Belden (BDC) 10-K 13 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 09, 2018	Jul. 02, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	BDC
Entity Registrant Name	BELDEN INC.
Entity Central Index Key	913,142
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		41,930,562
Entity Public Float			$ 2,453,273,327

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 561,108	$ 848,116
Receivables, net	473,570	388,059
Inventories, net	297,226	190,408
Other current assets	40,167	29,176
Assets held for sale	0	23,193
Total current assets	1,372,071	1,478,952
Property, plant and equipment, less accumulated depreciation	337,322	309,291
Goodwill	1,478,257	1,385,995
Intangible assets, less accumulated amortization	545,207	560,082
Deferred income taxes	42,549	33,706
Other long-lived assets	65,207	38,777
Total assets	3,840,613	3,806,803
Current liabilities:
Accounts payable	376,277	258,203
Accrued liabilities	302,651	310,340
Liabilities held for sale	0	1,736
Total current liabilities	678,928	570,279
Long-term debt	1,560,748	1,620,161
Postretirement benefits	102,085	104,050
Deferred income taxes	27,713	14,276
Other long-term liabilities	36,273	36,720
Stockholders’ equity:
Preferred stock, par value $0.01 per share— 2,000 shares authorized; 52 shares outstanding	1	1
Common stock, par value $0.01 per share— 200,000 shares authorized; 50,335 shares issued; 42,019 and 42,180 shares outstanding at 2017 and 2016, respectively	503	503
Additional paid-in capital	1,123,832	1,116,090
Retained earnings	833,610	783,812
Accumulated other comprehensive loss	(98,026)	(39,067)
Treasury stock, at cost— 8,316 and 8,155 shares at 2017 and 2016, respectively	(425,685)	(401,026)
Total Belden stockholders’ equity	1,434,235	1,460,313
Noncontrolling interest	631	1,004
Total stockholders’ equity	1,434,866	1,461,317
Total liabilities and stockholders' equity	$ 3,840,613	$ 3,806,803

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	2,000,000	2,000,000
Preferred stock, shares outstanding (in shares)	52,000	52,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	50,335,000	50,335,000
Common stock, shares outstanding (in shares)	42,019,000	42,180,000
Treasury stock, shares (in shares)	8,316,000	8,155,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenues	$ 2,388,643	$ 2,356,672	$ 2,309,222
Cost of sales	(1,454,604)	(1,375,678)	(1,391,049)
Gross profit	934,039	980,994	918,173
Selling, general and administrative expenses	(461,022)	(494,224)	(525,518)
Research and development	(134,330)	(140,601)	(148,311)
Amortization of intangibles	(103,997)	(98,385)	(103,791)
Impairment of assets held for sale	0	(23,931)	0
Operating income	234,690	223,853	140,553
Interest expense, net	(82,901)	(95,050)	(100,613)
Loss on debt extinguishment	(52,441)	(2,342)	0
Income from continuing operations before taxes	99,348	126,461	39,940
Income tax benefit (expense)	(6,495)	1,185	26,568
Income from continuing operations	92,853	127,646	66,508
Loss from discontinued operations, net of tax	0	0	(242)
Loss from disposal of discontinued operations, net of tax	0	0	(86)
Net income	92,853	127,646	66,180
Less: Net loss attributable to noncontrolling interest	(357)	(357)	(24)
Net income attributable to Belden	93,210	128,003	66,204
Less: Preferred stock dividends	34,931	15,428	0
Net income attributable to Belden common stockholders	$ 58,279	$ 112,575	$ 66,204
Weighted average number of common shares and equivalents:
Basic (in shares)	42,220	42,093	42,390
Diluted (in shares)	42,643	42,557	42,953
Basic income (loss) per share attributable to Belden common stockholders:
Continuing operations (in usd per share)	$ 1.38	$ 2.67	$ 1.57
Discontinued operations (in usd per share)	0	0	(0.01)
Net income (in usd per share)	1.38	2.67	1.56
Diluted income (loss) per share attributable to Belden common stockholders:
Continuing operations (in usd per share)	1.37	2.65	1.55
Discontinued operations (in usd per share)	0	0	(0.01)
Net income (in usd per share)	$ 1.37	$ 2.65	$ 1.54

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 92,853	$ 127,646	$ 66,180
Foreign currency translation, net of tax of $1.3 million, $1.2 million, and $1.3 million, respectively	(65,046)	18,687	(20,842)
Adjustments to pension and postretirement liability, net of tax of $2.2 million, $1.9 million, and $3.1 million, respectively	6,071	1,170	7,864
Other comprehensive income (loss), net of tax	(58,975)	19,857	(12,978)
Comprehensive income	33,878	147,503	53,202
Less: Comprehensive loss attributable to noncontrolling interest	(373)	(420)	(46)
Comprehensive income attributable to Belden	$ 34,251	$ 147,923	$ 53,248

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Foreign currency translation, tax expense (benefit)	$ 1.3	$ 1.2	$ 1.3
Adjustments to pension and postretirement liability, tax	$ 2.2	$ 1.9	$ 3.1

Consolidated Cash Flow Statemen

Consolidated Cash Flow Statements - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 92,853	$ 127,646	$ 66,180
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	149,650	145,593	150,342
Impairment of assets held for sale	0	23,931	0
Share-based compensation	14,647	18,178	17,745
Loss on debt extinguishment	52,441	2,342	0
Deferred income tax benefit	(24,098)	(30,034)	(45,674)
Changes in operating assets and liabilities, net of the effects of currency exchange rate changes and acquired businesses:
Receivables	(24,931)	(10,115)	6,066
Inventories	(84,088)	2,677	19,204
Accounts payable	100,752	39,298	(38,907)
Accrued liabilities	(25,076)	(13,181)	59,214
Accrued taxes	5,001	11,722	11,981
Other assets	(13,255)	760	(4,840)
Other liabilities	11,404	(4,023)	149
Net cash provided by operating activities	255,300	314,794	241,460
Net cash provided by operating activities
Cash used to acquire businesses, net of cash acquired	(166,896)	(18,848)	(695,345)
Capital expenditures	(64,261)	(53,974)	(54,969)
Other	0	(827)	0
Proceeds from disposal of business	0	0	3,527
Proceeds from disposal of tangible assets	1,039	392	533
Net cash used for investing activities	(230,118)	(73,257)	(746,254)
Cash flows from financing activities:
Payments under borrowing arrangements	(1,105,892)	(294,375)	(152,500)
Cash dividends paid	(43,376)	(16,079)	(8,395)
Payments under share repurchase program	(25,000)	0	(39,053)
Debt issuance costs paid	(17,316)	(3,910)	(898)
Withholding tax payments for share based payment awards, net of proceeds from the exercise of stock options	(6,564)	(7,480)	(11,693)
Borrowings under credit arrangements	866,700	222,050	200,000
Proceeds from the issuance of preferred stock, net	0	501,498	0
Contribution from noncontrolling interest	0	0	1,470
Net cash provided by (used for) financing activities	(331,448)	401,704	(11,069)
Effect of foreign currency exchange rate changes on cash and cash equivalents	19,258	(11,876)	(8,548)
Increase (decrease) in cash and cash equivalents	(287,008)	631,365	(524,411)
Cash and cash equivalents, beginning of period	848,116	216,751	741,162
Cash and cash equivalents, end of period	$ 561,108	$ 848,116	$ 216,751

Consolidated Stockholders' Equi

Consolidated Stockholders' Equity Statements - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]
Beginning balance, shares at Dec. 31, 2014		0	50,335
Beginning balance at Dec. 31, 2014	$ 807,186	$ 0	$ 503	$ 595,389	$ 621,896	$ (364,571)	$ (46,031)	$ 0
Beginning balance, Treasury shares at Dec. 31, 2014						(7,871)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Contribution from noncontrolling interest	1,470							1,470
Net income	66,180				66,204			(24)
Foreign currency translation gain (loss), net of $1.2 million, $1.3 million, and $1.8 million tax, respectively	(20,842)						(20,820)	(22)
Adjustments to pension and postretirement liability, net of $4.1 million, $3.1 million, and $3.6 million tax, respectively	7,864						7,864
Other comprehensive loss, net of tax	(12,978)
Exercise of stock options, net of tax withholding forfeitures	(6,166)			(6,070)		$ (96)
Exercise of stock options, net of tax withholding forfeitures, shares						100
Conversion of restricted stock units into common stock, net of tax withholding forfeitures	(5,527)			(6,454)		$ 927
Conversion of restricted stock units into common stock, net of tax withholding forfeitures, shares						115
Share repurchase program, shares						(698)
Share repurchase program	(39,053)					$ (39,053)
Share-based compensation related items	22,795			22,795
Common stock dividends ($0.20 per share)	(8,384)				(8,384)
Ending balance, shares at Dec. 31, 2015		0	50,335
Ending balance at Dec. 31, 2015	825,523	$ 0	$ 503	605,660	679,716	$ (402,793)	(58,987)	1,424
Ending balance, Treasury shares at Dec. 31, 2015						(8,354)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	127,646				128,003			(357)
Foreign currency translation gain (loss), net of $1.2 million, $1.3 million, and $1.8 million tax, respectively	18,687						18,750	(63)
Adjustments to pension and postretirement liability, net of $4.1 million, $3.1 million, and $3.6 million tax, respectively	1,170						1,170
Other comprehensive loss, net of tax	19,857
Preferred stock issuance, net, shares		52
Preferred stock issuance, net	501,498	$ 1		501,497
Exercise of stock options, net of tax withholding forfeitures	(4,088)			(4,205)		$ 117
Exercise of stock options, net of tax withholding forfeitures, shares						76
Conversion of restricted stock units into common stock, net of tax withholding forfeitures	(3,390)			(5,040)		$ 1,650
Conversion of restricted stock units into common stock, net of tax withholding forfeitures, shares						123
Share-based compensation related items	18,178			18,178
Preferred stock dividends	(15,428)				(15,428)
Common stock dividends ($0.20 per share)	(8,479)				(8,479)
Ending balance, shares at Dec. 31, 2016		52	50,335
Ending balance at Dec. 31, 2016	$ 1,461,317	$ 1	$ 503	1,116,090	783,812	$ (401,026)	(39,067)	1,004
Ending balance, Treasury shares at Dec. 31, 2016	(8,155)					(8,155)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 92,853				93,210			(357)
Foreign currency translation gain (loss), net of $1.2 million, $1.3 million, and $1.8 million tax, respectively	(65,046)						(65,030)	(16)
Adjustments to pension and postretirement liability, net of $4.1 million, $3.1 million, and $3.6 million tax, respectively	6,071						6,071
Other comprehensive loss, net of tax	(58,975)
Exercise of stock options, net of tax withholding forfeitures	(2,838)			(2,635)		$ (203)
Exercise of stock options, net of tax withholding forfeitures, shares						55
Conversion of restricted stock units into common stock, net of tax withholding forfeitures	(3,726)			(4,270)		$ 544
Conversion of restricted stock units into common stock, net of tax withholding forfeitures, shares						97
Share repurchase program, shares						(313)
Share repurchase program	(25,000)					$ (25,000)
Share-based compensation related items	14,647			14,647
Preferred stock dividends	(34,931)				(34,931)
Common stock dividends ($0.20 per share)	(8,481)				(8,481)
Ending balance, shares at Dec. 31, 2017		52	50,335
Ending balance at Dec. 31, 2017	$ 1,434,866	$ 1	$ 503	$ 1,123,832	$ 833,610	$ (425,685)	$ (98,026)	$ 631
Ending balance, Treasury shares at Dec. 31, 2017	(8,316)					(8,316)

Consolidated Stockholders' Equ9

Consolidated Stockholders' Equity Statements (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Foreign currency translation, tax expense (benefit)	$ 1.3	$ 1.2	$ 1.3
Adjustments to pension and postretirement liability, tax expense	$ 2.2	$ 1.9	$ 3.1
Dividends declared per share	$ 0.2	$ 0.20	$ 0.20

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation Business Description Belden Inc. (the Company, us, we, or our) is an innovative signal transmission solutions company built around four global business platforms – Broadcast Solutions, Enterprise Solutions, Industrial Solutions, and Network Solutions. Our comprehensive portfolio of signal transmission solutions provides industry leading secure and reliable transmission of data, sound, and video for mission critical applications. We sell our products to distributors, end-users, installers, and directly to original equipment manufacturers (OEMs). Consolidation The accompanying Consolidated Financial Statements include Belden Inc. and all of its subsidiaries, including variable interest entities for which we are the primary beneficiary. We eliminate all significant affiliate accounts and transactions in consolidation. Foreign Currency For international operations with functional currencies other than the United States (U.S.) dollar, we translate assets and liabilities at current exchange rates; we translate income and expenses using average exchange rates. We report the resulting translation adjustments, as well as gains and losses from certain affiliate transactions, in accumulated other comprehensive income (loss), a separate component of stockholders’ equity. We include exchange gains and losses on transactions in operating income. We determine the functional currency of our foreign subsidiaries based upon the currency of the primary economic environment in which each subsidiary operates. Typically, that is determined by the currency in which the subsidiary primarily generates and expends cash. We have concluded that the local currency is the functional currency for all of our material subsidiaries. Reporting Periods Our 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. Our fiscal second and third quarters each have 91 days. Use of Estimates in the Preparation of the Financial Statements The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. requires us to make estimates and assumptions that affect the reported amounts of assets, liabilities, and operating results and the disclosure of contingencies. Actual results could differ from those estimates. We make significant estimates with respect to the collectability and valuation of receivables, the valuation of inventory, the realization of deferred tax assets, the valuation of goodwill and indefinite-lived intangible assets, the valuation of contingent liabilities, the calculation of share-based compensation, the calculation of pension and other postretirement benefits expense, and the valuation of acquired businesses. Reclassifications We have made certain, insignificant reclassifications to the 2016 and 2015 Consolidated Financial Statements with no impact to reported net income in order to conform to the 2017 presentation.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies 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 December 31, 2017 , 2016 , and 2015 we utilized Level 1 inputs to determine the fair value of cash equivalents, and Level 3 inputs to determine the fair value of net assets acquired in business combinations (see Note 3) and for our annual impairment testing (see Note 11). We did not have any transfers between Level 1 and Level 2 fair value measurements during 2017 . 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 December 31, 2017 and 2016 , 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. Accounts Receivable We classify amounts owed to us and due within twelve months, arising from the sale of goods or services in the normal course of business, as current receivables. We classify receivables due after twelve months as other long-lived assets. At the time of sale, we establish an estimated reserve for trade, promotion, and other special price reductions such as contract pricing, discounts to meet competitor pricing, and on-time payment discounts. We also adjust receivable balances for, among other things, correction of billing errors, incorrect shipments, and settlement of customer disputes. Customers are allowed to return inventory if and when certain conditions regarding the physical state of the inventory and our approval of the return are met. Certain distribution customers are allowed to return inventory at original cost, in an amount not to exceed three percent of the prior year’s purchases, in exchange for an order of equal or greater value. Until we can process these reductions, corrections, and returns (together, the Changes) through individual customer records, we estimate the amount of outstanding Changes and recognize them by reducing revenues and accounts receivable. We also adjust inventory and cost of sales for the estimated level of returns. We base these estimates on historical and anticipated sales demand, trends in product pricing, and historical and anticipated Changes patterns. We make revisions to these estimates in the period in which the facts that give rise to each revision become known. Future market conditions might require us to take actions to further reduce prices and increase customer return authorizations. Unprocessed Changes recognized against our gross accounts receivable balance at December 31, 2017 and 2016 totaled $35.7 million and $23.3 million , respectively. We evaluate the collectability of accounts receivable based on the specific identification method. A considerable amount of judgment is required in assessing the realizability of accounts receivable, including the current creditworthiness of each customer and related aging of the past due balances. We perform ongoing credit evaluations of our customers’ financial condition. Through these evaluations, we may become aware of a situation where a customer may not be able to meet its financial obligations due to deterioration of its financial viability, credit ratings, or bankruptcy. We record a specific reserve for bad debts against amounts due to reduce the receivable to its estimated collectible balance. We recognized bad debt expense, net of recoveries, of $0.0 million , $1.5 million , and $(1.8) million in 2017 , 2016 , and 2015 , respectively. In 2015, we recovered approximately $2.7 million of accounts receivable from one significant customer. The allowance for doubtful accounts at December 31, 2017 and 2016 totaled $7.8 million and $8.1 million , respectively. Inventories and Related Reserves Inventories are stated at the lower of cost or market. We determine the cost of all raw materials, work-in-process, and finished goods inventories by the first in, first out method. Cost components of inventories include direct labor, applicable production overhead, and amounts paid to suppliers of materials and products as well as freight costs and, when applicable, duty costs to import the materials and products. We evaluate the realizability of our inventory on a product-by-product basis in light of historical and anticipated sales demand, technological changes, product life cycle, component cost trends, product pricing, and inventory condition. In circumstances where inventory levels are in excess of anticipated market demand, where inventory is deemed technologically obsolete or not saleable due to condition, or where inventory cost exceeds net realizable value, we record a charge to cost of sales and reduce the inventory to its net realizable value. The allowances for excess and obsolete inventories at December 31, 2017 and 2016 totaled $25.3 million and $24.6 million , respectively. Property, Plant and Equipment We record property, plant and equipment at cost. We calculate depreciation on a straight-line basis over the estimated useful lives of the related assets ranging from 10 to 40 years for buildings, 5 to 12 years for machinery and equipment, and 5 to 10 years for computer equipment and software. Construction in process reflects amounts incurred for the configuration and build-out of property, plant and equipment and for property, plant and equipment not yet placed into service. We charge maintenance and repairs—both planned major activities and less-costly, ongoing activities—to expense as incurred. We capitalize interest costs associated with the construction of capital assets and amortize the costs over the assets’ useful lives. Depreciation expense is included in costs of sales; selling, general and administrative expenses; and research and development expenses in the Consolidated Statements of Operations based on the specific categorization and use of the underlying assets being depreciated. We review property, plant and equipment to determine whether an event or change in circumstances indicates the carrying values of the assets may not be recoverable. We base our evaluation on the nature of the assets, the future economic benefit of the assets, and any historical or future profitability measurements, as well as other external market conditions or factors that may be present. If such impairment indicators are present or other factors exist that indicate that the carrying amount of an asset may not be recoverable, we determine whether impairment has occurred through the use of an undiscounted cash flow analysis. If impairment has occurred, we recognize a loss for the difference between the carrying amount and the fair value of the asset. For purposes of impairment testing of long-lived assets, we have identified asset groups at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Generally, our asset groups are based on an individual plant or operating facility level. In some circumstances, however, a combination of plants or operating facilities may be considered the asset group due to interdependence of operational activities and cash flows. Goodwill and Intangible Assets Our intangible assets consist of (a) definite-lived assets subject to amortization such as developed technology, customer relationships, certain in-service research and development, certain trademarks, backlog, and capitalized software intangible assets, and (b) indefinite-lived assets not subject to amortization such as goodwill, certain trademarks, and certain in-process research and development intangible assets. We record amortization of the definite-lived intangible assets over the estimated useful lives of the related assets, which generally range from one year or less for backlog to more than 25 years for certain of our customer relationships. We determine the amortization method for our definite-lived intangible assets based on the pattern in which the economic benefits of the intangible asset are consumed. In the event we cannot reliably determine that pattern, we utilize a straight-line amortization method. We test our goodwill and other indefinite-lived intangible assets not subject to amortization for impairment on an annual basis during the fourth quarter or when indicators of impairment exist. We base our estimates on assumptions we believe to be reasonable, but which are not predictable with precision and therefore are inherently uncertain. Actual future results could differ from these estimates. The accounting guidance related to goodwill impairment testing allows for the performance of an optional qualitative assessment of whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. Such an evaluation is made based on the weight of all available evidence and the significance of all identified events and circumstances that may influence the fair value of a reporting unit. If it is more likely than not that the fair value is less than the carrying value, then a quantitative assessment is required for the reporting unit, as described in the paragraph below. In 2017 , we performed a qualitative assessment for seven of our reporting units, which collectively represented approximately $547.2 million of our consolidated goodwill balance. For those reporting units for which we performed a qualitative assessment, we determined that it was more likely than not that the fair value was greater than the carrying value, and therefore, we did not perform the calculation of fair value for these reporting units as described in the paragraph below. For our annual impairment test in 2017 , we performed a quantitative assessment for five of our reporting units, which collectively represented approximately $931.1 million of our consolidated goodwill balance. Under a quantitative assessment for goodwill impairment, we determine the fair value using the income approach (using Level 3 inputs) as reconciled to our aggregate market capitalization. Under the income approach, we calculate the fair value of a reporting unit based on the present value of estimated future cash flows. If the fair value of the reporting unit exceeds the carrying value of the net assets including goodwill assigned to that unit, goodwill is not impaired. If the carrying value of the reporting unit’s net assets including goodwill exceeds the fair value of the reporting unit, then we record an impairment charge based on that difference. In addition to the income approach, we calculate the fair value of our reporting units under a market approach. The market approach measures the fair value of a reporting unit through analysis of financial multiples of comparable businesses. Consideration is given to the financial conditions and operating performance of the reporting unit being valued relative to those publicly-traded companies operating in the same or similar lines of business. The fair values of the five reporting units tested under a quantitative approach were in excess of the carrying values as of the impairment testing date. We did not recognize any goodwill impairment in 2017 , 2016 , or 2015 . See Note 10 for further discussion. We also evaluate indefinite lived intangible assets for impairment annually or at other times if events have occurred or circumstances exist that indicate the carrying values of those assets may no longer be recoverable. We compare the fair value of the asset with its carrying amount. If the carrying amount of the asset exceeds its fair value, we recognize an impairment loss in an amount equal to that excess. We did not recognize impairment charges for our indefinite lived intangible assets in 2017 , 2016 , or 2015 . See Note 11 for further discussion. We review intangible assets subject to amortization whenever an event or change in circumstances indicates the carrying values of the assets may not be recoverable. We test intangible assets subject to amortization for impairment and estimate their fair values using the same assumptions and techniques we employ on property, plant and equipment. We did not recognize any impairment charges for amortizable intangible assets in 2017 , 2016 , or 2015 . Equity Method Investment We had a 50% ownership interest in Xuzhou Hirschmann Electronics Co. Ltd (the Hirschmann JV). The Hirschmann JV is an entity located in China that supplies load-moment indicators to the mobile crane market. We sold the Hirschmann JV effective December 31, 2017 and recognized a loss on sale of the assets of $1.0 million . When we committed to a plan to sell the Hirschmann JV in 2016, the carrying value of our investment in the Hirschmann JV was classified as held for sale. As of December 31, 2016, the carrying value of our investment was $26.8 million . Prior to selling the Hirschmann JV, we accounted for this investment using the equity method of accounting. See Note 4. Pension and Other Postretirement Benefits Our pension and other postretirement benefit costs and obligations are dependent on the various actuarial assumptions used in calculating such amounts. These assumptions relate to discount rates, salary growth, long-term return on plan assets, health care cost trend rates, mortality tables, and other factors. We base the discount rate assumptions on current investment yields on high-quality corporate long-term bonds. The salary growth assumptions reflect our long-term actual experience and future or near-term outlook. We determine the long-term return on plan assets based on historical portfolio results and management’s expectation of the future economic environment. Our health care cost trend assumptions are developed based on historical cost data, the near-term outlook, and an assessment of likely long-term trends. Actual results that differ from our assumptions are accumulated and, if in excess of the lesser of 10% of the projected benefit obligation or the fair market value of plan assets, are amortized over the estimated future working life of the plan participants. Accrued Sales Rebates We grant incentive rebates to participating customers as part of our sales programs. The rebates are determined based on certain targeted sales volumes. Rebates are paid quarterly or annually in either cash or receivables credits. Until we can process these rebates through individual customer records, we estimate the amount of outstanding rebates and recognize them as accrued liabilities and reductions in our gross revenues. We base our estimates on both historical and anticipated sales demand and rebate program participation. We charge revisions to these estimates back to accrued liabilities and revenues in the period in which the facts that give rise to each revision become known. Future market conditions and product transitions might require us to take actions to increase sales rebates offered, possibly resulting in an incremental increase in accrued liabilities and an incremental reduction in revenues at the time the rebate is offered. Accrued sales rebates at December 31, 2017 and 2016 totaled $38.0 million and $33.1 million , respectively. 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. A significant amount of judgment and use of estimates is required to quantify our ultimate exposure in these matters. We review the valuation of these liabilities on a quarterly basis, and we adjust the balances to account for changes in circumstances for ongoing and emerging issues. We accrue environmental remediation costs based on estimates of known environmental remediation exposures developed in consultation with our environmental consultants and legal counsel, the amounts of which are not currently material. We expense environmental compliance costs, which include maintenance and operating costs with respect to ongoing monitoring programs, as incurred. We evaluate the range of potential costs to remediate environmental sites. The ultimate cost of site clean-up is difficult to predict given the uncertainties of our involvement in certain sites, uncertainties regarding the extent of the required clean-up, the availability of alternative clean-up methods, variations in the interpretation of applicable laws and regulations, the possibility of insurance recoveries with respect to certain sites, and other factors. 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. Assessments regarding the ultimate cost of lawsuits require judgments concerning matters such as the anticipated outcome of negotiations, the number and cost of pending and future claims, and the impact of evidentiary requirements. Based on facts currently available, we believe the disposition of the claims that are pending or asserted will not have a materially adverse effect on our financial position, results of operations or cash flow. Business Combination Accounting We allocate the purchase price of an acquired business to its identifiable assets and liabilities based on estimated fair values. The excess of the purchase price over the amount allocated to the assets and liabilities, if any, is recorded to goodwill. We use all available information to estimate fair values. We typically engage third party valuation specialists to assist in the fair value determination of inventories, tangible long-lived assets, and intangible assets other than goodwill. The carrying values of acquired receivables and accounts payable have historically approximated their fair values as of the business combination date. As necessary, we may engage third party specialists to assist in the estimation of fair value for certain liabilities, such as deferred revenue or postretirement benefit liabilities. We adjust the preliminary purchase price allocation, as necessary, typically up to one year after the acquisition closing date as we obtain more information regarding asset valuations and liabilities assumed. Revenue Recognition We recognize revenue when all of the following circumstances are satisfied: (1) persuasive evidence of an arrangement exists, (2) price is fixed or determinable, (3) collectability is reasonably assured, and (4) delivery has occurred. Delivery typically occurs in the period in which the customer takes title and assumes the risks and rewards of ownership of the products specified in the customer’s purchase order or sales agreement. At times, we enter into arrangements that involve the delivery of multiple elements. For these arrangements, when the elements can be separated, the revenue is allocated to each deliverable based on that element’s relative selling price and recognized based on the period of delivery for each element. Generally, we determine relative selling price using vendor specific objective evidence (VSOE). We record revenue net of estimated rebates, price allowances, invoicing adjustments, and product returns. We record revisions to these estimates in the period in which the facts that give rise to each revision become known. Taxes collected from customers and remitted to governmental authorities are not included in our revenues. We have certain products subject to the accounting guidance on software revenue recognition. For such products, software license revenue is recognized when persuasive evidence of an arrangement exists, delivery of the product has occurred, the fee is fixed or determinable, collection is probable and VSOE of the fair value of undelivered elements exists. As substantially all of the software licenses are sold in multiple-element arrangements that include either support or professional services, we use the residual method to determine the amount of software license revenue to be recognized. Under the residual method, consideration is allocated to undelivered elements based upon VSOE of the fair value of those elements, with the residual of the arrangement fee allocated to and recognized as software license revenue. We have established VSOE of the fair value of support, subscription-based software licenses, and professional services. Software license revenue is generally recognized upon delivery of the software if all revenue recognition criteria are met. Revenue allocated to support services under our support contracts is typically paid in advance and recognized ratably over the term of the service. Revenue allocated to subscription-based software and remote ongoing operational services is also paid in advance and recognized ratably over the term of the service. Revenue allocated to professional services is recognized as the services are performed. Contingent Gain On July 5, 2011, our wholly-owned subsidiary, PPC Broadband, Inc. (PPC), filed an action for patent infringement against Corning Optical Communications RF LLC (Corning). The Complaint alleged that Corning infringed two of PPC’s patents. In July 2015, a jury found that Corning willfully infringed both patents. In November 2016, following a series of post-trial motions, the trial judge issued rulings for a total judgment in our favor of approximately $61.3 million . In December 2016, Corning appealed the case to the U.S. Court of Appeals for the Federal Circuit, and that appeal remains pending. We have not recorded any amounts in our consolidated financial statements related to this matter due to the pendency of the appeal. In 2016, we entered into a patent settlement agreement with a company whereby we received $10.3 million of royalty revenues. Our Broadcast Solutions Segment Revenues in 2016 include $4.7 million of the $10.3 million total royalty revenues received from the patent settlement agreement. The remaining $5.6 million is a reconciling item from total Segment Revenues to consolidated revenues as this portion represented the settlement for royalties prior to 2016. See Note 6. Cost of Sales Cost of sales includes our total cost of inventory sold during the period, including material, labor, production overhead costs, variable manufacturing costs, and fixed manufacturing costs. Production overhead costs include operating supplies, applicable utility expenses, maintenance costs, and scrap. Variable manufacturing costs include inbound, interplant, and outbound freight, inventory shrinkage, and charges for excess and obsolete inventory. Fixed manufacturing costs include the costs associated with our purchasing, receiving, inspection, warehousing, distribution centers, production and inventory control, and manufacturing management. Cost of sales also includes the costs to provide maintenance and support and other professional services. Shipping and Handling Costs We recognize fees earned on the shipment of product to customers as revenues and recognize costs incurred on the shipment of product to customers as a cost of sales. Selling, General and Administrative Expenses Selling, general and administrative expenses include expenses not directly related to the production of inventory. They include all expenses related to selling and marketing our products, as well as the salary and benefit costs of associates performing the selling and marketing functions. Selling, general and administrative expenses also include salary and benefit costs, purchased services, and other costs related to our executive and administrative functions. Research and Development Costs Research and development costs are expensed as incurred. Advertising Costs Advertising costs are expensed as incurred. Advertising costs were $25.0 million , $27.2 million , and $27.5 million for 2017 , 2016 , and 2015 , respectively. Share-Based Compensation We compensate certain employees and non-employee directors with various forms of share-based payment awards and recognize compensation costs for these awards based on their fair values. We estimate the fair values of certain awards, primarily stock appreciation rights (SARs), on the grant date using the Black-Scholes-Merton option-pricing formula, which incorporates certain assumptions regarding the expected term of an award and expected stock price volatility. We develop the expected term assumption based on the vesting period and contractual term of an award, our historical exercise and cancellation experience, our stock price history, plan provisions that require exercise or cancellation of awards after employees terminate, and the extent to which currently available information indicates that the future is reasonably expected to differ from past experience. We develop the expected volatility assumption based on historical price data for our common stock. We estimate the fair value of certain restricted stock units with service vesting conditions and performance vesting conditions based on the grant date stock price. We estimate the fair value of certain restricted stock units with market conditions using a Monte Carlo simulation valuation model with the assistance of a third party valuation firm. After calculating the aggregate fair value of an award, we use an estimated forfeiture rate to discount the amount of share-based compensation cost expected to be recognized in our operating results over the service period of the award. We develop the forfeiture assumption based on our historical pre-vesting cancellation experience. Income Taxes Income taxes are provided based on earnings reported for financial statement purposes. The provision for income taxes differs from the amounts currently payable to taxing authorities because of the recognition of revenues and expenses in different periods for income tax purposes than for financial statement purposes. Income taxes are provided as if operations in all countries, including the U.S., were stand-alone businesses filing separate tax returns. The Tax Cuts and Jobs Act of 2017 included a one-time transition tax on unremitted foreign earnings, and accordingly, we recorded tax expense of $29.1 million related to the transition tax on the one-time mandatory deemed repatriation of all our foreign earnings as of December 31, 2017. See Note 16 Income Taxes in the accompanying notes to our consolidated financial statements. We recognize deferred tax assets resulting from tax credit carryforwards, net operating loss carryforwards, and deductible temporary differences between taxable income on our income tax returns and pretax income on our financial statements. Deferred tax assets generally represent future tax benefits to be received when these carryforwards can be applied against future taxable income or when expenses previously reported in our Consolidated Financial Statements become deductible for income tax purposes. A deferred tax asset valuation allowance is required when some portion or all of the deferred tax assets may not be realized. The Tax Cuts and Jobs Act of 2017 included a $36.0 million tax benefit for the remeasurement of deferred tax assets and liabilities to the 21% rate at which they are expected to reverse and a valuation allowance of $35.3 million recorded against foreign tax credit carryforwards that we no longer expect to be able to realize based upon the new tax law. Our effective tax rate is based on expected income, statutory tax rates, and tax planning opportunities available to us in the various jurisdictions in which we operate. Significant judgment is required in determining our effective tax rate and in evaluating our tax positions. We establish accruals for uncertain tax positions when we believe that the full amount of the associated tax benefit may not be realized. To the extent we were to prevail in matters for which accruals have been established or would be required to pay amounts in excess of reserves, there could be a material effect on our income tax provisions in the period in which such determination is made. Current-Year Adoption of Accounting Pronouncements In July 2015, the FASB issued Accounting Standards Update No. 2015-11, Inventory (Topic 330) : Simplifying the Measurement of Inventory. Under the new guidance, an entity is to measure inventory at the lower of cost and the net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. The standard is effective for fiscal years beginning after December 15, 2016. We adopted ASU 2015-11 effective January 1, 2017. Adoption had no impact on our results of operations. In January 2017, the FASB issued Accounting Standards Update No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . Under the new guidance, if a reporting unit’s carrying amount exceeds its fair value, an entity will record an impairment charge based on that difference. The impairment charge is limited to the amount of goodwill allocated to the reporting unit. ASU 2017-04 eliminates the prior requirement of calculating a goodwill impairment charge using Step 2. The standard is effective for fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We early adopted ASU 2017-04 effective January 1, 2017. Adoption had no impact on our results of operations. Pending Adoption of Recent Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (ASU 2014-09), which will replace most existing revenue recognition guidance in U.S. GAAP. The core principle of the ASU is that an entity should recognize revenue for the transfer of goods or services equal to the amount that it expects to be entitled to receive for those goods or services. ASU 2014-09 requires additional disclosure about the nature, amount, timing, and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments. We plan to adopt ASU 2014-09 on January 1, 2018, using the modified retrospective method of adoption. We are substantially complete with our evaluation of the impact of adopting ASU 2014-09 on our consolidated financial statements. We do not expect significant changes in the timing or method of revenue recognition for any of our material revenue streams. In connection with adopting ASU 2014-09, we expect to record a cumulative-effect adjustment net of tax to retained earnings of $2.6 million on January 1, 2018. This adjustment primarily relates to the deferral of costs to obtain a contract that were previously expensed at the beginning of the contract period. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (ASU 2016-02), a leasing standard for both lessees and lessors. Under its core principle, a lessee will recognize lease assets and liabilities on the balance sheet for all arrangements with terms longer than 12 months. Lessor accounting remains largely consistent with existing U.S. generally accepted accounting principles. The new standard will be effective for us beginning January 1, 2019. Early adoption is permitted. The standard requires the use of a modified retrospective transition method. We are stil

