Securities Continuous Unrealized Loss (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 64,655	$ 129,858
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	593	3,512
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	57,416	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	1,598	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	122,071	129,858
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	2,191	3,512
US Government and Government Agencies and Authorities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	9,871	20,352
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	67	973
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	15,655	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	587	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	25,526	20,352
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	654	973
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	46,620	89,062
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	375	1,805
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	34,051	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	799	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	80,671	89,062
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	1,174	1,805
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	8,164	20,444
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	151	734
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	7,710	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	212	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	15,874	20,444
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	$ 363	$ 734