,517	138,935
Total	81,033	87,517	138,935
Real estate loans: Commercial non-owner occupied
Other information concerning the credit quality
Current	332,572	332,984	254,678
90+ Days Past Due	918	560	1,337
Total	333,490	333,544	256,015
Non-Accruing	1,327	983	1,974
Real estate loans: Multi-family
Other information concerning the credit quality
Current	223,200	233,689	138,053
60-89 Days Past Due			1,047
Total	223,200	233,689	139,100
Real estate loans: One-to-four family
Other information concerning the credit quality
Current	141,348	145,041	87,021
30-59 Days Past Due	72	71	49
60-89 Days Past Due			30
90+ Days Past Due	49	123	9
Total	141,469	145,235	87,109
Non-Accruing	438	507	429
Real estate loans: Construction
Other information concerning the credit quality
Current	29,857	13,040
Total	29,857	13,040
Real estate loans: Land
Other information concerning the credit quality
Current	6,170	7,605	7,863
Total	6,170	7,605	7,863
Other loans
Other information concerning the credit quality
Current	3,480	3,709	4,690
30-59 Days Past Due		130
Total	$ 3,480	$ 3,839	$ 4,690