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Acquisitions	Acquisitions Thinklogical Holdings, LLC We acquired 100% of the outstanding ownership interest in Thinklogical Holdings, LLC (Thinklogical) on May 31, 2017 for cash of $171.3 million . Thinklogical designs, manufactures, and markets high-bandwidth fiber matrix switches, video, and keyboard/video/mouse extender solutions, camera extenders, and console management solutions. Thinklogical is headquartered in Connecticut. The results of Thinklogical have been included in our Consolidated Financial Statements from May 31, 2017, and are reported within the Broadcast Solutions segment. The following table summarizes the estimated, preliminary fair values of the assets acquired and the liabilities assumed as of May 31, 2017 (in thousands): Cash $ 5,376 Receivables 4,355 Inventory 16,424 Prepaid and other current assets 320 Property, plant, and equipment 4,289 Goodwill 71,394 Intangible assets 73,400 Total assets 175,558 Accounts payable 1,231 Accrued liabilities 1,353 Deferred revenue 1,702 Total liabilities 4,286 Net assets $ 171,272 A single estimate of fair value results from a complex series of judgments about future events and uncertainties and relies heavily on estimates and assumptions. The judgments we have used in estimating the preliminary fair values assigned to each class of acquired assets and assumed liabilities could materially affect the results of our operations. The preliminary fair value of acquired receivables is $4.4 million , which is equivalent to its gross contractual amount. For purposes of the above allocation, we based our estimate of the preliminary fair values for the acquired inventory, intangible assets, and deferred revenue on a preliminary valuation study performed by a third party valuation firm. We have estimated a preliminary fair value adjustment for inventories based on the estimated selling price of the work-in-process and finished goods acquired at the closing date less the sum of the costs to complete the work-in-process, the costs of disposal, and a reasonable profit allowance for our post acquisition selling efforts. We used various valuation methods including discounted cash flows, lost income, excess earnings, and relief from royalty to estimate the preliminary fair value of the identifiable intangible assets and deferred revenue (Level 3 valuation). The determination of the fair value of the assets acquired and liabilities assumed and the allocation of the purchase price is substantially complete pending the completion of taxes. Goodwill and other intangible assets reflected above were determined to meet the criterion for recognition apart from tangible assets acquired and liabilities assumed. The goodwill is primarily attributable to expected synergies and the assembled workforce. The expected synergies for the Thinklogical acquisition primarily consist of utilizing Belden's fiber and connectivity portfolio with Thinklogical's connections between matrix switch, control systems, transmitters and source to expand our product portfolio across our segments to both existing and new customers. Our tax basis in the acquired goodwill is approximately $44.0 million and is deductible for tax purposes over a period of 15 years up to the amount of the tax basis. The intangible assets related to the acquisition consisted of the following: Fair Value Amortization Period (In thousands) (In years) Intangible assets subject to amortization: Developed technologies $ 62,600 10.0 Customer relationships 6,500 8.0 Trademarks 2,900 10.0 Sales backlog 1,400 0.3 Total intangible assets subject to amortization 73,400 Intangible assets not subject to amortization: Goodwill 71,394 n/a Total intangible assets not subject to amortization 71,394 Total intangible assets $ 144,794 Weighted average amortization period 9.6 The amortizable intangible assets reflected in the table above were determined by us to have finite lives. The useful life for the developed technology intangible asset was based on the estimated time that the technology provides us with a competitive advantage and thus approximates the period and pattern of consumption of the intangible asset. The useful life for the customer relationship intangible asset was based on our forecasts of estimated sales from recurring customers. The useful life for the trademarks was based on the period of time we expect to continue to go to market using the trademarks. The useful life of the backlog intangible asset was based on our estimate of when the ordered items would ship. Our consolidated revenues and consolidated income from continuing operations before taxes for the year ended December 31, 2017 included $30.8 million and $(8.9) million , respectively, from Thinklogical. The loss before taxes from Thinklogical included $11.9 million of amortization of intangible assets and $6.1 million of cost of sales related to the adjustment of acquired inventory to fair value. The following table illustrates the unaudited pro forma effect on operating results as if the Thinklogical acquisition had been completed as of January 1, 2016. Years Ended December 31, 2017 December 31, 2016 (In thousands, except per share data) (Unaudited) Revenues $ 2,399,715 $ 2,407,830 Net income attributable to Belden common stockholders 60,690 113,014 Diluted income per share attributable to Belden common stockholders $ 1.42 $ 2.66 For purposes of the pro forma disclosures, the year ended December 31, 2016 includes nonrecurring expenses from the effects of purchase accounting, including cost of sales arising from the adjustment of inventory to fair value of $6.1 million and amortization of the sales backlog intangible asset of $1.4 million . The above unaudited pro forma financial information is presented for informational purposes only and does not purport to represent what our results of operations would have been had we completed the acquisition on the date assumed, nor is it necessarily indicative of the results that may be expected in future periods. Pro forma adjustments exclude cost savings from any synergies resulting from the acquisition. M2FX We acquired 100% of the shares of M2FX Limited (M2FX) on January 7, 2016 for a purchase price of $19.0 million . M2FX is a manufacturer of fiber optic cable and fiber protective solutions for broadband access and telecommunications networks. M2FX is located in the United Kingdom. The results of M2FX have been included in our Consolidated Financial Statements from January 7, 2016, and are reported within the Broadcast Solutions segment. The M2FX acquisition was not material to our financial position or results of operations. Of the total purchase price, $3.2 million was deferred as estimated earn-out consideration. We determined the estimated fair value of the earn-out with the assistance of a third party valuation specialist using a probability weighted discounted cash flow model. The estimated earn-out was scheduled to be paid in early 2017, however, the financial targets tied to the earn-out were not achieved. We reduced the earn-out liability to zero as of December 31, 2016 and recognized a $3.2 million benefit in Selling, General and Administrative expenses in the Consolidated Statements of Operations. This benefit was excluded from Segment EBITDA of our Broadcast Solutions segment. Tripwire We acquired 100% of the outstanding ownership interest in Tripwire, Inc. (Tripwire) on January 2, 2015 for a purchase price of $703.2 million . The purchase price was funded with cash on hand and $200.0 million of borrowings under our revolving credit agreement (see Note 13). Tripwire is a leading global provider of advanced threat, security and compliance solutions. Tripwire’s solutions enable enterprises, service providers, manufacturers, and government agencies to detect, prevent, and respond to growing security threats. Tripwire is headquartered in Portland, Oregon. The results of Tripwire have been included in our Consolidated Financial Statements from January 2, 2015. Tripwire is reported within the Network Solutions segment. The following table summarizes the estimated fair values of the assets acquired and the liabilities assumed as of January 2, 2015 (in thousands). Cash $ 2,364 Receivables 37,792 Inventories 603 Other current assets 2,453 Property, plant and equipment 10,021 Goodwill 462,215 Intangible assets 306,000 Other non-current assets 659 Total assets 822,107 Accounts payable 3,142 Accrued liabilities 12,142 Deferred revenue 8,000 Deferred income taxes 95,074 Other non-current liabilities 540 Total liabilities 118,898 Net assets $ 703,209 A single estimate of fair value results from a complex series of judgments about future events and uncertainties and relies heavily on estimates and assumptions. The judgments we have used in estimating the fair values assigned to each class of acquired assets and assumed liabilities could materially affect the results of our operations. The fair value of acquired receivables is $37.8 million , with a gross contractual amount of $38.0 million . For purposes of the above allocation, we based our estimate of the fair values for the acquired intangible assets, property, plant and equipment, and deferred revenue on a valuation study performed by a third party valuation firm. We used various valuation methods including discounted cash flows to estimate the fair value of the identifiable intangible assets and deferred revenue (Level 3 valuation). To determine the value of the acquired property, plant, and equipment, we used various valuation methods, including both the market approach, which considers sales prices of similar assets in similar conditions (Level 2 valuation), and the cost approach, which considers the cost to replace the asset adjusted for depreciation (Level 3 valuation). Goodwill and other intangible assets reflected above were determined to meet the criterion for recognition apart from tangible assets acquired and liabilities assumed. The goodwill is primarily attributable to expected synergies and the assembled workforce. The expected synergies for the Tripwire acquisition primarily consist of an expanded product portfolio with network security solutions that can be marketed to our existing broadcast, enterprise, and industrial customers. We do not have tax basis in the goodwill, and therefore, the goodwill is not deductible for tax purposes. The intangible assets related to the acquisition consisted of the following: Estimated Fair Value Amortization Period (In thousands) (In years) Intangible assets subject to amortization: Developed technology $ 210,000 5.8 Customer relationships 56,000 15 Trademarks 31,000 10 Backlog 3,000 1 Total intangible assets subject to amortization 300,000 Intangible assets not subject to amortization: Goodwill 462,215 In-process research and development 6,000 Total intangible assets not subject to amortization 468,215 Total intangible assets $ 768,215 Weighted average amortization period 7.9 The amortizable intangible assets reflected in the table above were determined by us to have finite lives. In connection with the segment change discussed in Note 6, we re-evaluated the useful life of the Tripwire trademark and concluded that an indefinite life was no longer appropriate; therefore, we began amortizing the Tripwire trademark in the first quarter of 2017. The useful life for the developed technology intangible asset was based on the estimated time that the technology provides us with a competitive advantage and thus approximates the period of consumption of the intangible asset. The useful life for the customer relationship intangible asset was based on our forecasts of customer turnover. The useful life for the trademarks was based on the period of time we expect to continue to go to market using the trademarks. The useful life of the backlog intangible asset was based on our estimate of when the ordered items would ship. In-process research and development assets are considered indefinite-lived intangible assets until the completion or abandonment of the associated research and development efforts. Upon completion of the development process, we will make a determination of the useful life of the asset and begin amortizing the assets over that period. If the project is abandoned, we will write-off the asset at such time. Our consolidated revenues and consolidated income from continuing operations before taxes for the year ended December 31, 2015 included $116.6 million and $(47.8) million , respectively, from Tripwire. In 2015, segment revenues for our Network Solutions segment included $50.4 million of revenues that would have been recorded by Tripwire had they remained an independent entity. Our consolidated revenues in 2015 do not include these revenues due to the purchase accounting effect of recording deferred revenue at fair value. The loss before taxes from Tripwire for the year ended December 31, 2015 included $43.2 million of amortization of intangible assets and $9.2 million of compensation expense related to the accelerated vesting of acquiree stock based compensation awards. The following table illustrates the unaudited pro forma effect on operating results as if the Tripwire acquisition had been completed as of January 1, 2014. Year Ended December 31, 2015 (In thousands, except per share data) (Unaudited) Revenues $ 2,354,191 Net income attributable to Belden common stockholders 92,104 Diluted income per share attributable to Belden common stockholders $ 2.14 For purposes of the pro forma disclosures, the year ended December 31, 2014 includes nonrecurring expenses from the effects of purchase accounting, including compensation expense from the accelerated vesting of acquiree stock compensation awards of $9.2 million and amortization of the sales backlog intangible asset of $3.0 million . The above unaudited pro forma financial information is presented for informational purposes only and does not purport to represent what our results of operations would have been had we completed the acquisition on the date assumed, nor is it necessarily indicative of the results that may be expected in future periods. Pro forma adjustments exclude cost savings from any synergies resulting from the acquisition.

Assets Held for Sale

Assets Held for Sale	12 Months Ended
	Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Assets Held for Sale	Assets Held for Sale We classify assets and liabilities as held for sale (disposal group) when management, having the authority to approve the action, commits to a plan to sell the disposal group, the sale is probable within one year, and the disposal group is available for immediate sale in its present condition. We also consider whether an active program to locate a buyer has been initiated, whether the disposal group is marketed actively for sale at a price that is reasonable in relation to its current fair value, and whether actions required to complete the plan indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. When we classify a disposal group as held for sale, we test for impairment. An impairment charge is recognized when the carrying value of the disposal group exceeds the estimated fair value, less costs to sell. We also cease depreciation and amortization for assets classified as held for sale. During the fourth quarter of 2016, we committed to a plan to sell our MCS business and Hirschmann JV and determined that we met all of the criteria to classify the assets and liabilities of these businesses as held for sale. The MCS business was part of the Industrial Solutions segment and the Hirschmann JV was an equity method investment that was not included in an operating segment. The MCS business operated in Germany and the United States, and the Hirschmann JV was an equity method investment located in China. During 2016, we reached an agreement in principle to sell this disposal group for a total sales price of $39 million plus a working capital adjustment. As the carrying value of the disposal group exceeded the fair value less costs to sell, which we determined based on the expected sales price, by $23.9 million , we recognized an impairment charge equal to this amount in 2016. Effective December 31, 2017, we sold the MCS business and Hirschmann JV for a total purchase price of $40.2 million and recognized a loss on sale of the assets of $1.0 million , which is included in selling, general and administrative expenses. This loss includes $2.8 million of accumulated other comprehensive losses that were recognized as a result of the sale. Our accounts receivable balance as of December 31, 2017 included $40.2 million from the MCS business and Hirschmann JV sale. The following table provides the major classes of assets and liabilities classified as held for sale as of December 31, 2016. In addition, the disposal group had $15.7 million of accumulated other comprehensive losses at December 31, 2016. December 31, 2016 (In thousands) Receivables, net $ 4,551 Inventories, net 2,848 Other current assets 1,131 Property, plant, and equipment, less accumulated depreciation 1,946 Intangible assets, less accumulated amortization 4,405 Goodwill 5,477 Other long-lived assets 26,766 Total assets of disposal group 47,124 Impairment of assets held for sale (23,931 ) Total assets held for sale $ 23,193 Accrued liabilities $ 1,288 Postretirement benefits 448 Total liabilities held for sale $ 1,736 Discontinued Operations In 2010, we completed the sale of Trapeze Networks, Inc. (Trapeze) for $152.1 million and recognized a pre-tax gain of $88.3 million ( $44.8 million after-tax). At the time the transaction closed, a portion of the sale price was placed in escrow as partial security for our indemnity obligations under the sale agreement. During 2015, we agreed to a final settlement with the buyer of Trapeze regarding the escrow, and collected $3.5 million of the escrow receivable and recognized a $0.2 million ( $0.1 million net of tax) loss from disposal of discontinued operations. Additionally, we recognized a $0.2 million net loss from discontinued operations for income tax expense related to this disposed business in 2015.

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Assets Held for Sale We classify assets and liabilities as held for sale (disposal group) when management, having the authority to approve the action, commits to a plan to sell the disposal group, the sale is probable within one year, and the disposal group is available for immediate sale in its present condition. We also consider whether an active program to locate a buyer has been initiated, whether the disposal group is marketed actively for sale at a price that is reasonable in relation to its current fair value, and whether actions required to complete the plan indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. When we classify a disposal group as held for sale, we test for impairment. An impairment charge is recognized when the carrying value of the disposal group exceeds the estimated fair value, less costs to sell. We also cease depreciation and amortization for assets classified as held for sale. During the fourth quarter of 2016, we committed to a plan to sell our MCS business and Hirschmann JV and determined that we met all of the criteria to classify the assets and liabilities of these businesses as held for sale. The MCS business was part of the Industrial Solutions segment and the Hirschmann JV was an equity method investment that was not included in an operating segment. The MCS business operated in Germany and the United States, and the Hirschmann JV was an equity method investment located in China. During 2016, we reached an agreement in principle to sell this disposal group for a total sales price of $39 million plus a working capital adjustment. As the carrying value of the disposal group exceeded the fair value less costs to sell, which we determined based on the expected sales price, by $23.9 million , we recognized an impairment charge equal to this amount in 2016. Effective December 31, 2017, we sold the MCS business and Hirschmann JV for a total purchase price of $40.2 million and recognized a loss on sale of the assets of $1.0 million , which is included in selling, general and administrative expenses. This loss includes $2.8 million of accumulated other comprehensive losses that were recognized as a result of the sale. Our accounts receivable balance as of December 31, 2017 included $40.2 million from the MCS business and Hirschmann JV sale. The following table provides the major classes of assets and liabilities classified as held for sale as of December 31, 2016. In addition, the disposal group had $15.7 million of accumulated other comprehensive losses at December 31, 2016. December 31, 2016 (In thousands) Receivables, net $ 4,551 Inventories, net 2,848 Other current assets 1,131 Property, plant, and equipment, less accumulated depreciation 1,946 Intangible assets, less accumulated amortization 4,405 Goodwill 5,477 Other long-lived assets 26,766 Total assets of disposal group 47,124 Impairment of assets held for sale (23,931 ) Total assets held for sale $ 23,193 Accrued liabilities $ 1,288 Postretirement benefits 448 Total liabilities held for sale $ 1,736 Discontinued Operations In 2010, we completed the sale of Trapeze Networks, Inc. (Trapeze) for $152.1 million and recognized a pre-tax gain of $88.3 million ( $44.8 million after-tax). At the time the transaction closed, a portion of the sale price was placed in escrow as partial security for our indemnity obligations under the sale agreement. During 2015, we agreed to a final settlement with the buyer of Trapeze regarding the escrow, and collected $3.5 million of the escrow receivable and recognized a $0.2 million ( $0.1 million net of tax) loss from disposal of discontinued operations. Additionally, we recognized a $0.2 million net loss from discontinued operations for income tax expense related to this disposed business in 2015.

Operating Segments and Geograph

Operating Segments and Geographic Information	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Operating Segments and Geographic Information	Operating Segments and Geographic Information We are organized around four global business platforms: Broadcast Solutions, Enterprise Solutions, Industrial Solutions, and Network Solutions. To leverage the Company’s strengths in networking, IoT, and cybersecurity technologies, the Network Solutions platform was formed in January 2017 with the combination of the former Industrial IT and Network Security platforms. The former Network Security platform was formed with our acquisition of Tripwire in January 2015. The formation of the Network Solutions platform is a natural evolution in our organic and inorganic strategies for a range of industrial and non-industrial applications. In addition, to capitalize on the adoption of IP technology and accelerate our penetration of the commercial audio-video market, we transferred responsibility of audio-video cable and connectors from our Broadcast Solutions platform to our Enterprise Solutions platform effective January 1, 2016. We have revised the prior period segment information to conform to the changes in the composition of these reportable segments. These changes had no impact to our reporting units for purposes of goodwill impairment testing. We have determined that each of the global business platforms represents a reportable segment. The segments design, manufacture, and market a portfolio of signal transmission solutions for mission critical applications used in a variety of end markets, including broadcast, enterprise, and industrial. We sell the products manufactured by our segments principally through distributors or directly to systems integrators, original equipment manufacturers (OEMs), end-users, and installers. The key measures of segment profit or loss reviewed by our chief operating decision maker are Segment Revenues and Segment EBITDA. Segment Revenues represent non-affiliate revenues and include revenues that would have otherwise been recorded by acquired businesses as independent entities but were not recognized in our Consolidated Statements of Operations due to the effects of purchase accounting and the associated write-down of acquired deferred revenue to fair value. Segment EBITDA excludes certain items, including depreciation expense; amortization of intangibles; asset impairment; severance, restructuring, and acquisition integration costs; purchase accounting effects related to acquisitions, such as the adjustment of acquired inventory and deferred revenue to fair value; and other costs. We allocate corporate expenses to the segments for purposes of measuring Segment EBITDA. Corporate expenses are allocated on the basis of each segment’s relative EBITDA prior to the allocation. Our measure of segment assets does not include cash, goodwill, intangible assets, deferred tax assets, or corporate assets. All goodwill is allocated to reporting units of our segments for purposes of impairment testing. The results of our former equity method investment in the Hirschmann JV, which we sold effective December 31, 2017 (see Note 4), were not included in the corporate expense allocation. Operating Segment Information Broadcast Solutions Years ended December 31, 2017 2016 2015 (In thousands) Segment revenues $ 725,139 $ 769,753 $ 739,970 Affiliate revenues 440 744 916 Segment EBITDA 112,849 137,870 113,638 Depreciation expense 15,763 16,229 16,295 Amortization of intangibles 49,325 47,248 49,812 Amortization of software development intangible assets 56 — — Severance, restructuring, and acquisition integration costs 5,532 10,414 39,078 Purchase accounting effects of acquisitions 6,133 (2,991 ) 132 Deferred gross profit adjustments — 1,774 2,446 Patent settlement — (5,554 ) — Acquisition of property, plant and equipment 21,314 15,713 27,365 Segment assets 405,842 325,396 346,095 Enterprise Solutions Years ended December 31, 2017 2016 2015 (In thousands) Segment revenues $ 631,166 $ 603,188 $ 605,910 Affiliate revenues 7,385 5,977 5,322 Segment EBITDA 103,650 101,298 100,214 Depreciation expense 10,509 13,226 12,591 Amortization of intangibles 1,729 1,718 1,720 Severance, restructuring, and acquisition integration costs 23,511 11,962 723 Purchase accounting effects of acquisitions — 912 52 Acquisition of property, plant and equipment 28,126 22,679 10,323 Segment assets 282,072 246,564 238,400 Industrial Solutions Years ended December 31, 2017 2016 2015 (In thousands) Segment revenues $ 628,458 $ 585,476 $ 603,350 Affiliate revenues 1,441 1,325 1,613 Segment EBITDA 119,642 101,248 99,941 Depreciation expense 12,968 11,038 11,235 Amortization of intangibles 2,571 2,394 3,154 Severance, restructuring, and acquisition integration costs 12,272 9,923 6,228 Purchase accounting effects of acquisitions — — 334 Acquisition of property, plant and equipment 8,151 10,486 8,836 Segment assets 300,172 226,306 231,265 Network Solutions Years ended December 31, 2017 2016 2015 (In thousands) Segment revenues $ 403,880 $ 399,388 $ 411,353 Affiliate revenues 96 79 78 Segment EBITDA 93,893 92,773 87,873 Depreciation expense 6,357 6,715 6,430 Amortization of intangibles 50,372 47,025 49,105 Severance, restructuring, and acquisition integration costs 1,475 6,471 1,141 Purchase accounting effects of acquisitions — — 9,229 Deferred gross profit adjustments — 4,913 50,430 Acquisition of property, plant and equipment 5,168 4,704 7,048 Segment assets 158,309 115,732 118,520 Total Segments Years ended December 31, 2017 2016 2015 (In thousands) Segment revenues $ 2,388,643 $ 2,357,805 $ 2,360,583 Affiliate revenues 9,362 8,125 7,929 Segment EBITDA 430,034 433,189 401,666 Depreciation expense 45,597 47,208 46,551 Amortization of intangibles 103,997 98,385 103,791 Amortization of software development intangible assets 56 — — Severance, restructuring, and acquisition integration costs 42,790 38,770 47,170 Purchase accounting effects of acquisitions 6,133 (2,079 ) 9,747 Deferred gross profit adjustments — 6,687 52,876 Patent settlement — (5,554 ) — Acquisition of property, plant and equipment 62,759 53,582 53,572 Segment assets 1,146,395 913,998 934,280 The following table is a reconciliation of the total of the reportable segments’ Revenues and EBITDA to consolidated revenues and consolidated income from continuing operations before taxes, respectively. Years Ended December 31, 2017 2016 2015 (In thousands) Total Segment Revenues $ 2,388,643 $ 2,357,805 $ 2,360,583 Deferred revenue adjustments (1) — (6,687 ) (51,361 ) Patent settlement (2) — 5,554 — Consolidated Revenues $ 2,388,643 $ 2,356,672 $ 2,309,222 Total Segment EBITDA $ 430,034 $ 433,189 $ 401,666 Amortization of intangibles (103,997 ) (98,385 ) (103,791 ) Depreciation expense (45,597 ) (47,208 ) (46,551 ) Severance, restructuring, and acquisition integration costs (3) (42,790 ) (38,770 ) (47,170 ) Purchase accounting effects related to acquisitions (4) (6,133 ) 2,079 (9,747 ) Loss on sale of assets (5) (1,013 ) — — Amortization of software development intangible assets (56 ) — — Impairment of assets held for sale (5) — (23,931 ) — Deferred gross profit adjustments (1) — (6,687 ) (52,876 ) Patent settlement (2) — 5,554 — Income from equity method investment 7,502 1,793 1,770 Eliminations (3,260 ) (3,781 ) (2,748 ) Consolidated operating income 234,690 223,853 140,553 Interest expense, net (82,901 ) (95,050 ) (100,613 ) Loss on debt extinguishment (52,441 ) (2,342 ) — Consolidated income from continuing operations before taxes $ 99,348 $ 126,461 $ 39,940 (1) Our segment results include revenues that would have been recorded by acquired businesses had they remained as independent entities. Our consolidated results do not include these revenues due to the purchase accounting effect of recording deferred revenue at fair value. See Note 3, Acquisitions , for details. (2) Both our consolidated revenues and gross profit were positively impacted by royalty revenues received during 2016 that related to years prior to 2016 as a result of a patent settlement. (3) See Note 13, Severance, Restructuring, and Acquisition Integration Activities, for details . (4) In 2017, we recognized $6.1 million of cost of sales related to the adjustment of acquired inventory to fair value for our Thinklogical acquisition. In 2016, we made a $3.2 million adjustment to reduce the earn-out liability associated with the M2FX acquisition. This adjustment was partially offset by $0.8 million and $0.2 million of cost of sales related to the adjustment of acquired inventory to fair value related to our Enterprise Solutions segment and M2FX acquisition, respectively. In 2015, we recognized $9.2 million of compensation expense related to the accelerated vesting of acquiree stock based compensation awards associated with our acquisition of Tripwire. In addition, we recognized $0.3 million of cost of sales related to the adjustment of acquired inventory to fair value related to our acquisition of Coast. (5) In 2017 and 2016, we recognized a $1.0 million loss on sale of assets and $23.9 million impairment of assets held for sale, respectively, for the sale of our MCS business and Hirschmann JV. See Note 4, Assets Held for Sale , for details. Below are reconciliations of other segment measures to the consolidated totals. Years Ended December 31, 2017 2016 2015 (In thousands) Total segment assets $ 1,146,395 $ 913,998 $ 934,280 Cash and cash equivalents 561,108 848,116 216,751 Goodwill 1,478,257 1,385,995 1,385,115 Intangible assets, less accumulated amortization 545,207 560,082 655,871 Deferred income taxes 42,549 33,706 34,295 Income tax receivable — — 3,787 Corporate assets 67,097 64,906 60,503 Total assets $ 3,840,613 $ 3,806,803 $ 3,290,602 Total segment acquisition of property, plant and equipment $ 62,759 $ 53,582 $ 53,572 Corporate acquisition of property, plant and equipment 1,502 392 1,397 Total acquisition of property, plant and equipment $ 64,261 $ 53,974 $ 54,969 Geographic Information The Company attributes foreign sales based on the location of the customer purchasing the product. The table below summarizes net sales and long-lived assets for the years ended December 31, 2017 , 2016 and 2015 for the following countries: the U.S., Canada, China, and Germany. No other individual foreign country’s net sales or long-lived assets are material to the Company. United States Canada China Germany All Other Total (In thousands, except percentages) Year ended December 31, 2017 Revenues $ 1,265,455 $ 167,605 $ 121,600 $ 113,990 $ 719,993 $ 2,388,643 Percent of total revenues 53 % 7 % 5 % 5 % 30 % 100 % Long-lived assets $ 231,938 $ 33,806 $ 34,774 $ 38,029 $ 63,982 $ 402,529 Year ended December 31, 2016 Revenues $ 1,283,925 $ 159,985 $ 114,605 $ 104,214 $ 693,943 $ 2,356,672 Percent of total revenues 55 % 7 % 5 % 4 % 29 % 100 % Long-lived assets $ 193,263 $ 31,278 $ 30,487 $ 32,386 $ 60,654 $ 348,068 Year ended December 31, 2015 Revenues $ 1,270,467 $ 170,522 $ 114,863 $ 103,106 $ 650,264 $ 2,309,222 Percent of total revenues 55 % 7 % 5 % 4 % 29 % 100 % Long-lived assets $ 188,032 $ 27,315 $ 62,794 $ 35,588 $ 64,434 $ 378,163 Major Customer Revenues generated from sales to the distributor Anixter International Inc., primarily in the Enterprise Solutions and Industrial Solutions segments, were $292.2 million ( 12% of revenues), $286.2 million ( 12% of revenues), and $281.9 million ( 12% of revenues) for 2017 , 2016 , and 2015 , respectively. At December 31, 2017 , we had $38.2 million in accounts receivable outstanding from Anixter International Inc. This represented approximately 8% of our total accounts receivable outstanding at December 31, 2017 .

