Debt - Additional Information (Detail)	9 Months Ended	12 Months Ended		9 Months Ended		9 Months Ended	12 Months Ended	9 Months Ended	3 Months Ended	12 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	3 Months Ended	12 Months Ended	9 Months Ended	3 Months Ended			12 Months Ended		12 Months Ended
	Sep. 30, 2013 USD ($)	Dec. 31, 2012	Mar. 31, 2014 Subsequent Event	Sep. 30, 2013 Term Loan USD ($)	Dec. 31, 2012 Equipment USD ($)	Sep. 30, 2013 Libor Plus Rate	Dec. 31, 2012 Libor Plus Rate	Sep. 30, 2013 Libor Plus Rate Term Loan	Mar. 31, 2014 Libor Plus Rate Term Loan Subsequent Event	Dec. 31, 2012 Capital expenditure, authorized Equipment	Sep. 30, 2013 Prime Rate Term Loan	Mar. 31, 2014 Base Rate Term Loan Subsequent Event	Sep. 30, 2013 Credit Facility USD ($)	Dec. 31, 2012 Credit Facility USD ($)	Sep. 30, 2013 Credit Facility Libor Plus Rate	Mar. 31, 2014 Credit Facility Libor Plus Rate Subsequent Event	Dec. 31, 2012 Credit Facility Libor Plus Rate Equipment USD ($)	Sep. 30, 2013 Credit Facility Prime Rate	Mar. 31, 2014 Credit Facility Base Rate Subsequent Event	Mar. 29, 2013 NeoPhotonics Semiconductor	Dec. 31, 2012 Series of Individually Immaterial Business Acquisitions USD ($)	Dec. 31, 2012 Series of Individually Immaterial Business Acquisitions Libor Plus Rate	Dec. 31, 2012 Series of Individually Immaterial Business Acquisitions Capital expenditure, authorized USD ($)	Dec. 31, 2012 Series of Individually Immaterial Business Acquisitions Credit Facility Libor Plus Rate	Mar. 29, 2013 Notes Payable To be paid in three equal installments NeoPhotonics Semiconductor USD ($)	Mar. 29, 2013 Notes Payable To be paid in three equal installments NeoPhotonics Semiconductor JPY (¥)
Debt Instrument [Line Items]
Liabilities assumed																									$ 11,130,000	¥ 1,050,000,000
Obligation bear interest																				1.50%
Revolving line of credit, maximum borrowing capacity													0	8,000,000
Line of credit facility remaining borrowing capacity													20,000,000	0			7,000,000						5,800,000
Interest rate description				Borrowings under the term loan include an interest rate option of a base rate as defined in the agreement plus 1.75% or LIBOR plus 2.75%.		borrowings under this revolving line of credit include an interest rate option of a base rate as defined in the agreement plus 1.5% or LIBOR plus 2.5%.	Borrowings under this facility bear interest at a rate of LIBOR plus 2%.			Borrowings under this facility would bear interest at a rate of LIBOR plus 2%												The advances bear interest at a rate of LIBOR plus 2%
Line of credit facility, marginal interest rate								2.75%	3.00%		1.75%	2.00%		2.00%	2.50%	2.75%	2.00%	1.50%	1.75%					2.00%
Credit facility outstanding balance				26,300,000	0																14,200,000
Line of credit facility, interest rate								2.93%							2.68%
Line of credit facility, expiration date				2017-06									2016-03
Debt Instrument, Covenant Compliance	The Company’s Credit Agreement requires the maintenance of specified financial covenants, including a liquidity ratio, restricts its ability to incur additional debt or to engage in specified transactions, restricts the payment of dividends and is secured by substantially all of its U.S. assets, other than intellectual property assets. A breach of any of these covenants in the future could have an adverse impact on availability of financial assurances. In addition, the amounts outstanding could also be subject to acceleration of maturity. If such acceleration were to occur, the Company may not have sufficient liquidity available to repay the indebtedness. As of September 30, 2013 and December 31, 2012, the Company was in compliance with the covenants contained in this agreement	The Company’s Credit Agreement requires the maintenance of specified financial covenants, including a liquidity ratio, restricts its ability to incur additional debt or to engage in specified transactions, restricts the payment of dividends and is secured by substantially all of its U.S. assets, other than intellectual property assets. A breach of any of these covenants in the future could have an adverse impact on availability of financial assurances. In addition, the amounts outstanding could also be subject to acceleration of maturity. If such acceleration were to occur, the Company may not have sufficient liquidity available to repay the indebtedness. As of September 30, 2013 and December 31, 2012, the Company was in compliance with the covenants contained in this agreement
Restricted cash	$ 1,600,000
Increase in margin			0.25%