Age Analysis of Past Due Financing receivables (Details) $ in Thousands	Dec. 31, 2018 USD ($) loan	Dec. 31, 2017 USD ($) loan	Dec. 31, 2016 USD ($)
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	400	319
Number of Loans 60-89 Days | loan	56	48
Number of Loans 90 Days or More | loan	110	92
Number of Loans Total Past Due | loan	566	459
Principal Balance Total Past Due	$ 46,348	$ 48,746
Current	6,859,846	6,306,807
Total loans	6,906,194	6,355,553	$ 5,999,605	[1]
Recorded Investment >90 Days and Accruing	$ 5	$ 8
Commercial and Industrial [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	0	2
Number of Loans 60-89 Days | loan	4	2
Number of Loans 90 Days or More | loan	11	14
Number of Loans Total Past Due | loan	15	18
Principal Balance Total Past Due	$ 26,693	$ 32,572
Current	1,066,936	855,956
Total loans	1,093,629	888,528	902,053
Recorded Investment >90 Days and Accruing	$ 0	$ 0
Commercial Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	9	7
Number of Loans 60-89 Days | loan	0	0
Number of Loans 90 Days or More | loan	8	9
Number of Loans Total Past Due | loan	17	16
Principal Balance Total Past Due	$ 3,877	$ 4,853
Current	3,247,371	3,111,708
Total loans	3,251,248	3,116,561	3,010,798
Recorded Investment >90 Days and Accruing	$ 0	$ 0
Construction Loans [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	1	0
Number of Loans 60-89 Days | loan	0	0
Number of Loans 90 Days or More | loan	1	0
Number of Loans Total Past Due | loan	2	0
Principal Balance Total Past Due	$ 1,582	$ 0
Current	363,583	401,797
Total loans	365,165	401,797	320,391
Recorded Investment >90 Days and Accruing	$ 0	$ 0
Small Business [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	15	17
Number of Loans 60-89 Days | loan	19	11
Number of Loans 90 Days or More | loan	24	10
Number of Loans Total Past Due | loan	58	38
Principal Balance Total Past Due	$ 755	$ 540
Current	163,921	131,830
Total loans	164,676	132,370	122,726
Recorded Investment >90 Days and Accruing	$ 0	$ 0
Residential Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	23	6
Number of Loans 60-89 Days | loan	6	13
Number of Loans 90 Days or More | loan	25	22
Number of Loans Total Past Due | loan	54	41
Principal Balance Total Past Due	$ 8,389	$ 6,726
Current	914,905	747,603
Total loans	923,294	754,329	644,426
Recorded Investment >90 Days and Accruing	$ 0	$ 0
Home Equity [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	22	22
Number of Loans 60-89 Days | loan	12	6
Number of Loans 90 Days or More | loan	29	20
Number of Loans Total Past Due | loan	63	48
Principal Balance Total Past Due	$ 4,849	$ 3,786
Current	1,087,235	1,048,302
Total loans	1,092,084	1,052,088	988,147
Recorded Investment >90 Days and Accruing	$ 0	$ 0
Consumer Portfolio Segment [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	330	265
Number of Loans 60-89 Days | loan	15	16
Number of Loans 90 Days or More | loan	12	17
Number of Loans Total Past Due | loan	357	298
Principal Balance Total Past Due	$ 203	$ 269
Current	15,895	9,611
Total loans	16,098	9,880	$ 11,064
Recorded Investment >90 Days and Accruing	5	8
Financing Receivables, 30 to 59 Days Past Due [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	8,402	5,971
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial and Industrial [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	0	195
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	1,627	3,060
Financing Receivables, 30 to 59 Days Past Due [Member] | Construction Loans [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	1,271	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Small Business [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	506	339
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	3,486	870
Financing Receivables, 30 to 59 Days Past Due [Member] | Home Equity [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	1,331	1,310
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	181	197
Financing Receivables, 60 to 89 Days Past Due [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	1,854	3,377
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial and Industrial [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	382	370
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Construction Loans [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Small Business [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	87	144
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	521	2,385
Financing Receivables, 60 to 89 Days Past Due [Member] | Home Equity [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	855	451
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	9	27
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	36,092	39,398
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial and Industrial [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	26,311	32,007
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	2,250	1,793
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Construction Loans [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	311	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Small Business [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	162	57
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	4,382	3,471
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Home Equity [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	2,663	2,025
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	$ 13	$ 45

[1] The amount of net deferred costs on originated loans included in the ending balance was $7.1 million, $6.1 million and $5.1 million at December 31, 2018, 2017 and 2016, respectively. Net unamortized discounts on acquired loans not deemed to be PCI included in the ending balance were $15.2 million, $9.4 million and $8.6 million at December 31, 2018, 2017 and 2016, respectively.