Noncontrolling Interest

Noncontrolling Interest	12 Months Ended
	Dec. 31, 2017
Noncontrolling Interest [Abstract]
Noncontrolling Interest	Noncontrolling Interest In 2015, we entered into a joint venture agreement with Shanghai Hi-Tech Control System Co, Ltd (Hite). The purpose of the joint venture is to develop and provide certain Network Solutions products and integrated solutions to customers in China. Belden and Hite contributed $1.53 million and $1.47 million , respectively, to the joint venture in 2015, reflecting ownership percentages of 51% and 49% , respectively. Belden and Hite are committed to fund an additional $1.53 million and $1.47 million 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 loss attributable to noncontrolling interest in the consolidated statements of operations. The joint venture is not material to our consolidated financial statements as of or for the years ended December 31, 2017 or 2016.

Income Per Share

Income Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Income Per Share	Income Per Share The following table presents the basis of the income per share computation: Years Ended December 31, 2017 2016 2015 (In thousands) Numerator: Income from continuing operations $ 92,853 $ 127,646 $ 66,508 Less: Net loss attributable to noncontrolling interest (357 ) (357 ) (24 ) Less: Preferred stock dividends 34,931 15,428 — Income from continuing operations attributable to Belden common stockholders 58,279 112,575 66,532 Loss from discontinued operations, net of tax, attributable to Belden common stockholders — — (242 ) Loss from disposal of discontinued operations, net of tax, attributable to Belden common stockholders — — (86 ) Net income attributable to Belden common stockholders $ 58,279 $ 112,575 $ 66,204 Denominator: Weighted average shares outstanding, basic 42,220 42,093 42,390 Effect of dilutive common stock equivalents 423 464 563 Weighted average shares outstanding, diluted 42,643 42,557 42,953 For the years ended December 31, 2017 , 2016 , and 2015 , diluted weighted average shares outstanding do not include outstanding equity awards of 0.5 million , 0.6 million , and 0.4 million , respectively, because to do so would have been anti-dilutive. In addition, for the years ended December 31, 2017 , 2016 , and 2015 , diluted weighted average shares outstanding do not include outstanding equity awards of 0.2 million , 0.1 million , and 0.0 million , respectively, because the related performance conditions have not been satisfied. Furthermore, for the years ended December 31, 2017 and 2016 , diluted weighted average shares outstanding do not include the weighted average impact of preferred shares that are convertible into 6.9 million and 3.0 million common shares, respectively, because deducting the preferred stock dividends from net income was more dilutive. For purposes of calculating basic earnings per share, unvested restricted stock units are not included in the calculation of basic weighted average shares outstanding until all necessary conditions have been satisfied and issuance of the shares underlying the restricted stock units is no longer contingent. Necessary conditions are not satisfied until the vesting date, at which time holders of our restricted stock units receive shares of our common stock. For purposes of calculating diluted earnings per share, unvested restricted stock units are included to the extent that they are dilutive. In determining whether unvested restricted stock units are dilutive, each issuance of restricted stock units is considered separately. Once a restricted stock unit has vested, it is included in the calculation of both basic and diluted weighted average shares outstanding.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Inventories	Inventories The major classes of inventories were as follows: December 31, 2017 2016 (In thousands) Raw materials $ 133,311 $ 90,019 Work-in-process 35,807 25,166 Finished goods 153,377 99,784 Gross inventories 322,495 214,969 Excess and obsolete reserves (25,269 ) (24,561 ) Net inventories $ 297,226 $ 190,408

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment The carrying values of property, plant and equipment were as follows: December 31, 2017 2016 (In thousands) Land and land improvements $ 31,963 $ 28,462 Buildings and leasehold improvements 148,598 136,230 Machinery and equipment 543,594 499,400 Computer equipment and software 136,509 123,909 Construction in process 46,898 35,191 Gross property, plant and equipment 907,562 823,192 Accumulated depreciation (570,240 ) (513,901 ) Net property, plant and equipment $ 337,322 $ 309,291 Depreciation Expense We recognized depreciation expense in income from continuing operations of $45.6 million , $47.2 million , and $46.6 million in 2017 , 2016 , and 2015 , respectively.

Intangible Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Intangible Assets The carrying values of intangible assets were as follows: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount (In thousands) (In thousands) Goodwill $ 1,478,257 $ — $ 1,478,257 $ 1,385,995 $ — $ 1,385,995 Definite-lived intangible assets subject to amortization: Developed technology $ 498,649 $ (318,366 ) $ 180,283 $ 420,928 $ (239,233 ) $ 181,695 Customer relationships 320,550 (98,175 ) 222,375 309,112 (77,872 ) 231,240 Trademarks 56,794 (18,648 ) 38,146 20,534 (10,915 ) 9,619 In-service research and development 23,428 (13,483 ) 9,945 22,977 (9,121 ) 13,856 Backlog 14,535 (14,535 ) — 12,638 (12,638 ) — Total intangible assets subject to amortization 913,956 (463,207 ) 450,749 786,189 (349,779 ) 436,410 Indefinite-lived intangible assets not subject to amortization: Trademarks 92,758 — 92,758 121,972 — 121,972 In-process research and development 1,700 — 1,700 1,700 — 1,700 Total intangible assets not subject to amortization 94,458 — 94,458 123,672 — 123,672 Intangible assets $ 1,008,414 $ (463,207 ) $ 545,207 $ 909,861 $ (349,779 ) $ 560,082 Segment Allocation of Goodwill and Trademarks The changes in the carrying amount of goodwill assigned to reporting units in our reportable segments are as follows: Broadcast Solutions Enterprise Solutions Industrial Solutions Network Solutions Consolidated (In thousands) Balance at December 31, 2015 $ 536,388 $ 73,278 $ 196,719 $ 578,730 $ 1,385,115 Acquisitions and purchase accounting adjustments 8,492 — — — 8,492 Translation impact (838 ) — 80 (1,377 ) (2,135 ) Reclassify to assets held for sale — — (5,477 ) — (5,477 ) Balance at December 31, 2016 $ 544,042 $ 73,278 $ 191,322 $ 577,353 $ 1,385,995 Acquisitions and purchase accounting adjustments 71,394 — — — 71,394 Translation impact 13,557 — 2,790 4,521 20,868 Balance at December 31, 2017 $ 628,993 $ 73,278 $ 194,112 $ 581,874 $ 1,478,257 The changes in the carrying amount of indefinite-lived trademarks are as follows: Broadcast Solutions Enterprise Solutions Industrial Solutions Network Solutions Consolidated (In thousands) Balance at December 31, 2015 $ 80,922 $ 4,063 $ 9,090 $ 35,596 $ 129,671 Translation impact (4,635 ) — 40 (199 ) (4,794 ) Reclassify to assets held for sale — — (2,905 ) — (2,905 ) Balance at December 31, 2016 $ 76,287 $ 4,063 $ 6,225 $ 35,397 $ 121,972 Translation impact 2,727 — 602 658 3,987 Reclassify to definite-lived — — (2,201 ) (31,000 ) (33,201 ) Balance at December 31, 2017 $ 79,014 $ 4,063 $ 4,626 $ 5,055 $ 92,758 Impairment The annual measurement date for our goodwill and indefinite-lived intangible assets impairment test is our fiscal November month-end. For our 2017 goodwill impairment test, we performed a quantitative assessment for five of our reporting units and determined the estimated fair values of our reporting units by calculating the present values of their estimated future cash flows using Level 3 inputs. We determined that the fair values of the reporting units were in excess of the carrying values; therefore, we did not record any goodwill impairment for the five reporting units. We performed a qualitative assessment for the remaining seven of our reporting units, and we determined that it was more likely than not that the fair value was greater than the carrying value. Therefore, we did not record any goodwill impairment for the seven reporting units. We also did not recognize any goodwill impairment in 2016 or 2015 based on the results of our annual goodwill impairment testing. Similar to the quantitative goodwill impairment test, we determined the estimated fair values of our indefinite-lived trademarks by calculating the present values of the estimated cash flows (using Level 3 inputs) attributable to the respective trademarks. We did not recognize any trademark impairment charges in 2017 , 2016 , or 2015 . Amortization Expense We recognized amortization expense in income from continuing operations of $104.0 million , $98.4 million , and $103.8 million in 2017 , 2016 , and 2015 , respectively. We expect to recognize annual amortization expense of $88.2 million in 2018 , $78.1 million in 2019 , $61.7 million in 2020 , $29.7 million in 2021 , and $27.0 million in 2022 related to our intangible assets balance as of December 31, 2017 . The weighted-average amortization period for our customer relationships, trademarks, developed technology, and in-service research and development is 18.5 years , 8.0 years , 6.5 years , and 4.7 years , respectively. In connection with the segment change discussed in Note 6, we re-evaluated the useful life of the Tripwire trademark and concluded that an indefinite life is no longer appropriate. We have estimated a useful life of 10 years and will re-evaluate this estimate if and when our expected use of the Tripwire trademark changes. We began amortizing the Tripwire trademark in the first quarter of 2017, which resulted in amortization expense of $3.1 million for the year ended December 31, 2017. As of December 31, 2017, the net book value of the Tripwire trademark was $27.9 million .

Accounts Payable and Accrued Li

Accounts Payable and Accrued Liabilities	12 Months Ended
	Dec. 31, 2017
Payables and Accruals [Abstract]
Accounts Payable and Accrued Liabilities	Accounts Payable and Accrued Liabilities The carrying values of accounts payable and accrued liabilities were as follows: December 31, 2017 2016 (In thousands) Accounts payable $ 376,277 $ 258,203 Current deferred revenue 90,639 80,503 Wages, severance and related taxes 57,633 76,157 Accrued rebates 38,025 33,071 Employee benefits 25,406 24,395 Accrued interest 22,019 27,202 Other (individual items less than 5% of total current liabilities) 68,929 69,012 Accounts payable and accrued liabilities $ 678,928 $ 568,543 The majority of our accounts payable balance is due to trade creditors. Our accounts payable balance as of December 31, 2017 and 2016 included $21.9 million and $12.4 million , respectively, of amounts due to banks under a commercial acceptance draft program. All accounts payable outstanding under the commercial acceptance draft program are expected to be settled within one year .

Severance, Restructuring, and A

Severance, Restructuring, and Acquisition Integration Activities	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Severance, Restructuring, and Acquisition Integration Activities	Severance, Restructuring, and Acquisition Integration Activities Industrial Manufacturing Footprint Program: 2016-2017 In the first quarter of 2016, we began a program to consolidate our manufacturing footprint. The manufacturing consolidation is expected to be completed in 2018. We recognized $30.6 million and $17.8 million of severance and other restructuring costs for this program during 2017 and 2016, respectively. The costs were incurred by the Enterprise Solutions and Industrial Solutions segments, as the manufacturing locations involved in the program serve both platforms. To date, we have incurred a total of $48.4 million in severance and other restructuring costs, including manufacturing inefficiencies for this program. We expect to incur approximately $6 million of additional severance and other restructuring costs for this program in 2018. We expect that the program will generate approximately $13 million of savings on an annualized basis, which we began to realize in the third quarter of 2017. Industrial and Network Solutions Restructuring Program: 2015-2016 Both our Industrial Solutions and Network Solutions segments were negatively impacted by a decline in sales volume in 2015. At such time, global demand for industrial products was negatively impacted by the strengthened U.S. dollar and lower energy prices. As a result, our customers reduced their capital spending. In response to these industrial market conditions, we began to execute a restructuring program in the fourth fiscal quarter of 2015 to reduce our cost structure. We recognized approximately $9.7 million and $3.3 million of severance and other restructuring costs for this program during 2016 and 2015, respectively. Most of these costs were incurred by our Network Solutions segment. We did not incur any severance and other restructuring costs for this program in 2017. We incurred a total of $13 million in severance and other restructuring costs for this program. We expected the restructuring program to generate approximately $18 million of savings on an annualized basis, and we are substantially realizing such benefits. Grass Valley Restructuring Program: 2015-2016 Our Broadcast Solutions segment’s Grass Valley brand was negatively impacted by a decline in global demand of broadcast technology infrastructure products beginning in 2015. Outside of the U.S., demand for these products was impacted by the relative price increase of products due to the strengthened U.S. dollar as well as the impact of weaker economic conditions which have resulted in lower capital spending. Within the U.S., demand for these products was impacted by deferred capital spending. We believe broadcast customers have deferred their capital spending as they navigate through a number of important industry transitions and a changing media landscape. In response to these broadcast market conditions, we began to execute a restructuring program beginning in the third fiscal quarter of 2015 to reduce our cost structure. We recognized approximately $8.7 million and $25.4 million of severance and other restructuring costs for this program during 2016 and 2015, respectively. We did not incur any severance and other restructuring costs for this program in 2017. We incurred a total of $34.1 million in severance and other restructuring costs for this program. We expected the restructuring program to generate approximately $30 million of savings on an annualized basis, and we are substantially realizing such benefits. Productivity Improvement Program and Acquisition Integration: 2014-2016 In 2014, we began a productivity improvement program and the integration of our acquisition of Grass Valley. The productivity improvement program focused on improving the productivity of our sales, marketing, finance, and human resources functions relative to our peers. The majority of the costs for the productivity improvement program related to the Industrial Solutions, Enterprise Solutions, and Network Solutions segments. The restructuring and integration activities related to our acquisition of Grass Valley focused on achieving desired cost savings by consolidating existing and acquired operating facilities and other support functions. The Grass Valley costs related to our Broadcast Solutions segment. In 2015, we recorded $18.5 million of such costs related to these two programs, as well as other cost reduction actions and the integration of our acquisitions of ProSoft, Coast, and Tripwire. In 2016, we recognized $2.6 million of costs, primarily related to our 2016 acquisition of M2FX. We did not incur any severance and other restructuring costs for this program in 2017. We expected the productivity improvement program to reduce our operating expenses by approximately $18 million on an annualized basis, and we are substantially realizing such benefits. The following tables summarize the costs by segment of the various programs described above as well as other immaterial programs and acquisition integration activities: Severance Other Restructuring and Integration Costs Total Costs (In thousands) Year Ended December 31, 2017 Broadcast Solutions $ 893 $ 4,639 $ 5,532 Enterprise Solutions 3,642 19,869 23,511 Industrial Solutions 886 11,386 12,272 Network Solutions (210 ) 1,685 1,475 Total $ 5,211 $ 37,579 $ 42,790 Year Ended December 31, 2016 Broadcast Solutions $ (116 ) $ 10,530 $ 10,414 Enterprise Solutions 636 11,326 11,962 Industrial Solutions 2,828 7,095 9,923 Network Solutions 3,734 2,737 6,471 Total $ 7,082 $ 31,688 $ 38,770 Year Ended December 31, 2015 Broadcast Solutions $ 16,694 $ 22,384 $ 39,078 Enterprise Solutions (186 ) 909 723 Industrial Solutions 3,309 2,919 6,228 Network Solutions (716 ) 1,857 1,141 Total $ 19,101 $ 28,069 $ 47,170 The other restructuring and integration costs in 2017 and 2016 primarily consisted of equipment transfers, costs to consolidate operating and support facilities, retention bonuses, relocation, travel, legal, and other costs. The other restructuring and integration costs in 2016 also included non-cash pension settlement charges due in part to our restructuring activities. The other restructuring and integration costs in 2015 primarily consisted of costs of integrating manufacturing operations, such as relocating inventory on a global basis, retention bonuses, relocation, travel, reserves for inventory obsolescence as a result of product line integration, costs to consolidate operating and support facilities, and other costs. The majority of the other restructuring and integration costs related to these actions were paid as incurred or are payable within the next 60 days . Of the total severance, restructuring, and acquisition integration costs recognized during 2017 , $32.6 million , $10.0 million , and $0.2 million were included in cost of sales; selling, general and administrative expenses; and research and development, respectively. Of the total severance, restructuring, and acquisition integration costs recognized during 2016 , $12.3 million , $25.7 million , and $0.8 million were included in cost of sales; selling, general and administrative expenses; and research and development, respectively. Of the total severance and other restructuring costs recognized during 2015 , $9.4 million , $31.7 million , and $6.1 million were included in cost of sales; selling, general and administrative expenses; and research and development, respectively. There were no significant severance accruals balances as of December 31, 2017 or 2016.

Long-Term Debt and Other Borrow

Long-Term Debt and Other Borrowing Arrangements	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Long-Term Debt and Other Borrowing Arrangements	Long-Term Debt and Other Borrowing Arrangements The carrying values of our long-term debt and other borrowing arrangements were as follows: December 31, 2017 2016 (In thousands) Revolving credit agreement due 2022 $ — $ — Senior subordinated notes: 3.375% Senior subordinated notes due 2027 540,810 — 4.125% Senior subordinated notes due 2026 240,360 209,081 2.875% Senior subordinated notes due 2025 360,540 — 5.25% Senior subordinated notes due 2024 200,000 200,000 5.50% Senior subordinated notes due 2023 242,522 529,146 5.50% Senior subordinated notes due 2022 — 700,000 9.25% Senior subordinated notes due 2019 — 5,221 Total senior subordinated notes 1,584,232 1,643,448 Less unamortized debt issuance costs (23,484 ) (23,287 ) Long-term debt $ 1,560,748 $ 1,620,161 Revolving Credit Agreement due 2022 On May 16, 2017, we entered into an Amended and Restated Credit Agreement (the Revolver) to amend and restate our prior Revolving Credit Agreement. The Revolver provides a $400.0 million multi-currency asset-based revolving credit facility. The borrowing base under the Revolver includes eligible accounts receivable; inventory; and property, plant and equipment of certain of our subsidiaries in the U.S., Canada, Germany, and the Netherlands. The maturity date of the Revolver is May 16, 2022. Interest on outstanding borrowings is variable, based upon LIBOR or other similar indices in foreign jurisdictions, plus a spread that ranges from 1.25% - 1.75% , depending upon our leverage position. We pay a commitment fee on our available borrowing capacity of 0.25% . In the event we borrow more than 90% of our borrowing base, we are subject to a fixed charge coverage ratio covenant. In 2017, we recognized a $0.8 million loss on debt extinguishment for unamortized debt issuance costs related to creditors no longer participating in the new Revolver. In connection with executing the Revolver, we also paid $2.3 million of fees to creditors and third parties that we will amortize over the remaining term of the Revolver. As of December 31, 2017 , we had no borrowings outstanding on the Revolver, and our available borrowing capacity was $348.6 million . Senior Subordinated Notes In July 2017, we completed an offering for €450.0 million ( $509.5 million at issuance) aggregate principal amount of 3.375% senior subordinated notes due 2027 (the 2027 Notes). The carrying value of the 2027 Notes as of December 31, 2017 is $540.8 million . The 2027 Notes are guaranteed on a senior subordinated basis by our current and future domestic subsidiaries. The 2027 Notes rank equal in right of payment with our senior subordinated notes due 2026, 2025, 2024, and 2023 and with any future subordinated debt, and they are subordinated to all of our senior debt and the senior debt of our subsidiary guarantors, including our Revolver. Interest is payable semiannually on January 15 and July 15 of each year, beginning on January 15, 2018. We paid approximately $8.8 million of fees associated with the issuance of the 2027 Notes, which will be amortized over the life of the 2027 Notes using the effective interest method. We used the net proceeds from this offering and cash on hand to repurchase all of the $700.0 million 2022 Notes outstanding for cash consideration of $722.7 million . In 2017, we recognized a $29.8 million loss on debt extinguishment including the write-off of unamortized debt issuance costs. In October 2016, we completed an offering for €200.0 million ( $222.2 million at issuance) aggregate principal amount of 4.125% senior subordinated notes due 2026 (the 2026 Notes). The carrying value of the 2026 Notes as of December 31, 2017 is $240.4 million . The 2026 Notes are guaranteed on a senior subordinated basis by our current and future domestic subsidiaries. The notes rank equal in right of payment with our senior subordinated notes due 2027, 2025, 2024, and 2023 and with any future subordinated debt, and they are subordinated to all of our senior debt and the senior debt of our subsidiary guarantors, including our Revolver. Interest is payable semiannually on April 15 and October 15 of each year, beginning on April 15, 2017. We paid approximately $3.9 million of fees associated with the issuance of the 2026 Notes, which are being amortized over the life of the 2026 Notes using the effective interest method. In September 2017, we completed an offering for €300.0 million ( $357.2 million at issuance) aggregate principal amount of 2.875% senior subordinated notes due 2025 (the 2025 Notes). The carrying value of the 2025 Notes as of December 31, 2017 is $360.5 million . The 2025 Notes are guaranteed on a senior subordinated basis by our current and future domestic subsidiaries. The 2025 Notes rank equal in right of payment with our senior subordinated notes due 2027, 2026, 2024, and 2023 and with any future subordinated debt, and they are subordinated to all of our senior debt and the senior debt of our subsidiary guarantors, including our Revolver. Interest is payable semiannually on March 15 and September 15 of each year, beginning on March 15, 2018. We paid approximately $6.2 million of fees associated with the issuance of the 2025 Notes, which will be amortized over the life of the 2025 Notes using the effective interest method. We used the net proceeds from this offering to repurchase €300.0 million of the €500.0 million 2023 Notes outstanding at such time. See further discussion below. We have outstanding $200 million aggregate principal amount of 5.25% senior subordinated notes due 2024 (the 2024 Notes). The 2024 Notes rank equal in right of payment with our senior subordinated notes due 2027, 2026, 2025, and 2023 and with any future subordinated debt, and they are subordinated to all of our senior debt and the senior debt of our subsidiary guarantors, including our Revolver. Interest is payable on January 15 and July 15 of each year. We paid approximately $4.2 million of fees associated with the issuance of the 2024 Notes, which are being amortized over the life of the 2024 Notes using the effective interest method. We used the net proceeds from the transaction for general corporate purposes. We had outstanding €500.0 million aggregate principal amount of 5.5% senior subordinated notes due 2023 (the 2023 Notes). In September 2017, we repurchased €300.0 million of the €500.0 million 2023 Notes outstanding for cash consideration of $377.9 million and recognized a $21.8 million loss on debt extinguishment including the write-off of unamortized debt issuance costs. The carrying value of the 2023 Notes as of December 31, 2017 is $242.5 million . The 2023 Notes are guaranteed on a senior subordinated basis by certain of our subsidiaries. The notes rank equal in right of payment with our senior subordinated notes due 2027, 2026, 2025, and 2024 and with any future subordinated debt, and they are subordinated to all of our senior debt and the senior debt of our subsidiary guarantors, including our Revolver. Interest is payable semiannually on April 15 and October 15 of each year. We had outstanding $5.2 million aggregate principal amount of 9.25% senior subordinated notes due 2019 (the 2019 Notes). On June 15, 2017, we repaid all of the 2019 Notes outstanding, plus accrued interest, and recognized an immaterial loss on debt extinguishment related to unamortized debt issuance costs. The senior subordinated notes due 2023, 2024, 2025, 2026 and 2027 are redeemable currently, after April 15, 2018, July 15, 2019, September 15, 2020, October 15, 2021 and July 15, 2022, respectively, at the following redemption prices as a percentage of the face amount of the notes: Senior Subordinated Notes due 2023 2024 2025 2026 2027 Year Percentage Year Percentage Year Percentage Year Percentage Year Percentage 2018 102.750 % 2019 102.625 % 2020 101.438 % 2021 102.063 % 2022 101.688 % 2019 101.833 % 2020 101.750 % 2021 100.719 % 2022 101.375 % 2023 101.125 % 2020 100.917 % 2021 100.875 % 2022 and thereafter 100.000 % 2023 100.688 % 2024 100.563 % 2021 and thereafter 100.000 % 2022 and thereafter 100.000 % 2024 and thereafter 100.000 % 2025 and thereafter 100.000 % Fair Value of Long-Term Debt The fair value of our senior subordinated notes as of December 31, 2017 was approximately $1,619.3 million based on quoted prices of the debt instruments in inactive markets (Level 2 valuation). This amount represents the fair values of our senior subordinated notes with a carrying value of $1,584.2 million as of December 31, 2017 . Maturities Maturities on outstanding long-term debt and other borrowings during each of the five years subsequent to December 31, 2017 are as follows (in thousands): 2018 $ — 2019 — 2020 — 2021 — 2022 — Thereafter 1,584,232 $ 1,584,232

Net Investment Hedge

Net Investment Hedge	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Net Investment Hedge	Net Investment Hedge All of our euro denominated notes were issued by Belden Inc., a USD functional currency ledger. As of December 31, 2017, all of our outstanding foreign denominated debt is designated as a net investment hedge on the foreign currency risk of our net investment in our euro foreign operations. The objective of the hedge is to protect the net investment in the foreign operation against adverse changes in exchange rates. The transaction gain or loss is reported in the cumulative translation adjustment section of other comprehensive income. The amount of the cumulative translation adjustment associated with these notes at December 31, 2017 and 2016 was a loss of $56.2 million and a gain of $13.0 million , respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Years ended December 31, 2017 2016 2015 (In thousands) Income (loss) from continuing operations before taxes: United States operations $ 2,177 $ (25,615 ) $ (6,924 ) Foreign operations 97,171 152,076 46,864 Income from continuing operations before taxes $ 99,348 $ 126,461 $ 39,940 Income tax expense (benefit): Currently payable United States federal $ — $ 2,981 $ — United States state and local 2,392 (1,038 ) 1,789 Foreign 28,201 26,906 17,317 30,593 28,849 19,106 Deferred United States federal (11,028 ) (27,677 ) (23,709 ) United States state and local (8,758 ) (3,139 ) (2,257 ) Foreign (4,312 ) 782 (19,708 ) (24,098 ) (30,034 ) (45,674 ) Income tax expense (benefit) $ 6,495 $ (1,185 ) $ (26,568 ) In addition to the above income tax expense (benefit) associated with continuing operations, we also recorded income tax expense (benefit) associated with discontinued operations $0.2 million in 2015 . Years Ended December 31, 2017 2016 2015 Effective income tax rate reconciliation from continuing operations: United States federal statutory rate 35.0 % 35.0 % 35.0 % State and local income taxes 0.8 % (0.9 )% (2.6 )% Impact of change in tax contingencies 2.2 % 2.4 % (4.2 )% Foreign income tax rate differences (13.1 )% (14.0 )% (8.4 )% Impact of change in deferred tax asset valuation allowance 1.5 % (7.3 )% (28.6 )% Impact of change in legal entity tax status — % (5.5 )% — % Impact of non-taxable translation gain (27.3 )% — % — % Impact of non-taxable interest income (5.5 )% (4.9 )% (15.6 )% Domestic permanent differences and tax credits (15.7 )% (5.7 )% (42.1 )% Impact of tax reform 28.6 % — % — % 6.5 % (0.9 )% (66.5 )% On December 22, 2017, the “Tax Cuts and Jobs Act” (the “Act”) was signed into law, making significant changes to the U.S. Internal Revenue Code. Changes include, but are not limited to, a corporate tax rate decrease from 35% to 21% effective for tax years beginning after December 31, 2017, the transition of U.S. international taxation from a worldwide tax system to a territorial tax system, and a one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings as of December 31, 2017. The Company has calculated its best estimate of the impact of the Act in its year end income tax provision in accordance with its understanding of the Act and guidance available as of the date of this filing and as a result has recorded $28.4 million as an additional income tax expense in the fourth quarter of 2017, the period in which the legislation was enacted. This provisional income tax expense is comprised of a $36.0 million tax benefit for the remeasurement of deferred tax assets and liabilities to the 21% rate at which they are expected to reverse, offset with a one-time tax expense on deemed repatriation of $29.1 million and a valuation allowance of $35.3 million recorded against foreign tax credit carryovers that we no longer expect to be able to realize based upon the new tax law. The Company continues to analyze its provisional estimate regarding the non-deductibility of certain covered employee compensation associated with amendments to IRC section 162(m). As of the date of this filing, the Company reasonably believes that the impact of these changes is immaterial. On December 22, 2017, Staff Accounting Bulletin No. 118 (“SAB 118”) was issued to address the application of US GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Act. In accordance with SAB 118, the Company has determined that the $36.0 million deferred tax benefit recorded in connection with the remeasurement of certain deferred tax assets and liabilities, the $29.1 million of current tax expense recorded in connection with the transition tax on the mandatory deemed repatriation of foreign earnings, the $35.3 million deferred tax expense recorded in connection with a valuation allowance on foreign tax credits, and the $0.0 million deferred tax expense recorded in connection with covered employee compensation were provisional amounts and reasonable estimates at December 31, 2017. Additional work is necessary to do a more detailed analysis of all provisional amounts associated with the Act referenced above as a result of pending issuance of Notices and Regulations related to the Act, ongoing legal analysis of compensation plans and finalization of foreign earnings and profits for 2017. Any subsequent adjustment to these amounts will be recorded to tax expense in the quarter of 2018 when the analysis is complete. An additional significant difference between the U.S. federal statutory tax rate and our effective tax rate was the impact of domestic permanent differences and tax credits. We recognized a total income tax benefit from domestic permanent differences and tax credits of $48.2 million in 2017. Of this income tax benefit, $27.1 million stems from a non-taxable translation gain associated with a debt instrument that is treated as a loan for U.S. GAAP purposes but as equity for tax purposes and $19.8 million stems from being able to recognize a significant balance of foreign tax credits related to one of our foreign jurisdictions as a result of implementing a tax planning strategy, net of the U.S. income tax consequences. An additional significant difference between the U.S. federal statutory tax rate and our effective tax rate was the impact of foreign tax rate differences. The statutory tax rates associated with our foreign earnings are generally lower than the 2017 statutory U.S. tax rate of 35% . The foreign tax rate differences are most significant in Germany, Canada, and the Netherlands, which have statutory tax rates of approximately 28% , 26% , and 25% , respectively. Foreign tax rate differences resulted in an income tax benefit of $13.0 million , $17.7 million , and $3.4 million in 2017, 2016, and 2015, respectively. Additionally, in 2017 and 2016, our income tax expense was reduced by $3.5 million and $2.9 million , respectively, due to a tax holiday for our operations in St. Kitts. The tax holiday in St. Kitts is scheduled to expire in 2022 . December 31, 2017 2016 (In thousands) Components of deferred income tax balances: Deferred income tax liabilities: Plant, equipment, and intangibles $ (120,171 ) $ (179,229 ) Deferred income tax assets: Postretirement, pensions, and stock compensation 28,736 35,500 Reserves and accruals 29,297 22,795 Net operating loss and tax credit carryforwards 228,815 245,135 Valuation allowances (151,841 ) (104,771 ) 135,007 198,659 Net deferred income tax asset $ 14,836 $ 19,430 The decrease in deferred income tax liabilities during 2017 is primarily due to the $36.0 million deferred tax benefit recorded in connection with the remeasurement of certain deferred tax assets and liabilities associated with the Act, as discussed above. The increase in our deferred tax valuation allowance is primarily due to the Company’s limited ability to utilize foreign tax credits before expiration as a result of the Act, as discussed above. As of December 31, 2017, we had $538.9 million of net operating loss carryforwards and $97.1 million of tax credit carryforwards. Unless otherwise utilized, net operating loss carryforwards will expire upon the filing of the tax returns for the following respective years: $1.0 million in 2017, $0.2 million in 2018, $7.9 million in 2019, $33.7 million between 2020 and 2022, and $143.4 million between 2023 and 2038. Net operating losses with an indefinite carryforward period total $352.7 million . Of the $538.9 million in net operating loss carryforwards, we have determined, based on the weight of all available evidence, both positive and negative, that we will utilize $158.6 million of these net operating loss carryforwards within their respective expiration periods. A valuation allowance has been recorded on the remaining portion of the net operating loss carryforwards. Unless otherwise utilized, tax credit carryforwards of $97.1 million will expire as follows: $0.1 million in 2018, $0.1 million in 2019, $4.7 million between 2020 and 2022, and $85.6 million between 2023 and 2038. Tax credit carryforwards with an indefinite carryforward period total $6.6 million . We have determined, based on the weight of all available evidence, both positive and negative, that we will utilize $58.4 million of these tax credit carryforwards within their respective expiration periods. A valuation allowance has been recorded on the remaining portion of the tax credit carryforwards. The following tables summarize our net operating loss carryforwards and tax credit carryforwards as of December 31, 2017 by jurisdiction: Net Operating Loss Carryforwards (In thousands) France $ 266,509 United States - various states 132,213 Luxembourg 25,034 Japan 22,245 Australia 16,433 Germany 14,127 Netherlands 13,063 Other 49,256 Total $ 538,880 Tax Credit Carryforwards (In thousands) United States $ 74,613 Canada 22,459 Total $ 97,072 In 2017, we recognized a net $1.9 million decrease to reserves for uncertain tax positions. A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows: 2017 2016 (In thousands) Balance at beginning of year $ 10,474 $ 7,293 Additions based on tax positions related to the current year 981 507 Additions for tax positions of prior years 2,549 2,675 Reductions for tax positions of prior years - Settlement (5,425 ) — Reduction for tax positions of prior years - Statute of limitations — (1 ) Balance at end of year $ 8,579 $ 10,474 The additions for tax positions of prior years relates to income tax audits of the U.S. and a foreign jurisdiction. The balance of $8.6 million at December 31, 2017, reflects tax positions that, if recognized, would impact our effective tax rate. As of December 31, 2017, we believe it is reasonably possible that $1.1 million of unrecognized tax benefits will change within the next twelve months primarily attributable to the expected completion of tax audits in the U.S. and foreign jurisdictions. Our practice is to recognize interest and penalties related to uncertain tax positions in interest expense and operating expenses, respectively. During 2017, 2016, and 2015, we recognized reductions of interest expense of $0.0 million , $(0.2) million , and $0.0 million , respectively, related to uncertain tax positions. We have approximately $0.0 million and $1.2 million accrued for the payment of interest and penalties as of December 31, 2017 and 2016, respectively. Our federal tax return for the tax years 2013 and later remain subject to examination by the Internal Revenue Service. Our state and foreign income tax returns for the tax years 2011 and later remain subject to examination by various state and foreign tax authorities.

