Revenue from Contracts with Customers (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 14,759,000	$ 13,312,000	$ 41,800,000	$ 41,336,000
Other sources of noninterest income	36,715,000	33,190,000	104,564,000	127,878,000
Total noninterest income	51,474,000	46,502,000	146,364,000	169,214,000
Contract with customer, asset, net	0		0		$ 0
Contract with Customer, Liability	0		0		$ 0
Consumer and Business Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	10,974,000	9,838,000	30,736,000	30,890,000
Other sources of noninterest income	4,129,000	3,299,000	12,642,000	41,280,000
Total noninterest income	15,103,000	13,137,000	43,378,000	72,170,000
Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,776,000	3,468,000	11,029,000	10,034,000
Other sources of noninterest income	29,955,000	24,393,000	80,902,000	76,009,000
Total noninterest income	33,731,000	27,861,000	91,931,000	86,043,000
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	9,000	6,000	35,000	412,000
Other sources of noninterest income	2,631,000	5,498,000	11,020,000	10,589,000
Total noninterest income	2,640,000	5,504,000	11,055,000	11,001,000
Deposit service charges and related fee income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8,788,000	8,627,000	26,017,000	26,799,000
Deposit service charges and related fee income | Consumer and Business Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,345,000	5,488,000	15,975,000	17,240,000
Deposit service charges and related fee income | Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,434,000	3,133,000	10,007,000	9,147,000
Deposit service charges and related fee income | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	9,000	6,000	35,000	412,000
Card income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,130,000	1,150,000	3,330,000	3,548,000
Card income | Consumer and Business Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	985,000	949,000	2,846,000	2,952,000
Card income | Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	145,000	201,000	484,000	596,000
Card income | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0	0	0
Wealth management fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,841,000	3,535,000	12,453,000	10,989,000
Wealth management fees | Consumer and Business Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,644,000	3,401,000	11,915,000	10,698,000
Wealth management fees | Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	197,000	134,000	538,000	291,000
Wealth management fees | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 0	$ 0	$ 0	$ 0