Investment Securities, Available-for-sale Securities, Maturities (Details) $ in Thousands	Sep. 30, 2016 USD ($)
Amortized Cost [Abstract]
Due in one year or less	$ 1,406
Due in one year through five years	142,461
Due after five years through ten years	15,139
Due after ten years	9
Amortized Cost	650,144
Fair Value [Abstract]
Due in one year or less	1,408
Due in one year through five years	142,415
Due after five years through ten years	15,140
Due after ten years	9
Fair Value	654,467
Mortgage-Backed Securities and Collateralized Mortgage Obligations-Residential [Member]
Amortized Cost [Abstract]
Securities, amortized cost	396,647
Fair Value [Abstract]
Securities, fair value	400,575
Small Business Administration-Guaranteed Participation Securities [Member]
Amortized Cost [Abstract]
Securities, amortized cost	84,268
Fair Value [Abstract]
Securities, fair value	84,687
Mortgage-Backed Securities and Collateralized Mortgage Obligations-Commercial [Member]
Amortized Cost [Abstract]
Securities, amortized cost	10,214
Fair Value [Abstract]
Securities, fair value	$ 10,233