Pension and Other Postretiremen

Pension and Other Postretirement Benefits	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Pension and Other Postretirement Benefits	Pension and Other Postretirement Benefits We sponsor defined benefit pension plans and defined contribution plans that cover substantially all employees in Canada, the Netherlands, the United Kingdom, the U.S., and certain employees in Germany, France, and Japan. We closed the U.S. defined benefit pension plan to new entrants effective January 1, 2010. Employees who were not active participants in the U.S. defined benefit pension plan on December 31, 2009, are not eligible to participate in the plan. During 2017, we sold our MCS business and its associated pension liabilities (see Note 4). Annual contributions to retirement plans equal or exceed the minimum funding requirements of applicable local regulations. The assets of the funded pension plans we sponsor are maintained in various trusts and are invested primarily in equity and fixed income securities. Benefits provided to employees under defined contribution plans include cash contributions by the Company based on either hours worked by the employee or a percentage of the employee’s compensation. Defined contribution expense for 2017 , 2016 , and 2015 was $13.9 million , $13.5 million , and $12.6 million , respectively. We sponsor unfunded postretirement medical and life insurance benefit plans for certain of our employees in Canada and the U.S. The medical benefit portion of the U.S. plan is only for employees who retired prior to 1989 as well as certain other employees who were near retirement and elected to receive certain benefits. The following tables provide a reconciliation of the changes in the plans’ benefit obligations and fair value of assets as well as a statement of the funded status and balance sheet reporting for these plans. Pension Benefits Other Benefits Years Ended December 31, 2017 2016 2017 2016 (In thousands) Change in benefit obligation: Benefit obligation, beginning of year $ (256,481 ) $ (275,205 ) $ (32,038 ) $ (32,313 ) Service cost (4,978 ) (4,981 ) (49 ) (46 ) Interest cost (7,671 ) (8,909 ) (1,139 ) (1,259 ) Participant contributions (91 ) (106 ) (7 ) (7 ) Actuarial gain (loss) (3,291 ) (16,250 ) 3,370 578 Divestiture 794 — — — Settlements 49 29,256 — — Curtailments — 227 — — Foreign currency exchange rate changes (14,299 ) 10,723 (2,022 ) (580 ) Benefits paid 13,943 8,764 1,552 1,589 Benefit obligation, end of year $ (272,025 ) $ (256,481 ) $ (30,333 ) $ (32,038 ) Pension Benefits Other Benefits Years Ended December 31, 2017 2016 2017 2016 (In thousands) Change in plan assets: Fair value of plan assets, beginning of year $ 182,370 $ 204,372 $ — $ — Actual return on plan assets 18,746 18,832 — — Employer contributions 4,425 5,698 1,545 1,582 Plan participant contributions 91 106 7 7 Settlements — (28,841 ) — — Foreign currency exchange rate changes 6,467 (9,033 ) — — Benefits paid (13,943 ) (8,764 ) (1,552 ) (1,589 ) Fair value of plan assets, end of year $ 198,156 $ 182,370 $ — $ — Funded status, end of year $ (73,869 ) $ (74,111 ) $ (30,333 ) $ (32,038 ) Amounts recognized in the balance sheets: Prepaid benefit cost $ 3,174 $ 3,148 $ — $ — Accrued benefit liability (current) (3,736 ) (3,022 ) (1,555 ) (1,778 ) Liabilities held for sale — (447 ) — — Accrued benefit liability (noncurrent) (73,307 ) (73,790 ) (28,778 ) (30,260 ) Net funded status $ (73,869 ) $ (74,111 ) $ (30,333 ) $ (32,038 ) The accumulated benefit obligation for all defined benefit pension plans was $269.2 million and $253.9 million at December 31, 2017 and 2016 , respectively. The projected benefit obligation, accumulated benefit obligation, and fair value of plan assets for the pension plans with an accumulated benefit obligation in excess of plan assets were $215.6 million , $212.7 million , and $138.5 million , respectively, as of December 31, 2017 , and were $205.8 million , $203.1 million , and $128.5 million , respectively, as of December 31, 2016 . The projected benefit obligation, accumulated benefit obligation, and fair value of plan assets for pension plans with an accumulated benefit obligation less than plan assets were $56.5 million , $56.5 million , and $59.6 million , respectively, as of December 31, 2017 and were $50.7 million , $50.7 million , and $53.9 million , respectively, as of December 31, 2016 . The following table provides the components of net periodic benefit costs for the plans. Pension Benefits Other Benefits Years Ended December 31, 2017 2016 2015 2017 2016 2015 (In thousands) Components of net periodic benefit cost: Service cost $ 4,978 $ 4,981 $ 5,505 $ 49 $ 46 $ 52 Interest cost 7,671 8,909 9,116 1,139 1,259 1,301 Expected return on plan assets (10,644 ) (12,013 ) (12,518 ) — — — Amortization of prior service credit (41 ) (42 ) (44 ) — (42 ) (87 ) Curtailment gain — (227 ) (128 ) — — — Settlement loss (gain) (8 ) 7,630 128 — — — Net loss recognition 2,597 2,670 5,082 — 86 328 Net periodic benefit cost $ 4,553 $ 11,908 $ 7,141 $ 1,188 $ 1,349 $ 1,594 During 2016 and 2015, we recorded settlement losses totaling $7.6 million and $0.1 million , respectively. These settlement losses were the result of lump-sum payments to participants that exceeded the sum of the pension plans’ respective annual service cost and interest cost amounts. The following table presents the assumptions used in determining the benefit obligations and the net periodic benefit cost amounts. Pension Benefits Other Benefits Years Ended December 31, 2017 2016 2017 2016 Weighted average assumptions for benefit obligations at year end: Discount rate 2.8 % 3.0 % 3.3 % 3.7 % Salary increase 3.6 % 3.3 % N/A N/A Weighted average assumptions for net periodic cost for the year: Discount rate 3.1 % 3.6 % 3.7 % 4.0 % Salary increase 3.6 % 3.5 % N/A N/A Expected return on assets 6.0 % 6.2 % N/A N/A Assumed health care cost trend rates: Health care cost trend rate assumed for next year N/A N/A 6.2 % 6.2 % Rate that the cost trend rate gradually declines to N/A N/A 5.0 % 5.0 % Year that the rate reaches the rate it is assumed to remain at N/A N/A 2024 2023 A one percentage-point change in the assumed health care cost trend rates would have the following effects on 2017 expense and year-end liabilities. 1% Increase 1% Decrease (In thousands) Effect on total of service and interest cost components $ 127 $ (103 ) Effect on postretirement benefit obligation 2,306 (1,943 ) Plan assets are invested using a total return investment approach whereby a mix of equity securities and fixed income securities are used to preserve asset values, diversify risk, and achieve our target investment return benchmark. Investment strategies and asset allocations are based on consideration of the plan liabilities, the plan’s funded status, and our financial condition. Investment performance and asset allocation are measured and monitored on an ongoing basis. Plan assets are managed in a balanced portfolio comprised of two major components: an equity portion and a fixed income portion. The expected role of equity investments is to maximize the long-term real growth of assets, while the role of fixed income investments is to generate current income, provide for more stable periodic returns, and provide some protection against a prolonged decline in the market value of equity investments. Absent regulatory or statutory limitations, the target asset allocation for the investment of the assets for our ongoing pension plans is 30 - 40% in fixed income securities and 60 - 70% in equity securities and for our pension plans where the majority of the participants are in payment or terminated vested status is 75 - 80% in fixed income securities and 20 - 25% in equity securities. Equity securities include U.S. and international equity, primarily invested through investment funds. Fixed income securities include government securities and investment grade corporate bonds, primarily invested through investment funds and group insurance contracts. We develop our expected long-term rate of return assumptions based on the historical rates of returns for equity and fixed income securities of the type in which our plans invest. The expected long-term rate of return on plan assets reflects the average rate of earnings expected on the invested assets and future assets to be invested to provide for the benefits included in the projected benefit obligation. We use historic plan asset returns combined with current market conditions to estimate the rate of return. The expected rate of return on plan assets is a long-term assumption based on an analysis of historical and forward looking returns considering the plan’s actual and target asset mix. The following table presents the fair values of the pension plan assets by asset category. December 31, 2017 December 31, 2016 Fair Market Value at December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fair Market Value at December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) (In thousands) Asset Category: Equity securities(a) Large-cap fund $ 75,165 $ — $ — $ — $ 65,495 $ — $ — $ — Mid-cap fund 13,046 — — — 11,419 — — — Small-cap fund 18,785 — — — 17,184 — — — Debt securities(b) Government bond fund 28,429 — — — 26,151 — — — Corporate bond fund 24,421 — — — 20,971 — — — Fixed income fund(c) 38,072 — 38,072 — 40,958 — 40,958 — Cash & equivalents 238 238 — — 192 192 — — Total $ 198,156 $ 238 $ 38,072 $ — $ 182,370 $ 192 $ 40,958 $ — (a) This category includes investments in actively managed and indexed investment funds that invest in a diversified pool of equity securities of companies located in the U.S., Canada, Western Europe and other developed countries throughout the world. The funds are valued using the net asset value method in which an average of the market prices for the underlying investments is used to value the fund. Funds valued using the net asset value method are not included in the fair value hierarchy. (b) This category includes investments in investment funds that invest in U.S. treasuries; other national, state and local government bonds; and corporate bonds of highly rated companies from diversified industries. The funds are valued using the net asset value method in which an average of the market prices for the underlying investments is used to value the fund. Funds valued using the net asset value method are not included in the fair value hierarchy. (c) This category includes guaranteed insurance contracts. The plans do not invest in individual securities. All investments are through well diversified investment funds. As a result, there are no significant concentrations of risk within the plan assets. The following table reflects the benefits as of December 31, 2017 expected to be paid in each of the next five years and in the aggregate for the five years thereafter from our pension and other postretirement plans. Because our other postretirement plans are unfunded, the anticipated benefits with respect to these plans will come from our own assets. Because our pension plans are primarily funded plans, the anticipated benefits with respect to these plans will come primarily from the trusts established for these plans. Pension Plans Other Plans (In thousands) 2018 $ 16,562 $ 1,580 2019 16,923 1,568 2020 17,937 1,562 2021 17,688 1,557 2022 15,787 1,553 2023-2027 83,382 7,753 Total $ 168,279 $ 15,573 We anticipate contributing $4.6 million and $1.6 million to our pension and other postretirement plans, respectively, during 2018. The pre-tax amounts in accumulated other comprehensive loss that have not yet been recognized as components of net periodic benefit cost at December 31, 2017 , the changes in these amounts during the year ended December 31, 2017 , and the expected amortization of these amounts as components of net periodic benefit cost for the year ended December 31, 2017 , are as follows. Pension Benefits Other Benefits (In thousands) Components of accumulated other comprehensive loss: Net actuarial loss (gain) $ 44,359 $ (1,545 ) Net prior service cost 11 — $ 44,370 $ (1,545 ) Pension Benefits Other Benefits (In thousands) Changes in accumulated other comprehensive loss: Net actuarial loss, beginning of year $ 49,260 $ 1,842 Amortization of actuarial loss (2,597 ) — Actuarial loss (gain) 3,291 (3,370 ) Asset gain (8,102 ) — Curtailment gain recognized — — Settlement gain recognized 8 — Divestiture (180 ) — Currency impact 2,679 (17 ) Net actuarial loss (gain), end of year $ 44,359 $ (1,545 ) Prior service credit, beginning of year $ (44 ) $ — Amortization of prior service credit 41 — Divestiture (10 ) — Currency impact 24 — Prior service cost, end of year $ 11 $ — Pension Benefits Other Benefits (In thousands) Expected 2018 amortization: Amortization of prior service credit $ (41 ) $ — Amortization of actuarial loss 2,758 — $ 2,717 $ —

Comprehensive Income and Accumu

Comprehensive Income and Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Comprehensive Income and Accumulated Other Comprehensive Income (Loss)	Comprehensive Income and Accumulated Other Comprehensive Income (Loss) The accumulated balances related to each component of other comprehensive income (loss), net of tax, are as follows: Foreign Currency Translation Component Pension and Other Postretirement Benefit Plans Accumulated Other Comprehensive Income (Loss) (In thousands) Balance at December 31, 2015 $ (23,411 ) $ (35,576 ) $ (58,987 ) Other comprehensive gain (loss) loss attributable to Belden before reclassifications 18,750 (5,166 ) 13,584 Amounts reclassified from accumulated other comprehensive loss — 6,336 6,336 Net current period other comprehensive gain attributable to Belden 18,750 1,170 19,920 Balance at December 31, 2016 (4,661 ) (34,406 ) (39,067 ) Other comprehensive gain (loss) attributable to Belden before reclassifications (65,030 ) 4,504 (60,526 ) Amounts reclassified from accumulated other comprehensive loss — 1,567 1,567 Net current period other comprehensive gain (loss) attributable to Belden (65,030 ) 6,071 (58,959 ) Balance at December 31, 2017 $ (69,691 ) $ (28,335 ) $ (98,026 ) The following table summarizes the effects of reclassifications from accumulated other comprehensive income (loss): Amount Reclassified from Accumulated Other Comprehensive Income (Loss) Affected Line Item in the Consolidated Statements of Operations and Comprehensive Income (In thousands) Amortization of pension and other postretirement benefit plan items: Settlement gain $ (8 ) (1 ) Actuarial losses 2,597 (1 ) Prior service credit (41 ) (1 ) Total before tax 2,548 Tax benefit (981 ) Total net of tax $ 1,567 (1) The amortization of these accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit costs (see Note 16).

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation Compensation cost charged against income, primarily selling, general and administrative expense, and the income tax benefit recognized for our share-based compensation arrangements is included below: Years Ended December 31, 2017 2016 2015 (In thousands) Total share-based compensation cost $ 14,647 $ 18,178 $ 17,745 Income tax benefit 5,566 7,069 6,867 We currently have outstanding stock appreciation rights (SARs), restricted stock units with service vesting conditions, restricted stock units with performance vesting conditions, and restricted stock units with market conditions. We grant SARs with an exercise price equal to the closing market price of our common stock on the grant date. Generally, SARs may be converted into shares of our common stock in equal amounts on each of the first three anniversaries of the grant date and expire 10 years from the grant date. Certain awards provide for accelerated vesting in certain circumstances, including following a change in control of the Company. Restricted stock units with service conditions generally vest 3 - 5 years from the grant date. Restricted stock units issued based on the attainment of the performance conditions generally vest on the second or third anniversary of their grant date. Restricted stock units issued based on the attainment of market conditions generally vest on the third anniversary of their grant date. We recognize compensation cost for all awards based on their fair values. The fair values for SARs are estimated on the grant date using the Black-Scholes-Merton option-pricing formula which incorporates the assumptions noted in the following table. Expected volatility is based on historical volatility, and expected term is based on historical exercise patterns of SAR holders. The fair value of restricted stock units with service vesting conditions or performance vesting conditions is the closing market price of our common stock on the date of grant. We estimate the fair value of certain restricted stock units with market conditions using a Monte Carlo simulation valuation model with the assistance of a third party valuation firm. Compensation costs for awards with service conditions are amortized to expense using the straight-line method. Compensation costs for awards with performance conditions and graded vesting are amortized to expense using the graded attribution method. Years Ended December 31, 2017 2016 2015 (In thousands, except weighted average fair value and assumptions) Weighted-average fair value of SARs and options granted $ 27.31 $ 18.79 $ 31.22 Total intrinsic value of SARs converted and options exercised 7,156 9,678 14,697 Cash received for options exercised — — 30 Tax benefit related to share-based compensation 967 1,171 5,050 Weighted-average fair value of restricted stock shares and units granted 79.96 54.52 96.52 Total fair value of restricted stock shares and units vested 10,355 8,171 7,696 Expected volatility 36.89 % 37.47 % 35.66 % Expected term (in years) 5.6 5.7 5.7 Risk-free rate 2.01 % 1.32 % 1.59 % Dividend yield 0.27 % 0.38 % 0.22 % SARs and Stock Options Restricted Shares and Units Number Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term Aggregate Intrinsic Value Number Weighted- Average Grant-Date Fair Value (In thousands, except exercise prices, fair values, and contractual terms) Outstanding at January 1, 2017 1,124 $ 56.79 454 $ 69.55 Granted 254 74.91 222 79.96 Exercised or converted (210 ) 44.08 (145 ) 71.27 Forfeited or expired (36 ) 71.02 (35 ) 75.56 Outstanding at December 31, 2017 1,132 $ 62.75 6.9 $ 16,327 496 $ 78.03 Vested or expected to vest at December 31, 2017 1,118 $ 62.65 6.8 $ 16,234 Exercisable or convertible at December 31, 2017 623 58.57 5.6 11,585 At December 31, 2017 , the total unrecognized compensation cost related to all nonvested awards was $21.1 million . That cost is expected to be recognized over a weighted-average period of 1.8 years . Historically, we have issued treasury shares, if available, to satisfy award conversions and exercises.

Preferred Stock

Preferred Stock	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Preferred Stock	Preferred Stock On July 26, 2016, we issued 5.2 million depositary shares, each of which represents 1/100th interest in a share of 6.75% Series B Mandatory Convertible Preferred Stock (the Preferred Stock), for an offering price of $100 per depositary share. Holders of the Preferred Stock may elect to convert their shares into common stock at any time prior to the mandatory conversion date. Unless earlier converted, each share of Preferred Stock will automatically convert into common stock on or around July 15, 2019 into between 120.46 and 132.50 shares of Belden common stock, subject to customary anti-dilution adjustments. This represents a range of 6.2 million to 6.9 million shares of Belden common stock to be issued upon conversion. The number of shares of Belden common stock issuable upon the mandatory conversion of the Preferred Stock will be determined based upon the volume-weighted average price of Belden’s common stock over the 20 day trading period beginning on, and including, the 22nd scheduled trading day prior to July 15, 2019. The net proceeds from this offering were approximately $501 million . The net proceeds are for general corporate purposes. With respect to dividend and liquidation rights, the Preferred Stock ranks senior to our common stock and junior to all of our existing and future indebtedness.

Stockholder Rights Plan

Stockholder Rights Plan	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholder Rights Plan	Stockholder Rights Plan Under our Stockholder Rights Plan, each share of our common stock generally has “attached” to it one preferred share purchase right. Each right, when exercisable, entitles the holder to purchase 1/1000th of a share of our Junior Participating Preferred Stock Series A at a purchase price of $325.00 (subject to adjustment). Each 1/1000th of a share of Series A Junior Participating Preferred Stock will be substantially equivalent to one share of our common stock and will be entitled to one vote, voting together with the shares of common stock. The rights will become exercisable only if, without the prior approval of the Board of Directors, a person or group of persons acquires or announces the intention to acquire 20% or more of our common stock. If we are acquired through a merger or other business combination transaction, each right will entitle the holder to purchase $300.00 worth of the surviving company’s common stock for $150.00 (subject to adjustment). In addition, if a person or group of persons acquires 20% or more of our common stock, each right not owned by the 20% or greater shareholder would permit the holder to purchase $300.00 worth of our common stock for $150.00 (subject to adjustment). The rights are redeemable, at our option, at $0.01 per right at any time prior to an announcement of a beneficial owner of 20% or more of our common stock then outstanding. The rights expire on December 10, 2019.

Share Repurchases

Share Repurchases	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Share Repurchases	Share Repurchases On May 25, 2017, our Board of Directors authorized a share repurchase program, which allows us to purchase up to $200.0 million of our common stock through open market repurchases, negotiated transactions, or other means, in accordance with applicable securities laws and other restrictions. This program is funded with cash on hand and cash flows from operating activities. The program does not have an expiration date and may be suspended at any time at the discretion of the Company. During 2017, we repurchased 0.3 million shares of our common stock under the program for an aggregate cost of $25.0 million and an average price per share of $79.75 .

Operating Leases

Operating Leases	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Operating Leases	Operating Leases Operating lease expense incurred primarily for manufacturing and office space, machinery, and equipment was $38.6 million , $40.3 million , and $40.6 million in 2017 , 2016 , and 2015 , respectively. Minimum annual lease payments for noncancelable operating leases in effect at December 31, 2017 are as follows (in thousands): 2018 $ 22,440 2019 18,006 2020 13,787 2021 11,001 2022 8,561 Thereafter 23,494 $ 97,289 Certain of our operating leases include step rent provisions and rent escalations. We include these step rent provisions and rent escalations in our minimum lease payments obligations and recognize them as a component of rental expense on a straight-line basis over the minimum lease term.

Market Concentrations and Risks

Market Concentrations and Risks	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
Market Concentrations and Risks	Market Concentrations and Risks Concentrations of Credit We sell our products to many customers in several markets across multiple geographic areas. The ten largest customers, of which six are distributors, constitute in aggregate approximately 35% , 33% , and 33% of revenues in 2017 , 2016 , and 2015 , respectively. Unconditional Commodity Purchase Obligations At December 31, 2017 , we were committed to purchase approximately 2.3 million pounds of copper at an aggregate fixed cost of $7.0 million . At December 31, 2017 , this fixed cost was $0.5 million less than the market cost that would be incurred on a spot purchase of the same amount of copper. The aggregate market cost was based on the current market price of copper obtained from the New York Mercantile Exchange. Labor Approximately 21% of our labor force is covered by collective bargaining agreements at various locations around the world. Approximately 16% of our labor force is covered by collective bargaining agreements that we expect to renegotiate during 2018. Fair Value of Financial Instruments Our financial instruments consist primarily of cash and cash equivalents, trade receivables, trade payables, and debt instruments. The carrying amounts of cash and cash equivalents, trade receivables, and trade payables at December 31, 2017 are considered representative of their respective fair values. The fair value of our senior subordinated notes at December 31, 2017 and 2016 was approximately $1,619.3 million and $1,693.2 million , respectively, based on quoted prices of the debt instruments in inactive markets (Level 2 valuation). This amount represents the fair values of our senior subordinated notes with a carrying value of $1,584.2 million and $1,643.4 million as of December 31, 2017 and 2016 , respectively.

Contingent Liabilities

Contingent Liabilities	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Contingent Liabilities	Contingent Liabilities General Various claims are asserted against us in the ordinary course of business including those pertaining to income tax examinations, product liability, customer, employment, vendor, and patent matters. Based on facts currently available, management believes that the disposition of the claims that are pending or asserted will not have a materially adverse effect on our financial position, operating results, or cash flow. Letters of Credit, Guarantees and Bonds At December 31, 2017 , we were party to unused standby letters of credit, surety bonds, and bank guarantees totaling $7.5 million , $2.3 million , and $1.7 million , respectively. These commitments are generally issued to secure obligations we have for a variety of commercial reasons, such as workers compensation self-insurance programs in several states and the importation and exportation of product.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2017
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information Supplemental cash flow information is as follows: Years Ended December 31, 2017 2016 2015 (In thousands) Income tax refunds received $ 5,031 $ 3,838 $ 4,068 Income taxes paid (35,893 ) (26,587 ) (24,960 ) Interest paid, net of amount capitalized (79,047 ) (87,076 ) (91,496 )

Quarterly Operating Results (Un

Quarterly Operating Results (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Operating Results (Unaudited)	Quarterly Operating Results (Unaudited) 2017 1st 2nd 3rd 4th Year (In thousands, except days and per share amounts) Number of days in quarter 92 91 91 91 365 Revenues $ 551,381 $ 610,633 $ 621,745 $ 604,884 $ 2,388,643 Gross profit 222,114 242,509 239,824 229,592 934,039 Operating income 51,337 62,481 60,791 60,081 234,690 Net income 25,581 35,891 945 30,436 92,853 Less: Net loss attributable to noncontrolling interest (106 ) (86 ) (82 ) (83 ) (357 ) Net income attributable to Belden 25,687 35,977 1,027 30,519 93,210 Less: Preferred stock dividends 8,733 8,733 8,732 8,733 34,931 Net income (loss) attributable to Belden common stockholders 16,954 27,244 (7,705 ) 21,786 58,279 Basic income (loss) per share attributable to Belden common stockholders: $ 0.40 $ 0.64 $ (0.18 ) $ 0.52 $ 1.38 Diluted income (loss) per share attributable to Belden stockholders: $ 0.40 $ 0.64 $ (0.18 ) $ 0.51 $ 1.37 During the financial closing process for the fourth quarter of 2017, we determined that certain consolidated financial statement amounts were not recorded correctly in prior interim periods of 2017. We have evaluated these errors and concluded that they were not material to any of our previously issued interim financial statements and did not require restatement of the quarters. The errors primarily related to recognizing revenue prior to satisfying all of the delivery criteria in one business within our Broadcast segment. The impact of the errors in the first, second, and third quarters of 2017 was an overstatement of revenues of $6.1 million , $10.4 million , and $11.8 million , respectively, and an overstatement of net income of $3.0 million , $1.3 million , and $2.6 million , respectively. The impact of the errors in the fourth quarter of 2017 was an understatement of revenues of $27.8 million and an understatement of net income of $5.2 million . All of the errors have been corrected as of December 31, 2017. Included in the first, second, third, and fourth quarters of 2017 are severance, restructuring, and integration costs of $6.6 million , $9.6 million , $16.7 million , and $9.9 million , respectively. 2016 1st 2nd 3rd 4th Year (In thousands, except days and per share amounts) Number of days in quarter 94 91 91 90 366 Revenues $ 541,497 $ 601,631 $ 601,109 $ 612,435 $ 2,356,672 Gross profit 225,035 248,213 245,962 261,784 980,994 Operating income 40,964 62,241 61,980 58,668 223,853 Net Income 16,358 41,933 36,072 33,283 127,646 Less: Net loss attributable to noncontrolling interest (99 ) (99 ) (88 ) (71 ) (357 ) Net income attributable to Belden 16,457 42,032 36,160 33,354 128,003 Less: Preferred stock dividends — — 6,695 8,733 15,428 Net income attributable to Belden common stockholders 16,457 42,032 29,465 24,621 112,575 Basic income per share attributable to Belden common stockholders: $ 0.39 $ 1.00 $ 0.70 $ 0.58 $ 2.67 Diluted income per share attributable to Belden stockholders: $ 0.39 $ 0.99 $ 0.69 $ 0.58 $ 2.65 Included in the first, second, third, and fourth quarters of 2016 are severance, restructuring, and integration costs of $8.4 million , $5.9 million , $12.8 million , and $11.7 million , respectively. Included in the fourth quarter of 2016 are royalty revenues of $10.3 million from a patent settlement during the quarter.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On February 8, 2018, we acquired a company for a purchase price of $75.8 million , plus we assumed debt of $18.4 million . The acquisition includes a potential earn-out for which we have not yet estimated a fair value. This acquisition was funded with cash on hand. We are in the preliminary phase of the purchase accounting process, including obtaining third party valuations of certain tangible and intangible assets acquired. As such, the purchase accounting process is incomplete and we cannot provide the required disclosures of the estimated fair value of the assets and liabilities acquired for this business combination.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2017
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	Schedule II – Valuation and Qualifying Accounts Beginning Balance Charged to Costs and Expenses Divestitures/ Acquisitions Charge Offs Recoveries Currency Movement Ending Balance (In thousands) Accounts Receivable— Allowance for Doubtful Accounts: 2017 $ 8,104 $ 950 $ 38 $ (905 ) $ (995 ) $ 574 $ 7,766 2016 8,281 2,517 (1 ) (1,336 ) (1,046 ) (311 ) 8,104 2015 11,503 2,561 40 (803 ) (4,353 ) (667 ) 8,281 Inventories— Excess and Obsolete Allowances: 2017 $ 24,561 $ 2,348 $ 2,628 $ (3,219 ) $ (2,205 ) $ 1,156 $ 25,269 2016 22,531 3,921 (706 ) — (1,142 ) (43 ) 24,561 2015 31,823 3,001 2,755 (12,744 ) (1,407 ) (897 ) 22,531 Deferred Income Tax Asset— Valuation Allowance: 2017 $ 104,771 $ 39,307 $ — $ (3,322 ) $ (1,712 ) $ 12,797 $ 151,841 2016 117,071 10,782 616 (8,074 ) (10,526 ) (5,098 ) 104,771 2015 157,317 2,840 (14,425 ) (1,823 ) (13,988 ) (12,850 ) 117,071

