Business Acquisition - Summary of Balance Sheet Reclassification Adjustments (Details) - USD ($) $ in Thousands		Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Assets
Cash and cash equivalents				$ 0
Cash and due from banks		$ 22,604		5,197
Interest-bearing deposits in banks		839,547		519,766
Total cash and cash equivalents		862,151		524,963
Restricted cash	[1]	77,577		103,522
Securities available for sale at fair value		274,930		142,226
Loans held for investment at fair value				0
Loans held for investment by the Company at fair value				0
Loans held for sale by the Company at fair value				0
Loans held for sale at fair value	[1]	152,160		121,902
Retail and certificate loans held for investment at fair value	[1]	298,541		636,686
Other loans held for investment at fair value	[1]	27,229		49,954
Accrued interest receivable				0
Property, equipment and software, net		96,073		96,641
Operating lease assets		79,862		0
Intangible assets, net		22,521		0
Other assets	[1]	283,126		187,399
Total assets		4,750,760		1,863,293
Liabilities and Equity
Accounts payable		7,866		0
Accrued interest payable				0
Operating lease liabilities		95,543		0
Accrued expenses and other liabilities				0
Payable to investors		20,910		0
Credit facilities and securities sold under repurchase agreements				0
Short-term borrowings		46,110		104,989
Retail notes, certificates and secured borrowings at fair value	[1]	298,541		636,774
Payable on Structured Program borrowings	[1]	89,252		152,808
Other liabilities	[1]	265,840		244,551
Total liabilities		3,945,970		1,139,122
Equity
Common stock		998		881
Additional paid-in capital		1,594,646		1,508,020
Accumulated deficit		(796,742)		(786,214)
Accumulated other comprehensive income		5,980		1,484
Total equity		804,790	$ 762,359	724,171	$ 733,892	$ 746,142	$ 900,187
Total liabilities and equity		$ 4,750,760		1,863,293
LendingClub Historical Presentation
Assets
Cash and cash equivalents				524,963
Cash and due from banks				0
Interest-bearing deposits in banks				0
Total cash and cash equivalents				0
Restricted cash				103,522
Securities available for sale at fair value				142,226
Loans held for investment at fair value				636,686
Loans held for investment by the Company at fair value				49,954
Loans held for sale by the Company at fair value				121,902
Loans held for sale at fair value				0
Retail and certificate loans held for investment at fair value				0
Other loans held for investment at fair value				0
Accrued interest receivable				5,205
Property, equipment and software, net				96,641
Operating lease assets				74,037
Intangible assets, net				11,427
Other assets				96,730
Total assets				1,863,293
Liabilities and Equity
Accounts payable				3,698
Accrued interest payable				4,572
Operating lease liabilities				94,538
Accrued expenses and other liabilities				101,457
Payable to investors				40,286
Credit facilities and securities sold under repurchase agreements				104,989
Short-term borrowings				0
Retail notes, certificates and secured borrowings at fair value				636,774
Payable on Structured Program borrowings				152,808
Other liabilities				0
Total liabilities				1,139,122
Equity
Common stock				881
Additional paid-in capital				1,508,020
Accumulated deficit				(786,214)
Accumulated other comprehensive income				1,484
Total equity				724,171
Total liabilities and equity				1,863,293
Reclassification Adjustments
Assets
Cash and cash equivalents				(524,963)
Cash and due from banks				5,197
Interest-bearing deposits in banks				519,766
Total cash and cash equivalents				524,963
Restricted cash				0
Securities available for sale at fair value				0
Loans held for investment at fair value				(636,686)
Loans held for investment by the Company at fair value				(49,954)
Loans held for sale by the Company at fair value				(121,902)
Loans held for sale at fair value				121,902
Retail and certificate loans held for investment at fair value				636,686
Other loans held for investment at fair value				49,954
Accrued interest receivable				(5,205)
Property, equipment and software, net				0
Operating lease assets				(74,037)
Intangible assets, net				(11,427)
Other assets				90,669
Total assets				0
Liabilities and Equity
Accounts payable				(3,698)
Accrued interest payable				(4,572)
Operating lease liabilities				(94,538)
Accrued expenses and other liabilities				(101,457)
Payable to investors				(40,286)
Credit facilities and securities sold under repurchase agreements				(104,989)
Short-term borrowings				104,989
Retail notes, certificates and secured borrowings at fair value				0
Payable on Structured Program borrowings				0
Other liabilities				244,551
Total liabilities				0
Equity
Common stock				0
Additional paid-in capital				0
Accumulated deficit				0
Accumulated other comprehensive income				0
Total equity				0
Total liabilities and equity				$ 0

[1] Includes amounts in consolidated variable interest entities (VIEs) presented separately in the table below.