Business Acquisitions - Summary of Income Statement Reclassification Adjustments (Details) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021		Jun. 30, 2020
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Compensation and benefits		$ (4,098,000)	$ (6,032,000)	$ (9,419,000)	[1]	$ (95,818,000)	[1]
Net interest income and fair value adjustments		45,905,000	18,937,000	64,411,000		43,135,000
Gain on sales of loans		19,317,000	1,724,000	27,640,000		15,985,000
Non-interest income
Marketplace revenue	[2]	151,735,000	18,881,000	233,462,000		121,358,000
Other non-interest income	[2]	6,741,000	2,540,000	12,348,000		7,051,000
Total non-interest income	[2]	158,476,000	21,421,000	245,810,000		128,409,000
Interest income
Interest on loans held for sale	[2]	8,694,000	25,287,000	13,851,000		52,663,000
Interest on retail and certificate loans held for investment at fair value	[2]	16,014,000	29,700,000	36,276,000		65,076,000
Interest on other loans held for investment at fair value	[2]	1,222,000	2,074,000	2,701,000		4,073,000
Interest on securities available for sale	[2]	2,539,000	3,397,000	4,774,000		7,176,000
Other interest income	[2]	190,000	102,000	346,000		983,000
Total interest income	[2]	67,727,000	60,560,000	112,317,000		129,971,000
Interest expense
Interest on short-term borrowings	[2]	1,003,000	5,755,000	2,267,000		13,153,000
Interest on retail notes, certificates and secured borrowings	[2]	16,014,000	29,700,000	36,276,000		65,076,000
Interest on Structured Program borrowings	[2]	2,668,000	6,073,000	5,876,000		8,372,000
Interest on other long-term debt	[2]	438,000	95,000	774,000		235,000
Total interest expense	[2]	21,822,000	41,623,000	47,906,000		86,836,000
Net interest income	[2]	45,905,000	18,937,000	64,411,000		43,135,000
Total net revenue	[2]	204,381,000	40,358,000	310,221,000		171,544,000
Provision for credit losses	[2]	34,634,000	(3,511,000)	56,127,000	[1]	7,469,000	[1]
Non-interest expense
Compensation and benefits	[2]	71,925,000	65,797,000	136,345,000		141,342,000
Marketing	[2]	35,107,000	1,814,000	54,652,000		40,895,000
Equipment and software	[2]	9,281,000	8,011,000	17,174,000		14,501,000
Occupancy	[2]	6,157,000	8,962,000	13,057,000		15,775,000
Depreciation and amortization	[2]	11,508,000	16,611,000	23,274,000		29,484,000
Professional services	[2]	11,520,000	9,765,000	23,123,000		23,906,000
Other non-interest expense	[2]	14,641,000	11,380,000	26,766,000		24,411,000
Total non-interest expense	[2]	160,139,000	122,340,000	294,391,000		290,314,000
Income (Loss) before income tax expense		9,608,000	(78,471,000)	(40,297,000)		(126,239,000)
Income tax expense		237,000	0	(2,584,000)		319,000
Consolidated net loss		9,371,000	(78,471,000)	(37,713,000)	[1]	(126,558,000)	[1]
LendingClub
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total interest income			0			0
Compensation and benefits			0			0
Gain on sales of loans			0			0
Net investor revenue			0			0
Other revenue			0			0
Total net revenue			0			0
Non-interest income
Marketplace revenue			18,881,000			121,358,000
Other non-interest income			2,540,000			7,051,000
Total non-interest income			21,421,000			128,409,000
Interest income
Interest on loans held for sale			25,287,000			52,663,000
Interest on retail and certificate loans held for investment at fair value			29,700,000			65,076,000
Interest on other loans held for investment at fair value			2,074,000			4,073,000
Interest on securities available for sale			3,397,000			7,176,000
Other interest income			102,000			983,000
Total interest income			60,560,000			129,971,000
Interest expense
Interest on short-term borrowings			5,755,000			13,153,000
Interest on retail notes, certificates and secured borrowings			29,700,000			65,076,000
Interest on Structured Program borrowings			6,073,000			8,372,000
Interest on other long-term debt			95,000			235,000
Total interest expense			41,623,000			86,836,000
Net interest income			18,937,000			43,135,000
Total net revenue			40,358,000			171,544,000
Provision for credit losses			(3,511,000)			7,469,000
Operating expenses
Sales and marketing			0			0
Origination and servicing			0			0
Engineering and product development			0			0
Other general and administrative			0			0
Total operating expenses			0			0
Non-interest expense
Compensation and benefits			65,797,000			141,342,000
Marketing			1,814,000			40,895,000
Equipment and software			8,011,000			14,501,000
Occupancy			8,962,000			15,775,000
Depreciation and amortization			16,611,000			29,484,000
Professional services			9,765,000			23,906,000
Other non-interest expense			11,380,000			24,411,000
Total non-interest expense			122,340,000			290,314,000
Income (Loss) before income tax expense			(78,471,000)			(126,239,000)
Income tax expense			0			319,000
Consolidated net loss			(78,471,000)			(126,558,000)
Transaction fees
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net Revenue		$ 113,802,000	3,874,000	$ 169,361,000		140,117,000
Transaction fees | LendingClub
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net Revenue			0			0
Investor fees | LendingClub
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net Revenue			0			0
LendingClub Historical Presentation | LendingClub
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total interest income			60,560,000			129,971,000
