Revenue from Contracts with Customers Revenue from Contracts with Customers (Schedule of Bank Card Transaction Fees) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	$ 171,576	$ 155,100	$ 154,043
Debit Card [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	39,738	35,636	33,441
Debit Card [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	41,522	40,134	39,430
Debit Card [Member] | Network Charges Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(1,784)	(4,498)	(5,989)
Credit Card [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	12,965	14,576	14,834
Credit Card [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	26,799	25,275	24,650
Credit Card [Member] | Network Charges and Rewards Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(13,834)	(10,699)	(9,816)
Corporate Card Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	99,640	84,819	82,725
Corporate Card Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	199,651	179,642	166,576
Corporate Card Fees [Member] | Network Charges and Rewards Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(100,011)	(94,823)	(83,851)
Merchant Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	19,233	20,069	23,043
Merchant Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	30,241	31,863	37,407
Merchant Fees [Member] | Network Charges Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(3,177)	(3,566)	(4,779)
Merchant Fees [Member] | Fees to Cardholder Banks [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	$ (7,831)	$ (8,228)	$ (9,585)