Basis of Presentation (Policies

Basis of Presentation (Policies)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business Description	Business Description Belden Inc. (the Company, us, we, or our) is an innovative signal transmission solutions company built around four global business platforms – Broadcast Solutions, Enterprise Solutions, Industrial Solutions, and Network Solutions. Our comprehensive portfolio of signal transmission solutions provides industry leading secure and reliable transmission of data, sound, and video for mission critical applications. We sell our products to distributors, end-users, installers, and directly to original equipment manufacturers (OEMs).
Consolidation	Consolidation The accompanying Consolidated Financial Statements include Belden Inc. and all of its subsidiaries, including variable interest entities for which we are the primary beneficiary. We eliminate all significant affiliate accounts and transactions in consolidation.
Foreign Currency	Foreign Currency For international operations with functional currencies other than the United States (U.S.) dollar, we translate assets and liabilities at current exchange rates; we translate income and expenses using average exchange rates. We report the resulting translation adjustments, as well as gains and losses from certain affiliate transactions, in accumulated other comprehensive income (loss), a separate component of stockholders’ equity. We include exchange gains and losses on transactions in operating income. We determine the functional currency of our foreign subsidiaries based upon the currency of the primary economic environment in which each subsidiary operates. Typically, that is determined by the currency in which the subsidiary primarily generates and expends cash. We have concluded that the local currency is the functional currency for all of our material subsidiaries.
Reporting Periods	Reporting Periods Our 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. Our fiscal second and third quarters each have 91 days.
Use of Estimates in the Preparation of the Financial Statements	Use of Estimates in the Preparation of the Financial Statements The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. requires us to make estimates and assumptions that affect the reported amounts of assets, liabilities, and operating results and the disclosure of contingencies. Actual results could differ from those estimates. We make significant estimates with respect to the collectability and valuation of receivables, the valuation of inventory, the realization of deferred tax assets, the valuation of goodwill and indefinite-lived intangible assets, the valuation of contingent liabilities, the calculation of share-based compensation, the calculation of pension and other postretirement benefits expense, and the valuation of acquired businesses.
Reclassifications	Reclassifications We have made certain, insignificant reclassifications to the 2016 and 2015 Consolidated Financial Statements with no impact to reported net income in order to conform to the 2017 presentation.
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 December 31, 2017 , 2016 , and 2015 we utilized Level 1 inputs to determine the fair value of cash equivalents, and Level 3 inputs to determine the fair value of net assets acquired in business combinations (see Note 3) and for our annual impairment testing (see Note 11). We did not have any transfers between Level 1 and Level 2 fair value measurements during 2017 .
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 December 31, 2017 and 2016 , we did not have any such cash equivalents on hand.
Accounts Receivable	Accounts Receivable We classify amounts owed to us and due within twelve months, arising from the sale of goods or services in the normal course of business, as current receivables. We classify receivables due after twelve months as other long-lived assets. At the time of sale, we establish an estimated reserve for trade, promotion, and other special price reductions such as contract pricing, discounts to meet competitor pricing, and on-time payment discounts. We also adjust receivable balances for, among other things, correction of billing errors, incorrect shipments, and settlement of customer disputes. Customers are allowed to return inventory if and when certain conditions regarding the physical state of the inventory and our approval of the return are met. Certain distribution customers are allowed to return inventory at original cost, in an amount not to exceed three percent of the prior year’s purchases, in exchange for an order of equal or greater value. Until we can process these reductions, corrections, and returns (together, the Changes) through individual customer records, we estimate the amount of outstanding Changes and recognize them by reducing revenues and accounts receivable. We also adjust inventory and cost of sales for the estimated level of returns. We base these estimates on historical and anticipated sales demand, trends in product pricing, and historical and anticipated Changes patterns. We make revisions to these estimates in the period in which the facts that give rise to each revision become known. Future market conditions might require us to take actions to further reduce prices and increase customer return authorizations. Unprocessed Changes recognized against our gross accounts receivable balance at December 31, 2017 and 2016 totaled $35.7 million and $23.3 million , respectively. We evaluate the collectability of accounts receivable based on the specific identification method. A considerable amount of judgment is required in assessing the realizability of accounts receivable, including the current creditworthiness of each customer and related aging of the past due balances. We perform ongoing credit evaluations of our customers’ financial condition. Through these evaluations, we may become aware of a situation where a customer may not be able to meet its financial obligations due to deterioration of its financial viability, credit ratings, or bankruptcy. We record a specific reserve for bad debts against amounts due to reduce the receivable to its estimated collectible balance.
Inventories and Related Reserves	Inventories and Related Reserves Inventories are stated at the lower of cost or market. We determine the cost of all raw materials, work-in-process, and finished goods inventories by the first in, first out method. Cost components of inventories include direct labor, applicable production overhead, and amounts paid to suppliers of materials and products as well as freight costs and, when applicable, duty costs to import the materials and products. We evaluate the realizability of our inventory on a product-by-product basis in light of historical and anticipated sales demand, technological changes, product life cycle, component cost trends, product pricing, and inventory condition. In circumstances where inventory levels are in excess of anticipated market demand, where inventory is deemed technologically obsolete or not saleable due to condition, or where inventory cost exceeds net realizable value, we record a charge to cost of sales and reduce the inventory to its net realizable value.
Property, Plant and Equipment	Property, Plant and Equipment We record property, plant and equipment at cost. We calculate depreciation on a straight-line basis over the estimated useful lives of the related assets ranging from 10 to 40 years for buildings, 5 to 12 years for machinery and equipment, and 5 to 10 years for computer equipment and software. Construction in process reflects amounts incurred for the configuration and build-out of property, plant and equipment and for property, plant and equipment not yet placed into service. We charge maintenance and repairs—both planned major activities and less-costly, ongoing activities—to expense as incurred. We capitalize interest costs associated with the construction of capital assets and amortize the costs over the assets’ useful lives. Depreciation expense is included in costs of sales; selling, general and administrative expenses; and research and development expenses in the Consolidated Statements of Operations based on the specific categorization and use of the underlying assets being depreciated. We review property, plant and equipment to determine whether an event or change in circumstances indicates the carrying values of the assets may not be recoverable. We base our evaluation on the nature of the assets, the future economic benefit of the assets, and any historical or future profitability measurements, as well as other external market conditions or factors that may be present. If such impairment indicators are present or other factors exist that indicate that the carrying amount of an asset may not be recoverable, we determine whether impairment has occurred through the use of an undiscounted cash flow analysis. If impairment has occurred, we recognize a loss for the difference between the carrying amount and the fair value of the asset. For purposes of impairment testing of long-lived assets, we have identified asset groups at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Generally, our asset groups are based on an individual plant or operating facility level. In some circumstances, however, a combination of plants or operating facilities may be considered the asset group due to interdependence of operational activities and cash flows.
Goodwill and Intangible Assets	Goodwill and Intangible Assets Our intangible assets consist of (a) definite-lived assets subject to amortization such as developed technology, customer relationships, certain in-service research and development, certain trademarks, backlog, and capitalized software intangible assets, and (b) indefinite-lived assets not subject to amortization such as goodwill, certain trademarks, and certain in-process research and development intangible assets. We record amortization of the definite-lived intangible assets over the estimated useful lives of the related assets, which generally range from one year or less for backlog to more than 25 years for certain of our customer relationships. We determine the amortization method for our definite-lived intangible assets based on the pattern in which the economic benefits of the intangible asset are consumed. In the event we cannot reliably determine that pattern, we utilize a straight-line amortization method. We test our goodwill and other indefinite-lived intangible assets not subject to amortization for impairment on an annual basis during the fourth quarter or when indicators of impairment exist. We base our estimates on assumptions we believe to be reasonable, but which are not predictable with precision and therefore are inherently uncertain. Actual future results could differ from these estimates. The accounting guidance related to goodwill impairment testing allows for the performance of an optional qualitative assessment of whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. Such an evaluation is made based on the weight of all available evidence and the significance of all identified events and circumstances that may influence the fair value of a reporting unit. If it is more likely than not that the fair value is less than the carrying value, then a quantitative assessment is required for the reporting unit, as described in the paragraph below. In 2017 , we performed a qualitative assessment for seven of our reporting units, which collectively represented approximately $547.2 million of our consolidated goodwill balance. For those reporting units for which we performed a qualitative assessment, we determined that it was more likely than not that the fair value was greater than the carrying value, and therefore, we did not perform the calculation of fair value for these reporting units as described in the paragraph below. For our annual impairment test in 2017 , we performed a quantitative assessment for five of our reporting units, which collectively represented approximately $931.1 million of our consolidated goodwill balance. Under a quantitative assessment for goodwill impairment, we determine the fair value using the income approach (using Level 3 inputs) as reconciled to our aggregate market capitalization. Under the income approach, we calculate the fair value of a reporting unit based on the present value of estimated future cash flows. If the fair value of the reporting unit exceeds the carrying value of the net assets including goodwill assigned to that unit, goodwill is not impaired. If the carrying value of the reporting unit’s net assets including goodwill exceeds the fair value of the reporting unit, then we record an impairment charge based on that difference. In addition to the income approach, we calculate the fair value of our reporting units under a market approach. The market approach measures the fair value of a reporting unit through analysis of financial multiples of comparable businesses. Consideration is given to the financial conditions and operating performance of the reporting unit being valued relative to those publicly-traded companies operating in the same or similar lines of business. The fair values of the five reporting units tested under a quantitative approach were in excess of the carrying values as of the impairment testing date. We did not recognize any goodwill impairment in 2017 , 2016 , or 2015 . See Note 10 for further discussion. We also evaluate indefinite lived intangible assets for impairment annually or at other times if events have occurred or circumstances exist that indicate the carrying values of those assets may no longer be recoverable. We compare the fair value of the asset with its carrying amount. If the carrying amount of the asset exceeds its fair value, we recognize an impairment loss in an amount equal to that excess. We did not recognize impairment charges for our indefinite lived intangible assets in 2017 , 2016 , or 2015 . See Note 11 for further discussion. We review intangible assets subject to amortization whenever an event or change in circumstances indicates the carrying values of the assets may not be recoverable. We test intangible assets subject to amortization for impairment and estimate their fair values using the same assumptions and techniques we employ on property, plant and equipment. We did not recognize any impairment charges for amortizable intangible assets in 2017 , 2016 , or 2015 .
Equity Method Investment	Equity Method Investment We had a 50% ownership interest in Xuzhou Hirschmann Electronics Co. Ltd (the Hirschmann JV). The Hirschmann JV is an entity located in China that supplies load-moment indicators to the mobile crane market. We sold the Hirschmann JV effective December 31, 2017 and recognized a loss on sale of the assets of $1.0 million . When we committed to a plan to sell the Hirschmann JV in 2016, the carrying value of our investment in the Hirschmann JV was classified as held for sale. As of December 31, 2016, the carrying value of our investment was $26.8 million . Prior to selling the Hirschmann JV, we accounted for this investment using the equity method of accounting. See Note 4.
Pension and Other Postretirement Benefits	Pension and Other Postretirement Benefits Our pension and other postretirement benefit costs and obligations are dependent on the various actuarial assumptions used in calculating such amounts. These assumptions relate to discount rates, salary growth, long-term return on plan assets, health care cost trend rates, mortality tables, and other factors. We base the discount rate assumptions on current investment yields on high-quality corporate long-term bonds. The salary growth assumptions reflect our long-term actual experience and future or near-term outlook. We determine the long-term return on plan assets based on historical portfolio results and management’s expectation of the future economic environment. Our health care cost trend assumptions are developed based on historical cost data, the near-term outlook, and an assessment of likely long-term trends. Actual results that differ from our assumptions are accumulated and, if in excess of the lesser of 10% of the projected benefit obligation or the fair market value of plan assets, are amortized over the estimated future working life of the plan participants.
Accrued Sales Rebates	Accrued Sales Rebates We grant incentive rebates to participating customers as part of our sales programs. The rebates are determined based on certain targeted sales volumes. Rebates are paid quarterly or annually in either cash or receivables credits. Until we can process these rebates through individual customer records, we estimate the amount of outstanding rebates and recognize them as accrued liabilities and reductions in our gross revenues. We base our estimates on both historical and anticipated sales demand and rebate program participation. We charge revisions to these estimates back to accrued liabilities and revenues in the period in which the facts that give rise to each revision become known. Future market conditions and product transitions might require us to take actions to increase sales rebates offered, possibly resulting in an incremental increase in accrued liabilities and an incremental reduction in revenues at the time the rebate is offered.
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. A significant amount of judgment and use of estimates is required to quantify our ultimate exposure in these matters. We review the valuation of these liabilities on a quarterly basis, and we adjust the balances to account for changes in circumstances for ongoing and emerging issues. We accrue environmental remediation costs based on estimates of known environmental remediation exposures developed in consultation with our environmental consultants and legal counsel, the amounts of which are not currently material. We expense environmental compliance costs, which include maintenance and operating costs with respect to ongoing monitoring programs, as incurred. We evaluate the range of potential costs to remediate environmental sites. The ultimate cost of site clean-up is difficult to predict given the uncertainties of our involvement in certain sites, uncertainties regarding the extent of the required clean-up, the availability of alternative clean-up methods, variations in the interpretation of applicable laws and regulations, the possibility of insurance recoveries with respect to certain sites, and other factors. 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. Assessments regarding the ultimate cost of lawsuits require judgments concerning matters such as the anticipated outcome of negotiations, the number and cost of pending and future claims, and the impact of evidentiary requirements. Based on facts currently available, we believe the disposition of the claims that are pending or asserted will not have a materially adverse effect on our financial position, results of operations or cash flow.
Business Combination Accounting	Business Combination Accounting We allocate the purchase price of an acquired business to its identifiable assets and liabilities based on estimated fair values. The excess of the purchase price over the amount allocated to the assets and liabilities, if any, is recorded to goodwill. We use all available information to estimate fair values. We typically engage third party valuation specialists to assist in the fair value determination of inventories, tangible long-lived assets, and intangible assets other than goodwill. The carrying values of acquired receivables and accounts payable have historically approximated their fair values as of the business combination date. As necessary, we may engage third party specialists to assist in the estimation of fair value for certain liabilities, such as deferred revenue or postretirement benefit liabilities. We adjust the preliminary purchase price allocation, as necessary, typically up to one year after the acquisition closing date as we obtain more information regarding asset valuations and liabilities assumed.
Revenue Recognition	Revenue Recognition We recognize revenue when all of the following circumstances are satisfied: (1) persuasive evidence of an arrangement exists, (2) price is fixed or determinable, (3) collectability is reasonably assured, and (4) delivery has occurred. Delivery typically occurs in the period in which the customer takes title and assumes the risks and rewards of ownership of the products specified in the customer’s purchase order or sales agreement. At times, we enter into arrangements that involve the delivery of multiple elements. For these arrangements, when the elements can be separated, the revenue is allocated to each deliverable based on that element’s relative selling price and recognized based on the period of delivery for each element. Generally, we determine relative selling price using vendor specific objective evidence (VSOE). We record revenue net of estimated rebates, price allowances, invoicing adjustments, and product returns. We record revisions to these estimates in the period in which the facts that give rise to each revision become known. Taxes collected from customers and remitted to governmental authorities are not included in our revenues. We have certain products subject to the accounting guidance on software revenue recognition. For such products, software license revenue is recognized when persuasive evidence of an arrangement exists, delivery of the product has occurred, the fee is fixed or determinable, collection is probable and VSOE of the fair value of undelivered elements exists. As substantially all of the software licenses are sold in multiple-element arrangements that include either support or professional services, we use the residual method to determine the amount of software license revenue to be recognized. Under the residual method, consideration is allocated to undelivered elements based upon VSOE of the fair value of those elements, with the residual of the arrangement fee allocated to and recognized as software license revenue. We have established VSOE of the fair value of support, subscription-based software licenses, and professional services. Software license revenue is generally recognized upon delivery of the software if all revenue recognition criteria are met. Revenue allocated to support services under our support contracts is typically paid in advance and recognized ratably over the term of the service. Revenue allocated to subscription-based software and remote ongoing operational services is also paid in advance and recognized ratably over the term of the service. Revenue allocated to professional services is recognized as the services are performed.
Cost of Sales	Cost of Sales Cost of sales includes our total cost of inventory sold during the period, including material, labor, production overhead costs, variable manufacturing costs, and fixed manufacturing costs. Production overhead costs include operating supplies, applicable utility expenses, maintenance costs, and scrap. Variable manufacturing costs include inbound, interplant, and outbound freight, inventory shrinkage, and charges for excess and obsolete inventory. Fixed manufacturing costs include the costs associated with our purchasing, receiving, inspection, warehousing, distribution centers, production and inventory control, and manufacturing management. Cost of sales also includes the costs to provide maintenance and support and other professional services.
Shipping and Handling Costs	Shipping and Handling Costs We recognize fees earned on the shipment of product to customers as revenues and recognize costs incurred on the shipment of product to customers as a cost of sales.
Selling, General and Administrative Expenses	Selling, General and Administrative Expenses Selling, general and administrative expenses include expenses not directly related to the production of inventory. They include all expenses related to selling and marketing our products, as well as the salary and benefit costs of associates performing the selling and marketing functions. Selling, general and administrative expenses also include salary and benefit costs, purchased services, and other costs related to our executive and administrative functions.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred.
Advertising Costs	Advertising Costs Advertising costs are expensed as incurred.
Share-Based Compensation	Share-Based Compensation We compensate certain employees and non-employee directors with various forms of share-based payment awards and recognize compensation costs for these awards based on their fair values. We estimate the fair values of certain awards, primarily stock appreciation rights (SARs), on the grant date using the Black-Scholes-Merton option-pricing formula, which incorporates certain assumptions regarding the expected term of an award and expected stock price volatility. We develop the expected term assumption based on the vesting period and contractual term of an award, our historical exercise and cancellation experience, our stock price history, plan provisions that require exercise or cancellation of awards after employees terminate, and the extent to which currently available information indicates that the future is reasonably expected to differ from past experience. We develop the expected volatility assumption based on historical price data for our common stock. We estimate the fair value of certain restricted stock units with service vesting conditions and performance vesting conditions based on the grant date stock price. We estimate the fair value of certain restricted stock units with market conditions using a Monte Carlo simulation valuation model with the assistance of a third party valuation firm. After calculating the aggregate fair value of an award, we use an estimated forfeiture rate to discount the amount of share-based compensation cost expected to be recognized in our operating results over the service period of the award. We develop the forfeiture assumption based on our historical pre-vesting cancellation experience.
Income Taxes	Income Taxes Income taxes are provided based on earnings reported for financial statement purposes. The provision for income taxes differs from the amounts currently payable to taxing authorities because of the recognition of revenues and expenses in different periods for income tax purposes than for financial statement purposes. Income taxes are provided as if operations in all countries, including the U.S., were stand-alone businesses filing separate tax returns. The Tax Cuts and Jobs Act of 2017 included a one-time transition tax on unremitted foreign earnings, and accordingly, we recorded tax expense of $29.1 million related to the transition tax on the one-time mandatory deemed repatriation of all our foreign earnings as of December 31, 2017. See Note 16 Income Taxes in the accompanying notes to our consolidated financial statements. We recognize deferred tax assets resulting from tax credit carryforwards, net operating loss carryforwards, and deductible temporary differences between taxable income on our income tax returns and pretax income on our financial statements. Deferred tax assets generally represent future tax benefits to be received when these carryforwards can be applied against future taxable income or when expenses previously reported in our Consolidated Financial Statements become deductible for income tax purposes. A deferred tax asset valuation allowance is required when some portion or all of the deferred tax assets may not be realized. The Tax Cuts and Jobs Act of 2017 included a $36.0 million tax benefit for the remeasurement of deferred tax assets and liabilities to the 21% rate at which they are expected to reverse and a valuation allowance of $35.3 million recorded against foreign tax credit carryforwards that we no longer expect to be able to realize based upon the new tax law. Our effective tax rate is based on expected income, statutory tax rates, and tax planning opportunities available to us in the various jurisdictions in which we operate. Significant judgment is required in determining our effective tax rate and in evaluating our tax positions. We establish accruals for uncertain tax positions when we believe that the full amount of the associated tax benefit may not be realized. To the extent we were to prevail in matters for which accruals have been established or would be required to pay amounts in excess of reserves, there could be a material effect on our income tax provisions in the period in which such determination is made.
Recent Accounting Pronouncements	Current-Year Adoption of Accounting Pronouncements In July 2015, the FASB issued Accounting Standards Update No. 2015-11, Inventory (Topic 330) : Simplifying the Measurement of Inventory. Under the new guidance, an entity is to measure inventory at the lower of cost and the net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. The standard is effective for fiscal years beginning after December 15, 2016. We adopted ASU 2015-11 effective January 1, 2017. Adoption had no impact on our results of operations. In January 2017, the FASB issued Accounting Standards Update No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . Under the new guidance, if a reporting unit’s carrying amount exceeds its fair value, an entity will record an impairment charge based on that difference. The impairment charge is limited to the amount of goodwill allocated to the reporting unit. ASU 2017-04 eliminates the prior requirement of calculating a goodwill impairment charge using Step 2. The standard is effective for fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We early adopted ASU 2017-04 effective January 1, 2017. Adoption had no impact on our results of operations. Pending Adoption of Recent Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (ASU 2014-09), which will replace most existing revenue recognition guidance in U.S. GAAP. The core principle of the ASU is that an entity should recognize revenue for the transfer of goods or services equal to the amount that it expects to be entitled to receive for those goods or services. ASU 2014-09 requires additional disclosure about the nature, amount, timing, and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments. We plan to adopt ASU 2014-09 on January 1, 2018, using the modified retrospective method of adoption. We are substantially complete with our evaluation of the impact of adopting ASU 2014-09 on our consolidated financial statements. We do not expect significant changes in the timing or method of revenue recognition for any of our material revenue streams. In connection with adopting ASU 2014-09, we expect to record a cumulative-effect adjustment net of tax to retained earnings of $2.6 million on January 1, 2018. This adjustment primarily relates to the deferral of costs to obtain a contract that were previously expensed at the beginning of the contract period. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (ASU 2016-02), a leasing standard for both lessees and lessors. Under its core principle, a lessee will recognize lease assets and liabilities on the balance sheet for all arrangements with terms longer than 12 months. Lessor accounting remains largely consistent with existing U.S. generally accepted accounting principles. The new standard will be effective for us beginning January 1, 2019. Early adoption is permitted. The standard requires the use of a modified retrospective transition method. We are still evaluating the effect that ASU 2016-02 will have on our consolidated financial statements and related disclosures, but our initial assessment indicates that it will have a material impact to total assets and liabilities as we will be required to recognize lease assets and liabilities for all operating leases in which we are the lessee. In August 2016, the FASB issued Accounting Standards Update No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments . The new guidance addresses how the following eight specific cash flow items are to be presented: Debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies (including bank-owned life insurance policies); distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. The standard is effective for fiscal years beginning after December 15, 2017, and early adoption is permitted. We do not expect the standard to have a material impact on our consolidated financial statements and related disclosures. In October 2016, the FASB issued Accounting Standards Update No. 2016-16, Intra-Entity Transfers of Assets Other Than Inventory (ASU 2016-16), which requires recognition of the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. Consequently, the standard eliminates the exception to the recognition of current and deferred income taxes for an intra-entity asset transfer other than for inventory until the asset has been sold to an outside party. The new standard will be effective for us beginning January 1, 2018. We are evaluating the effect that ASU 2016-16 will have on our consolidated financial statements and related disclosures. In March 2017, the FASB issued Accounting Standards Update No. 2017-07, Compensation - Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost (ASU 2017-07), which requires an entity to report the service cost component in the same line item or items as other compensation costs arising from the service rendered by their employees during the period. The other components of net benefit cost are required to be presented in the Statement of Operations separately from the service cost component after Operating Income. Additionally, only the service cost component will be eligible for capitalization, when applicable. The standard requires the amendments to be applied retrospectively for the presentation of the service cost component and the other cost components of net periodic pension cost and net periodic OPEB cost in the Statement of Operations and prospectively, on and after the effective date, for the capitalization of the service cost component of net periodic pension and OPEB costs. The new standard will be effective for us beginning January 1, 2018. We are evaluating the effect that ASU 2017-07 will have on our consolidated financial statements and related disclosures. In August 2017, the FASB issued Accounting Standards Update No. ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities . The new guidance better aligns an entity’s risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results. The new guidance also makes certain targeted improvements to simplify the application of hedge accounting guidance and ease the administrative burden of hedge documentation requirements and assessing hedge effectiveness. The standard is effective for fiscal years beginning after December 15, 2018, and early adoption is permitted. We do not expect the standard to have a material impact on our consolidated financial statements and related disclosures. In January 2018, the FASB released guidance on the accounting for tax on the global intangible low-taxed income (“GILTI”) provisions of the Tax Cuts and Jobs Act (the “Act”). The GILTI provisions impose a tax on foreign income in excess of a deemed return on tangible assets of foreign corporations. The guidance indicates that either accounting for deferred taxes related to GILTI inclusions or to treat any taxes on GILTI inclusions as a period cost are both acceptable methods subject to an accounting policy election. Pending further anticipated clarification and guidance related to the application of the GILTI provisions and their impact to Belden, the Company intends to further assess the materiality of the anticipated GILTI inclusion before a policy election is made.

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2017
Thinklogical Holdings LLC [Member]
Fair Value of Assets Acquired and Liabilities Assumed	The following table summarizes the estimated, preliminary fair values of the assets acquired and the liabilities assumed as of May 31, 2017 (in thousands): Cash $ 5,376 Receivables 4,355 Inventory 16,424 Prepaid and other current assets 320 Property, plant, and equipment 4,289 Goodwill 71,394 Intangible assets 73,400 Total assets 175,558 Accounts payable 1,231 Accrued liabilities 1,353 Deferred revenue 1,702 Total liabilities 4,286 Net assets $ 171,272
Intangible Assets Related to Acquisition	The intangible assets related to the acquisition consisted of the following: Fair Value Amortization Period (In thousands) (In years) Intangible assets subject to amortization: Developed technologies $ 62,600 10.0 Customer relationships 6,500 8.0 Trademarks 2,900 10.0 Sales backlog 1,400 0.3 Total intangible assets subject to amortization 73,400 Intangible assets not subject to amortization: Goodwill 71,394 n/a Total intangible assets not subject to amortization 71,394 Total intangible assets $ 144,794 Weighted average amortization period 9.6
Pro Forma Effect on Operating Results	The following table illustrates the unaudited pro forma effect on operating results as if the Thinklogical acquisition had been completed as of January 1, 2016. Years Ended December 31, 2017 December 31, 2016 (In thousands, except per share data) (Unaudited) Revenues $ 2,399,715 $ 2,407,830 Net income attributable to Belden common stockholders 60,690 113,014 Diluted income per share attributable to Belden common stockholders $ 1.42 $ 2.66
Tripwire [Member]
Fair Value of Assets Acquired and Liabilities Assumed	The following table summarizes the estimated fair values of the assets acquired and the liabilities assumed as of January 2, 2015 (in thousands). Cash $ 2,364 Receivables 37,792 Inventories 603 Other current assets 2,453 Property, plant and equipment 10,021 Goodwill 462,215 Intangible assets 306,000 Other non-current assets 659 Total assets 822,107 Accounts payable 3,142 Accrued liabilities 12,142 Deferred revenue 8,000 Deferred income taxes 95,074 Other non-current liabilities 540 Total liabilities 118,898 Net assets $ 703,209
Intangible Assets Related to Acquisition	The intangible assets related to the acquisition consisted of the following: Estimated Fair Value Amortization Period (In thousands) (In years) Intangible assets subject to amortization: Developed technology $ 210,000 5.8 Customer relationships 56,000 15 Trademarks 31,000 10 Backlog 3,000 1 Total intangible assets subject to amortization 300,000 Intangible assets not subject to amortization: Goodwill 462,215 In-process research and development 6,000 Total intangible assets not subject to amortization 468,215 Total intangible assets $ 768,215 Weighted average amortization period 7.9
Pro Forma Effect on Operating Results	The following table illustrates the unaudited pro forma effect on operating results as if the Tripwire acquisition had been completed as of January 1, 2014. Year Ended December 31, 2015 (In thousands, except per share data) (Unaudited) Revenues $ 2,354,191 Net income attributable to Belden common stockholders 92,104 Diluted income per share attributable to Belden common stockholders $ 2.14

Assets Held for Sale (Tables)

Assets Held for Sale (Tables)	12 Months Ended
	Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Summary of Major Assets and Liabilities Classified as Held For Sale	The following table provides the major classes of assets and liabilities classified as held for sale as of December 31, 2016. In addition, the disposal group had $15.7 million of accumulated other comprehensive losses at December 31, 2016. December 31, 2016 (In thousands) Receivables, net $ 4,551 Inventories, net 2,848 Other current assets 1,131 Property, plant, and equipment, less accumulated depreciation 1,946 Intangible assets, less accumulated amortization 4,405 Goodwill 5,477 Other long-lived assets 26,766 Total assets of disposal group 47,124 Impairment of assets held for sale (23,931 ) Total assets held for sale $ 23,193 Accrued liabilities $ 1,288 Postretirement benefits 448 Total liabilities held for sale $ 1,736

