Revenue from Contracts with Customers Revenue from Contracts with Customers (Schedule of Bank Card Transaction Fees) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	$ 42,427	$ 39,166	$ 127,095	$ 112,212
Debit Card Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	9,917	9,234	29,515	25,629
Debit Card Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	10,396	9,986	30,740	29,952
Debit Card Fees [Member] | Network Charges Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(479)	(752)	(1,225)	(4,323)
Credit Card Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	2,580	3,560	9,177	10,114
Credit Card Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	6,826	6,371	19,671	18,594
Credit Card Fees [Member] | Network Charges and Rewards Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(4,246)	(2,811)	(10,494)	(8,480)
Corporate Card Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	24,750	21,570	73,538	61,430
Corporate Card Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	50,187	45,413	147,204	131,093
Corporate Card Fees [Member] | Network Charges and Rewards Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(25,437)	(23,843)	(73,666)	(69,663)
Merchant Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	5,180	4,802	14,865	15,039
Merchant Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	7,553	7,558	22,460	23,847
Merchant Fees [Member] | Network Charges Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(554)	(771)	(2,173)	(2,654)
Merchant Fees [Member] | Fees to Cardholder Banks [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	$ (1,819)	$ (1,985)	$ (5,422)	$ (6,154)