Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands		12 Months Ended
	Jan. 01, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Noninterest Expense		$ 416,303	$ 415,909	$ 339,500
Non-cash transfer of equity securities previously classified as trading securities and securities and securities available-for-sale		30,800
Estimated sale-leaseback deferred gain, net		65,500	$ 74,600
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated sale-leaseback deferred gain, net		47,300
Reduction to lease expense		6,000
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Noninterest Expense		16,100
Difference between Revenue Guidance in Effect before and after Topic 606 | Card-based | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Noninterest Expense		7,500
Difference between Revenue Guidance in Effect before and after Topic 606 | Merchant servicing | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Noninterest Expense		$ 8,600
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of tax effects from AOCI to retained earnings	$ 6,800
Subsequent Event | Scenario, Forecast | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, liability					$ 145,000
Right-of-use asset					$ 145,000