Derivative Instruments - Summary of Derivative Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Derivatives
Notional Amount
Derivative Assets	301,802	106,642
Derivative Liabilities	15,840	14,312
Derivative asset netting	(2,861)	(540)
Derivative liability netting	498	(5,109)
Total derivative assets, net	298,941	106,102
Total derivative liabilities, net	16,338	9,203
Other assets
Derivatives
Derivative Assets	301,802	106,642
Derivative asset netting	(2,861)	(540)
Total derivative assets, net	298,941	106,102
Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	15,840	14,312
Derivative liability netting	498	(5,109)
Total derivative liabilities, net	16,338	9,203
Derivatives designated as hedges
Derivatives
Notional Amount
Derivatives designated as hedges | Other assets
Derivatives
Derivative Assets	2,237	0
Derivatives designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	169	3,419
Derivatives not designated as hedges
Derivatives
Notional Amount
Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	299,565	106,642
Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	15,671	10,893
Interest rate contracts
Derivatives
Derivative Assets	279,710	102,893
Derivative Liabilities	14,085	6,040
Derivative asset netting	0	(492)
Derivative liability netting	0	(491)
Total derivative assets, net	279,710	102,401
Total derivative liabilities, net	14,085	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	84	168
Interest rate contracts | Derivatives not designated as hedges
Derivatives
Notional Amount	5,773,205	5,095,969
Interest rate contracts | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	279,710	102,893
Interest rate contracts | Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	14,001	5,872
Risk participation agreements
Derivatives
Derivative Assets	163	202
Derivative Liabilities	171	354
Derivative asset netting	0	0
Derivative liability netting	0	0
Total derivative assets, net	163	202
Total derivative liabilities, net	171	354
Risk participation agreements | Derivatives not designated as hedges
Derivatives
Notional Amount	445,120	316,353
Risk participation agreements | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	163	202
Risk participation agreements | Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	171	354
Forward foreign exchange contracts
Derivatives
Derivative Assets	2,774	0
Derivative Liabilities	210	6,519
Derivative asset netting	(2,740)	0
Derivative liability netting	760	(4,214)
Total derivative assets, net	34	0
Total derivative liabilities, net	970	2,305
Forward foreign exchange contracts | Derivatives designated as hedges
Derivatives
Notional Amount	196,852	177,593
Forward foreign exchange contracts | Derivatives designated as hedges | Other assets
Derivatives
Derivative Assets	2,237	0
Forward foreign exchange contracts | Derivatives designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	85	3,251
Forward foreign exchange contracts | Derivatives not designated as hedges
Derivatives
Notional Amount	95,052	262,656
Forward foreign exchange contracts | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	537	0
Forward foreign exchange contracts | Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	125	3,268
Interest rate lock commitments
Derivatives
Derivative Assets	18,596	2,772
Derivative Liabilities	4	20
Derivative asset netting	(4)	(7)
Derivative liability netting	(4)	(7)
Total derivative assets, net	18,592	2,765
Total derivative liabilities, net	0	13
Interest rate lock commitments | Derivatives not designated as hedges
Derivatives
Notional Amount	579,456	158,111
Interest rate lock commitments | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	18,596	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	117	41
Derivative Liabilities	786	289
Derivative asset netting	(117)	(41)
Derivative liability netting	(117)	(41)
Total derivative assets, net	0	0
Total derivative liabilities, net	669	248
Forward loan sales commitments | Derivatives not designated as hedges
Derivatives
Notional Amount	805,887	174,013
Forward loan sales commitments | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	117	41
Forward loan sales commitments | Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	786	289
Power Equity CDs
Derivatives
Derivative Assets	442	734
Derivative Liabilities	443	734
Derivative asset netting	0	0
Derivative liability netting	0	0
Total derivative assets, net	442	734
Total derivative liabilities, net	443	734
Power Equity CDs | Derivatives not designated as hedges
Derivatives
Notional Amount	21,958	29,009
Power Equity CDs | Derivatives not designated as hedges | Other assets
Derivatives
Derivative Assets	442	734
Power Equity CDs | Derivatives not designated as hedges | Accrued expenses and other liabilities
Derivatives
Derivative Liabilities	443	734
Swap agreement
Derivatives
Derivative Liabilities	141	356
Derivative liability netting	(141)	(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	$ 141	$ 356