Operating Segments and Geogra42

Operating Segments and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Operating Segment Information	Operating Segment Information Broadcast Solutions Years ended December 31, 2017 2016 2015 (In thousands) Segment revenues $ 725,139 $ 769,753 $ 739,970 Affiliate revenues 440 744 916 Segment EBITDA 112,849 137,870 113,638 Depreciation expense 15,763 16,229 16,295 Amortization of intangibles 49,325 47,248 49,812 Amortization of software development intangible assets 56 — — Severance, restructuring, and acquisition integration costs 5,532 10,414 39,078 Purchase accounting effects of acquisitions 6,133 (2,991 ) 132 Deferred gross profit adjustments — 1,774 2,446 Patent settlement — (5,554 ) — Acquisition of property, plant and equipment 21,314 15,713 27,365 Segment assets 405,842 325,396 346,095 Enterprise Solutions Years ended December 31, 2017 2016 2015 (In thousands) Segment revenues $ 631,166 $ 603,188 $ 605,910 Affiliate revenues 7,385 5,977 5,322 Segment EBITDA 103,650 101,298 100,214 Depreciation expense 10,509 13,226 12,591 Amortization of intangibles 1,729 1,718 1,720 Severance, restructuring, and acquisition integration costs 23,511 11,962 723 Purchase accounting effects of acquisitions — 912 52 Acquisition of property, plant and equipment 28,126 22,679 10,323 Segment assets 282,072 246,564 238,400 Industrial Solutions Years ended December 31, 2017 2016 2015 (In thousands) Segment revenues $ 628,458 $ 585,476 $ 603,350 Affiliate revenues 1,441 1,325 1,613 Segment EBITDA 119,642 101,248 99,941 Depreciation expense 12,968 11,038 11,235 Amortization of intangibles 2,571 2,394 3,154 Severance, restructuring, and acquisition integration costs 12,272 9,923 6,228 Purchase accounting effects of acquisitions — — 334 Acquisition of property, plant and equipment 8,151 10,486 8,836 Segment assets 300,172 226,306 231,265 Network Solutions Years ended December 31, 2017 2016 2015 (In thousands) Segment revenues $ 403,880 $ 399,388 $ 411,353 Affiliate revenues 96 79 78 Segment EBITDA 93,893 92,773 87,873 Depreciation expense 6,357 6,715 6,430 Amortization of intangibles 50,372 47,025 49,105 Severance, restructuring, and acquisition integration costs 1,475 6,471 1,141 Purchase accounting effects of acquisitions — — 9,229 Deferred gross profit adjustments — 4,913 50,430 Acquisition of property, plant and equipment 5,168 4,704 7,048 Segment assets 158,309 115,732 118,520 Total Segments Years ended December 31, 2017 2016 2015 (In thousands) Segment revenues $ 2,388,643 $ 2,357,805 $ 2,360,583 Affiliate revenues 9,362 8,125 7,929 Segment EBITDA 430,034 433,189 401,666 Depreciation expense 45,597 47,208 46,551 Amortization of intangibles 103,997 98,385 103,791 Amortization of software development intangible assets 56 — — Severance, restructuring, and acquisition integration costs 42,790 38,770 47,170 Purchase accounting effects of acquisitions 6,133 (2,079 ) 9,747 Deferred gross profit adjustments — 6,687 52,876 Patent settlement — (5,554 ) — Acquisition of property, plant and equipment 62,759 53,582 53,572 Segment assets 1,146,395 913,998 934,280
Reconciliation of Total Reportable Segments' Revenues and EBITDA to Consolidated Revenues and Consolidated Income from Continuing Operations Before Taxes	The following table is a reconciliation of the total of the reportable segments’ Revenues and EBITDA to consolidated revenues and consolidated income from continuing operations before taxes, respectively. Years Ended December 31, 2017 2016 2015 (In thousands) Total Segment Revenues $ 2,388,643 $ 2,357,805 $ 2,360,583 Deferred revenue adjustments (1) — (6,687 ) (51,361 ) Patent settlement (2) — 5,554 — Consolidated Revenues $ 2,388,643 $ 2,356,672 $ 2,309,222 Total Segment EBITDA $ 430,034 $ 433,189 $ 401,666 Amortization of intangibles (103,997 ) (98,385 ) (103,791 ) Depreciation expense (45,597 ) (47,208 ) (46,551 ) Severance, restructuring, and acquisition integration costs (3) (42,790 ) (38,770 ) (47,170 ) Purchase accounting effects related to acquisitions (4) (6,133 ) 2,079 (9,747 ) Loss on sale of assets (5) (1,013 ) — — Amortization of software development intangible assets (56 ) — — Impairment of assets held for sale (5) — (23,931 ) — Deferred gross profit adjustments (1) — (6,687 ) (52,876 ) Patent settlement (2) — 5,554 — Income from equity method investment 7,502 1,793 1,770 Eliminations (3,260 ) (3,781 ) (2,748 ) Consolidated operating income 234,690 223,853 140,553 Interest expense, net (82,901 ) (95,050 ) (100,613 ) Loss on debt extinguishment (52,441 ) (2,342 ) — Consolidated income from continuing operations before taxes $ 99,348 $ 126,461 $ 39,940 (1) Our segment results include revenues that would have been recorded by acquired businesses had they remained as independent entities. Our consolidated results do not include these revenues due to the purchase accounting effect of recording deferred revenue at fair value. See Note 3, Acquisitions , for details. (2) Both our consolidated revenues and gross profit were positively impacted by royalty revenues received during 2016 that related to years prior to 2016 as a result of a patent settlement. (3) See Note 13, Severance, Restructuring, and Acquisition Integration Activities, for details . (4) In 2017, we recognized $6.1 million of cost of sales related to the adjustment of acquired inventory to fair value for our Thinklogical acquisition. In 2016, we made a $3.2 million adjustment to reduce the earn-out liability associated with the M2FX acquisition. This adjustment was partially offset by $0.8 million and $0.2 million of cost of sales related to the adjustment of acquired inventory to fair value related to our Enterprise Solutions segment and M2FX acquisition, respectively. In 2015, we recognized $9.2 million of compensation expense related to the accelerated vesting of acquiree stock based compensation awards associated with our acquisition of Tripwire. In addition, we recognized $0.3 million of cost of sales related to the adjustment of acquired inventory to fair value related to our acquisition of Coast. (5) In 2017 and 2016, we recognized a $1.0 million loss on sale of assets and $23.9 million impairment of assets held for sale, respectively, for the sale of our MCS business and Hirschmann JV. See Note 4, Assets Held for Sale , for details.
Reconciliations of Other Segment Measures to Consolidated Totals	Below are reconciliations of other segment measures to the consolidated totals. Years Ended December 31, 2017 2016 2015 (In thousands) Total segment assets $ 1,146,395 $ 913,998 $ 934,280 Cash and cash equivalents 561,108 848,116 216,751 Goodwill 1,478,257 1,385,995 1,385,115 Intangible assets, less accumulated amortization 545,207 560,082 655,871 Deferred income taxes 42,549 33,706 34,295 Income tax receivable — — 3,787 Corporate assets 67,097 64,906 60,503 Total assets $ 3,840,613 $ 3,806,803 $ 3,290,602 Total segment acquisition of property, plant and equipment $ 62,759 $ 53,582 $ 53,572 Corporate acquisition of property, plant and equipment 1,502 392 1,397 Total acquisition of property, plant and equipment $ 64,261 $ 53,974 $ 54,969
Schedule of Revenue from External Customers and Long-Lived Assets Based on Physical Location	The table below summarizes net sales and long-lived assets for the years ended December 31, 2017 , 2016 and 2015 for the following countries: the U.S., Canada, China, and Germany. No other individual foreign country’s net sales or long-lived assets are material to the Company. United States Canada China Germany All Other Total (In thousands, except percentages) Year ended December 31, 2017 Revenues $ 1,265,455 $ 167,605 $ 121,600 $ 113,990 $ 719,993 $ 2,388,643 Percent of total revenues 53 % 7 % 5 % 5 % 30 % 100 % Long-lived assets $ 231,938 $ 33,806 $ 34,774 $ 38,029 $ 63,982 $ 402,529 Year ended December 31, 2016 Revenues $ 1,283,925 $ 159,985 $ 114,605 $ 104,214 $ 693,943 $ 2,356,672 Percent of total revenues 55 % 7 % 5 % 4 % 29 % 100 % Long-lived assets $ 193,263 $ 31,278 $ 30,487 $ 32,386 $ 60,654 $ 348,068 Year ended December 31, 2015 Revenues $ 1,270,467 $ 170,522 $ 114,863 $ 103,106 $ 650,264 $ 2,309,222 Percent of total revenues 55 % 7 % 5 % 4 % 29 % 100 % Long-lived assets $ 188,032 $ 27,315 $ 62,794 $ 35,588 $ 64,434 $ 378,163

Income Per Share (Tables)

Income Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Basis for Income Per Share Computations	The following table presents the basis of the income per share computation: Years Ended December 31, 2017 2016 2015 (In thousands) Numerator: Income from continuing operations $ 92,853 $ 127,646 $ 66,508 Less: Net loss attributable to noncontrolling interest (357 ) (357 ) (24 ) Less: Preferred stock dividends 34,931 15,428 — Income from continuing operations attributable to Belden common stockholders 58,279 112,575 66,532 Loss from discontinued operations, net of tax, attributable to Belden common stockholders — — (242 ) Loss from disposal of discontinued operations, net of tax, attributable to Belden common stockholders — — (86 ) Net income attributable to Belden common stockholders $ 58,279 $ 112,575 $ 66,204 Denominator: Weighted average shares outstanding, basic 42,220 42,093 42,390 Effect of dilutive common stock equivalents 423 464 563 Weighted average shares outstanding, diluted 42,643 42,557 42,953

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Major Classes of Inventories	The major classes of inventories were as follows: December 31, 2017 2016 (In thousands) Raw materials $ 133,311 $ 90,019 Work-in-process 35,807 25,166 Finished goods 153,377 99,784 Gross inventories 322,495 214,969 Excess and obsolete reserves (25,269 ) (24,561 ) Net inventories $ 297,226 $ 190,408

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Summary of Carrying Values of Property, Plant and Equipment	The carrying values of property, plant and equipment were as follows: December 31, 2017 2016 (In thousands) Land and land improvements $ 31,963 $ 28,462 Buildings and leasehold improvements 148,598 136,230 Machinery and equipment 543,594 499,400 Computer equipment and software 136,509 123,909 Construction in process 46,898 35,191 Gross property, plant and equipment 907,562 823,192 Accumulated depreciation (570,240 ) (513,901 ) Net property, plant and equipment $ 337,322 $ 309,291

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Carrying Value of Intangible Assets	The carrying values of intangible assets were as follows: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount (In thousands) (In thousands) Goodwill $ 1,478,257 $ — $ 1,478,257 $ 1,385,995 $ — $ 1,385,995 Definite-lived intangible assets subject to amortization: Developed technology $ 498,649 $ (318,366 ) $ 180,283 $ 420,928 $ (239,233 ) $ 181,695 Customer relationships 320,550 (98,175 ) 222,375 309,112 (77,872 ) 231,240 Trademarks 56,794 (18,648 ) 38,146 20,534 (10,915 ) 9,619 In-service research and development 23,428 (13,483 ) 9,945 22,977 (9,121 ) 13,856 Backlog 14,535 (14,535 ) — 12,638 (12,638 ) — Total intangible assets subject to amortization 913,956 (463,207 ) 450,749 786,189 (349,779 ) 436,410 Indefinite-lived intangible assets not subject to amortization: Trademarks 92,758 — 92,758 121,972 — 121,972 In-process research and development 1,700 — 1,700 1,700 — 1,700 Total intangible assets not subject to amortization 94,458 — 94,458 123,672 — 123,672 Intangible assets $ 1,008,414 $ (463,207 ) $ 545,207 $ 909,861 $ (349,779 ) $ 560,082
Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill assigned to reporting units in our reportable segments are as follows: Broadcast Solutions Enterprise Solutions Industrial Solutions Network Solutions Consolidated (In thousands) Balance at December 31, 2015 $ 536,388 $ 73,278 $ 196,719 $ 578,730 $ 1,385,115 Acquisitions and purchase accounting adjustments 8,492 — — — 8,492 Translation impact (838 ) — 80 (1,377 ) (2,135 ) Reclassify to assets held for sale — — (5,477 ) — (5,477 ) Balance at December 31, 2016 $ 544,042 $ 73,278 $ 191,322 $ 577,353 $ 1,385,995 Acquisitions and purchase accounting adjustments 71,394 — — — 71,394 Translation impact 13,557 — 2,790 4,521 20,868 Balance at December 31, 2017 $ 628,993 $ 73,278 $ 194,112 $ 581,874 $ 1,478,257
Changes in Carrying Amount of Trademarks	The changes in the carrying amount of indefinite-lived trademarks are as follows: Broadcast Solutions Enterprise Solutions Industrial Solutions Network Solutions Consolidated (In thousands) Balance at December 31, 2015 $ 80,922 $ 4,063 $ 9,090 $ 35,596 $ 129,671 Translation impact (4,635 ) — 40 (199 ) (4,794 ) Reclassify to assets held for sale — — (2,905 ) — (2,905 ) Balance at December 31, 2016 $ 76,287 $ 4,063 $ 6,225 $ 35,397 $ 121,972 Translation impact 2,727 — 602 658 3,987 Reclassify to definite-lived — — (2,201 ) (31,000 ) (33,201 ) Balance at December 31, 2017 $ 79,014 $ 4,063 $ 4,626 $ 5,055 $ 92,758

Accounts Payable and Accrued 47

Accounts Payable and Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Payables and Accruals [Abstract]
Carrying Value of Accounts Payable and Accrued Liabilities	The carrying values of accounts payable and accrued liabilities were as follows: December 31, 2017 2016 (In thousands) Accounts payable $ 376,277 $ 258,203 Current deferred revenue 90,639 80,503 Wages, severance and related taxes 57,633 76,157 Accrued rebates 38,025 33,071 Employee benefits 25,406 24,395 Accrued interest 22,019 27,202 Other (individual items less than 5% of total current liabilities) 68,929 69,012 Accounts payable and accrued liabilities $ 678,928 $ 568,543

Severance, Restructuring, and48

Severance, Restructuring, and Acquisition Integration Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Severance, Restructuring and Integration Costs by Segment	The following tables summarize the costs by segment of the various programs described above as well as other immaterial programs and acquisition integration activities: Severance Other Restructuring and Integration Costs Total Costs (In thousands) Year Ended December 31, 2017 Broadcast Solutions $ 893 $ 4,639 $ 5,532 Enterprise Solutions 3,642 19,869 23,511 Industrial Solutions 886 11,386 12,272 Network Solutions (210 ) 1,685 1,475 Total $ 5,211 $ 37,579 $ 42,790 Year Ended December 31, 2016 Broadcast Solutions $ (116 ) $ 10,530 $ 10,414 Enterprise Solutions 636 11,326 11,962 Industrial Solutions 2,828 7,095 9,923 Network Solutions 3,734 2,737 6,471 Total $ 7,082 $ 31,688 $ 38,770 Year Ended December 31, 2015 Broadcast Solutions $ 16,694 $ 22,384 $ 39,078 Enterprise Solutions (186 ) 909 723 Industrial Solutions 3,309 2,919 6,228 Network Solutions (716 ) 1,857 1,141 Total $ 19,101 $ 28,069 $ 47,170

Long-Term Debt and Other Borr49

Long-Term Debt and Other Borrowing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Carrying Values of Long-Term Debt and Other Borrowing Arrangements	The carrying values of our long-term debt and other borrowing arrangements were as follows: December 31, 2017 2016 (In thousands) Revolving credit agreement due 2022 $ — $ — Senior subordinated notes: 3.375% Senior subordinated notes due 2027 540,810 — 4.125% Senior subordinated notes due 2026 240,360 209,081 2.875% Senior subordinated notes due 2025 360,540 — 5.25% Senior subordinated notes due 2024 200,000 200,000 5.50% Senior subordinated notes due 2023 242,522 529,146 5.50% Senior subordinated notes due 2022 — 700,000 9.25% Senior subordinated notes due 2019 — 5,221 Total senior subordinated notes 1,584,232 1,643,448 Less unamortized debt issuance costs (23,484 ) (23,287 ) Long-term debt $ 1,560,748 $ 1,620,161
Schedule of Senior Subordinated Notes	The senior subordinated notes due 2023, 2024, 2025, 2026 and 2027 are redeemable currently, after April 15, 2018, July 15, 2019, September 15, 2020, October 15, 2021 and July 15, 2022, respectively, at the following redemption prices as a percentage of the face amount of the notes: Senior Subordinated Notes due 2023 2024 2025 2026 2027 Year Percentage Year Percentage Year Percentage Year Percentage Year Percentage 2018 102.750 % 2019 102.625 % 2020 101.438 % 2021 102.063 % 2022 101.688 % 2019 101.833 % 2020 101.750 % 2021 100.719 % 2022 101.375 % 2023 101.125 % 2020 100.917 % 2021 100.875 % 2022 and thereafter 100.000 % 2023 100.688 % 2024 100.563 % 2021 and thereafter 100.000 % 2022 and thereafter 100.000 % 2024 and thereafter 100.000 % 2025 and thereafter 100.000 %
Maturities on Outstanding Long-Term Debt and Other Borrowings	Maturities on outstanding long-term debt and other borrowings during each of the five years subsequent to December 31, 2017 are as follows (in thousands): 2018 $ — 2019 — 2020 — 2021 — 2022 — Thereafter 1,584,232 $ 1,584,232

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Components of Income Tax Expense	Years ended December 31, 2017 2016 2015 (In thousands) Income (loss) from continuing operations before taxes: United States operations $ 2,177 $ (25,615 ) $ (6,924 ) Foreign operations 97,171 152,076 46,864 Income from continuing operations before taxes $ 99,348 $ 126,461 $ 39,940 Income tax expense (benefit): Currently payable United States federal $ — $ 2,981 $ — United States state and local 2,392 (1,038 ) 1,789 Foreign 28,201 26,906 17,317 30,593 28,849 19,106 Deferred United States federal (11,028 ) (27,677 ) (23,709 ) United States state and local (8,758 ) (3,139 ) (2,257 ) Foreign (4,312 ) 782 (19,708 ) (24,098 ) (30,034 ) (45,674 ) Income tax expense (benefit) $ 6,495 $ (1,185 ) $ (26,568 )
Effective Income Tax Rate Reconciliation from Continuing Operations	Years Ended December 31, 2017 2016 2015 Effective income tax rate reconciliation from continuing operations: United States federal statutory rate 35.0 % 35.0 % 35.0 % State and local income taxes 0.8 % (0.9 )% (2.6 )% Impact of change in tax contingencies 2.2 % 2.4 % (4.2 )% Foreign income tax rate differences (13.1 )% (14.0 )% (8.4 )% Impact of change in deferred tax asset valuation allowance 1.5 % (7.3 )% (28.6 )% Impact of change in legal entity tax status — % (5.5 )% — % Impact of non-taxable translation gain (27.3 )% — % — % Impact of non-taxable interest income (5.5 )% (4.9 )% (15.6 )% Domestic permanent differences and tax credits (15.7 )% (5.7 )% (42.1 )% Impact of tax reform 28.6 % — % — % 6.5 % (0.9 )% (66.5 )%
Components of Deferred Income Tax Balances	December 31, 2017 2016 (In thousands) Components of deferred income tax balances: Deferred income tax liabilities: Plant, equipment, and intangibles $ (120,171 ) $ (179,229 ) Deferred income tax assets: Postretirement, pensions, and stock compensation 28,736 35,500 Reserves and accruals 29,297 22,795 Net operating loss and tax credit carryforwards 228,815 245,135 Valuation allowances (151,841 ) (104,771 ) 135,007 198,659 Net deferred income tax asset $ 14,836 $ 19,430
Summary of Net Operating Loss Carryforwards	Net Operating Loss Carryforwards (In thousands) France $ 266,509 United States - various states 132,213 Luxembourg 25,034 Japan 22,245 Australia 16,433 Germany 14,127 Netherlands 13,063 Other 49,256 Total $ 538,880
Summary of Tax Credit Carryforwards	Tax Credit Carryforwards (In thousands) United States $ 74,613 Canada 22,459 Total $ 97,072
Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows: 2017 2016 (In thousands) Balance at beginning of year $ 10,474 $ 7,293 Additions based on tax positions related to the current year 981 507 Additions for tax positions of prior years 2,549 2,675 Reductions for tax positions of prior years - Settlement (5,425 ) — Reduction for tax positions of prior years - Statute of limitations — (1 ) Balance at end of year $ 8,579 $ 10,474

Pension and Other Postretirem51

Pension and Other Postretirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Change in Benefit Obligation	The following tables provide a reconciliation of the changes in the plans’ benefit obligations and fair value of assets as well as a statement of the funded status and balance sheet reporting for these plans. Pension Benefits Other Benefits Years Ended December 31, 2017 2016 2017 2016 (In thousands) Change in benefit obligation: Benefit obligation, beginning of year $ (256,481 ) $ (275,205 ) $ (32,038 ) $ (32,313 ) Service cost (4,978 ) (4,981 ) (49 ) (46 ) Interest cost (7,671 ) (8,909 ) (1,139 ) (1,259 ) Participant contributions (91 ) (106 ) (7 ) (7 ) Actuarial gain (loss) (3,291 ) (16,250 ) 3,370 578 Divestiture 794 — — — Settlements 49 29,256 — — Curtailments — 227 — — Foreign currency exchange rate changes (14,299 ) 10,723 (2,022 ) (580 ) Benefits paid 13,943 8,764 1,552 1,589 Benefit obligation, end of year $ (272,025 ) $ (256,481 ) $ (30,333 ) $ (32,038 )
Change in Plan Assets	Pension Benefits Other Benefits Years Ended December 31, 2017 2016 2017 2016 (In thousands) Change in plan assets: Fair value of plan assets, beginning of year $ 182,370 $ 204,372 $ — $ — Actual return on plan assets 18,746 18,832 — — Employer contributions 4,425 5,698 1,545 1,582 Plan participant contributions 91 106 7 7 Settlements — (28,841 ) — — Foreign currency exchange rate changes 6,467 (9,033 ) — — Benefits paid (13,943 ) (8,764 ) (1,552 ) (1,589 ) Fair value of plan assets, end of year $ 198,156 $ 182,370 $ — $ —
Amounts Recognized in Balance Sheets	Funded status, end of year $ (73,869 ) $ (74,111 ) $ (30,333 ) $ (32,038 ) Amounts recognized in the balance sheets: Prepaid benefit cost $ 3,174 $ 3,148 $ — $ — Accrued benefit liability (current) (3,736 ) (3,022 ) (1,555 ) (1,778 ) Liabilities held for sale — (447 ) — — Accrued benefit liability (noncurrent) (73,307 ) (73,790 ) (28,778 ) (30,260 ) Net funded status $ (73,869 ) $ (74,111 ) $ (30,333 ) $ (32,038 )
Components of Net Periodic Benefit Costs	The following table provides the components of net periodic benefit costs for the plans. Pension Benefits Other Benefits Years Ended December 31, 2017 2016 2015 2017 2016 2015 (In thousands) Components of net periodic benefit cost: Service cost $ 4,978 $ 4,981 $ 5,505 $ 49 $ 46 $ 52 Interest cost 7,671 8,909 9,116 1,139 1,259 1,301 Expected return on plan assets (10,644 ) (12,013 ) (12,518 ) — — — Amortization of prior service credit (41 ) (42 ) (44 ) — (42 ) (87 ) Curtailment gain — (227 ) (128 ) — — — Settlement loss (gain) (8 ) 7,630 128 — — — Net loss recognition 2,597 2,670 5,082 — 86 328 Net periodic benefit cost $ 4,553 $ 11,908 $ 7,141 $ 1,188 $ 1,349 $ 1,594
Assumptions Used in Determining Benefit Obligations and Net Periodic Benefit Cost Amounts	The following table presents the assumptions used in determining the benefit obligations and the net periodic benefit cost amounts. Pension Benefits Other Benefits Years Ended December 31, 2017 2016 2017 2016 Weighted average assumptions for benefit obligations at year end: Discount rate 2.8 % 3.0 % 3.3 % 3.7 % Salary increase 3.6 % 3.3 % N/A N/A Weighted average assumptions for net periodic cost for the year: Discount rate 3.1 % 3.6 % 3.7 % 4.0 % Salary increase 3.6 % 3.5 % N/A N/A Expected return on assets 6.0 % 6.2 % N/A N/A Assumed health care cost trend rates: Health care cost trend rate assumed for next year N/A N/A 6.2 % 6.2 % Rate that the cost trend rate gradually declines to N/A N/A 5.0 % 5.0 % Year that the rate reaches the rate it is assumed to remain at N/A N/A 2024 2023
Effect of One Percentage - Point Change in Assumed Health Care Cost Trend Rates	A one percentage-point change in the assumed health care cost trend rates would have the following effects on 2017 expense and year-end liabilities. 1% Increase 1% Decrease (In thousands) Effect on total of service and interest cost components $ 127 $ (103 ) Effect on postretirement benefit obligation 2,306 (1,943 )
Fair Values of Pension Plan Assets by Asset Category	The following table presents the fair values of the pension plan assets by asset category. December 31, 2017 December 31, 2016 Fair Market Value at December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fair Market Value at December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) (In thousands) Asset Category: Equity securities(a) Large-cap fund $ 75,165 $ — $ — $ — $ 65,495 $ — $ — $ — Mid-cap fund 13,046 — — — 11,419 — — — Small-cap fund 18,785 — — — 17,184 — — — Debt securities(b) Government bond fund 28,429 — — — 26,151 — — — Corporate bond fund 24,421 — — — 20,971 — — — Fixed income fund(c) 38,072 — 38,072 — 40,958 — 40,958 — Cash & equivalents 238 238 — — 192 192 — — Total $ 198,156 $ 238 $ 38,072 $ — $ 182,370 $ 192 $ 40,958 $ — (a) This category includes investments in actively managed and indexed investment funds that invest in a diversified pool of equity securities of companies located in the U.S., Canada, Western Europe and other developed countries throughout the world. The funds are valued using the net asset value method in which an average of the market prices for the underlying investments is used to value the fund. Funds valued using the net asset value method are not included in the fair value hierarchy. (b) This category includes investments in investment funds that invest in U.S. treasuries; other national, state and local government bonds; and corporate bonds of highly rated companies from diversified industries. The funds are valued using the net asset value method in which an average of the market prices for the underlying investments is used to value the fund. Funds valued using the net asset value method are not included in the fair value hierarchy. (c) This category includes guaranteed insurance contracts.
Benefits Expected to be Paid in Subsequent Years from Our Pension and Other Postretirement as Well as Medicare Subsidy Receipts	The following table reflects the benefits as of December 31, 2017 expected to be paid in each of the next five years and in the aggregate for the five years thereafter from our pension and other postretirement plans. Because our other postretirement plans are unfunded, the anticipated benefits with respect to these plans will come from our own assets. Because our pension plans are primarily funded plans, the anticipated benefits with respect to these plans will come primarily from the trusts established for these plans. Pension Plans Other Plans (In thousands) 2018 $ 16,562 $ 1,580 2019 16,923 1,568 2020 17,937 1,562 2021 17,688 1,557 2022 15,787 1,553 2023-2027 83,382 7,753 Total $ 168,279 $ 15,573
Summary of Accumulated Other Comprehensive Loss, Changes in these Amounts and Expected Amortization of these Amounts as Components of Net Periodic Benefit Cost	The pre-tax amounts in accumulated other comprehensive loss that have not yet been recognized as components of net periodic benefit cost at December 31, 2017 , the changes in these amounts during the year ended December 31, 2017 , and the expected amortization of these amounts as components of net periodic benefit cost for the year ended December 31, 2017 , are as follows. Pension Benefits Other Benefits (In thousands) Components of accumulated other comprehensive loss: Net actuarial loss (gain) $ 44,359 $ (1,545 ) Net prior service cost 11 — $ 44,370 $ (1,545 ) Pension Benefits Other Benefits (In thousands) Changes in accumulated other comprehensive loss: Net actuarial loss, beginning of year $ 49,260 $ 1,842 Amortization of actuarial loss (2,597 ) — Actuarial loss (gain) 3,291 (3,370 ) Asset gain (8,102 ) — Curtailment gain recognized — — Settlement gain recognized 8 — Divestiture (180 ) — Currency impact 2,679 (17 ) Net actuarial loss (gain), end of year $ 44,359 $ (1,545 ) Prior service credit, beginning of year $ (44 ) $ — Amortization of prior service credit 41 — Divestiture (10 ) — Currency impact 24 — Prior service cost, end of year $ 11 $ — Pension Benefits Other Benefits (In thousands) Expected 2018 amortization: Amortization of prior service credit $ (41 ) $ — Amortization of actuarial loss 2,758 — $ 2,717 $ —

Comprehensive Income and Accu52

Comprehensive Income and Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Components of Other Comprehensive Income (Loss), Net of Tax	The accumulated balances related to each component of other comprehensive income (loss), net of tax, are as follows: Foreign Currency Translation Component Pension and Other Postretirement Benefit Plans Accumulated Other Comprehensive Income (Loss) (In thousands) Balance at December 31, 2015 $ (23,411 ) $ (35,576 ) $ (58,987 ) Other comprehensive gain (loss) loss attributable to Belden before reclassifications 18,750 (5,166 ) 13,584 Amounts reclassified from accumulated other comprehensive loss — 6,336 6,336 Net current period other comprehensive gain attributable to Belden 18,750 1,170 19,920 Balance at December 31, 2016 (4,661 ) (34,406 ) (39,067 ) Other comprehensive gain (loss) attributable to Belden before reclassifications (65,030 ) 4,504 (60,526 ) Amounts reclassified from accumulated other comprehensive loss — 1,567 1,567 Net current period other comprehensive gain (loss) attributable to Belden (65,030 ) 6,071 (58,959 ) Balance at December 31, 2017 $ (69,691 ) $ (28,335 ) $ (98,026 )
Summary of Effects of Reclassifications from Accumulated Other Comprehensive Income (Loss)	The following table summarizes the effects of reclassifications from accumulated other comprehensive income (loss): Amount Reclassified from Accumulated Other Comprehensive Income (Loss) Affected Line Item in the Consolidated Statements of Operations and Comprehensive Income (In thousands) Amortization of pension and other postretirement benefit plan items: Settlement gain $ (8 ) (1 ) Actuarial losses 2,597 (1 ) Prior service credit (41 ) (1 ) Total before tax 2,548 Tax benefit (981 ) Total net of tax $ 1,567 (1) The amortization of these accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit costs (see Note 16).

