Organization and Summary of Significant Accounting Policies - Summary of Effect of Restatement on Previously Reported Unaudited Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands		Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents		$ 34,160	$ 46,666	$ 56,818
Restricted cash		6,343	6,808	6,848
Accounts receivable - trade, net		78,950	86,114
Other receivables		9,898	10,621
Inventories		70,085	56,893
Contract assets		902	2,184
Prepaid expenses and other current assets		10,019	5,690
Total current assets		210,357	214,976
Property, plant and equipment, net		10,277	9,842
Right-of-use assets from operating leases		11,751	12,640
Goodwill		6,145	6,145	5,675
Intangible assets, net		4,820	5,115
Other assets		9,904	8,950
Total assets		253,254	257,668
Current liabilities:
Accounts payable - trade		63,774	64,258
Contract liabilities		8,506	6,091
Operating lease liabilities		3,927	4,097
Accrued and other liabilities		16,916	16,032
Total current liabilities		93,123	90,478
Contract liabilities - non-current		2,881	3,044
Operating lease liabilities - non-current		11,029	12,103
Pension liabilities		16,106	16,527
Other long-term liabilities		3,704	3,609
Total liabilities		126,843	125,761
Stockholders’ equity:
Common stock		27	27
Additional paid-in capital		226,163	223,336
Accumulated other comprehensive loss		(4,793)	(4,457)
Accumulated deficit		(94,986)	(86,999)
Total stockholders’ equity		126,411	131,907	$ 131,502	$ 93,579
Total liabilities and stockholders’ equity		253,254	$ 257,668
As Previously Reported
Current assets:
Cash and cash equivalents		34,160
Restricted cash		6,343
Accounts receivable - trade, net		82,607
Other receivables		9,898
Inventories		66,459
Contract assets		902
Prepaid expenses and other current assets		13,039
Total current assets		213,408
Property, plant and equipment, net		10,277
Right-of-use assets from operating leases		11,751
Goodwill		6,145
Intangible assets, net		4,820
Other assets		9,904
Total assets		256,305
Current liabilities:
Accounts payable - trade		63,774
Contract liabilities		7,103
Operating lease liabilities		3,927
Accrued and other liabilities		16,832
Total current liabilities		91,636
Contract liabilities - non-current		2,881
Operating lease liabilities - non-current		11,029
Pension liabilities		16,106
Other long-term liabilities		3,704
Total liabilities		125,356
Stockholders’ equity:
Common stock		27
Additional paid-in capital		226,163
Accumulated other comprehensive loss		(4,793)
Accumulated deficit		(90,448)
Total stockholders’ equity		130,949
Total liabilities and stockholders’ equity		256,305
Adjustments
Current assets:
Accounts receivable - trade, net	[1]	(3,657)
Inventories	[1]	3,626
Prepaid expenses and other current assets	[2]	(3,020)
Total current assets		(3,051)
Total assets		(3,051)
Current liabilities:
Contract liabilities	[1]	1,403
Accrued and other liabilities	[2]	84
Total current liabilities		1,487
Total liabilities		1,487
Stockholders’ equity:
Accumulated deficit		(4,538)
Total stockholders’ equity	[1]	(4,538)
Total liabilities and stockholders’ equity		$ (3,051)

[1] Error corrections relating to the timing of revenue recognition with respect to certain customer projects.

[2] Tax impact on the error corrections relating to the timing of revenue recognition with respect to certain customer projects.