Related Party Transactions - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Related Party Transaction [Line Items]
Outstanding from related party borrowings	$ 0		$ 0		$ 29,800,000
Operating lease cost	952,000	$ 1,335,000	3,301,000	$ 4,024,000
Right-of-use assets from operating leases	12,932,000		12,932,000		18,483,000
Operating lease liability	$ 16,812,000		$ 16,812,000		20,453,000
DASAN | Majority Shareholder
Related Party Transaction [Line Items]
DNI direct ownership interest	37.10%		37.10%
Guarantee fee, percent			0.90%
DNS Korea
Related Party Transaction [Line Items]
Operating lease cost	$ 400,000	$ 400,000	$ 1,300,000	$ 1,300,000
Right-of-use assets from operating leases	6,700,000		6,700,000		8,600,000
Operating lease liability	$ 6,700,000		$ 6,700,000		$ 8,600,000