Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Third parties	$ 93,395	$ 71,292	$ 209,882	$ 227,407
Related parties	552	232	2,077	1,870
Total net revenue	93,947	71,524	211,959	229,277
Products and services - third parties	64,937	48,755	141,090	151,805
Products and services - related parties	408	190	1,713	1,427
Amortization of intangible assets	410	402	1,201	1,216
Total cost of revenue	65,755	49,347	144,004	154,448
Gross profit	28,192	22,177	67,955	74,829
Operating expenses:
Research and product development	8,903	9,898	26,865	29,512
Selling, marketing, general and administrative	16,925	15,716	43,845	45,684
Amortization of intangible assets	387	464	1,130	1,406
Total operating expenses	26,215	26,078	71,840	76,602
Operating income (loss)	1,977	(3,901)	(3,885)	(1,773)
Interest income	14	374	98	524
Interest expense	(446)	(1,124)	(1,503)	(3,239)
Loss on extinguishment of debt			(1,369)
Other income (expense), net	(41)	944	69	2,517
Income (loss) before income taxes	1,504	(3,707)	(6,590)	(1,971)
Income tax provision	1,619	289	2,452	1,098
Net income (loss)	(115)	(3,996)	(9,042)	(3,069)
Net income (loss) attributable to non-controlling interest		37		194
Net income (loss) attributable to DZS Inc.	(115)	(4,033)	(9,042)	(3,263)
Foreign currency translation adjustments	1,112	(2,426)	(1,519)	(4,123)
Actuarial gain (loss)		38	285	(1,115)
Comprehensive income (loss)	997	(6,384)	(10,276)	(8,307)
Comprehensive income (loss) attributable to non- controlling interest		31		209
Comprehensive income (loss) attributable to DZS Inc.	$ 997	$ (6,415)	$ (10,276)	$ (8,516)
Net income (loss) per share attributable to DZS Inc.
Basic	$ (0.01)	$ (0.19)	$ (0.42)	$ (0.17)
Diluted	$ (0.01)	$ (0.19)	$ (0.42)	$ (0.17)
Weighted average shares outstanding used to compute basic net income (loss) per share	21,592	21,384	21,532	18,732
Weighted average shares outstanding used to compute diluted net income (loss) per share	21,592	21,384	21,532	18,732