Summary of Significant Accounting Policies - Additional Information (Details)				1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 26, 2022 USD ($)	Feb. 28, 2022 USD ($)	May 15, 2020 shares	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) shares	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) Facility Segment shares	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Accounting Policies [Line Items]
Other comprehensive income (loss)					$ 0	$ 0	$ 0	$ 0
Cash deposits included in restricted cash					153,741,000		153,741,000		$ 82,450,000
Interest income					3,935,000	2,062,000	7,887,000	4,358,000
Interest expense					9,533,000	3,880,000	$ 18,913,000	7,692,000
Number of reporting units | Segment							4
Valuation allowance for finance receivables classified as held for sale					3,100,000		$ 3,100,000
Debt instrument aggregate principal amount					$ 169,830,000		$ 169,830,000
Issuance of shares | shares					0		0
RA Agreement
Accounting Policies [Line Items]
Common stock, issued | shares			183,870
Performance Shares
Accounting Policies [Line Items]
Issuance of shares | shares			2,684
0.75% Unsecured Convertible Senior Notes Due 2026
Accounting Policies [Line Items]
Debt instrument aggregate principal amount				$ 625,000,000.0		$ 625,000,000.0		$ 625,000,000.0
Debt instrument interest rate				0.75%		0.75%		0.75%
Debt instrument maturity year				2026
Warehouse Credit Facility
Accounting Policies [Line Items]
Cash deposits included in restricted cash					$ 13,032,000		$ 13,032,000
Selling, General and Administrative Expenses
Accounting Policies [Line Items]
Advertising expense					21,100,000	$ 23,500,000	54,900,000	$ 53,100,000
Amount of Upfront Shares was Written Off	$ 2,100,000
Selling, General and Administrative Expenses | Shipping and Handling
Accounting Policies [Line Items]
Shipping and handling expenses					8,200,000	$ 20,200,000	35,000,000.0	$ 35,300,000
Other Loss (Income), Net
Accounting Policies [Line Items]
Other net losses due to changes in fair value					300,000		12,300,000
Finance [Member]
Accounting Policies [Line Items]
Interest income					14,200,000		25,100,000
Interest expense					1,200,000		2,000,000.0
UACC
Accounting Policies [Line Items]
Net proceeds from securitization		$ 317,300,000
Percentage of notes and residual certificates sold		5.00%
Collateralized finance receivable							318,500,000
Carrying value of finance receivables							287,700,000
Asset-backed Securities | UACC
Accounting Policies [Line Items]
Securitization transaction		$ 281,400,000
Residual Interest, 2022-1 Securitization | UACC
Accounting Policies [Line Items]
Securitization transaction		$ 32,300,000
Vehicle Floorplan Facility | Line Of Credit
Accounting Policies [Line Items]
Increased borrowing capacity					700,000,000.0		700,000,000.0
Lenders | Cash Deposits
Accounting Policies [Line Items]
Cash deposits included in restricted cash					77,000,000.0		$ 77,000,000.0
Diverse Bank Group | UACC
Accounting Policies [Line Items]
Number of warehouse credit facilities | Facility							3
Diverse Bank Group | UACC | Warehouse Credit Facility
Accounting Policies [Line Items]
Increased borrowing capacity					$ 400,000,000.0		$ 400,000,000.0