Revenue from Contracts with Customers Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 45,043	$ 53,406	$ 98,210	$ 105,631
Non-interest income	60,076	75,853	133,454	144,465
Deposit service fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	35,839	43,118	78,409	86,142
Wealth and investment services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	7,102	8,309	15,841	15,960
Other non interest income [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,102	1,979	3,960	3,529
Non-interest income within the scope of other GAAP topics [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	15,033
Non-interest income		22,447	35,244	38,834
Operating Segments [Member] | Commercial Banking [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	5,290	5,627	10,877	11,147
Non-interest income	14,725	14,645	27,964	28,656
Operating Segments [Member] | Commercial Banking [Member] | Deposit service fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,703	3,085	5,762	6,121
Operating Segments [Member] | Commercial Banking [Member] | Wealth and investment services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,587	2,542	5,115	5,026
Operating Segments [Member] | Commercial Banking [Member] | Other non interest income [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Operating Segments [Member] | Commercial Banking [Member] | Non-interest income within the scope of other GAAP topics [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	9,435
Non-interest income		9,018	17,087	17,509
Operating Segments [Member] | HSA Bank [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	23,103	24,979	49,486	50,556
Non-interest income	23,103	24,979	49,486	50,556
Operating Segments [Member] | HSA Bank [Member] | Deposit service fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	21,741	23,704	46,583	48,232
Operating Segments [Member] | HSA Bank [Member] | Wealth and investment services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Operating Segments [Member] | HSA Bank [Member] | Other non interest income [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,362	1,275	2,903	2,324
Operating Segments [Member] | HSA Bank [Member] | Non-interest income within the scope of other GAAP topics [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0
Non-interest income		0	0	0
Operating Segments [Member] | Community Banking [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	16,781	22,769	37,908	43,810
Non-interest income	23,405	27,675	51,025	53,057
Operating Segments [Member] | Community Banking [Member] | Deposit service fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	11,488	16,289	26,080	31,654
Operating Segments [Member] | Community Banking [Member] | Wealth and investment services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,553	5,776	10,771	10,951
Operating Segments [Member] | Community Banking [Member] | Other non interest income [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	740	704	1,057	1,205
Operating Segments [Member] | Community Banking [Member] | Non-interest income within the scope of other GAAP topics [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	6,624
Non-interest income		4,906	13,117	9,247
Corporate, Non-Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(131)	31	(61)	118
Non-interest income	(1,157)	8,554	4,979	12,196
Corporate, Non-Segment [Member] | Deposit service fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(93)	40	(16)	135
Corporate, Non-Segment [Member] | Wealth and investment services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(38)	(9)	(45)	(17)
Corporate, Non-Segment [Member] | Other non interest income [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Corporate, Non-Segment [Member] | Non-interest income within the scope of other GAAP topics [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ (1,026)
Non-interest income		$ 8,523	$ 5,040	$ 12,078