Derivative Financial Instruments - Free-Standing, Contingent Features and Counterparty Credit Risk (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		96 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Derivative financial instruments
Counterparty credit risk adjustments	$ 100	$ 0	$ 200	$ 200
Visa | Class B shares
Derivative financial instruments
Number of shares sold			274,000		0
Interest rate swaps | Maximum
Derivative financial instruments
Collateral thresholds for derivative agreements with credit risk related contingent features	500		$ 500
Derivatives Not Designated as Hedging Instruments | Interest rate swaps
Derivative financial instruments
Notional Amount	1,062,236		1,062,236		$ 682,621
Positive fair value, derivative asset	32,400		32,400		10,900
Fair value loss (derivative liability)	35,600		35,600		$ 14,100
Net interest expense on derivative	$ 300	300	$ 800	900
Derivatives Not Designated as Hedging Instruments | Interest rate swaps | Minimum
Derivative financial instruments
Fixed interest rate (as a percent)	0.53%		0.53%		1.34%
Derivatives Not Designated as Hedging Instruments | Interest rate swaps | Maximum
Derivative financial instruments
Fixed interest rate (as a percent)	4.90%		4.90%		4.90%
Derivatives Not Designated as Hedging Instruments | Interest rate swaps | Customer swap program
Derivative financial instruments
Notional Amount	$ 1,000,000		$ 1,000,000		$ 652,600
Positive fair value, derivative asset	32,400		32,400		10,900
Fair value loss (derivative liability)	32,400		32,400		$ 10,900
Upfront fees on the dealer swap	700	$ 600	4,300	$ 2,700
Derivatives Not Designated as Hedging Instruments | Funding Swap (Visa Derivative)
Derivative financial instruments
Notional Amount	35,784		35,784
Fair value loss (derivative liability)	$ 7,900		$ 7,900