Components of Other Comprehensive Income/(Loss) - Schedule of Reclassification from AOCI (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Debt securities gains/(losses), net	$ (267)	$ 0	$ (267)	$ 52
Provision/(benefit) for income taxes	34,467	19,697	61,525	49,628
Amounts reclassified from AOCI	3,096	2,522	6,010	3,615
Interest and fees on loans	352,112	323,974	684,050	623,467
All other expense (Note 8)	29,211	50,999	48,997	86,331
Securities AFS
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	201	0	201	(39)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	1,334	463	2,785	308
Pension and Post-retirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	1,561	2,059	3,024	3,346
Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	3,096	2,522	6,010	3,615
Reclassification out of Accumulated Other Comprehensive Income \| Securities AFS
Accumulated Other Comprehensive Income (Loss) [Line Items]
Debt securities gains/(losses), net	267	0	267	(52)
Provision/(benefit) for income taxes	(66)	0	(66)	13
Amounts reclassified from AOCI	201	0	201	(39)
Reclassification out of Accumulated Other Comprehensive Income \| Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Provision/(benefit) for income taxes	(438)	(152)	(914)	(101)
Amounts reclassified from AOCI	1,334	463	2,785	308
Interest and fees on loans	1,772	615	3,699	409
Reclassification out of Accumulated Other Comprehensive Income \| Pension and Post-retirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	1,561	2,059	3,024	3,346
All other expense (Note 8)	2,074	2,735	4,017	4,444
Reclassification from AOCI, current period, tax	$ (513)	$ (676)	$ (993)	$ (1,098)

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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