Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 14,641	$ 13,702	$ 28,024	$ 27,961
Other sources of noninterest income	33,627	33,542	94,688	135,111
Total noninterest income	48,268	47,244	122,712	163,072
Retail Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	11,172	10,435	21,052	20,545
Other sources of noninterest income	3,413	3,206	37,981	6,660
Total noninterest income	14,585	13,641	59,033	27,205
Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,221	3,146	6,566	7,190
Other sources of noninterest income	27,523	23,438	51,616	45,128
Total noninterest income	30,744	26,584	58,182	52,318
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	248	121	406	226
Other sources of noninterest income	2,691	6,898	5,091	83,323
Total noninterest income	2,939	7,019	5,497	83,549
Deposit service charges and related fee income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8,986	9,090	18,172	17,774
Deposit service charges and related fee income | Retail Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,738	6,157	11,752	11,994
Deposit service charges and related fee income | Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,000	2,812	6,014	5,554
Deposit service charges and related fee income | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	248	121	406	226
Card income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,154	1,231	2,398	2,471
Card income | Retail Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	933	1,029	2,003	2,056
Card income | Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	221	202	395	415
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	4,501	3,381	7,454	7,716
Wealth management fees | Retail Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,501	3,249	7,297	6,495
Wealth management fees | Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	132	157	1,221
Wealth management fees | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 0	$ 0	$ 0	$ 0