Summary of Significant Accounting Policies (Policies)	3 Months Ended
Apr. 04, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying Condensed Consolidated Financial Statements include Belden Inc. and all of its subsidiaries (the Company, us, we, or our). We eliminate all significant affiliate accounts and transactions in consolidation. The accompanying Condensed Consolidated Financial Statements presented as of any date other than December 31, 2020: •Are prepared from the books and records without audit, and •Are prepared in accordance with the instructions for Form 10-Q and do not include all of the information required by accounting principles generally accepted in the United States for complete statements, but •Include all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the financial statements. These Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and Supplementary Data contained in our 2020 Annual Report on Form 10-K
Business Description	Business DescriptionWe are a global supplier of specialty networking solutions built around two global business platforms - Enterprise Solutions and Industrial Solutions. Our comprehensive portfolio of solutions enables customers to transmit and secure data, sound, and video for mission critical applications across complex enterprise and industrial environments.
Reporting Periods	Reporting PeriodsOur fiscal year and fiscal fourth quarter both end on December 31. Our fiscal first quarter ends on the Sunday falling closest to 91 days after December 31, which was April 4, 2021, the 94th day of our fiscal year 2021. Our fiscal second and third quarters each have 91 days. The three months ended April 4, 2021 and March 29, 2020 included 94 and 89 days, respectively.
Fair Value Measurement	Fair Value Measurement Accounting guidance for fair value measurements specifies a hierarchy of valuation techniques based upon whether the inputs to those valuation techniques reflect assumptions other market participants would use based upon market data obtained from independent sources or reflect our own assumptions of market participant valuation. The hierarchy is broken down into three levels based on the reliability of the inputs as follows: •Level 1 – Quoted prices in active markets that are unadjusted and accessible at the measurement date for identical, unrestricted assets or liabilities; •Level 2 – Quoted prices for identical assets and liabilities in markets that are not active, quoted prices for similar assets and liabilities in active markets, or financial instruments for which significant inputs are observable, either directly or indirectly; and •Level 3 – Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable. As of and during the three months ended April 4, 2021 and March 29, 2020, we utilized Level 1 inputs to determine the fair value of cash equivalents, and we utilized Level 2 and Level 3 inputs to determine the fair value of net assets acquired in business combinations (see Note 3) and for impairment testing (see Notes 4 and 10). We did not have any transfers between Level 1 and Level 2 fair value measurements during the three months ended April 4, 2021 and March 29, 2020.
Cash and Cash Equivalents	Cash and Cash Equivalents We classify cash on hand and deposits in banks, including commercial paper, money market accounts, and other investments with an original maturity of three months or less, that we hold from time to time, as cash and cash equivalents. We periodically have cash equivalents consisting of short-term money market funds and other investments. As of April 4, 2021, we did not have any such cash equivalents on hand. The primary objective of our investment activities is to preserve our capital for the purpose of funding operations. We do not enter into investments for trading or speculative purposes. During the three months ended March 29, 2020, we paid the sellers of Snell Advanced Media (SAM) the full earnout consideration of $31.4 million in cash in accordance with the purchase agreement. SAM was acquired on February 8, 2018 and was included in the Grass Valley disposal group.
Contingent Liabilities	Contingent Liabilities We have established liabilities for environmental and legal contingencies that are probable of occurrence and reasonably estimable, the amounts of which are currently not material. We accrue environmental remediation costs based on estimates of known environmental remediation exposures developed in consultation with our environmental consultants and legal counsel. We are, from time to time, subject to routine litigation incidental to our business. These lawsuits primarily involve claims for damages arising out of the use of our products, allegations of patent or trademark infringement, and litigation and administrative proceedings involving employment matters and commercial disputes. Based on facts currently available, we believe the disposition of the claims that are pending or asserted will not have a material adverse effect on our financial position, results of operations, or cash flow. As of April 4, 2021, we were party to bank guaranties, standby letters of credit, and surety bonds totaling $7.1 million, $6.0 million, and $3.3 million, respectively.
Revenue Recognition	Revenue Recognition We recognize revenue consistent with the principles as outlined in the following five step model: (1) identify the contract with the customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when (or as) each performance obligation is satisfied. See Note 2.
Subsequent Events	Subsequent Events We evaluated subsequent events after the balance sheet date through the financial statement issuance date for appropriate accounting and disclosure.
Noncontrolling Interest	Noncontrolling Interest We have a 51% ownership percentage in a joint venture with Shanghai Hi-Tech Control System Co, Ltd (Hite). The purpose of the joint venture is to develop and provide certain Industrial Solutions products and integrated solutions to customers in China. Belden and Hite are committed to fund $1.53 million and $1.47 million, respectively, to the joint venture in the future. The joint venture is determined to not have sufficient equity at risk; therefore, it is considered a variable interest entity. We have determined that Belden is the primary beneficiary of the joint venture, due to both our ownership percentage and our control over the activities of the joint venture that most significantly impact its economic performance based on the terms of the joint venture agreement with Hite. Because Belden is the primary beneficiary of the joint venture, we have consolidated the joint venture in our financial statements. The results of the joint venture attributable to Hite’s ownership are presented as net income (loss) attributable to noncontrolling interest in the Condensed Consolidated Statements of Operations. The joint venture is not material to our Condensed Consolidated financial statements as of or for the periods ended April 4, 2021 and March 29, 2020. Furthermore, certain subsidiaries of our Opterna and OTN Systems N.V. (OTN) businesses, which we acquired in April of 2019 and January 2021, respectively, include noncontrolling interests. Because we have a controlling financial interest in these subsidiaries, they are consolidated into our financial statements. The results of these subsidiaries were consolidated into our financial statements as of the respective acquisition dates. The results that are attributable to the noncontrolling interest holders are presented as net income (loss) attributable to noncontrolling interests in the Condensed Consolidated Statements of Operations. An immaterial amount of Opterna's annual revenues are generated from transactions with the noncontrolling interests. The subsidiaries of Opterna and OTN that include noncontrolling interests are not material to our Condensed Consolidated financial statements as of or for the periods ended April 4, 2021 and March 29, 2020.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Apr. 04, 2021

