Financing Receivables - Changes (Details) $ in Thousands	6 Months Ended		12 Months Ended
	Dec. 31, 2021 USD ($) loan	Jul. 09, 2021 USD ($) loan	Dec. 31, 2020 USD ($) loan
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance		$ 246
Provision for credit losses	$ 1,217	1,172	$ 1,350
Ending Balance	386		246
Financing Receivable [Roll Forward]
Beginning Balance		40,613
Provision for credit losses	(1,217)	(1,172)	(1,350)
Ending Balance	71,152		40,613
Advances
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	211	121	215
Provision for credit losses	358	90	(94)
Realized losses	(120)	0	0
Ending Balance	238	211	121
Financing Receivable [Roll Forward]
Beginning Balance		35,280
Provision for credit losses	(358)	(90)	94
Ending Balance	66,839		35,280
Advances | Revision Of Prior Period, Including Business Combination Fair Value Adjustments, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	0
Ending Balance		0
Loans and Loan Participations
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	111	125	96
Provision for credit losses	859	1,082	1,444
Realized losses	(711)	(1,096)	(1,415)
Ending Balance	148	111	125
Financing Receivable [Roll Forward]
Beginning Balance	4,712	5,333	5,130
Purchases, net	716	1,170	2,839
Proceeds from principal repayments, net	(710)	(832)	(1,316)
Accretion of loan discount	61	123	124
Provision for credit losses	(859)	(1,082)	(1,444)
Ending Balance	4,313	4,712	5,333
Loans and Loan Participations | Revision Of Prior Period, Including Business Combination Fair Value Adjustments, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	0
Ending Balance		0
Financing Receivable [Roll Forward]
Beginning Balance	5,105
Ending Balance		5,105
Residential solar loans
Financing Receivable [Roll Forward]
Purchases, net	$ 0	$ 100	$ 1,600
Number of loans purchased | loan	0	54	1,007
Indirect Channel Loans
Financing Receivable [Roll Forward]
Purchases, net	$ 400	$ 1,100	$ 1,200
Number of loans purchased | loan	20	51	49