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Income Tax Benefit Recognized for our Share-Based Compensation Arrangements	Compensation cost charged against income, primarily selling, general and administrative expense, and the income tax benefit recognized for our share-based compensation arrangements is included below: Years Ended December 31, 2017 2016 2015 (In thousands) Total share-based compensation cost $ 14,647 $ 18,178 $ 17,745 Income tax benefit 5,566 7,069 6,867
Fair Values for SARs and Stock Options Estimated on Grant Date Using Black-Scholes-Merton Option-Pricing Formula Which Incorporates Assumptions	We recognize compensation cost for all awards based on their fair values. The fair values for SARs are estimated on the grant date using the Black-Scholes-Merton option-pricing formula which incorporates the assumptions noted in the following table. Expected volatility is based on historical volatility, and expected term is based on historical exercise patterns of SAR holders. The fair value of restricted stock units with service vesting conditions or performance vesting conditions is the closing market price of our common stock on the date of grant. We estimate the fair value of certain restricted stock units with market conditions using a Monte Carlo simulation valuation model with the assistance of a third party valuation firm. Compensation costs for awards with service conditions are amortized to expense using the straight-line method. Compensation costs for awards with performance conditions and graded vesting are amortized to expense using the graded attribution method. Years Ended December 31, 2017 2016 2015 (In thousands, except weighted average fair value and assumptions) Weighted-average fair value of SARs and options granted $ 27.31 $ 18.79 $ 31.22 Total intrinsic value of SARs converted and options exercised 7,156 9,678 14,697 Cash received for options exercised — — 30 Tax benefit related to share-based compensation 967 1,171 5,050 Weighted-average fair value of restricted stock shares and units granted 79.96 54.52 96.52 Total fair value of restricted stock shares and units vested 10,355 8,171 7,696 Expected volatility 36.89 % 37.47 % 35.66 % Expected term (in years) 5.6 5.7 5.7 Risk-free rate 2.01 % 1.32 % 1.59 % Dividend yield 0.27 % 0.38 % 0.22 %
Summary of Share Based Compensation Activity	SARs and Stock Options Restricted Shares and Units Number Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term Aggregate Intrinsic Value Number Weighted- Average Grant-Date Fair Value (In thousands, except exercise prices, fair values, and contractual terms) Outstanding at January 1, 2017 1,124 $ 56.79 454 $ 69.55 Granted 254 74.91 222 79.96 Exercised or converted (210 ) 44.08 (145 ) 71.27 Forfeited or expired (36 ) 71.02 (35 ) 75.56 Outstanding at December 31, 2017 1,132 $ 62.75 6.9 $ 16,327 496 $ 78.03 Vested or expected to vest at December 31, 2017 1,118 $ 62.65 6.8 $ 16,234 Exercisable or convertible at December 31, 2017 623 58.57 5.6 11,585

Operating Leases (Tables)

Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Summary of Minimum Annual Lease Payments for Noncancelable Operating Leases	Minimum annual lease payments for noncancelable operating leases in effect at December 31, 2017 are as follows (in thousands): 2018 $ 22,440 2019 18,006 2020 13,787 2021 11,001 2022 8,561 Thereafter 23,494 $ 97,289

Supplemental Cash Flow Inform55

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2017
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental cash flow information is as follows: Years Ended December 31, 2017 2016 2015 (In thousands) Income tax refunds received $ 5,031 $ 3,838 $ 4,068 Income taxes paid (35,893 ) (26,587 ) (24,960 ) Interest paid, net of amount capitalized (79,047 ) (87,076 ) (91,496 )

Quarterly Operating Results (56

Quarterly Operating Results (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Operating Results (Unaudited)	2017 1st 2nd 3rd 4th Year (In thousands, except days and per share amounts) Number of days in quarter 92 91 91 91 365 Revenues $ 551,381 $ 610,633 $ 621,745 $ 604,884 $ 2,388,643 Gross profit 222,114 242,509 239,824 229,592 934,039 Operating income 51,337 62,481 60,791 60,081 234,690 Net income 25,581 35,891 945 30,436 92,853 Less: Net loss attributable to noncontrolling interest (106 ) (86 ) (82 ) (83 ) (357 ) Net income attributable to Belden 25,687 35,977 1,027 30,519 93,210 Less: Preferred stock dividends 8,733 8,733 8,732 8,733 34,931 Net income (loss) attributable to Belden common stockholders 16,954 27,244 (7,705 ) 21,786 58,279 Basic income (loss) per share attributable to Belden common stockholders: $ 0.40 $ 0.64 $ (0.18 ) $ 0.52 $ 1.38 Diluted income (loss) per share attributable to Belden stockholders: $ 0.40 $ 0.64 $ (0.18 ) $ 0.51 $ 1.37 During the financial closing process for the fourth quarter of 2017, we determined that certain consolidated financial statement amounts were not recorded correctly in prior interim periods of 2017. We have evaluated these errors and concluded that they were not material to any of our previously issued interim financial statements and did not require restatement of the quarters. The errors primarily related to recognizing revenue prior to satisfying all of the delivery criteria in one business within our Broadcast segment. The impact of the errors in the first, second, and third quarters of 2017 was an overstatement of revenues of $6.1 million , $10.4 million , and $11.8 million , respectively, and an overstatement of net income of $3.0 million , $1.3 million , and $2.6 million , respectively. The impact of the errors in the fourth quarter of 2017 was an understatement of revenues of $27.8 million and an understatement of net income of $5.2 million . All of the errors have been corrected as of December 31, 2017. Included in the first, second, third, and fourth quarters of 2017 are severance, restructuring, and integration costs of $6.6 million , $9.6 million , $16.7 million , and $9.9 million , respectively. 2016 1st 2nd 3rd 4th Year (In thousands, except days and per share amounts) Number of days in quarter 94 91 91 90 366 Revenues $ 541,497 $ 601,631 $ 601,109 $ 612,435 $ 2,356,672 Gross profit 225,035 248,213 245,962 261,784 980,994 Operating income 40,964 62,241 61,980 58,668 223,853 Net Income 16,358 41,933 36,072 33,283 127,646 Less: Net loss attributable to noncontrolling interest (99 ) (99 ) (88 ) (71 ) (357 ) Net income attributable to Belden 16,457 42,032 36,160 33,354 128,003 Less: Preferred stock dividends — — 6,695 8,733 15,428 Net income attributable to Belden common stockholders 16,457 42,032 29,465 24,621 112,575 Basic income per share attributable to Belden common stockholders: $ 0.39 $ 1.00 $ 0.70 $ 0.58 $ 2.67 Diluted income per share attributable to Belden stockholders: $ 0.39 $ 0.99 $ 0.69 $ 0.58 $ 2.65

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Details) - 12 months ended Dec. 31, 2017	Segment	Reporting_Unit
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	4	5

Summary of Significant Accoun58

Summary of Significant Accounting Policies - Additional Information (Details)	Jan. 01, 2018USD ($)	Jul. 05, 2011patent	Nov. 30, 2016USD ($)	Jul. 31, 2015patent	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)Customer	Dec. 31, 2017USD ($)	Dec. 31, 2017USD ($)Segment	Dec. 31, 2017USD ($)Reporting_Unit	Dec. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)Customer	Dec. 31, 2015USD ($)
Significant Accounting Policies [Line Items]
Amount of inventory as a percentage of prior year purchases that can be returned by certain distributors											3.00%
Unprocessed adjustments recognized against gross accounts receivables										$ 35,700,000		$ 23,300,000
Bad debt expense, net of recoveries										0		$ 1,500,000	$ (1,800,000)
Accounts receivable recovered													2,700,000
Number of customers with accounts receivable recovered | Customer						1						1
Allowance for doubtful accounts					$ 7,800,000	$ 8,100,000	$ 7,800,000	$ 7,800,000	$ 7,800,000	7,800,000	$ 7,800,000	$ 8,100,000
Obsolescence and other reserves					25,269,000	24,561,000	25,269,000	25,269,000	$ 25,269,000	25,269,000	25,269,000	24,561,000
Number of reporting units used in qualitative assessment | Reporting_Unit									7
Goodwill qualitative assessment					547,200,000		547,200,000	547,200,000	$ 547,200,000	547,200,000	547,200,000
Goodwill, portion related to reporting units					931,100,000		931,100,000	$ 931,100,000	$ 931,100,000	931,100,000	931,100,000
Number of reportable segments								4	5
Accrued rebates					38,025,000	33,071,000	$ 38,025,000	$ 38,025,000	$ 38,025,000	38,025,000	$ 38,025,000	33,071,000
Royalty revenues						10,300,000
Advertising costs										25,000,000		27,200,000	27,500,000
Tax Cuts and Jobs Act of 2017, transition tax for accumulated foreign earnings, income tax expense					29,100,000					29,100,000
Tax Cuts and Jobs Act of 2017, remeasurement of deferred tax assets and liabilities					36,000,000					36,000,000
Tax Cuts and Jobs Act of 2017, valuation allowance against foreign tax credit carryforward					$ (35,300,000)					(35,300,000)
Goodwill impairment										0		0	0
Indefinite lived intangible asset impairment										0		0	0
Amortizable intangible asset impairment										0		0	0
Reportable Segment [Member]
Significant Accounting Policies [Line Items]
Royalty revenues										0		5,554,000	0
Broadcast Solutions [Member] | Reportable Segment [Member]
Significant Accounting Policies [Line Items]
Royalty revenues										0		5,554,000	$ 0
Subsidiaries [Member] | Corning [Member]
Significant Accounting Policies [Line Items]
Patents allegedly infringed upon | patent		2
Litigation settlement, amount			$ 61,300,000
Royalty revenues												10,300,000
Number of patents found infringed upon | patent				2
Subsidiaries [Member] | Corning [Member] | Reportable Segment [Member]
Significant Accounting Policies [Line Items]
Royalty revenues												5,600,000
Subsidiaries [Member] | Corning [Member] | Broadcast Solutions [Member]
Significant Accounting Policies [Line Items]
Royalty revenues												4,700,000
Hirschmann Jv [Member] | Discontinued Operations, Held-for-sale [Member]
Significant Accounting Policies [Line Items]
Equity method investment, realized Loss on disposal										$ 1,000,000
Equity method investments						$ 26,800,000						$ 26,800,000
Hirschmann Jv [Member]
Significant Accounting Policies [Line Items]
Equity method investment, ownership percentage					50.00%		50.00%	50.00%	50.00%	50.00%	50.00%
Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of related assets							1 year
Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of related assets							25 years
Buildings [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of related assets							P10Y
Buildings [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of related assets							P40Y
Machinery and Equipment [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of related assets							P5Y
Machinery and Equipment [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of related assets							P12Y
Computer Equipment and Software [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of related assets							P5Y
Computer Equipment and Software [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of related assets							P10Y
Scenario, Forecast [Member] | Accounting Standards Update 2014-09 [Member]
Significant Accounting Policies [Line Items]
Cumulative effect on retained earnings expected in next year	$ 2,600,000

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details) - USD ($)	May 31, 2017	Dec. 31, 2016	Jan. 07, 2016	Jan. 02, 2015	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Revenues					$ 604,884,000	$ 621,745,000	$ 610,633,000	$ 551,381,000	$ 612,435,000	$ 601,109,000	$ 601,631,000	$ 541,497,000	$ 2,388,643,000	$ 2,356,672,000	$ 2,309,222,000
Loss before taxes													99,348,000	126,461,000	39,940,000
Amortization of intangible assets													103,997,000	98,385,000	103,791,000
Thinklogical Holdings LLC [Member]
Business Acquisition [Line Items]
Percentage of outstanding shares acquired	100.00%
Acquisition price	$ 171,300,000
Fair value of acquired receivables	$ 4,400,000
Goodwill acquired					$ 44,000,000								$ 44,000,000
Goodwill, expected tax deductible amount period													15 years
Revenues													$ 30,800,000
Loss before taxes													8,900,000
Amortization of intangible assets													11,900,000
Net income attributable to Belden common stockholders													60,690,000	113,014,000
M2 FX Limited [Member]
Business Acquisition [Line Items]
Percentage of outstanding shares acquired			100.00%
Acquisition price			$ 19,000,000
Estimated earn-out consideration		$ 0	$ 3,200,000										3,200,000
Benefit included in selling, general, and administrative expense														3,200,000
Tripwire [Member]
Business Acquisition [Line Items]
Percentage of outstanding shares acquired				100.00%
Acquisition price				$ 703,200,000
Fair value of acquired receivables				37,800,000
Amortization of intangible assets															43,200,000
Net income attributable to Belden common stockholders															92,104,000
Acquired receivable, gross contractual amount				38,000,000
Post acquisition revenues															116,600,000
Post acquisition income (loss) from continuing operations															47,800,000
Impact on reported revenue due to reduction of acquired deferred revenue balance to fair value															50,400,000
Compensation expense														9,200,000	$ 9,200,000
Tripwire [Member] | Pro Forma [Member]
Business Acquisition [Line Items]
Amortization of intangible assets																$ 3,000,000
Compensation expense																$ 9,200,000
Tripwire [Member] | Revolving Credit Agreement Mature 2018 [Member]
Business Acquisition [Line Items]
Revolving credit agreement due 2022				$ 200,000,000
Fair Value Adjustment to Inventory [Member] | Thinklogical Holdings LLC [Member]
Business Acquisition [Line Items]
Net income attributable to Belden common stockholders													$ (6,100,000)	6,100,000
Amortization Of Sales Backlog Intangible Asset [Member] | Thinklogical Holdings LLC [Member]
Business Acquisition [Line Items]
Net income attributable to Belden common stockholders														$ 1,400,000

Acquisitions - Fair Value of As

Acquisitions - Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2017	May 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 02, 2015
Business Acquisition [Line Items]
Goodwill	$ 1,478,257		$ 1,385,995	$ 1,385,115
Thinklogical Holdings LLC [Member]
Business Acquisition [Line Items]
Cash		$ 5,376
Receivables		4,355
Inventory		16,424
Prepaid and other current assets		320
Property, plant, and equipment		4,289
Goodwill		71,394
Intangible assets		73,400
Total assets		175,558
Accounts payable		1,231
Accrued liabilities		1,353
Deferred revenue		1,702
Total liabilities		4,286
Net assets		$ 171,272
Tripwire [Member]
Business Acquisition [Line Items]
Cash					$ 2,364
Receivables					37,792
Inventory					603
Other current assets					2,453
Property, plant, and equipment					10,021
Goodwill					462,215
Intangible assets					306,000
Other non-current assets					659
Total assets					822,107
Accounts payable					3,142
Accrued liabilities					12,142
Deferred revenue					8,000
Deferred income taxes					95,074
Other non-current liabilities					540
Total liabilities					118,898
Net assets					$ 703,209

Acquisitions - Intangible Asset

Acquisitions - Intangible Assets Related to Acquisition (Details) - USD ($) $ in Thousands	May 31, 2017	Jan. 02, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill			$ 1,478,257	$ 1,385,995	$ 1,385,115
Developed Technology [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted average amortization period			6 years 6 months
Customer Relationships [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted average amortization period			18 years 6 months
Trademarks [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted average amortization period			8 years
Thinklogical Holdings LLC [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	$ 73,400
Goodwill	71,394
Intangible assets not subject to amortization	71,394
Total intangible assets	$ 144,794
Weighted average amortization period	9 years 7 months 6 days
Thinklogical Holdings LLC [Member] | Developed Technology [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	$ 62,600
Weighted average amortization period	10 years
Thinklogical Holdings LLC [Member] | Customer Relationships [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	$ 6,500
Weighted average amortization period	8 years
Thinklogical Holdings LLC [Member] | Trademarks [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	$ 2,900
Weighted average amortization period	10 years
Thinklogical Holdings LLC [Member] | Sales Backlog [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	$ 1,400
Weighted average amortization period	3 months 19 days
Tripwire [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization		$ 300,000
Goodwill		462,215
Intangible assets not subject to amortization		468,215
Total intangible assets		$ 768,215
Weighted average amortization period		7 years 11 months
Tripwire [Member] | In-Process Research and Development [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets not subject to amortization		$ 6,000
Tripwire [Member] | Developed Technology [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization		$ 210,000
Weighted average amortization period		5 years 9 months 18 days
Tripwire [Member] | Customer Relationships [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization		$ 56,000
Weighted average amortization period		15 years
Tripwire [Member] | Trademarks [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization		$ 31,000
Weighted average amortization period		10 years	10 years
Tripwire [Member] | Backlog [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization		$ 3,000
Weighted average amortization period		1 year

Acquisitions - Pro Forma Effect

Acquisitions - Pro Forma Effect on Operating Results (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Thinklogical Holdings LLC [Member]
Business Acquisition [Line Items]
Revenues	$ 2,399,715	$ 2,407,830
Net income attributable to Belden common stockholders	$ 60,690	$ 113,014
Diluted income per share attributable to Belden common stockholders	$ 1.42	$ 2.66
Tripwire [Member]
Business Acquisition [Line Items]
Revenues			$ 2,354,191
Net income attributable to Belden common stockholders			$ 92,104
Diluted income per share attributable to Belden common stockholders			$ 2.14

Assets Held for Sale - Addition

Assets Held for Sale - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of assets held for sale		$ 0	$ 23,931	$ 0
Accumulated other comprehensive loss	$ (39,067)	(98,026)	(39,067)
Hirschmann Jv [Member] | Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales price	39,000	40,200	39,000
Impairment of assets held for sale	23,900		23,931
Loss on sale of assets (5)		(1,000)
Accumulated other comprehensive loss	$ 15,700	$ 2,800	$ 15,700

Assets Held for Sale - Summary

Assets Held for Sale - Summary of Major Assets and Liabilities Classified as Held For Sale (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of assets held for sale		$ 0	$ (23,931)	$ 0
Total assets held for sale	$ 23,193	0	23,193
Total liabilities held for sale	1,736	$ 0	1,736
Hirschmann Jv [Member] | Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net	4,551		4,551
Inventories, net	2,848		2,848
Other current assets	1,131		1,131
Property, plant, and equipment, less accumulated depreciation	1,946		1,946
Intangible assets, less accumulated amortization	4,405		4,405
Goodwill	5,477		5,477
Other long-lived assets	26,766		26,766
Total assets of disposal group	47,124		47,124
Impairment of assets held for sale	(23,900)		(23,931)
Total assets held for sale	23,193		23,193
Accrued liabilities	1,288		1,288
Postretirement benefits	448		448
Total liabilities held for sale	$ 1,736		$ 1,736

Discontinued Operations - Addit

Discontinued Operations - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2010
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain/(loss) on disposal of discontinued operations, net of tax	$ 0	$ 0	$ (86)
Loss from discontinued operations, net of tax	$ 0	$ 0	(242)
Trapeze [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sale price for business				$ 152,100
Gain/(loss) on disposal of discontinued operations, before income tax			(200)	88,300
Gain/(loss) on disposal of discontinued operations, net of tax			(100)	$ 44,800
Escrow receivable collected			3,500
Loss from discontinued operations, net of tax			$ (200)

Operating Segments and Geogra66

Operating Segments and Geographic Information - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)Segment	Dec. 31, 2017USD ($)Reporting_Unit	Dec. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments	4	5
Anixter International Inc. [Member]
Segment Reporting Information [Line Items]
Revenues generated from sales			$ 292.2		$ 286.2	$ 281.9
Accounts receivable outstanding	$ 38.2	$ 38.2	$ 38.2	$ 38.2
Anixter International Inc. [Member] | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Percentage of total accounts receivable outstanding	8.00%	8.00%	8.00%	8.00%
Anixter International Inc. [Member] | Customer Concentration Risk [Member] | Revenues [Member]
Segment Reporting Information [Line Items]
Percent of total revenues				12.00%	12.00%	12.00%

Operating Segments and Geogra67

Operating Segments and Geographic Information - Operating Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Depreciation expense									$ 45,600	$ 47,200	$ 46,600
Amortization of intangibles									103,997	98,385	103,791
Severance, restructuring, and acquisition integration costs	$ 9,900	$ 16,700	$ 9,600	$ 6,600	$ 11,700	$ 12,800	$ 5,900	$ 8,400	42,790	38,770	47,170
Patent settlement					(10,300)
Acquisition of property, plant and equipment									64,261	53,974	54,969
Segment assets	3,840,613				3,806,803				3,840,613	3,806,803	3,290,602
Broadcast Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs									5,532	10,414	39,078
Enterprise Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs									23,511	11,962	723
Industrial Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs									12,272	9,923	6,228
Network Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs									1,475	6,471	1,141
Reportable Segment [Member]
Segment Reporting Information [Line Items]
Segment revenues									2,388,643	2,357,805	2,360,583
Affiliate revenues									9,362	8,125	7,929
Segment EBITDA									430,034	433,189	401,666
Depreciation expense									45,597	47,208	46,551
Amortization of intangibles									103,997	98,385	103,791
Severance, restructuring, and acquisition integration costs									42,790	38,770	47,170
Purchase accounting effects of acquisitions									6,133	(2,079)	9,747
Deferred gross profit adjustments									0	6,687	52,876
Patent settlement									0	(5,554)	0
Acquisition of property, plant and equipment									62,759	53,582	53,572
Segment assets	1,146,395				913,998				1,146,395	913,998	934,280
Reportable Segment [Member] | Broadcast Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues									725,139	769,753	739,970
Affiliate revenues									440	744	916
Segment EBITDA									112,849	137,870	113,638
Depreciation expense									15,763	16,229	16,295
Amortization of intangibles									49,325	47,248	49,812
Severance, restructuring, and acquisition integration costs									5,532	10,414	39,078
Purchase accounting effects of acquisitions									6,133	(2,991)	132
Deferred gross profit adjustments									0	1,774	2,446
Patent settlement									0	(5,554)	0
Acquisition of property, plant and equipment									21,314	15,713	27,365
Segment assets	405,842				325,396				405,842	325,396	346,095
Reportable Segment [Member] | Enterprise Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues									631,166	603,188	605,910
Affiliate revenues									7,385	5,977	5,322
Segment EBITDA									103,650	101,298	100,214
Depreciation expense									10,509	13,226	12,591
Amortization of intangibles									1,729	1,718	1,720
Severance, restructuring, and acquisition integration costs									23,511	11,962	723
Purchase accounting effects of acquisitions									0	912	52
Acquisition of property, plant and equipment									28,126	22,679	10,323
Segment assets	282,072				246,564				282,072	246,564	238,400
Reportable Segment [Member] | Industrial Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues									628,458	585,476	603,350
Affiliate revenues									1,441	1,325	1,613
Segment EBITDA									119,642	101,248	99,941
Depreciation expense									12,968	11,038	11,235
Amortization of intangibles									2,571	2,394	3,154
Severance, restructuring, and acquisition integration costs									12,272	9,923	6,228
Purchase accounting effects of acquisitions									0	0	334
Acquisition of property, plant and equipment									8,151	10,486	8,836
Segment assets	300,172				226,306				300,172	226,306	231,265
Reportable Segment [Member] | Network Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues									403,880	399,388	411,353
Affiliate revenues									96	79	78
Segment EBITDA									93,893	92,773	87,873
Depreciation expense									6,357	6,715	6,430
Amortization of intangibles									50,372	47,025	49,105
Severance, restructuring, and acquisition integration costs									1,475	6,471	1,141
Purchase accounting effects of acquisitions									0	0	9,229
Deferred gross profit adjustments									0	4,913	50,430
Acquisition of property, plant and equipment									5,168	4,704	7,048
Segment assets	$ 158,309				$ 115,732				158,309	115,732	118,520
Software Development [Member] | Reportable Segment [Member]
Segment Reporting Information [Line Items]
Amortization of intangibles									56	0	0
Software Development [Member] | Reportable Segment [Member] | Broadcast Solutions [Member]
Segment Reporting Information [Line Items]
Amortization of intangibles									$ 56	$ 0	$ 0

Operating Segments and Geogra68

Operating Segments and Geographic Information - Reconciliation of Total Reportable Segments' Revenues and EBITDA to Consolidated Revenues and Consolidated Income from Continuing Operations Before Taxes (Details) - USD ($)	Dec. 31, 2016	Jan. 07, 2016	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 02, 2015
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Patent settlement (2)							$ 10,300,000
Consolidated Revenues			$ 604,884,000	$ 621,745,000	$ 610,633,000	$ 551,381,000	612,435,000	$ 601,109,000	$ 601,631,000	$ 541,497,000	$ 2,388,643,000	$ 2,356,672,000	$ 2,309,222,000
Amortization of intangibles											(103,997,000)	(98,385,000)	(103,791,000)
Depreciation expense											(45,600,000)	(47,200,000)	(46,600,000)
Severance, restructuring, and acquisition integration costs (3)			(9,900,000)	(16,700,000)	(9,600,000)	(6,600,000)	(11,700,000)	(12,800,000)	(5,900,000)	(8,400,000)	(42,790,000)	(38,770,000)	(47,170,000)
Impairment of assets held for sale											0	(23,931,000)	0
Operating income			60,081,000	$ 60,791,000	$ 62,481,000	$ 51,337,000	$ 58,668,000	$ 61,980,000	$ 62,241,000	$ 40,964,000	234,690,000	223,853,000	140,553,000
Interest expense, net											(82,901,000)	(95,050,000)	(100,613,000)
Loss on debt extinguishment											(52,441,000)	(2,342,000)	0
Income from continuing operations before taxes											99,348,000	126,461,000	39,940,000
Reportable Segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Segment Revenues											2,388,643,000	2,357,805,000	2,360,583,000
Deferred revenue adjustments (1)											0	(6,687,000)	(51,361,000)
Patent settlement (2)											0	5,554,000	0
Consolidated Revenues											2,388,643,000	2,356,672,000	2,309,222,000
Total Segment EBITDA											430,034,000	433,189,000	401,666,000
Amortization of intangibles											(103,997,000)	(98,385,000)	(103,791,000)
Depreciation expense											(45,597,000)	(47,208,000)	(46,551,000)
Severance, restructuring, and acquisition integration costs (3)											(42,790,000)	(38,770,000)	(47,170,000)
Purchase accounting effects related to acquisitions (4)											(6,133,000)	2,079,000	(9,747,000)
Loss on sale of assets (5)											(1,013,000)	0	0
Impairment of assets held for sale											0	(23,931,000)	0
Deferred gross profit adjustments											0	(6,687,000)	(52,876,000)
Income from equity method investment											7,502,000	1,793,000	1,770,000
Eliminations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income											(3,260,000)	(3,781,000)	(2,748,000)
M2 FX Limited [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjustment to reduce earn-out liability	$ 0	$ 3,200,000									3,200,000
Acquired inventory			200,000								200,000
Tripwire [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Amortization of intangibles													(43,200,000)
Acquired inventory														$ 603,000
Compensation expense												9,200,000	9,200,000
Coast Wire And Plastic Tech [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Cost of sales related to adjustment of acquired inventory												300,000
Enterprise Solutions [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Severance, restructuring, and acquisition integration costs (3)											(23,511,000)	(11,962,000)	(723,000)
Acquired inventory			$ 800,000								800,000
Enterprise Solutions [Member] | Reportable Segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Segment Revenues											631,166,000	603,188,000	605,910,000
Total Segment EBITDA											103,650,000	101,298,000	100,214,000
Amortization of intangibles											(1,729,000)	(1,718,000)	(1,720,000)
Depreciation expense											(10,509,000)	(13,226,000)	(12,591,000)
Severance, restructuring, and acquisition integration costs (3)											(23,511,000)	(11,962,000)	(723,000)
Purchase accounting effects related to acquisitions (4)											0	(912,000)	(52,000)
Software Development [Member] | Reportable Segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Amortization of intangibles											$ (56,000)	$ 0	$ 0

Operating Segments and Geogra69

Operating Segments and Geographic Information - Reconciliations of Other Segment Measures to Consolidated Totals (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total assets	$ 3,840,613	$ 3,806,803	$ 3,290,602
Cash and cash equivalents	561,108	848,116	216,751	$ 741,162
Goodwill	1,478,257	1,385,995	1,385,115
Intangible assets, less accumulated amortization	545,207	560,082	655,871
Deferred income taxes	42,549	33,706	34,295
Income tax receivable	0	0	3,787
Acquisition of property, plant and equipment	64,261	53,974	54,969
Reportable Segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total assets	1,146,395	913,998	934,280
Acquisition of property, plant and equipment	62,759	53,582	53,572
Corporate assets [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total assets	67,097	64,906	60,503
Acquisition of property, plant and equipment	$ 1,502	$ 392	$ 1,397

Operating Segments and Geogra70

Operating Segments and Geographic Information - Schedule of Revenue from External Customers and Long-Lived Assets Based on Physical Location (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 604,884	$ 621,745	$ 610,633	$ 551,381	$ 612,435	$ 601,109	$ 601,631	$ 541,497	$ 2,388,643	$ 2,356,672	$ 2,309,222
Percent of total revenues									100.00%	100.00%	100.00%
Long-lived assets	402,529				348,068				$ 402,529	$ 348,068	$ 378,163
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									$ 1,265,455	$ 1,283,925	$ 1,270,467
Percent of total revenues									53.00%	55.00%	55.00%
Long-lived assets	231,938				193,263				$ 231,938	$ 193,263	$ 188,032
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									$ 167,605	$ 159,985	$ 170,522
Percent of total revenues									7.00%	7.00%	7.00%
Long-lived assets	33,806				31,278				$ 33,806	$ 31,278	$ 27,315
China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									$ 121,600	$ 114,605	$ 114,863
Percent of total revenues									5.00%	5.00%	5.00%
Long-lived assets	34,774				30,487				$ 34,774	$ 30,487	$ 62,794
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									$ 113,990	$ 104,214	$ 103,106
Percent of total revenues									5.00%	4.00%	4.00%
Long-lived assets	38,029				32,386				$ 38,029	$ 32,386	$ 35,588
All Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									$ 719,993	$ 693,943	$ 650,264
Percent of total revenues									30.00%	29.00%	29.00%
Long-lived assets	$ 63,982				$ 60,654				$ 63,982	$ 60,654	$ 64,434

Noncontrolling Interest - Addit

Noncontrolling Interest - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2015
Variable Interest Entity, Primary Beneficiary [Member]
Noncontrolling Interest [Line Items]
Contribution to joint venture		$ 1,530
Additional contribution commitments to joint venture	$ 1,530
Hite [Member]
Noncontrolling Interest [Line Items]
Contribution to joint venture		$ 1,470
Ownership percentage		49.00%
Additional contribution commitments to joint venture	$ 1,470
Hite [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Noncontrolling Interest [Line Items]
Variable interest entity, ownership percentage		51.00%

Income Per Share - Basis for In

Income Per Share - Basis for Income Per Share Computations (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Numerator:
Income from continuing operations									$ 92,853	$ 127,646	$ 66,508
Less: Net loss attributable to noncontrolling interest	$ (83)	$ (82)	$ (86)	$ (106)	$ (71)	$ (88)	$ (99)	$ (99)	(357)	(357)	(24)
Less: Preferred stock dividends	8,733	8,732	8,733	8,733	8,733	6,695	0	0	34,931	15,428	0
Income from continuing operations attributable to Belden common stockholders									58,279	112,575	66,532
Loss from discontinued operations, net of tax, attributable to Belden common stockholders									0	0	(242)
Loss from disposal of discontinued operations, net of tax, attributable to Belden common stockholders									0	0	(86)
Net income attributable to Belden common stockholders	$ 21,786	$ (7,705)	$ 27,244	$ 16,954	$ 24,621	$ 29,465	$ 42,032	$ 16,457	$ 58,279	$ 112,575	$ 66,204
Denominator:
Weighted average shares outstanding, basic (in shares)									42,220	42,093	42,390
Effect of dilutive common stock equivalents (in shares)									423	464	563
Weighted average shares outstanding, diluted (in shares)									42,643	42,557	42,953

Income Per Share - Additional I

Income Per Share - Additional Information (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from diluted weighted average shares outstanding (in shares)	0.5	0.6	0.4
Anti-dilutive shares excluded form diluted weighted average shares outstanding due to performance conditions not met (in shares)	0.2	0.1	0
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from diluted weighted average shares outstanding (in shares)	6.9	3

Inventories - Major Classes of

Inventories - Major Classes of Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 133,311	$ 90,019
Work-in-process	35,807	25,166
Finished goods	153,377	99,784
Gross inventories	322,495	214,969
Excess and obsolete reserves	(25,269)	(24,561)
Net inventories	$ 297,226	$ 190,408

Property, Plant and Equipment -

Property, Plant and Equipment - Summary of Carrying Values of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 907,562	$ 823,192
Accumulated depreciation	(570,240)	(513,901)
Net property, plant and equipment	337,322	309,291
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	31,963	28,462
Buildings and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	148,598	136,230
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	543,594	499,400
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	136,509	123,909
Construction in Process [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 46,898	$ 35,191

