Loans and Allowance for Loan Losses (Activity in Allowance for Loan Losses by Portfolio Segment) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Reserve for unfunded commitments	$ 11,000	$ 22,000	$ 17,000
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	21,166,000	21,116,000	21,590,000
Loans charged off	(3,805,000)	(2,616,000)	(3,444,000)
Recoveries	486,000	728,000	746,000
Ending balance	23,116,000	21,166,000	21,116,000
Ending Balance: Individually evaluated for impairment	2,007,000	1,369,000	953,000
Ending Balance: Collectively evaluated for impairment	21,109,000	19,797,000	20,163,000
Ending Balance: Individually evaluated for impairment	20,254,000	15,235,000	12,924,000
Ending Balance: Collectively evaluated for impairment	2,574,310,000	2,474,971,000	1,759,686,000
Total loan balances	2,594,564,000	2,490,206,000	1,772,610,000
Provision for Loan and Lease Losses	5,269,000	1,938,000	2,224,000
Residential real estate loans
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	4,545,000	4,899,000	5,603,000
Loans charged off	(356,000)	(801,000)	(785,000)
Recoveries	95,000	55,000	165,000
Ending balance	4,160,000	4,545,000	4,899,000
Ending Balance: Individually evaluated for impairment	483,000	544,000	787,000
Ending Balance: Collectively evaluated for impairment	3,677,000	4,001,000	4,112,000
Ending Balance: Individually evaluated for impairment	4,348,000	6,026,000	6,411,000
Ending Balance: Collectively evaluated for impairment	798,146,000	814,591,000	579,057,000
Total loan balances	802,494,000	820,617,000	585,468,000
Provision for Loan and Lease Losses	(124,000)	392,000	(84,000)
Commercial real estate loans
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	10,432,000	7,951,000	7,206,000
Loans charged off	(315,000)	(481,000)	(361,000)
Recoveries	50,000	74,000	136,000
Ending balance	12,154,000	10,432,000	7,951,000
Ending Balance: Individually evaluated for impairment	1,373,000	644,000	78,000
Ending Balance: Collectively evaluated for impairment	10,781,000	9,788,000	7,873,000
Ending Balance: Individually evaluated for impairment	13,317,000	4,610,000	5,379,000
Ending Balance: Collectively evaluated for impairment	1,037,463,000	923,341,000	635,282,000
Total loan balances	1,050,780,000	927,951,000	640,661,000
Provision for Loan and Lease Losses	1,987,000	2,888,000	970,000
Commercial loans
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	3,241,000	3,354,000	3,388,000
Loans charged off	(2,218,000)	(655,000)	(1,544,000)
Recoveries	332,000	389,000	394,000
Ending balance	3,755,000	3,241,000	3,354,000
Ending Balance: Individually evaluated for impairment		92,000	10,000
Ending Balance: Collectively evaluated for impairment	3,755,000	3,149,000	3,344,000
Ending Balance: Individually evaluated for impairment	2,028,000	3,937,000	646,000
Ending Balance: Collectively evaluated for impairment	331,611,000	293,784,000	256,869,000
Total loan balances	333,639,000	297,721,000	257,515,000
Provision for Loan and Lease Losses	2,400,000	153,000	1,116,000
Home equity loans
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	2,731,000	2,247,000	2,403,000
Loans charged off	(308,000)	(525,000)	(611,000)
Recoveries	2,000	188,000	19,000
Ending balance	2,194,000	2,731,000	2,247,000
Ending Balance: Individually evaluated for impairment	86,000	89,000
Ending Balance: Collectively evaluated for impairment	2,108,000	2,642,000	2,247,000
Ending Balance: Individually evaluated for impairment	457,000	588,000	331,000
Ending Balance: Collectively evaluated for impairment	329,450,000	348,046,000	271,378,000
Total loan balances	329,907,000	348,634,000	271,709,000
Provision for Loan and Lease Losses	(231,000)	821,000	436,000
Consumer loans
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	193,000	281,000	319,000
Loans charged off	(101,000)	(154,000)	(143,000)
Recoveries	7,000	22,000	32,000
Ending balance	181,000	193,000	281,000
Ending Balance: Individually evaluated for impairment			78,000
Ending Balance: Collectively evaluated for impairment	181,000	193,000	203,000
Ending Balance: Individually evaluated for impairment	7,000	74,000	157,000
Ending Balance: Collectively evaluated for impairment	17,325,000	17,879,000	17,100,000
Total loan balances	17,332,000	17,953,000	17,257,000
Provision for Loan and Lease Losses	82,000	44,000	73,000
HPFC Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	24,000	0
Loans charged off	(507,000)
Ending balance	672,000	24,000	0
Ending Balance: Individually evaluated for impairment	65,000
Ending Balance: Collectively evaluated for impairment	607,000	24,000
Ending Balance: Individually evaluated for impairment	97,000
Ending Balance: Collectively evaluated for impairment	60,315,000	77,330,000
Total loan balances	60,412,000	77,330,000
Provision for Loan and Lease Losses	1,155,000	24,000
Unallocated
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	0	2,384,000	2,671,000
Ending balance	$ 0	0	2,384,000
Ending Balance: Collectively evaluated for impairment			2,384,000
Provision for Loan and Lease Losses		$ (2,384,000)	$ (287,000)