Loans (Past Due Loans) (Details) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		$ 21,255	$ 17,559
Current		3,160,100	2,995,568
Total loans	[1]	3,181,355	3,013,127
Commercial Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		10,352	4,555
Current		1,075,823	927,398
Total loans		1,086,175	931,953
Commercial Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	0
Current		98,735	122,297
Total loans		98,735	122,297
Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		1,047	462
Current		571,258	599,835
Total loans		572,305	600,297
Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		8,291	9,286
Current		1,044,538	975,151
Total loans		1,052,829	984,437
Homeowner Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	0
Current		27,058	29,118
Total loans		27,058	29,118
Home Equity Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		110	1,774
Current		265,128	253,791
Total loans		265,238	255,565
Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		1,309	1,460
Current		36,955	45,189
Total loans		38,264	46,649
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		146	22
Current		40,605	42,789
Total loans		40,751	42,811
30-59
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		3,294	5,137
30-59 | Commercial Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	51
30-59 | Commercial Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	0
30-59 | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	405
30-59 | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		2,737	3,028
30-59 | Homeowner Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	0
30-59 | Home Equity Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		110	883
30-59 | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		412	748
30-59 | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		35	22
60-89
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		3,525	3,836
60-89 | Commercial Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		2,497	0
60-89 | Commercial Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	0
60-89 | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	9
60-89 | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		860	2,964
60-89 | Homeowner Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	0
60-89 | Home Equity Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	373
60-89 | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		166	490
60-89 | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		2	0
Over 90
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		14,436	8,586
Over 90 | Commercial Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		7,855	4,504
Over 90 | Commercial Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	0
Over 90 | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		1,047	48
Over 90 | Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		4,694	3,294
Over 90 | Homeowner Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	0
Over 90 | Home Equity Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		0	518
Over 90 | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		731	222
Over 90 | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		$ 109	$ 0

[1] Includes net unamortized loan origination costs of $2.8 million and $2.6 million, respectively, at September 30, 2016 and December 31, 2015 and net unamortized premiums on purchased loans of $641 thousand and $84 thousand, respectively, at September 30, 2016 and December 31, 2015.