Age Analysis of Past Due Financing receivables (Details) $ in Thousands	Dec. 31, 2019 USD ($) loan	Dec. 31, 2018 USD ($) loan	Dec. 31, 2017 USD ($)
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	447	400
Number of Loans 60-89 Days | loan	43	56
Number of Loans 90 Days or More | loan	113	110
Number of Loans Total Past Due | loan	603	566
Principal Balance Total Past Due	$ 25,485	$ 46,348
Current	8,848,154	6,859,846
Total loans	8,873,639	6,906,194	$ 6,355,553	[1]
Recorded Investment >90 Days and Accruing	$ 2,157	$ 5
Commercial and Industrial [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	1	0
Number of Loans 60-89 Days | loan	2	4
Number of Loans 90 Days or More | loan	5	11
Number of Loans Total Past Due | loan	8	15
Principal Balance Total Past Due	$ 1,336	$ 26,693
Current	1,393,700	1,066,936
Total loans	1,395,036	1,093,629	888,528
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	7	9
Number of Loans 60-89 Days | loan	1	0
Number of Loans 90 Days or More | loan	8	8
Number of Loans Total Past Due | loan	16	17
Principal Balance Total Past Due	$ 3,922	$ 3,877
Current	3,998,437	3,247,371
Total loans	4,002,359	3,251,248	3,116,561
Recorded Investment >90 Days and Accruing	$ 218	$ 0
Construction Loans [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	1	1
Number of Loans 60-89 Days | loan	0	0
Number of Loans 90 Days or More | loan	0	1
Number of Loans Total Past Due | loan	1	2
Principal Balance Total Past Due	$ 560	$ 1,582
Current	546,733	363,583
Total loans	547,293	365,165	401,797
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	11	15
Number of Loans 60-89 Days | loan	3	19
Number of Loans 90 Days or More | loan	6	24
Number of Loans Total Past Due | loan	20	58
Principal Balance Total Past Due	$ 967	$ 755
Current	173,530	163,921
Total loans	174,497	164,676	132,370
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	17	23
Number of Loans 60-89 Days | loan	17	6
Number of Loans 90 Days or More | loan	38	25
Number of Loans Total Past Due | loan	72	54
Principal Balance Total Past Due	$ 12,312	$ 8,389
Current	1,578,257	914,905
Total loans	1,590,569	923,294	754,329
Recorded Investment >90 Days and Accruing	$ 1,652	$ 0
Home Equity [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	23	22
Number of Loans 60-89 Days | loan	8	12
Number of Loans 90 Days or More | loan	40	29
Number of Loans Total Past Due | loan	71	63
Principal Balance Total Past Due	$ 6,067	$ 4,849
Current	1,127,731	1,087,235
Total loans	1,133,798	1,092,084	1,052,088
Recorded Investment >90 Days and Accruing	$ 265	$ 0
Consumer Portfolio Segment [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	387	330
Number of Loans 60-89 Days | loan	12	15
Number of Loans 90 Days or More | loan	16	12
Number of Loans Total Past Due | loan	415	357
Principal Balance Total Past Due	$ 321	$ 203
Current	29,766	15,895
Total loans	30,087	16,098	$ 9,880
Recorded Investment >90 Days and Accruing	22	5
Financial Asset, 30 to 59 Days Past Due [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	7,511	8,402
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial and Industrial [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	253	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	1,690	1,627
Financial Asset, 30 to 59 Days Past Due [Member] | Construction Loans [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	560	1,271
Financial Asset, 30 to 59 Days Past Due [Member] | Small Business [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	837	506
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	2,237	3,486
Financial Asset, 30 to 59 Days Past Due [Member] | Home Equity [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	1,689	1,331
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	245	181
Financial Asset, 60 to 89 Days Past Due [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	4,155	1,854
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial and Industrial [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	323	382
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	194	0
Financial Asset, 60 to 89 Days Past Due [Member] | Construction Loans [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Small Business [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	15	87
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	3,055	521
Financial Asset, 60 to 89 Days Past Due [Member] | Home Equity [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	524	855
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	44	9
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	13,819	36,092
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial and Industrial [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	760	26,311
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	2,038	2,250
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Construction Loans [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	0	311
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Small Business [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	115	162
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	7,020	4,382
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Home Equity [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	3,854	2,663
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	$ 32	$ 13

[1] The amount of net deferred costs on originated loans included in the ending balance was $7.1 million, at December 31, 2019 and 2018 and $6.1 million and at December 31, 2017. Net unamortized discounts on acquired loans not deemed to be PCI included in the ending balance were $21.6 million, $15.2 million and $9.4 million at December 31, 2019, 2018 and 2017, respectively.