Components of Other Comprehensive Income/(Loss) - Schedule of Reclassification from AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Debt securities gains/(losses), net	$ (267)	$ 52	$ 483
Interest and fees on loans	1,394,442	1,286,470	816,806
All other expense	126,130	134,997	112,607
Tax expense/(benefit)	133,291	157,602	131,892
Net income/(loss)	(452,373)	(556,507)	(176,980)
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net income/(loss)	11,952	10,997	2,375
Reclassification out of Accumulated Other Comprehensive Income | Securities AFS
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Debt securities gains/(losses), net	267	(52)	(483)
Tax expense/(benefit)	(66)	13	185
Net income/(loss)	201	(39)	(298)
Reclassification out of Accumulated Other Comprehensive Income | Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Interest and fees on loans	5,452	2,845	(4,771)
Tax expense/(benefit)	(1,347)	(703)	1,826
Net income/(loss)	4,105	2,142	(2,945)
Reclassification out of Accumulated Other Comprehensive Income | Pension and Post-retirement Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
All other expense	10,156	11,814	9,101
Tax expense/(benefit)	(2,510)	(2,920)	(3,483)
Net income/(loss)	$ 7,646	$ 8,894	$ 5,618