The Company leases certain properties and buildings (including manufacturing facilities, warehouses, and office spaces) and equipment under various arrangements which provide the right to use the underlying asset and require lease payments for the lease term. The Company’s lease portfolio consists of operating leases which expire at various dates through 2028.

In August 2020, the Company completed its relocation of its corporate headquarters from Alameda, California to Plano, Texas and established a new U.S.-based Engineering Center of Excellence in Plano. In September 2020, the Company entered into a lease agreement for additional office space at its headquarters in Plano, Texas. On the commencement date of this lease in March 2021, the Company recognized an aggregate of approximately $1.7 million in right-of-use assets and operating lease liabilities in connection with these leases.

During the nine months ended September 30, 2021, the Company recorded $4.2 million in impairment charges on the right-of-use assets, including $2.5 million related to the restructuring in Hanover, Germany and $1.7 million related to the headquarters relocation to Plano, Texas. See Note 9 Restructuring and Other Charges for further information about the Company's restructuring activities in Hanover, Germany.

	Three months ended September 30,				Nine months ended September 30,
	2021		2020		2021		2020
Operating lease cost	$	952	$	1,335	$	3,301	$	4,024
Short-term lease cost		382		252		1,146		752
Total net lease cost	$	1,334	$	1,587	$	4,447	$	4,776

Variable lease cost was not significant for the three and nine months ended September 30, 2021 and 2020.

Supplemental cash flow information related to the Company’s operating leases was as follows (in thousands):

	Three months ended September 30,				Nine months ended September 30,
	2021		2020		2021		2020
Operating cash outflows from operating leases	$	1,923	$	1,357	$	4,690	$	3,903
Right-of-use assets obtained in exchange for operating lease obligations		409		—		2,283		1,364

The following table presents the weighted average remaining lease term and weighted average discount rates related to the Company’s operating leases as of September 30, 2021 and December 31, 2020, respectively (in thousands, excluding years and percentages):

	September 30, 2021			December 31, 2020
Lease Assets and Liabilities
Assets:
Right-of-use assets from operating leases	$	12,932		$	18,483

Liabilities:
Operating lease liabilities - current	$	4,118		$	4,494
Operating lease liabilities - non-current		12,694			15,959
Total operating lease liabilities	$	16,812		$	20,453
Weighted average remaining lease term	4.4 years			4.6 years
Weighted average discount rate		5.5	%		5.7	%

The following table presents the maturity of the Company’s operating lease liabilities as of September 30, 2021 (in thousands):

Remainder of 2021	$	1,701
2022		4,877
2023		4,442
2024		3,866
2025		2,531
Thereafter		2,457
Total operating lease payments		19,874
Less: imputed interest		(3,062	)
Total operating lease liabilities	$	16,812