Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue out of scope of ASC 606	$ (3,281)	$ 4,405	$ 2,392	$ (21,173)
Noninterest income	49,631	55,492	154,903	162,636
Noninterest expense out of scope of ASC 606	2,582	3,724	8,897	12,043
Noninterest expense	2,203	3,880	9,281	12,654
Fees and service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Revenue out of scope of ASC 606	3,878	38	3,902	98
Noninterest income	34,384	29,175	88,504	83,703
Wealth management revenue
Disaggregation of Revenue [Line Items]
Revenue out of scope of ASC 606	3,194	0	3,194	0
Noninterest income	4,241	0	4,241	0
Card and ATM revenue
Disaggregation of Revenue [Line Items]
Revenue out of scope of ASC 606	1,816	61	1,827	179
Noninterest income	23,315	20,074	62,470	58,313
Other noninterest income
Disaggregation of Revenue [Line Items]
Revenue out of scope of ASC 606	(12,169)	4,306	(6,531)	(21,450)
Noninterest income	(12,309)	6,243	(312)	20,620
Consumer Banking
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	51,858	47,954	144,230	172,292
Noninterest expense within the scope of ASC 606	(593)	215	(152)	719
Consumer Banking | Fees and service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	29,198	28,055	81,098	80,468
Consumer Banking | Wealth management revenue
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	1,047	0	1,047	0
Consumer Banking | Card and ATM revenue
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	21,476	19,999	60,581	58,095
Consumer Banking | Other noninterest income
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	137	(100)	1,504	33,729
Commercial Banking
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	(1,556)	(1,553)	(1,705)	(3,595)
Noninterest expense within the scope of ASC 606	214	(59)	536	(108)
Commercial Banking | Fees and service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	1,308	1,082	3,504	3,137
Commercial Banking | Wealth management revenue
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	0	0	0	0
Commercial Banking | Card and ATM revenue
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	23	14	62	39
Commercial Banking | Other noninterest income
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	(2,887)	(2,649)	(5,271)	(6,771)
Enterprise Services
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	2,610	4,686	9,986	15,112
Noninterest expense within the scope of ASC 606	0	0	0	0
Enterprise Services | Fees and service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	0	0	0	0
Enterprise Services | Wealth management revenue
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	0	0	0	0
Enterprise Services | Card and ATM revenue
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	0	0	0	0
Enterprise Services | Other noninterest income
Disaggregation of Revenue [Line Items]
Revenues within the scope of 606	$ 2,610	$ 4,686	$ 9,986	$ 15,112