Fair Value Measurements (Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financial assets:
Cash and cash equivalents	$ 2,580	$ 1,297
Investment in equity securities	37	422
Warrants, fair value	2	20
Financial liabilities:
Non-recourse debt	2,197	3,212
Level 1 Estimated Fair Value [Member]
Financial assets:
Cash and cash equivalents	2,580	1,297
Investment in equity securities	37	422	$ 70
Warrants, fair value	0	0
Financial liabilities:
Non-recourse debt	0	0
Level 2 Estimated Fair Value [Member]
Financial assets:
Cash and cash equivalents	0	0
Investment in equity securities	0	0
Warrants, fair value	0	0
Financial liabilities:
Non-recourse debt	0	0
Level 3 Estimated Fair Value [Member]
Financial assets:
Cash and cash equivalents	0	0
Investment in equity securities	0	0
Warrants, fair value	2	20	$ 225
Financial liabilities:
Non-recourse debt	2,197	3,212
Carrying Amount
Financial assets:
Cash and cash equivalents	2,580	1,297
Investment in equity securities	37	422
Warrants, fair value	2	20
Financial liabilities:
Non-recourse debt	$ 2,163	$ 3,108

ATEL 15, LLC 10-K