Revenue from Contracts with Customers Revenue from Contracts with Customers (Schedule of Bank Card Transaction Fees) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	$ 43,215	$ 37,295	$ 84,668	$ 73,046
Debit Card Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	10,207	8,404	19,598	16,395
Debit Card Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	10,582	10,325	20,344	19,966
Debit Card Fees [Member] | Network Charges Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(375)	(1,921)	(746)	(3,571)
Credit Card Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	3,496	3,560	6,597	6,554
Credit Card Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	6,800	6,483	12,845	12,223
Credit Card Fees [Member] | Network Charges and Rewards Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(3,304)	(2,923)	(6,248)	(5,669)
Corporate Card Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	24,620	19,896	48,788	39,860
Corporate Card Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	49,141	43,261	97,017	85,680
Corporate Card Fees [Member] | Network Charges and Rewards Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(24,521)	(23,365)	(48,229)	(45,820)
Merchant Fees [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	4,892	5,435	9,685	10,237
Merchant Fees [Member] | Fee income [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	7,606	8,350	14,907	16,289
Merchant Fees [Member] | Network Charges Expense [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	(836)	(835)	(1,619)	(1,883)
Merchant Fees [Member] | Fees to Cardholder Banks [Member]
Bank Card Transaction Fees [Line Items]
Bank card transaction fees	$ (1,878)	$ (2,080)	$ (3,603)	$ (4,169)