Revenue from Contracts with Customers (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 13,588,000	$ 14,641,000	$ 27,041,000	$ 28,024,000
Other sources of noninterest income	39,171,000	33,627,000	67,849,000	94,688,000
Total noninterest income	52,759,000	48,268,000	94,890,000	122,712,000
Contract with customer, asset, net	0		0		$ 0
Contracts with customers, receivables, net	0		0		$ 0
Consumer and Business Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	9,890,000	11,172,000	19,762,000	21,052,000
Other sources of noninterest income	4,613,000	3,413,000	8,513,000	37,981,000
Total noninterest income	14,503,000	14,585,000	28,275,000	59,033,000
Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,688,000	3,221,000	7,253,000	6,566,000
Other sources of noninterest income	29,968,000	27,523,000	50,947,000	51,616,000
Total noninterest income	33,656,000	30,744,000	58,200,000	58,182,000
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	10,000	248,000	26,000	406,000
Other sources of noninterest income	4,590,000	2,691,000	8,389,000	5,091,000
Total noninterest income	4,600,000	2,939,000	8,415,000	5,497,000
Deposit service charges and related fee income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8,706,000	8,986,000	17,229,000	18,172,000
Deposit service charges and related fee income | Consumer and Business Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,397,000	5,738,000	10,630,000	11,752,000
Deposit service charges and related fee income | Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,299,000	3,000,000	6,573,000	6,014,000
Deposit service charges and related fee income | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	10,000	248,000	26,000	406,000
Card income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,082,000	1,154,000	2,200,000	2,398,000
Card income | Consumer and Business Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	928,000	933,000	1,861,000	2,003,000
Card income | Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	154,000	221,000	339,000	395,000
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	3,800,000	4,501,000	7,612,000	7,454,000
Wealth management fees | Consumer and Business Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,565,000	4,501,000	7,271,000	7,297,000
Wealth management fees | Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	235,000	0	341,000	157,000
Wealth management fees | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 0	$ 0	$ 0	$ 0