Delinquencies (Details 6) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Other information concerning the credit quality
Total	$ 2,118,323	$ 1,628,445	$ 1,466,350
Non-Accruing	4,382	1,444	1,941
Commercial and industrial
Other information concerning the credit quality
Total	454,463	428,207	319,541
Non-Accruing	2,147	0	24
Commercial owner occupied
Other information concerning the credit quality
Total	382,537	210,995	216,784
Non-Accruing	578	514	549
SBA
Other information concerning the credit quality
Total	50,306	28,404	15,115
Non-Accruing	0	0	0
Warehouse facilities
Other information concerning the credit quality
Total	198,113	113,798	114,032
Non-Accruing	0	0	0
Commercial non-owner occupied
Other information concerning the credit quality
Total	402,786	359,213	360,288
Non-Accruing	1,454	848	910
Multi-family
Other information concerning the credit quality
Total	400,237	262,965	251,512
Non-Accruing	0	0	0
One-to-four family
Other information concerning the credit quality
Total	84,283	122,795	132,020
Non-Accruing	88	82	458
Construction
Other information concerning the credit quality
Total	124,448	89,682	47,034
Non-Accruing	0	0	0
Land
Other information concerning the credit quality
Total	16,339	9,088	6,271
Non-Accruing	23	0	0
Other loans
Other information concerning the credit quality
Total	4,811	3,298	3,753
Non-Accruing	92	0	0
Current
Other information concerning the credit quality
Current	2,115,638	1,628,347	1,465,048
Current | Commercial and industrial
Other information concerning the credit quality
Current	452,383	428,183	319,418
Current | Commercial owner occupied
Other information concerning the credit quality
Current	382,537	210,995	216,367
Current | SBA
Other information concerning the credit quality
Current	50,306	28,404	15,115
Current | Warehouse facilities
Other information concerning the credit quality
Current	198,113	113,798	114,032
Current | Commercial non-owner occupied
Other information concerning the credit quality
Current	402,297	359,213	360,288
Current | Multi-family
Other information concerning the credit quality
Current	400,237	262,965	251,512
Current | One-to-four family
Other information concerning the credit quality
Current	84,218	122,722	131,258
Current | Construction
Other information concerning the credit quality
Current	124,448	89,682	47,034
Current | Land
Other information concerning the credit quality
Current	16,316	9,088	6,271
Current | Other loans
Other information concerning the credit quality
Current	4,783	3,297	3,753
30-59
Other information concerning the credit quality
Days Past Due	943	20	236
30-59 | Commercial and industrial
Other information concerning the credit quality
Days Past Due	452	0	0
30-59 | Commercial owner occupied
Other information concerning the credit quality
Days Past Due	0	0	0
30-59 | SBA
Other information concerning the credit quality
Days Past Due	0	0	0
30-59 | Warehouse facilities
Other information concerning the credit quality
Days Past Due	0	0	0
30-59 | Commercial non-owner occupied
Other information concerning the credit quality
Days Past Due	489	0	0
30-59 | Multi-family
Other information concerning the credit quality
Days Past Due	0	0	0
30-59 | One-to-four family
Other information concerning the credit quality
Days Past Due	2	19	236
30-59 | Construction
Other information concerning the credit quality
Days Past Due	0	0	0
30-59 | Land
Other information concerning the credit quality
Days Past Due	0	0	0
30-59 | Other loans
Other information concerning the credit quality
Days Past Due	0	1	0
60-89
Other information concerning the credit quality
Days Past Due	28	24	994
60-89 | Commercial and industrial
Other information concerning the credit quality
Days Past Due	0	24	99
60-89 | Commercial owner occupied
Other information concerning the credit quality
Days Past Due	0	0	417
60-89 | SBA
Other information concerning the credit quality
Days Past Due	0	0	0
60-89 | Warehouse facilities
Other information concerning the credit quality
Days Past Due	0	0	0
60-89 | Commercial non-owner occupied
Other information concerning the credit quality
Days Past Due	0	0	0
60-89 | Multi-family
Other information concerning the credit quality
Days Past Due	0	0	0
60-89 | One-to-four family
Other information concerning the credit quality
Days Past Due	0	0	478
60-89 | Construction
Other information concerning the credit quality
Days Past Due	0	0	0
60-89 | Land
Other information concerning the credit quality
Days Past Due	0	0	0
60-89 | Other loans
Other information concerning the credit quality
Days Past Due	28	0	0
90
Other information concerning the credit quality
Days Past Due	1,714	54	72
90 | Commercial and industrial
Other information concerning the credit quality
Days Past Due	1,628	0	24
90 | Commercial owner occupied
Other information concerning the credit quality
Days Past Due	0	0	0
90 | SBA
Other information concerning the credit quality
Days Past Due	0	0	0
90 | Warehouse facilities
Other information concerning the credit quality
Days Past Due	0	0	0
90 | Commercial non-owner occupied
Other information concerning the credit quality
Days Past Due	0	0	0
90 | Multi-family
Other information concerning the credit quality
Days Past Due	0	0	0
90 | One-to-four family
Other information concerning the credit quality
Days Past Due	63	54	48
90 | Construction
Other information concerning the credit quality
Days Past Due	0	0	0
90 | Land
Other information concerning the credit quality
Days Past Due	23	0	0
90 | Other loans
Other information concerning the credit quality
Days Past Due	$ 0	$ 0	$ 0