Securities - Summary of AFS Securities Portfolio (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	$ 357,552	$ 136,740
Gross Unrealized gains	3,195	1,881
Gross Unrealized losses	(188)	(351)
Securities available-for-sale (“AFS”)	360,559	138,270
U.S. Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	300	300
Securities available-for-sale (“AFS”)	300	300
FNMA and FHLB Agency Notes
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	16,167	10,496
Gross Unrealized gains	69
Gross Unrealized losses		(219)
Securities available-for-sale (“AFS”)	16,236	10,277
Agency Mortgage-backed Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	341,085	125,944
Gross Unrealized gains	3,126	1,881
Gross Unrealized losses	(188)	(132)
Securities available-for-sale (“AFS”)	$ 344,023	$ 127,693