Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Noninterest income	$ 37,917	$ 32,122	$ 116,489	$ 111,700
Noninterest expense	(109,661)	$ (119,539)	(315,832)	$ (321,972)
Noninterest income from contracts with customers within the scope of ASC 606
Disaggregation of Revenue [Line Items]
Noninterest income	8,153		25,004
Service charges and fees on deposit accounts
Disaggregation of Revenue [Line Items]
Noninterest income	4,820		13,744
Wealth management revenue
Disaggregation of Revenue [Line Items]
Noninterest income	811		3,868
Other charges and fees for customer services
Disaggregation of Revenue [Line Items]
Noninterest income	2,522		7,392
Noninterest income within the scope of other GAAP topics
Disaggregation of Revenue [Line Items]
Noninterest income	29,764		91,485
Other
Disaggregation of Revenue [Line Items]
Noninterest expense	$ (50)		$ (734)