Regulatory Matters (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments without Regulatory Approval	$ 92.3
Capital Ratios, Basel III, Capital Conservation Buffer	0.625%
Capital Ratios, Basel III, Capital Conservation Buffer, Year Two	1.25%
Capital Ratios, Basel III, Capital Conservation Buffer, Year Three	1.875%
Capital Ratios, Basel III, Capital Conservation Buffer, Year Four	2.50%
Regulatory buffer percentage	1.25%
Pennsylvania [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Leverage Ratio: Ratio	6.00%
Common Equity Tier 1 Risk-based Capital Ratio: Ratio	10.00%
Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Leverage Ratio: Ratio	9.64%	10.02%	[1]
Common Equity Tier 1 Risk-based Capital Ratio: Ratio	13.93%	14.29%	[2]
Common Equity Tier 1 Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	6.50%	6.50%	[2]
Tier 1 Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	8.00%	8.00%	[3]
Tier 1 Leverage Ratio: Well Capitalized Minimum: Ratio	5.00%	5.00%	[1]
Total Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	10.00%	10.00%	[4]
Capital ratios, capital conservation buffer	7.19%
Total Risk-based Capital Ratio: Adequately Capitalized Minimum: Ratio	8.00%	8.00%	[4]
Total Risk-based Capital Ratio: Ratio	15.19%	15.55%	[4]

[1] Tier 1 capital / average quarterly assets

[2] Common equity Tier 1 capital / total risk-weighted assets

[3] Tier 1 capital / total risk-weighted assets

[4] Total risk-based capital / total risk-weighted assets