Revenue from Contracts with Customers (Tables)

6 Months Ended

Jun. 30, 2020

Revenue from Contract with Customer [Abstract]


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2019		2020		2019		2020
Volume-related ⁽¹⁾	$	66,260	$	50,231	$	140,788	$	125,290
Station construction sales		5,943		5,277		9,113		10,800
AFTC ⁽²⁾		—		4,366		—		9,790
Other		115		—		115		—
Total revenue	$	72,318	$	59,874	$	150,016	$	145,880

(1)

Includes changes in fair value of derivative instruments related to the Company’s commodity swap and customer fueling contracts associated with the Company’s Zero Now truck financing program. The amounts are classified as revenue because the Company’s commodity swap contracts are used to economically offset the risk associated with the diesel-to-natural gas price spread resulting from customer fueling contracts under the Company’s Zero Now truck financing program. See Note 6 for more information about these derivative instruments. For the three and six months ended June 30, 2019, changes in the fair value of commodity swaps and customer fueling contracts amounted to a gain of $0.6 million and a loss of $4.4 million, respectively. For the three and six months ended June 30, 2020, changes in the fair value of commodity swaps and customer fueling contracts amounted to a loss of $1.5 million and a gain of $4.2 million, respectively.

(2)	Represents the federal alternative fuel excise tax credit that we refer to as “AFTC,” which had previously expired but on December 20, 2019 was retroactively extended for vehicle fuel sales made beginning January 1, 2018 through December 31, 2020. See Note 19 for more information.

Summary of contract balances

As of December 31, 2019 and June 30, 2020, the Company’s contract balances were as follows (in thousands):


	December 31,		June 30,
	2019		2020
Accounts receivable, net	$	61,760	$	48,141

Contract assets - current	$	455	$	1,537
Contract assets - non-current		3,777		3,829
Contract assets - total	$	4,232	$	5,366

Contract liabilities - current	$	5,329	$	2,044
Contract liabilities - non-current		6,339		—
Contract liabilities - total	$	11,668	$	2,044