The accompanying Condensed Consolidated Financial Statements include Belden Inc. and all of its subsidiaries (the Company, us, we, or our). We eliminate all significant affiliate accounts and transactions in consolidation.

The accompanying Condensed Consolidated Financial Statements presented as of any date other than December 31, 2020:

•Are prepared from the books and records without audit, and

•Are prepared in accordance with the instructions for Form 10-Q and do not include all of the information required by accounting principles generally accepted in the United States for complete statements, but

•Include all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the financial statements.

These Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and Supplementary Data contained in our 2020 Annual Report on Form 10-K

Business Description

Business DescriptionWe are a global supplier of specialty networking solutions built around two global business platforms - Enterprise Solutions and Industrial Solutions. Our comprehensive portfolio of solutions enables customers to transmit and secure data, sound, and video for mission critical applications across complex enterprise and industrial environments.

Reporting Periods

Reporting PeriodsOur fiscal year and fiscal fourth quarter both end on December 31. Our fiscal first quarter ends on the Sunday falling closest to 91 days after December 31, which was April 4, 2021, the 94th day of our fiscal year 2021. Our fiscal second and third quarters each have 91 days. The three months ended April 4, 2021 and March 29, 2020 included 94 and 89 days, respectively.

Fair Value Measurement

Accounting guidance for fair value measurements specifies a hierarchy of valuation techniques based upon whether the inputs to those valuation techniques reflect assumptions other market participants would use based upon market data obtained from independent sources or reflect our own assumptions of market participant valuation. The hierarchy is broken down into three levels based on the reliability of the inputs as follows:

•Level 1 – Quoted prices in active markets that are unadjusted and accessible at the measurement date for identical, unrestricted assets or liabilities;

•Level 2 – Quoted prices for identical assets and liabilities in markets that are not active, quoted prices for similar assets and liabilities in active markets, or financial instruments for which significant inputs are observable, either directly or indirectly; and

•Level 3 – Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable.

