Revenue from Contracts with Customers Reclassification of Bank Card Transaction Fees (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reclassification of Bank Card Transaction Fees [Line Items]
Bank card transaction fees	$ 41,453	$ 35,751
Non-interest income	119,690	109,613
Data processing and software	20,690	19,905
Other	15,374	15,703
Noninterest Expense	$ 182,277	179,377
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Reclassification of Bank Card Transaction Fees [Line Items]
Bank card transaction fees		43,204
Non-interest income		117,066
Data processing and software		23,097
Other		19,964
Noninterest Expense		186,830
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Reclassification of Bank Card Transaction Fees [Line Items]
Bank card transaction fees		(7,453)
Non-interest income		(7,453)
Data processing and software		(3,192)
Other		(4,261)
Noninterest Expense		(7,453)
Initial Application Period Cumulative Effect Transition [Domain]
Reclassification of Bank Card Transaction Fees [Line Items]
Bank card transaction fees		35,751
Non-interest income		109,613
Data processing and software		19,905
Other		15,703
Noninterest Expense		$ 179,377