Allowance for Loan Losses, Allowance for Losses on Lending-Related Commitments and Impaired Loans (Summary of Impaired Loans Evaluated for Impairment by Loan Class) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	$ 62,886	$ 60,219
Impaired loans with no related ASC 310 allowance recorded	57,159	67,050
Total loans, net of unearned income	120,045	127,269
Unpaid Principal Balance
Total loans, net of unearned income	149,144	139,246
Related Allowance	12,336	11,437
Average Recorded Investment
Total loans, net of unearned income	151,761	133,481	$ 115,300
Interest Income Recognized
Total loans, net of unearned income	9,383	7,347	$ 6,300
Home equity
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	8,650	3,133
Impaired loans with no related ASC 310 allowance recorded	10,458	9,122
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	9,157	3,470
Impaired loans with no related ASC 310 allowance recorded	13,265	12,383
Related Allowance	450	282
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	8,746	3,165
Impaired loans with no related ASC 310 allowance recorded	11,955	9,323
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	337	131
Impaired loans with no related ASC 310 allowance recorded	666	564
Residential real estate
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	6,816	4,011
Impaired loans with no related ASC 310 allowance recorded	15,712	18,053
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	6,936	4,263
Impaired loans with no related ASC 310 allowance recorded	18,227	20,765
Related Allowance	387	204
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	6,889	4,056
Impaired loans with no related ASC 310 allowance recorded	16,176	18,552
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	224	159
Impaired loans with no related ASC 310 allowance recorded	827	883
Consumer and other
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	179	116
Impaired loans with no related ASC 310 allowance recorded	233	281
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	198	129
Impaired loans with no related ASC 310 allowance recorded	388	407
Related Allowance	142	116
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	186	119
Impaired loans with no related ASC 310 allowance recorded	258	293
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	13	7
Impaired loans with no related ASC 310 allowance recorded	20	20
Commercial, industrial and other | Commercial
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	23,821	16,703
Impaired loans with no related ASC 310 allowance recorded	12,756	18,314
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	29,713	17,029
Impaired loans with no related ASC 310 allowance recorded	17,124	21,501
Related Allowance	5,593	4,866
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	30,125	17,868
Impaired loans with no related ASC 310 allowance recorded	21,850	20,547
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	2,450	1,181
Impaired loans with no related ASC 310 allowance recorded	1,469	1,143
Franchise | Commercial
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	0	16,021
Impaired loans with no related ASC 310 allowance recorded	2,391	5,152
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	0	16,256
Impaired loans with no related ASC 310 allowance recorded	8,845	5,154
Related Allowance	0	1,375
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	0	16,221
Impaired loans with no related ASC 310 allowance recorded	9,621	5,320
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	0	909
Impaired loans with no related ASC 310 allowance recorded	855	403
Asset-based lending | Commercial
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	130	557
Impaired loans with no related ASC 310 allowance recorded	128	207
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	130	557
Impaired loans with no related ASC 310 allowance recorded	1,385	601
Related Allowance	1	317
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	130	689
Impaired loans with no related ASC 310 allowance recorded	4,876	569
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	8	50
Impaired loans with no related ASC 310 allowance recorded	273	51
Leases | Commercial
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	2,038	1,730
Impaired loans with no related ASC 310 allowance recorded	866	845
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	2,038	1,730
Impaired loans with no related ASC 310 allowance recorded	903	879
Related Allowance	125	0
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	2,196	1,812
Impaired loans with no related ASC 310 allowance recorded	980	936
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	106	91
Impaired loans with no related ASC 310 allowance recorded	58	56
Construction | Commercial real estate
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	0	1,554
Impaired loans with no related ASC 310 allowance recorded	1,030	1,117
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	0	1,554
Impaired loans with no related ASC 310 allowance recorded	1,554	1,117
Related Allowance	0	550
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	0	1,554
Impaired loans with no related ASC 310 allowance recorded	1,117	1,218
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	0	76
Impaired loans with no related ASC 310 allowance recorded	84	52
Land | Commercial real estate
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	88	0
Impaired loans with no related ASC 310 allowance recorded	994	3,396
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	88	0
Impaired loans with no related ASC 310 allowance recorded	1,303	3,491
Related Allowance	7	0
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	93	0
Impaired loans with no related ASC 310 allowance recorded	1,137	3,751
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	7	0
Impaired loans with no related ASC 310 allowance recorded	70	198
Office | Commercial real estate
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	7,475	573
Impaired loans with no related ASC 310 allowance recorded	559	3,629
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	7,759	638
Impaired loans with no related ASC 310 allowance recorded	645	3,642
Related Allowance	3,305	21
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	7,542	587
Impaired loans with no related ASC 310 allowance recorded	1,072	3,651
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	356	25
Impaired loans with no related ASC 310 allowance recorded	59	184
Industrial | Commercial real estate
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	0	0
Impaired loans with no related ASC 310 allowance recorded	99	322
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	0	0
Impaired loans with no related ASC 310 allowance recorded	209	450
Related Allowance	0	0
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	0	0
Impaired loans with no related ASC 310 allowance recorded	116	363
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	0	0
Impaired loans with no related ASC 310 allowance recorded	12	30
Retail | Commercial real estate
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	4,993	14,633
Impaired loans with no related ASC 310 allowance recorded	6,789	1,592
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	4,993	14,633
Impaired loans with no related ASC 310 allowance recorded	10,010	1,945
Related Allowance	26	3,413
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	5,058	14,694
Impaired loans with no related ASC 310 allowance recorded	7,340	1,699
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	229	676
Impaired loans with no related ASC 310 allowance recorded	535	110
Multi-family | Commercial real estate
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	1,158	0
Impaired loans with no related ASC 310 allowance recorded	913	1,498
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	1,158	0
Impaired loans with no related ASC 310 allowance recorded	1,024	1,595
Related Allowance	22	0
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	1,174	0
Impaired loans with no related ASC 310 allowance recorded	1,166	1,529
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	52	0
Impaired loans with no related ASC 310 allowance recorded	56	55
Mixed use and other | Commercial real estate
Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	7,538	1,188
Impaired loans with no related ASC 310 allowance recorded	4,231	3,522
Unpaid Principal Balance
Impaired loans with a related ASC 310 allowance recorded	7,592	1,221
Impaired loans with no related ASC 310 allowance recorded	4,500	3,836
Related Allowance	2,278	293
Average Recorded Investment
Impaired loans with a related ASC 310 allowance recorded	7,603	1,354
Impaired loans with no related ASC 310 allowance recorded	4,355	3,611
Interest Income Recognized
Impaired loans with a related ASC 310 allowance recorded	357	66
Impaired loans with no related ASC 310 allowance recorded	$ 260	$ 227