Fair Value of Assets and Liabilities - Summary Of Changes In Level 3 Assets And Liabilities Measured At Fair Value (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance, net derivative	$ (31,540)	$ (5,645)	$ (6,245)
Total net gains/(losses) included in: Net Income, net derivatives	(3,946)	(4,677)	(596)
Purchases, net derivatives	0	(28,100)	0
Sales, net derivatives	0	0	0
Settlements, net derivatives	12,691	6,882	1,196
Net transfers in/(out) level 3, net derivatives	0	0	0
Ending balance, net derivative	(22,795)	(31,540)	(5,645)
Net unrealized gains/(losses) included in net income	(3,946)	(4,677)	(596)
Trading securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance, assets	1,524	2,151	2,573
Total net gains/(losses) included in : Net income, assets	(285)	173	448
Purchases, assets	0	0	0
Sales, assets	0	0	(5)
Settlements, assets	(298)	(800)	(865)
Net transfers into/(out of) Level 3, assets	0	0	0
Ending balance, assets	941	1,524	2,151
Net unrealized gains/(losses) included in net income	(66)	6	303
Interest-Only Strip (elected fair value)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance, assets	9,902	1,270	0
Total net gains/(losses) included in : Net income, assets	(4,725)	(398)	1,021
Purchases, assets	86	0	1,413
Sales, assets	(47,469)	(16,840)	(11,431)
Settlements, assets	0	0	0
Net transfers into/(out of) Level 3, assets	61,342	25,870	10,267
Ending balance, assets	19,136	9,902	1,270
Net unrealized gains/(losses) included in net income	(1,984)	(1,025)	(171)
Loans Held For Sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance, assets	16,273	18,926	21,924
Total net gains/(losses) included in : Net income, assets	1,828	1,239	1,547
Purchases, assets	10	62	168
Sales, assets	0	0	0
Settlements, assets	(4,078)	(3,598)	(4,346)
Net transfers into/(out of) Level 3, assets	0	(356)	(367)
Ending balance, assets	14,033	16,273	18,926
Net unrealized gains/(losses) included in net income	$ 1,828	$ 1,239	$ 1,547

Amount of unrealized gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3) and still held.

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Amount of transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy.

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Amount of unrealized gain (loss) recognized in income for derivative asset (liability) after deduction of derivative liability (asset), measured at fair value using unobservable input (level 3) and still held.

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Amount of gain (loss) recognized in income from derivative asset (liability) after deduction of derivative liability (asset), measured at fair value on recurring basis using unobservable input (level 3).

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Amount of purchases of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfers of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset) into (out of) level 3 of the fair value hierarchy.

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