Investment Securities, Available-for-sale Securities, Gross Unrealized Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Available for sale securities unrealized loss position - Fair Value [Abstract]
Less than 12 months - Fair Value	$ 85,273	$ 242,473
12 months or more - Fair Value	20,470	264,996
Total - Fair Value	105,743	507,468
Available for sale securities unrealized loss position - Gross Unrealized Loss [Abstract]
Less than 12 months - Gross Unrealized Loss	222	2,501
12 months or more - Gross Unrealized Loss	140	5,452
Total - Gross Unrealized Loss	362	7,953
U. S. Government Sponsored Enterprises [Member]
Available for sale securities unrealized loss position - Fair Value [Abstract]
Less than 12 months - Fair Value	14,996	41,786
12 months or more - Fair Value	0	9,932
Total - Fair Value	14,996	51,718
Available for sale securities unrealized loss position - Gross Unrealized Loss [Abstract]
Less than 12 months - Gross Unrealized Loss	4	113
12 months or more - Gross Unrealized Loss	0	68
Total - Gross Unrealized Loss	4	181
Mortgage Backed Securities and Collateralized Mortgage Obligations-Residential [Member]
Available for sale securities unrealized loss position - Fair Value [Abstract]
Less than 12 months - Fair Value	29,252	187,605
12 months or more - Fair Value	5,138	167,549
Total - Fair Value	34,390	355,153
Available for sale securities unrealized loss position - Gross Unrealized Loss [Abstract]
Less than 12 months - Gross Unrealized Loss	116	2,147
12 months or more - Gross Unrealized Loss	28	3,179
Total - Gross Unrealized Loss	144	5,326
Corporate Bonds [Member]
Available for sale securities unrealized loss position - Fair Value [Abstract]
Less than 12 months - Fair Value	41,025
12 months or more - Fair Value	0
Total - Fair Value	41,025
Available for sale securities unrealized loss position - Gross Unrealized Loss [Abstract]
Less than 12 months - Gross Unrealized Loss	102
12 months or more - Gross Unrealized Loss	0
Total - Gross Unrealized Loss	102
Small Business Administration-Guaranteed Participation Securities [Member]
Available for sale securities unrealized loss position - Fair Value [Abstract]
Less than 12 months - Fair Value	0	7,529
12 months or more - Fair Value	15,332	82,888
Total - Fair Value	15,332	90,417
Available for sale securities unrealized loss position - Gross Unrealized Loss [Abstract]
Less than 12 months - Gross Unrealized Loss	0	111
12 months or more - Gross Unrealized Loss	112	2,093
Total - Gross Unrealized Loss	$ 112	2,204
Mortgage Backed Securities and Collateralized Mortgage Obligations-Commercial [Member]
Available for sale securities unrealized loss position - Fair Value [Abstract]
Less than 12 months - Fair Value		5,553
12 months or more - Fair Value		4,627
Total - Fair Value		10,180
Available for sale securities unrealized loss position - Gross Unrealized Loss [Abstract]
Less than 12 months - Gross Unrealized Loss		130
12 months or more - Gross Unrealized Loss		112
Total - Gross Unrealized Loss		$ 242