Long Term Debt - Additional Information (Details)				1 Months Ended		6 Months Ended	12 Months Ended
	Dec. 21, 2023 BusinessDays $ / shares	May 03, 2023 USD ($)	Jun. 18, 2021 USD ($) d $ / shares shares	Feb. 29, 2024 USD ($) $ / shares	Jul. 31, 2003 USD ($)	Jun. 30, 2022	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Feb. 28, 2024 $ / shares
Debt Instrument [Line Items]
Debt instrument aggregate principal amount								$ 82,556,000
Initial conversion price per share | $ / shares	$ 1
Repurchases of convertible senior notes							$ 36,536,000	90,208,000
Gain on debt extinguishment							37,878,000	164,684,000
Consecutive trading days | BusinessDays	30
Restricted cash							73,234,000	73,095,000
Expected payments, 2024							147,600,000
Expected payments, 2025							91,800,000
Expected payments, 2026							47,800,000
Expected payments, 2027							26,800,000
Expected payments, 2028							4,100,000
Redemption price							208,476,000	192,839,000
Outstanding balance							626,583,000	449,393,000
Current portion of long term debt							172,410,000	47,239,000
Long term debt, net of current portion							454,173,000	402,154,000
Junior subordinated debentures					$ 10,000,000
Subsequent Events
Debt Instrument [Line Items]
Initial conversion price per share | $ / shares									$ 1
Junior Subordinated Debentures
Debt Instrument [Line Items]
Long-term debt, maturity date					Oct. 07, 2033
Long term debt, net of current portion							10,310,000	10,310,000
Percentage of owned finance subsidiary					100.00%
Financing of Beneficial Interest in Securizations
Debt Instrument [Line Items]
Current portion of long term debt							8,894,000
Long term debt, net of current portion							6,484,000
SOFR | Junior Subordinated Debentures
Debt Instrument [Line Items]
Variable interest rate					3.05%
Securitization Debt of Consolidated VIEs
Debt Instrument [Line Items]
Restricted cash							28,500,000	9,000,000
Securitization Debt of Consolidated VIEs | Subsequent Events
Debt Instrument [Line Items]
Redemption price				$ 35,600,000
UACC
Debt Instrument [Line Items]
Expected beneficial interests in securitizations pledged as collateral		$ 24,500,000
Expected proceeds from beneficial interests in securitizations pledged as collateral		$ 24,100,000
Expected repurchases period start, month and year		2025-03
Expected repurchases period end, month and year		2029-09
Investment, Type [Extensible Enumeration]		us-gaap:RepurchaseAgreementsMember
UACC | Financing of Beneficial Interest in Securizations
Debt Instrument [Line Items]
Fair value of the collateral pledged amount							15,800,000
Outstanding balance							15,400,000
Current portion of long term debt							8,900,000
Long term debt, net of current portion							$ 6,500,000
Investment, Type [Extensible Enumeration]							us-gaap:RepurchaseAgreementsMember
Maximum | Subsequent Events
Debt Instrument [Line Items]
Initial conversion price per share | $ / shares				$ 1
0.75% Unsecured Convertible Senior Notes Due 2026
Debt Instrument [Line Items]
Debt instrument aggregate principal amount			$ 625,000,000
Debt instrument interest rate			0.75%
Aggregate principal amount exercise in overallotment option granted to initial purchasers			$ 75,000,000
Long-term debt, frequency of periodic payment						semiannually
Long-term debt, beginning date of payment			Jan. 01, 2022
Long-term debt, maturity date			Jul. 01, 2026
Long-term debt payment terms						The Notes bear interest at a rate of 0.75% per annum, payable semiannually in arrears on January 1 and July 1 of each year, beginning on January 1, 2022.
Net proceeds from offering, after deducting commissions paid to initial purchasers and debt issuance costs paid to third-parties			$ 608,900,000
Debt conversion, each principal amount initially be convertible			$ 1,000
Initial conversion price per share | $ / shares			$ 4,480.29
Debt instrument conversion date			Apr. 01, 2026
Aggregate principal amount							$ 74,200,000	254,300,000
Repurchases of convertible senior notes							36,500,000	90,200,000
Gain on debt extinguishment							37,900,000	164,700,000
Unamortized debt discount and debt issuance costs							3,700,000	6,500,000
Net carrying value of debt							286,800,000	359,300,000
Interest expense							$ 4,300,000	$ 7,200,000
Effective interest rate							1.30%
0.75% Unsecured Convertible Senior Notes Due 2026 | During any Fiscal Quarter Commencing After Fiscal Quarter Ending on September 30, 2021
Debt Instrument [Line Items]
Consecutive trading days | d			30
0.75% Unsecured Convertible Senior Notes Due 2026 | During any Fiscal Quarter Commencing After Fiscal Quarter Ending on September 30, 2021 | Minimum
Debt Instrument [Line Items]
Trading days | d			20
Conversion price			130.00%
0.75% Unsecured Convertible Senior Notes Due 2026 | During Five Consecutive Business Day Period After any Ten Consecutive Trading Day Period
Debt Instrument [Line Items]
Debt conversion, each principal amount initially be convertible			$ 1,000
Consecutive trading days | d			10
0.75% Unsecured Convertible Senior Notes Due 2026 | During Five Consecutive Business Day Period After any Ten Consecutive Trading Day Period | Maximum
Debt Instrument [Line Items]
Conversion price			98.00%
0.75% Unsecured Convertible Senior Notes Due 2026 | Company May Redeem On or after July 6, 2024
Debt Instrument [Line Items]
Consecutive trading days | d			30
Redemption percentage of principal amount			100.00%
0.75% Unsecured Convertible Senior Notes Due 2026 | Company May Redeem On or after July 6, 2024 | Minimum
Debt Instrument [Line Items]
Trading days | d			20
Conversion price			130.00%
0.75% Unsecured Convertible Senior Notes Due 2026 | Common Stock
Debt Instrument [Line Items]
Debt conversion, for each principal amount conversion to shares | shares			0.2232