Regulatory Matters (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Regulatory Matters [Abstract]
Required Reserve Balances with Federal Reserve Bank	$ 17,000	$ 16,300
Holding Company
Regulatory Capital Requirements
Common Equity Tier 1 Capital	$ 306,506	$ 288,416
Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets	12.90%	13.40%
Common Equity Tier 1 Risk Based Capital Required for Capital Adequacy	$ 106,801	$ 97,142
Common Equity Tier 1 Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Common Equity Tier 1 Risk Based Capital Required to be Well Capitalized	$ 154,268	$ 140,316
Common Equity Tier 1 Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Capital	$ 334,957	$ 313,974
Capital to Risk Weighted Assets	14.10%	14.50%
Capital Required for Capital Adequacy	$ 189,869	$ 172,697
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Capital Required to be Well Capitalized	$ 237,336	$ 215,871
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%	10.00%
Tier One Risk Based Capital	$ 313,430	$ 295,151
Tier One Risk Based Capital to Risk Weighted Assets	13.20%	13.70%
Tier One Risk Based Capital Required for Capital Adequacy	$ 142,402	$ 129,523
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	6.00%
Tier One Risk Based Capital Required to be Well Capitalized	$ 189,869	$ 172,697
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	8.00%	8.00%
Tier One Leverage Capital	$ 313,430	$ 295,151
Tier One Leverage Capital to Average Assets	9.70%	9.50%
Tier One Leverage Capital Required for Capital Adequacy	$ 129,803	$ 123,973
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Tier One Leverage Capital Required to be Well Capitalized	$ 162,254	$ 154,967
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	5.00%	5.00%
Risk Weighted Assets	$ 2,373,359	$ 2,158,713
Bank
Regulatory Capital Requirements
Common Equity Tier 1 Capital	$ 271,319	$ 257,045
Common Equity Tier 1 Risk Based Capital to Risk Weighted Assets	11.50%	11.90%
Common Equity Tier 1 Risk Based Capital Required for Capital Adequacy	$ 106,474	$ 96,974
Common Equity Tier 1 Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Common Equity Tier 1 Risk Based Capital Required to be Well Capitalized	$ 153,795	$ 140,074
Common Equity Tier 1 Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Capital	$ 309,749	$ 293,823
Capital to Risk Weighted Assets	13.10%	13.60%
Capital Required for Capital Adequacy	$ 189,287	$ 172,399
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Capital Required to be Well Capitalized	$ 236,608	$ 215,499
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%	10.00%
Tier One Risk Based Capital	$ 291,319	$ 277,045
Tier One Risk Based Capital to Risk Weighted Assets	12.30%	12.90%
Tier One Risk Based Capital Required for Capital Adequacy	$ 141,965	$ 129,299
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	6.00%
Tier One Risk Based Capital Required to be Well Capitalized	$ 189,287	$ 172,399
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	8.00%	8.00%
Tier One Leverage Capital	$ 291,319	$ 277,045
Tier One Leverage Capital to Average Assets	9.00%	9.00%
Tier One Leverage Capital Required for Capital Adequacy	$ 129,633	$ 123,742
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Tier One Leverage Capital Required to be Well Capitalized	$ 162,041	$ 154,677
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	5.00%	5.00%
Risk Weighted Assets	$ 2,366,082	$ 2,154,985