Loans and Allowance for Loan Losses (Loan Aging Analysis by Portfolio Segment (Including Loans Past Due Over Ninety Days and Non Accrual Loans) and Summary of Non Accrual Loans) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 25,465	$ 23,212
Current	2,569,099	2,466,994
Total loan balances	2,594,564	2,490,206	$ 1,772,610
Non-Accrual Loans	20,713	18,322
Residential real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,611	9,973
Current	796,883	810,644
Total loan balances	802,494	820,617	585,468
Non-Accrual Loans	3,945	7,253
Commercial real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	13,703	8,230
Current	1,037,077	919,721
Total loan balances	1,050,780	927,951	640,661
Non-Accrual Loans	12,849	4,529
Commercial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,526	1,819
Current	331,113	295,902
Total loan balances	333,639	297,721	257,515
Non-Accrual Loans	2,088	4,489
Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,347	2,788
Current	327,560	345,846
Total loan balances	329,907	348,634	271,709
Non-Accrual Loans	1,620	1,933
Consumer loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	42	237
Current	17,290	17,716
Total loan balances	17,332	17,953	$ 17,257
Non-Accrual Loans	4	118
HPFC Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,236	165
Current	59,176	77,165
Total loan balances	60,412	77,330
Non-Accrual Loans	207
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	18,639	10,286
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,904	6,077
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	12,625	1,584
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,675	1,002
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,321	1,505
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4	118
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | HPFC Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	110
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,187	4,195
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	924	571
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	223	2,427
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	218	550
Financing Receivables, 60 to 89 Days Past Due [Member] | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	134	640
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		7
Financing Receivables, 60 to 89 Days Past Due [Member] | HPFC Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	688
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,639	8,731
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,783	3,325
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	855	4,219
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	633	267
Financing Receivables, 30 to 59 Days Past Due [Member] | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	892	643
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	38	112
Financing Receivables, 30 to 59 Days Past Due [Member] | HPFC Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 438	$ 165