Debt (Details)			1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Aug. 13, 2020	Jul. 15, 2020 USD ($)	Nov. 01, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Jul. 31, 2020 USD ($)	Mar. 30, 2020 USD ($)	Aug. 10, 2018 USD ($)	Jan. 31, 2018 USD ($)	Dec. 01, 2017 USD ($)
Debt Instrument [Line Items]
Seller Trust L Bonds				$ 366,892,000		$ 366,892,000		$ 366,892,000			$ 366,900,000
Other borrowings				152,118,000		152,118,000		153,086,000
Other Borrowings
Debt Instrument [Line Items]
Other borrowings				152,100,000		152,100,000		153,100,000
Unamortized premium								900,000
Senior Credit Agreement
Debt Instrument [Line Items]
Other borrowings				77,400,000		77,400,000		77,500,000
Subordinate Credit Agreement
Debt Instrument [Line Items]
Other borrowings				72,100,000		72,100,000		72,200,000
Additional Other Borrowings
Debt Instrument [Line Items]
Other borrowings				2,600,000		$ 2,600,000		2,500,000
LIBOR | Other Borrowings
Debt Instrument [Line Items]
Basis spread on variable rate						3.95%
Subsequent Event | Other Borrowings
Debt Instrument [Line Items]
Repayment of principal		$ 25,000,000.0
Extension fee percentage		0.025
Repayment of principal, interest, and extension fee		$ 28,600,000
Subsequent Event | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	8.00%
L Bonds
Debt Instrument [Line Items]
Debt offering, maximum										$ 2,000,000,000.0		$ 1,000,000,000.0	$ 1,000,000,000.0
Long-term debt, gross				$ 1,100,000,000		$ 1,100,000,000		$ 900,000,000
Debt, weighted average interest rate				7.21%		7.21%		7.15%			7.50%
Amortization				$ 4,200,000	$ 3,200,000	$ 8,100,000	$ 6,000,000.0
Debt issuance costs, gross				$ 43,100,000		$ 43,100,000
Amortization period of deferred financing cost						7 years
L Bonds | Subsequent Event
Debt Instrument [Line Items]
Debentures remaining capacity (less than)									$ 500,000
LNV Corporation
Debt Instrument [Line Items]
Senior credit facility			$ 300,000,000.0
LIBOR floor						1.50%
Effective interest rate				9.00%		9.00%
Additional collateral pledged			298,300,000
Advance received			$ 37,100,000
Portfolio pledged, percentage						77.20%
Line of credit facility, maximum month-end outstanding amount						$ 213,100,000		$ 184,600,000
LNV Corporation | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate						7.50%