Interest expense			(37,766,000)			(82,007,000)
Compensation and benefits			(6,378,000)			(108,116,000)
Net interest income and fair value adjustments			16,416,000			(60,152,000)
Gain on sales of loans			1,724,000			15,985,000
Net investor revenue			37,455,000			16,907,000
Other revenue			2,540,000			7,051,000
Total net revenue			43,869,000			164,075,000
Non-interest income
Marketplace revenue			0			0
Other non-interest income			0			0
Total non-interest income			0			0
Interest income
Interest on loans held for sale			0			0
Interest on retail and certificate loans held for investment at fair value			0			0
Interest on other loans held for investment at fair value			0			0
Interest on securities available for sale			0			0
Other interest income			0			0
Total interest income			0			0
Interest expense
Interest on short-term borrowings			0			0
Interest on retail notes, certificates and secured borrowings			0			0
Interest on Structured Program borrowings			0			0
Interest on other long-term debt			0			0
Total net revenue			0			0
Provision for credit losses			0			0
Operating expenses
Sales and marketing			8,723,000			58,507,000
Origination and servicing			17,830,000			38,824,000
Engineering and product development			39,167,000			77,877,000
Other general and administrative			56,620,000			115,106,000
Total operating expenses			122,340,000			290,314,000
Non-interest expense
Compensation and benefits			0			0
Marketing			0			0
Equipment and software			0			0
Occupancy			0			0
Depreciation and amortization			0			0
Professional services			0			0
Other non-interest expense			0			0
Total non-interest expense			0			0
Income (Loss) before income tax expense			(78,471,000)			(126,239,000)
Income tax expense			0			319,000
Consolidated net loss			(78,471,000)			(126,558,000)
LendingClub Historical Presentation | Transaction fees | LendingClub
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net Revenue			3,874,000			140,117,000
LendingClub Historical Presentation | Investor fees | LendingClub
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net Revenue			19,315,000			61,074,000
Reclassification Adjustments | LendingClub
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total interest income			(60,560,000)			(129,971,000)
Interest expense			37,766,000			82,007,000
Compensation and benefits			6,378,000			108,116,000
Net interest income and fair value adjustments			(16,416,000)			60,152,000
Gain on sales of loans			(1,724,000)			(15,985,000)
Net investor revenue			(37,455,000)			(16,907,000)
Other revenue			(2,540,000)			(7,051,000)
Total net revenue			(43,869,000)			(164,075,000)
Non-interest income
Marketplace revenue			18,881,000			121,358,000
Other non-interest income			2,540,000			7,051,000
Total non-interest income			21,421,000			128,409,000
Interest income
Interest on loans held for sale			25,287,000			52,663,000
Interest on retail and certificate loans held for investment at fair value			29,700,000			65,076,000
Interest on other loans held for investment at fair value			2,074,000			4,073,000
Interest on securities available for sale			3,397,000			7,176,000
Other interest income			102,000			983,000
Total interest income			60,560,000			129,971,000
Interest expense
Interest on short-term borrowings			5,755,000			13,153,000
Interest on retail notes, certificates and secured borrowings			29,700,000			65,076,000
Interest on Structured Program borrowings			6,073,000			8,372,000
Interest on other long-term debt			95,000			235,000
Total interest expense			41,623,000			86,836,000
Net interest income			18,937,000			43,135,000
Total net revenue			40,358,000			171,544,000
Provision for credit losses			(3,511,000)			7,469,000
Operating expenses
Sales and marketing			(8,723,000)			(58,507,000)
Origination and servicing			(17,830,000)			(38,824,000)
Engineering and product development			(39,167,000)			(77,877,000)
Other general and administrative			(56,620,000)			(115,106,000)
Total operating expenses			(122,340,000)			(290,314,000)
Non-interest expense
Compensation and benefits			65,797,000			141,342,000
Marketing			1,814,000			40,895,000
Equipment and software			8,011,000			14,501,000
Occupancy			8,962,000			15,775,000
Depreciation and amortization			16,611,000			29,484,000
Professional services			9,765,000			23,906,000
Other non-interest expense			11,380,000			24,411,000
Total non-interest expense			122,340,000			290,314,000
Income (Loss) before income tax expense			0			0
Income tax expense			0			0
Consolidated net loss			0			0
Reclassification Adjustments | Transaction fees | LendingClub
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net Revenue			(3,874,000)			(140,117,000)
Reclassification Adjustments | Investor fees | LendingClub
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net Revenue			$ (19,315,000)			$ (61,074,000)

[1] Prior period amounts have been reclassified to conform to the current period presentation. See “Notes to Condensed Consolidated Financial Statements – Note 1. Summary of Significant Accounting Policies” for additional information.

[2] Prior period amounts have been reclassified to conform to the current period presentation. See “Notes to Condensed Consolidated Financial Statements – Note 1. Summary of Significant Accounting Policies” for additional information.