As of and during the three months ended April 4, 2021 and March 29, 2020, we utilized Level 1 inputs to determine the fair value of cash equivalents, and we utilized Level 2 and Level 3 inputs to determine the fair value of net assets acquired in business combinations (see Note 3) and for impairment testing (see Notes 4 and 10). We did not have any transfers between Level 1 and Level 2 fair value measurements during the three months ended April 4, 2021 and March 29, 2020.

Cash and Cash Equivalents

We classify cash on hand and deposits in banks, including commercial paper, money market accounts, and other investments with an original maturity of three months or less, that we hold from time to time, as cash and cash equivalents. We periodically have cash equivalents consisting of short-term money market funds and other investments. As of April 4, 2021, we did not have any such cash equivalents on hand. The primary objective of our investment activities is to preserve our capital for the purpose of funding operations. We do not enter into investments for trading or speculative purposes.

During the three months ended March 29, 2020, we paid the sellers of Snell Advanced Media (SAM) the full earnout consideration of $31.4 million in cash in accordance with the purchase agreement. SAM was acquired on February 8, 2018 and was included in the Grass Valley disposal group.

Contingent Liabilities

We have established liabilities for environmental and legal contingencies that are probable of occurrence and reasonably estimable, the amounts of which are currently not material. We accrue environmental remediation costs based on estimates of known environmental remediation exposures developed in consultation with our environmental consultants and legal counsel. We are, from time to time, subject to routine litigation incidental to our business. These lawsuits primarily involve claims for damages arising out of the use of our products, allegations of patent or trademark infringement, and litigation and administrative proceedings involving employment matters and commercial disputes. Based on facts currently available, we believe the disposition of the claims that are pending or asserted will not have a material adverse effect on our financial position, results of operations, or cash flow.

As of April 4, 2021, we were party to bank guaranties, standby letters of credit, and surety bonds totaling $7.1 million, $6.0 million, and $3.3 million, respectively.

Revenue Recognition

We recognize revenue consistent with the principles as outlined in the following five step model: (1) identify the contract with the customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when (or as) each performance obligation is satisfied. See Note 2.

Subsequent Events

We evaluated subsequent events after the balance sheet date through the financial statement issuance date for appropriate accounting and disclosure.

Noncontrolling Interest

We have a 51% ownership percentage in a joint venture with Shanghai Hi-Tech Control System Co, Ltd (Hite). The purpose of the joint venture is to develop and provide certain Industrial Solutions products and integrated solutions to customers in China. Belden and Hite are committed to fund $1.53 million and $1.47 million, respectively, to the joint venture in the future. The joint venture is determined to not have sufficient equity at risk; therefore, it is considered a variable interest entity. We have determined that Belden is the primary beneficiary of the joint venture, due to both our ownership percentage and our control over the activities of the joint venture that most significantly impact its economic performance based on the terms of the joint venture agreement with Hite. Because Belden is the primary beneficiary of the joint venture, we have consolidated the joint venture in our financial statements. The results of the joint venture attributable to Hite’s ownership are presented as net income (loss) attributable to noncontrolling interest in the Condensed Consolidated Statements of Operations. The joint venture is not material to our Condensed Consolidated financial statements as of or for the periods ended April 4, 2021 and March 29, 2020.

Furthermore, certain subsidiaries of our Opterna and OTN Systems N.V. (OTN) businesses, which we acquired in April of 2019 and January 2021, respectively, include noncontrolling interests. Because we have a controlling financial interest in these subsidiaries, they are consolidated into our financial statements. The results of these subsidiaries were consolidated into our financial statements as of the respective acquisition dates. The results that are attributable to the noncontrolling interest holders are presented as net income (loss) attributable to noncontrolling interests in the Condensed Consolidated Statements of Operations. An immaterial amount of Opterna's annual revenues are generated from transactions with the noncontrolling interests. The subsidiaries of Opterna and OTN that include noncontrolling interests are not material to our Condensed Consolidated financial statements as of or for the periods ended April 4, 2021 and March 29, 2020.