Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2022

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The following tables presents the asset reported in "other assets" in the consolidated balance sheet measured at its fair value on a recurring basis as of June 30, 2022 and 2021 by level within the fair value hierarchy.

June 30, 2022			Quoted prices in active markets for identical assets		Significant other observable inputs		Significant unobservable inputs		Unrealized
Description	Total		Level 1		Level 2		Level 3		Gains
Recurring fair value measurements
Marketable equity securities
EuroSite Power Inc.	$	112,492	$	—	$	112,492	$	—	$	37,497
Total recurring fair value measurements	$	112,492	$	—	$	112,492	$	—	$	37,497
June 30, 2021			Quoted prices in active markets for identical assets		Significant other observable inputs		Significant unobservable inputs		Unrealized
Description	Total		Level 1		Level 2		Level 3		Gains
Recurring fair value measurements
Marketable equity securities
EuroSite Power Inc.	$	168,739	$	—	$	168,739	$	—	$	56,246
Total recurring fair value measurements	$	168,739	$	—	$	168,739	$	—	$	56,246

Schedule of Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings

The following table summarizes changes in Level 2 assets which are comprised of marketable equity securities for the six months ended June 30, 2022 and 2021:

Fair value at December 31, 2021	$	74,995
Unrealized gains	37,497
Fair value at June 30, 2022	$	112,492
Fair value at December 31, 2020	$	118,084
Sale of 93,187 shares	(5,591)
Unrealized gains	56,246
Fair value at June 30, 2021	$	168,739