Revenue from Contracts with Customers Revenue from Contracts with Customers (Schedule of Bank Card Transaction Fees) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	$ 41,453	$ 35,751
Debit Card Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	9,391	7,991
Debit Card Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	9,762	9,641
Debit Card Fees [Member] | Network Charges Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(371)	(1,650)
Credit Card Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	3,101	2,994
Credit Card Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	6,045	5,740
Credit Card Fees [Member] | Network Charges and Rewards Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(2,944)	(2,746)
Corporate Card Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	24,168	19,964
Corporate Card Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	47,876	42,419
Corporate Card Fees [Member] | Network Charges and Rewards Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(23,708)	(22,455)
Merchant Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	4,793	4,802
Merchant Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	7,301	7,939
Merchant Fees [Member] | Network Charges Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(783)	(1,048)
Merchant Fees [Member] | Fees to Cardholder Banks [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	$ (1,725)	$ (2,089)