Derivative Instruments - Summary of Derivative Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Derivatives
Notional Amount
Derivative Assets	306,289	106,642
Derivative Liabilities	27,906	14,312
Derivative asset netting	(11,433)	(540)
Derivative liability netting	(4,731)	(5,109)
Total derivative assets, net	294,856	106,102
Total derivative liabilities, net	23,175	9,203
Other assets
Derivatives
Derivative Assets	306,289	106,642
Derivative asset netting	(11,433)	(540)
Total derivative assets, net	294,856	106,102
Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	27,906	14,312
Derivative liability netting	(4,731)	(5,109)
Total derivative liabilities, net	23,175	9,203
Derivatives designated as hedges
Derivatives
Notional Amount
Derivatives designated as hedges | Other assets
Derivatives
Derivative Assets	5,938	0
Derivatives designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	3	3,419
Derivatives not designated as hedges
Derivatives
Notional Amount
Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	300,351	106,642
Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	27,903	10,893
Interest rate contracts
Derivatives
Derivative Assets	283,410	102,893
Derivative Liabilities	15,970	6,040
Derivative asset netting	(2,215)	(492)
Derivative liability netting	(2,215)	(491)
Total derivative assets, net	281,195	102,401
Total derivative liabilities, net	13,755	5,549
Interest rate contracts | Derivatives designated as hedges
Derivatives
Notional Amount	150,000	150,000
Interest rate contracts | Derivatives designated as hedges | Other assets
Derivatives
Derivative Assets	0	0
Interest rate contracts | Derivatives designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	3	168
Interest rate contracts | Derivatives not designated as hedges
Derivatives
Notional Amount	5,875,131	5,095,969
Interest rate contracts | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	283,410	102,893
Interest rate contracts | Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	15,967	5,872
Risk participation agreements
Derivatives
Derivative Assets	22	202
Derivative Liabilities	118	354
Derivative asset netting	0	0
Derivative liability netting	0	0
Total derivative assets, net	22	202
Total derivative liabilities, net	118	354
Risk participation agreements | Derivatives not designated as hedges
Derivatives
Notional Amount	398,579	316,353
Risk participation agreements | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	22	202
Risk participation agreements | Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	118	354
Forward foreign exchange contracts
Derivatives
Derivative Assets	9,188	0
Derivative Liabilities	2,200	6,519
Derivative asset netting	(9,188)	0
Derivative liability netting	(2,200)	(4,214)
Total derivative assets, net	0	0
Total derivative liabilities, net	0	2,305
Forward foreign exchange contracts | Derivatives designated as hedges
Derivatives
Notional Amount	167,488	177,593
Forward foreign exchange contracts | Derivatives designated as hedges | Other assets
Derivatives
Derivative Assets	5,938	0
Forward foreign exchange contracts | Derivatives designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	0	3,251
Forward foreign exchange contracts | Derivatives not designated as hedges
Derivatives
Notional Amount	239,076	262,656
Forward foreign exchange contracts | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	3,250	0
Forward foreign exchange contracts | Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	2,200	3,268
Interest rate lock commitments
Derivatives
Derivative Assets	13,134	2,772
Derivative Liabilities	4	20
Derivative asset netting	(4)	(7)
Derivative liability netting	(4)	(7)
Total derivative assets, net	13,130	2,765
Total derivative liabilities, net	0	13
Interest rate lock commitments | Derivatives not designated as hedges
Derivatives
Notional Amount	452,544	158,111
Interest rate lock commitments | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	13,134	2,772
Interest rate lock commitments | Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	4	20
Forward loan sales commitments
Derivatives
Derivative Assets	26	41
Derivative Liabilities	8,819	289
Derivative asset netting	(26)	(41)
Derivative liability netting	(26)	(41)
Total derivative assets, net	0	0
Total derivative liabilities, net	8,793	248
Forward loan sales commitments | Derivatives not designated as hedges
Derivatives
Notional Amount	539,741	174,013
Forward loan sales commitments | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	26	41
Forward loan sales commitments | Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	8,819	289
Power Equity CDs
Derivatives
Derivative Assets	509	734
Derivative Liabilities	509	734
Derivative asset netting	0	0
Derivative liability netting	0	0
Total derivative assets, net	509	734
Total derivative liabilities, net	509	734
Power Equity CDs | Derivatives not designated as hedges
Derivatives
Notional Amount	27,726	29,009
Power Equity CDs | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	509	734
Power Equity CDs | Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	509	734
Swap agreement
Derivatives
Derivative Liabilities	286	356
Derivative liability netting	(286)	(356)
Total derivative liabilities, net	0	0
Swap agreement | Derivatives not designated as hedges
Derivatives
Notional Amount	12,652	12,652
Swap agreement | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	0	0
Swap agreement | Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	$ 286	$ 356