Property, Plant and Equipment76

Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 45.6	$ 47.2	$ 46.6

Intangible Assets - Carrying Va

Intangible Assets - Carrying Value of Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Intangible Assets [Line Items]
Goodwill, Gross carrying amount	$ 1,478,257	$ 1,385,995
Goodwill, Accumulated amortization	0	0
Goodwill, Net carrying amount	1,478,257	1,385,995	$ 1,385,115
Finite-lived intangible assets, Gross Carrying Amount	913,956	786,189
Finite-lived intangible assets, Accumulated amortization	(463,207)	(349,779)
Finite-lived intangible assets, Net carrying amount	450,749	436,410
Indefinite-lived intangible assets, Carrying amount	94,458	123,672
Intangible assets, Gross carrying amount	1,008,414	909,861
Intangible assets, Net carrying amount	545,207	560,082	$ 655,871
Trademarks [Member]
Intangible Assets [Line Items]
Indefinite-lived intangible assets, Carrying amount	92,758	121,972
In-Process Research and Development [Member]
Intangible Assets [Line Items]
Indefinite-lived intangible assets, Carrying amount	1,700	1,700
Developed Technology [Member]
Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	498,649	420,928
Finite-lived intangible assets, Accumulated amortization	(318,366)	(239,233)
Finite-lived intangible assets, Net carrying amount	180,283	181,695
Customer Relationships [Member]
Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	320,550	309,112
Finite-lived intangible assets, Accumulated amortization	(98,175)	(77,872)
Finite-lived intangible assets, Net carrying amount	222,375	231,240
Trademarks [Member]
Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	56,794	20,534
Finite-lived intangible assets, Accumulated amortization	(18,648)	(10,915)
Finite-lived intangible assets, Net carrying amount	38,146	9,619
In-Process Research and Development [Member]
Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	23,428	22,977
Finite-lived intangible assets, Accumulated amortization	(13,483)	(9,121)
Finite-lived intangible assets, Net carrying amount	9,945	13,856
Backlog [Member]
Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	14,535	12,638
Finite-lived intangible assets, Accumulated amortization	(14,535)	(12,638)
Finite-lived intangible assets, Net carrying amount	$ 0	$ 0

Intangible Assets - Changes in

Intangible Assets - Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 1,385,995	$ 1,385,115
Acquisitions and purchase accounting adjustments	71,394	8,492
Translation impact	20,868	(2,135)
Reclassify to assets held for sale		(5,477)
Goodwill, Ending Balance	1,478,257	1,385,995
Broadcast Solutions [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	544,042	536,388
Acquisitions and purchase accounting adjustments	71,394	8,492
Translation impact	13,557	(838)
Reclassify to assets held for sale		0
Goodwill, Ending Balance	628,993	544,042
Enterprise Solutions [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	73,278	73,278
Acquisitions and purchase accounting adjustments	0	0
Translation impact	0	0
Reclassify to assets held for sale		0
Goodwill, Ending Balance	73,278	73,278
Industrial Solutions [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	191,322	196,719
Acquisitions and purchase accounting adjustments	0	0
Translation impact	2,790	80
Reclassify to assets held for sale		(5,477)
Goodwill, Ending Balance	194,112	191,322
Network Solutions [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	577,353	578,730
Acquisitions and purchase accounting adjustments	0	0
Translation impact	4,521	(1,377)
Reclassify to assets held for sale		0
Goodwill, Ending Balance	$ 581,874	$ 577,353

Intangible Assets - Changes i79

Intangible Assets - Changes in Carrying Amount of Trademarks (Details) - Trademarks [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Indefinite-lived Intangible Assets [Roll Forward]
Trademarks, Beginning Balance	$ 121,972	$ 129,671
Translation impact	3,987	(4,794)
Reclassify to assets held for sale	(33,201)	(2,905)
Trademarks, Ending Balance	92,758	121,972
Broadcast Solutions [Member]
Indefinite-lived Intangible Assets [Roll Forward]
Trademarks, Beginning Balance	76,287	80,922
Translation impact	2,727	(4,635)
Reclassify to assets held for sale	0	0
Trademarks, Ending Balance	79,014	76,287
Enterprise Solutions [Member]
Indefinite-lived Intangible Assets [Roll Forward]
Trademarks, Beginning Balance	4,063	4,063
Translation impact	0	0
Reclassify to assets held for sale	0	0
Trademarks, Ending Balance	4,063	4,063
Industrial Solutions [Member]
Indefinite-lived Intangible Assets [Roll Forward]
Trademarks, Beginning Balance	6,225	9,090
Translation impact	602	40
Reclassify to assets held for sale	(2,201)	(2,905)
Trademarks, Ending Balance	4,626	6,225
Network Solutions [Member]
Indefinite-lived Intangible Assets [Roll Forward]
Trademarks, Beginning Balance	35,397	35,596
Translation impact	658	(199)
Reclassify to assets held for sale	(31,000)	0
Trademarks, Ending Balance	$ 5,055	$ 35,397

Intangible Assets - Additional

Intangible Assets - Additional Information (Details)	Jan. 02, 2015	Dec. 31, 2017USD ($)Reporting_Unit	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Finite And Indefinite Intangible Assets [Line Items]
Number of reporting units used in quantitative assessment | Reporting_Unit		5
Number of reporting units used in qualitative assessment | Reporting_Unit		7
Recognized amortization expenses		$ 103,997,000	$ 98,385,000	$ 103,791,000
Estimated amortization expense in 2018		88,200,000
Estimated amortization expense in 2019		78,100,000
Estimated amortization expense in 2020		61,700,000
Estimated amortization expense in 2021		29,700,000
Estimated amortization expense in 2022		27,000,000
Finite-lived intangible assets, net carrying amount		450,749,000	436,410,000
Goodwill impairment charges		0	0	0
Impairment charges		$ 0	0	0
Customer Relationships [Member]
Finite And Indefinite Intangible Assets [Line Items]
Weighted-average amortization period		18 years 6 months
Finite-lived intangible assets, net carrying amount		$ 222,375,000	231,240,000
Trademarks [Member]
Finite And Indefinite Intangible Assets [Line Items]
Weighted-average amortization period		8 years
Finite-lived intangible assets, net carrying amount		$ 38,146,000	9,619,000
Impairment charges		$ 0	0	0
Developed Technology [Member]
Finite And Indefinite Intangible Assets [Line Items]
Weighted-average amortization period		6 years 6 months
Finite-lived intangible assets, net carrying amount		$ 180,283,000	181,695,000
In-Process Research and Development [Member]
Finite And Indefinite Intangible Assets [Line Items]
Weighted-average amortization period		4 years 8 months 15 days
Finite-lived intangible assets, net carrying amount		$ 9,945,000	$ 13,856,000
Tripwire [Member]
Finite And Indefinite Intangible Assets [Line Items]
Recognized amortization expenses				$ 43,200,000
Weighted-average amortization period	7 years 11 months
Tripwire [Member] | Customer Relationships [Member]
Finite And Indefinite Intangible Assets [Line Items]
Weighted-average amortization period	15 years
Tripwire [Member] | Trademarks [Member]
Finite And Indefinite Intangible Assets [Line Items]
Recognized amortization expenses		$ 3,100,000
Weighted-average amortization period	10 years	10 years
Finite-lived intangible assets, net carrying amount		$ 27,900,000
Tripwire [Member] | Developed Technology [Member]
Finite And Indefinite Intangible Assets [Line Items]
Weighted-average amortization period	5 years 9 months 18 days

Accounts Payable and Accrued 81

Accounts Payable and Accrued Liabilities - Carrying Value of Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Accounts payable	$ 376,277	$ 258,203
Current deferred revenue	90,639	80,503
Wages, severance and related taxes	57,633	76,157
Accrued rebates	38,025	33,071
Employee benefits	25,406	24,395
Accrued interest	22,019	27,202
Other (individual items less than 5% of total current liabilities)	68,929	69,012
Accounts payable and accrued liabilities	$ 678,928	$ 568,543

Accounts Payable and Accrued 82

Accounts Payable and Accrued Liabilities - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Accounts payable due to bank	$ 21.9	$ 12.4
Settlement of accounts payable outstanding	1 year

Severance, Restructuring, and83

Severance, Restructuring, and Acquisition Integration Activities Severance, Restructuring, and Acquisition Integration Activities - Additional Information (Details)

3 Months Ended

6 Months Ended

12 Months Ended

24 Months Ended

27 Months Ended

30 Months Ended

Dec. 31, 2017USD ($)

Oct. 01, 2017USD ($)

Jul. 02, 2017USD ($)

Apr. 02, 2017USD ($)

Dec. 31, 2016USD ($)

Oct. 02, 2016USD ($)

Jul. 03, 2016USD ($)

Apr. 03, 2016USD ($)

Dec. 31, 2015USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)

Dec. 31, 2015USD ($)Program

Dec. 31, 2017USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2018USD ($)

Segment Reporting Information [Line Items]

Severance, restructuring, and acquisition integration costs

$ 9,900,000

$ 16,700,000

$ 9,600,000

$ 6,600,000

$ 11,700,000

$ 12,800,000

$ 5,900,000

$ 8,400,000

$ 42,790,000

$ 38,770,000

$ 47,170,000

Cost of Sales [Member]

Segment Reporting Information [Line Items]

Severance, restructuring, and acquisition integration costs

32,600,000

12,300,000

9,400,000

Selling, General and Administrative Expenses [Member]

Segment Reporting Information [Line Items]

Severance, restructuring, and acquisition integration costs

10,000,000

25,700,000

31,700,000

Research and Development Expense [Member]

Segment Reporting Information [Line Items]

Severance, restructuring, and acquisition integration costs

$ 200,000

800,000

6,100,000

Maximum [Member]

Segment Reporting Information [Line Items]

Restructuring and integration cost payable period

60 days

Industrial Manufacturing Footprint Program [Member]

Segment Reporting Information [Line Items]

Severance, restructuring, and acquisition integration costs

$ 30,600,000

17,800,000

$ 48,400,000

$ 34,100,000

Expected savings from restructuring

$ 13,000,000

Industrial Manufacturing Footprint Program [Member] | Scenario, Forecast [Member]

Segment Reporting Information [Line Items]

Expected restructuring cost remaining

$ 6,000,000

Industrial Restructuring Program [Member]

Segment Reporting Information [Line Items]

Severance, restructuring, and acquisition integration costs

9,700,000

3,300,000

$ 13,000,000

Expected savings from restructuring

$ 18,000,000

Grass Valley Restructuring Program [Member]

Segment Reporting Information [Line Items]

Severance, restructuring, and acquisition integration costs

0

8,700,000

25,400,000

Expected savings from restructuring

$ 30,000,000

Productivity Improvement Program and Acquisition Integration [Member]

Segment Reporting Information [Line Items]

Severance, restructuring, and acquisition integration costs

$ 18,500,000

Number of restructuring programs | Program

2

Reduction in operating expenses

$ 18,000,000

Productivity Improvement Program and Acquisition Integration [Member] | M2 FX Limited [Member]

Segment Reporting Information [Line Items]

Severance, restructuring, and acquisition integration costs

$ 2,600,000

Severance, Restructuring, and84

Severance, Restructuring, and Acquisition Integration Activities Severance, Restructuring, and Acquisition Integration Activities - Severance, Restructuring and Integration Costs by Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Severance									$ 5,211	$ 7,082	$ 19,101
Other Restructuring and Integration Costs									37,579	31,688	28,069
Total Costs	$ 9,900	$ 16,700	$ 9,600	$ 6,600	$ 11,700	$ 12,800	$ 5,900	$ 8,400	42,790	38,770	47,170
Broadcast Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Severance									893	(116)	16,694
Other Restructuring and Integration Costs									4,639	10,530	22,384
Total Costs									5,532	10,414	39,078
Enterprise Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Severance									3,642	636	(186)
Other Restructuring and Integration Costs									19,869	11,326	909
Total Costs									23,511	11,962	723
Industrial Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Severance									886	2,828	3,309
Other Restructuring and Integration Costs									11,386	7,095	2,919
Total Costs									12,272	9,923	6,228
Network Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Severance									(210)	3,734	(716)
Other Restructuring and Integration Costs									1,685	2,737	1,857
Total Costs									$ 1,475	$ 6,471	$ 1,141

Long-Term Debt and Other Borr85

Long-Term Debt and Other Borrowing Arrangements - Carrying Values of Long-Term Debt and Other Borrowing Arrangements (Details) - USD ($)	Dec. 31, 2017	Sep. 30, 2017	Jul. 31, 2017	Dec. 31, 2016	Oct. 31, 2016
Debt Instrument [Line Items]
Less unamortized debt issuance costs	$ (23,484,000)			$ (23,287,000)
Long-term debt	1,560,748,000			1,620,161,000
Revolving Credit Facility Mature Two Thousand Twenty Two [Member]
Debt Instrument [Line Items]
Revolving credit agreement due 2022	$ 0			$ 0
3.375% Senior Subordinated Notes Due 2027 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate	3.375%			3.375%
Total senior subordinated notes	$ 540,810,000			$ 0
4.125% Senior Subordinated Notes Due 2026 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate	4.125%			4.125%	4.125%
Total senior subordinated notes	$ 240,360,000			$ 209,081,000
2.875% Senior Subordinated Notes Due 2025 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate	2.875%			2.875%
Total senior subordinated notes	$ 360,540,000			$ 0
5.25% Senior Subordinated Notes Due 2024 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate	5.25%			5.25%
Total senior subordinated notes	$ 200,000,000			$ 200,000,000
5.50% Senior subordinated notes due 2023 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate	5.50%			5.50%
Total senior subordinated notes	$ 242,522,000			$ 529,146,000
5.50% Senior subordinated notes due 2022 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate	5.50%			5.50%
Total senior subordinated notes	$ 0			$ 700,000,000
9.25% Senior Subordinated Notes Due 2019 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate	9.25%			9.25%
Total senior subordinated notes	$ 0			$ 5,221,000
Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Total senior subordinated notes	$ 1,584,232,000			$ 1,643,448,000
Senior Subordinated Notes [Member] | 3.375% Senior Subordinated Notes Due 2027 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate			3.375%
Senior Subordinated Notes [Member] | 2.875% Senior Subordinated Notes Due 2025 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate		2.875%
Senior Subordinated Notes [Member] | 5.25% Senior Subordinated Notes Due 2024 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate	5.25%
Senior Subordinated Notes [Member] | 5.50% Senior subordinated notes due 2023 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate	5.50%

Long-Term Debt and Other Borr86

Long-Term Debt and Other Borrowing Arrangements - Additional Information (Details)	May 16, 2017USD ($)	Sep. 30, 2017USD ($)	Jul. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2017EUR (€)	Aug. 31, 2017EUR (€)	Jul. 31, 2017EUR (€)	Oct. 31, 2016USD ($)	Oct. 31, 2016EUR (€)	Nov. 30, 2014USD ($)
Debt Instrument [Line Items]
Loss on debt extinguishment				$ 52,441,000	$ 2,342,000	$ 0
Payments of debt issuance costs				17,316,000	3,910,000	$ 898,000
Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Total senior subordinated notes				1,584,232,000	1,643,448,000
Fair value of debt instrument				1,619,300,000	1,693,200,000
Revolving Credit Agreement Mature 2018 [Member]
Debt Instrument [Line Items]
Borrowing under line of credit facility				$ 400,000,000
Line of credit commitment fees				0.25%
Revolving credit facility restrictive covenants fixed charge coverage ratio minimum threshold				90.00%
Line of credit borrowing base				$ 348,600,000
Revolving Credit Facility Mature Two Thousand Twenty Two [Member]
Debt Instrument [Line Items]
Loss on debt extinguishment	$ 800,000
Debt fee amount	$ 2,300,000
Revolving credit agreement due 2022				$ 0	$ 0
Revolving Credit Facility Mature Two Thousand Twenty Two [Member] | Minimum [Member]
Debt Instrument [Line Items]
Line of credit spread on variable rate	1.25%
Revolving Credit Facility Mature Two Thousand Twenty Two [Member] | Maximum [Member]
Debt Instrument [Line Items]
Line of credit spread on variable rate	1.75%
3.375% Senior Subordinated Notes Due 2027 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate				3.375%	3.375%
Total senior subordinated notes				$ 540,810,000	$ 0
3.375% Senior Subordinated Notes Due 2027 [Member] | Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Debt fee amount			$ 8,800,000
Aggregate principal amount outstanding of senior subordinated notes			$ 509,500,000						€ 450,000,000
Senior subordinated notes interest rate			3.375%						3.375%
5.50% Senior subordinated notes due 2022 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate				5.50%	5.50%
Total senior subordinated notes				$ 0	$ 700,000,000
5.50% Senior subordinated notes due 2022 [Member] | Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount outstanding of senior subordinated notes				700,000,000
Repayments of debt			$ 722,700,000
Variable Term loan Due 2020 [Member]
Debt Instrument [Line Items]
Loss on debt extinguishment				$ 29,800,000
4.125% Senior Subordinated Notes Due 2026 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate				4.125%	4.125%					4.125%	4.125%
Total senior subordinated notes				$ 240,360,000	$ 209,081,000
4.125% Senior Subordinated Notes Due 2026 [Member] | Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount outstanding of senior subordinated notes										$ 222,200,000	€ 200,000,000
Payments of debt issuance costs				$ 3,900,000
2.875% Senior Subordinated Notes Due 2025 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate				2.875%	2.875%
Total senior subordinated notes				$ 360,540,000	$ 0
2.875% Senior Subordinated Notes Due 2025 [Member] | Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Debt fee amount		$ 6,200,000
Aggregate principal amount outstanding of senior subordinated notes		$ 357,200,000					€ 300,000,000
Senior subordinated notes interest rate		2.875%					2.875%
5.50% Senior subordinated notes due 2023 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate				5.50%	5.50%
Total senior subordinated notes				$ 242,522,000	$ 529,146,000
5.50% Senior subordinated notes due 2023 [Member] | Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Loss on debt extinguishment		$ 21,800,000
Aggregate principal amount outstanding of senior subordinated notes								€ 500,000,000				$ 500,000,000
Senior subordinated notes interest rate				5.50%
Repayments of debt		$ 377,900,000
Debt repurchase amount | €							€ 300,000,000
5.25% Senior Subordinated Notes Due 2024 [Member]
Debt Instrument [Line Items]
Senior subordinated notes interest rate				5.25%	5.25%
Total senior subordinated notes				$ 200,000,000	$ 200,000,000
5.25% Senior Subordinated Notes Due 2024 [Member] | Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount outstanding of senior subordinated notes				$ 200,000,000
Senior subordinated notes interest rate				5.25%
Payments of debt issuance costs				$ 4,200,000
9.25% Senior Subordinated Notes Due 2019 [Member]
Debt Instrument [Line Items]
Aggregate principal amount outstanding of senior subordinated notes				$ 5,200,000
Senior subordinated notes interest rate				9.25%	9.25%
Total senior subordinated notes				$ 0	$ 5,221,000

Long-Term Debt and Other Borr87

Long-Term Debt and Other Borrowing Arrangements - Schedule of Senior Subordinated Notes (Details)	12 Months Ended
	Dec. 31, 2017
2018 [Member] | Senior Subordinated Notes Due 2023 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	102.75%
2019 [Member] | Senior Subordinated Notes Due 2023 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	101.833%
2019 [Member] | Senior Subordinated Notes Due 2024 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	102.625%
2020 [Member] | Senior Subordinated Notes Due 2023 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.917%
2020 [Member] | Senior Subordinated Notes Due 2024 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	101.75%
2020 [Member] | Senior Subordinated Notes Due 2025 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	101.438%
2021 [Member] | Senior Subordinated Notes Due 2024 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.875%
2021 [Member] | Senior Subordinated Notes Due 2025 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.719%
2021 [Member] | Senior Subordinated Notes Due 2026 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	102.063%
2022 [Member] | Senior Subordinated Notes Due 2026 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	101.375%
2022 [Member] | Senior Subordinated Notes Due 2027 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	101.688%
2023 [Member] | Senior Subordinated Notes Due 2026 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.688%
2023 [Member] | Senior Subordinated Notes Due 2027 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	101.125%
2022 and Thereafter [Member] | Senior Subordinated Notes Due 2024 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.00%
2022 and Thereafter [Member] | Senior Subordinated Notes Due 2025 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.00%
2024 [Member] | Senior Subordinated Notes Due 2027 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.563%
2021 and Thereafter [Member] | Senior Subordinated Notes Due 2023 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.00%
2024 and Thereafter [Member] | Senior Subordinated Notes Due 2026 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.00%
2025 and Thereafter [Member] | Senior Subordinated Notes Due 2027 [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.00%

Long-Term Debt and Other Borr88

Long-Term Debt and Other Borrowing Arrangements - Maturities on Outstanding Long-Term Debt and Other Borrowings (Details) $ in Thousands	Dec. 31, 2017USD ($)
Debt Disclosure [Abstract]
2,018	$ 0
2,019	0
2,020	0
2,021	0
2,022	0
Thereafter	1,584,232
Total gross debt and other borrowing arrangements	$ 1,584,232

Net Investment Hedge Net Invest

Net Investment Hedge Net Investment Hedge (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Foreign currency translation gain (loss), net of $1.2 million, $1.3 million, and $1.8 million tax, respectively	$ (65,046)	$ 18,687	$ (20,842)
Senior Subordinated Notes [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Foreign currency translation gain (loss), net of $1.2 million, $1.3 million, and $1.8 million tax, respectively	$ (56,200)	$ 13,000

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income (loss) from continuing operations before taxes:
United States operations	$ 2,177	$ (25,615)	$ (6,924)
Foreign operations	97,171	152,076	46,864
Income from continuing operations before taxes	99,348	126,461	39,940
Currently payable
United States federal	0	2,981	0
United States state and local	2,392	(1,038)	1,789
Foreign	28,201	26,906	17,317
Income tax expense (benefit)	30,593	28,849	19,106
Deferred
United States federal	(11,028)	(27,677)	(23,709)
United States state and local	(8,758)	(3,139)	(2,257)
Foreign	(4,312)	782	(19,708)
Deferred Income tax expense (benefit)	(24,098)	(30,034)	(45,674)
Income tax expense (benefit)	$ 6,495	$ (1,185)	$ (26,568)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2038	Dec. 31, 2022	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Income tax expense (benefit) for discontinued operations				$ 200
Tax Cuts and Jobs Act of 2017, income tax expense	$ 28,400
Tax Cuts and Jobs Act of 2017, remeasurement of deferred tax assets and liabilities	36,000	$ 36,000
Tax Cuts and Jobs Act of 2017, transition tax for accumulated foreign earnings, income tax expense	29,100	29,100
Tax Cuts and Jobs Act of 2017, valuation allowance against foreign tax credit carryforward	(35,300)	(35,300)
Tax Cuts and Jobs Act of 2017, income tax expense related to employee compensation	0
Income tax benefit from domestic permanent differences and tax credits		48,200
Income tax benefit from domestic permanent differences and tax credits, non-taxable translation gain		27,100
Income tax benefit from foreign jurisdiction tax credits		$ 19,800
Statutory tax rates		35.00%	35.00%	35.00%
Foreign tax rate differences benefit in income tax		$ 13,000	$ 17,700	$ 3,400
Income tax expense tax holiday		3,500	2,900
Net operating loss carryforwards	538,880	538,880
Net tax credit carryforwards	97,100	97,100
Operating loss carryforwards that will be used in expiration periods	158,600	158,600
Net tax credit carryforwards that will expire	97,072	97,072
Net tax credit carry forwards with indefinite carry forward period	6,600	6,600
Net tax credit carryforwards that expected to be utilized prior to expiry	58,400	58,400
Net decrease in reserve for uncertain tax positions		1,900
Balance at end of the year of unrecognized tax benefits	8,579	8,579	10,474	7,293
Estimate the range of reasonably possible changes to unrecognized tax positions	1,100	1,100
Recognized interest expense (income) and penalties of unrecognized tax benefits		0	(200)	$ 0
Accrued interest expense (income) and penalties of unrecognized tax benefits	0	0	$ 1,200
Scenario, Forecast [Member]
Income Taxes [Line Items]
Net tax credit carryforwards that will expire					$ 85,600	$ 4,700	$ 100	$ 100
Net Operating Loss Carry Forwards Expires In 2017 [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	1,000	1,000
Net Operating Loss Carry Forwards Expires In 2018 [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	200	200
Net Operating Loss Carry Forwards Expires In 2019 [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	7,900	7,900
2020 and 2022 [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	33,700	33,700
2023 and 2038 [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	143,400	143,400
Net Operating Loss Carry Forward Indefinite Period [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	352,700	$ 352,700
Germany [Member]
Income Taxes [Line Items]
Statutory tax rates		28.00%
Net operating loss carryforwards	14,127	$ 14,127
Canada [Member]
Income Taxes [Line Items]
Statutory tax rates		26.00%
Net tax credit carryforwards that will expire	22,459	$ 22,459
Netherlands [Member]
Income Taxes [Line Items]
Statutory tax rates		25.00%
Net operating loss carryforwards	$ 13,063	$ 13,063

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate Reconciliation from Continuing Operations (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective income tax rate reconciliation from continuing operations:
United States federal statutory rate	35.00%	35.00%	35.00%
State and local income taxes	0.80%	(0.90%)	(2.60%)
Impact of change in tax contingencies	2.20%	2.40%	(4.20%)
Foreign income tax rate differences	(13.10%)	(14.00%)	(8.40%)
Impact of change in deferred tax asset valuation allowance	1.50%	(7.30%)	(28.60%)
Impact of change in legal entity tax status	0.00%	(5.50%)	0.00%
Impact of non-taxable translation gain	(27.30%)	0.00%	0.00%
Impact of non-taxable interest income	(5.50%)	(4.90%)	(15.60%)
Domestic permanent differences and tax credits	(15.70%)	(5.70%)	(42.10%)
Impact of tax reform	28.60%	0.00%	0.00%
Effective income tax rate reconciliation from continuing operations	6.50%	(0.90%)	(66.50%)

Income Taxes - Components of De

Income Taxes - Components of Deferred Income Tax Balances (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred income tax liabilities:
Plant, equipment, and intangibles	$ (120,171)	$ (179,229)
Deferred income tax assets:
Postretirement, pensions, and stock compensation	28,736	35,500
Reserves and accruals	29,297	22,795
Net operating loss and tax credit carryforwards	228,815	245,135
Valuation allowances	(151,841)	(104,771)
Deferred tax assets	135,007	198,659
Net deferred income tax asset	$ 14,836	$ 19,430

Income Taxes - Summary of Net O

Income Taxes - Summary of Net Operating Loss Carryforwards (Details) $ in Thousands	Dec. 31, 2017USD ($)
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	$ 538,880
France [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	266,509
United States - various states [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	132,213
Luxembourg [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	25,034
Japan [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	22,245
Australia [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	16,433
Germany [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	14,127
Netherlands [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	13,063
All Other [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	$ 49,256

Income Taxes - Summary of Tax C

Income Taxes - Summary of Tax Credit Carryforwards (Details) $ in Thousands	Dec. 31, 2017USD ($)
Tax Credit Carryforward [Line Items]
Tax Credit Carryforwards	$ 97,072
United States [Member]
Tax Credit Carryforward [Line Items]
Tax Credit Carryforwards	74,613
Canada [Member]
Tax Credit Carryforward [Line Items]
Tax Credit Carryforwards	$ 22,459

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 10,474	$ 7,293
Additions based on tax positions related to the current year	981	507
Additions for tax positions of prior years	2,549	2,675
Reductions for tax positions of prior years - Settlement	(5,425)	0
Reduction for tax positions of prior years - Statute of limitations	0	(1)
Balance at end of year	$ 8,579	$ 10,474

Pension and Other Postretirem97

Pension and Other Postretirement Benefits - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Defined contribution expense	$ 13,900	$ 13,500	$ 12,600
Accumulated benefit obligation	269,200	253,900
Project benefit obligation for the pension plans with an accumulated benefit obligation in excess of plan assets	215,600	205,800
Accumulated benefit obligation for the pension plans with an accumulated benefit obligation in excess of assets	212,700	203,100
Fair value of plan assets for the pension plans with an accumulated benefit obligations in excess of plan assets	138,500	128,500
Projected benefit obligation of plan assets	56,500	50,700
Accumulated benefit obligation for the pension plans with an accumulated benefit obligation less than plan assets	56,500	50,700
Fair value of plan assets for the pension plans with an accumulated benefit obligations less than plan assets	$ 59,600	53,900
Target asset allocation for the investment of the assets in fixed income securities minimum	75.00%
Target asset allocation for the investment of the assets in fixed income securities maximum	80.00%
Target asset allocation for the investment of the assets in equity securities minimum	20.00%
Target asset allocation for the investment of the assets in equity securities maximum	25.00%
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation for the investment of the assets in fixed income securities	30.00%
Target asset allocation for the investment of the assets in equity securities	60.00%
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation for the investment of the assets in fixed income securities	40.00%
Target asset allocation for the investment of the assets in equity securities	70.00%
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement loss (gain)	$ (8)	7,630	128
Pension and other postretirement plans	4,600
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement loss (gain)	0	$ 0	$ 0
Pension and other postretirement plans	$ 1,600

Pension and Other Postretirem98

Pension and Other Postretirement Benefits - Change in Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits [Member]
Change in benefit obligation:
Benefit obligation, beginning of year	$ (256,481)	$ (275,205)
Service cost	(4,978)	(4,981)	$ (5,505)
Interest cost	(7,671)	(8,909)	(9,116)
Participant contributions	(91)	(106)
Actuarial gain (loss)	(3,291)	(16,250)
Divestiture	794	0
Settlements	49	29,256
Curtailments	0	227
Foreign currency exchange rate changes	(14,299)	10,723
Benefits paid	13,943	8,764
Benefit obligation, end of year	(272,025)	(256,481)	(275,205)
Other Benefits [Member]
Change in benefit obligation:
Benefit obligation, beginning of year	(32,038)	(32,313)
Service cost	(49)	(46)	(52)
Interest cost	(1,139)	(1,259)	(1,301)
Participant contributions	(7)	(7)
Actuarial gain (loss)	3,370	578
Divestiture	0	0
Settlements	0	0
Curtailments	0	0
Foreign currency exchange rate changes	(2,022)	(580)
Benefits paid	1,552	1,589
Benefit obligation, end of year	$ (30,333)	$ (32,038)	$ (32,313)

Pension and Other Postretirem99

Pension and Other Postretirement Benefits - Change in Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Change in plan assets:
Fair value of plan assets, beginning of year	$ 182,370
Fair value of plan assets, end of year	198,156	$ 182,370
Pension Benefits [Member]
Change in plan assets:
Fair value of plan assets, beginning of year	182,370	204,372
Actual return on plan assets	18,746	18,832
Employer contributions	4,425	5,698
Plan participant contributions	91	106
Settlements	0	(28,841)
Foreign currency exchange rate changes	6,467	(9,033)
Benefits paid	(13,943)	(8,764)
Fair value of plan assets, end of year	198,156	182,370
Other Benefits [Member]
Change in plan assets:
Fair value of plan assets, beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	1,545	1,582
Plan participant contributions	7	7
Settlements	0	0
Foreign currency exchange rate changes	0	0
Benefits paid	(1,552)	(1,589)
Fair value of plan assets, end of year	$ 0	$ 0

Pension and Other Postretire100

Pension and Other Postretirement Benefits - Amounts Recognized in Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amounts recognized in the balance sheets:
Accrued benefit liability (noncurrent)	$ (102,085)	$ (104,050)
Pension Benefits [Member]
Amounts recognized in the balance sheets:
Prepaid benefit cost	3,174	3,148
Accrued benefit liability (current)	(3,736)	(3,022)
Liabilities held for sale	0	(447)
Accrued benefit liability (noncurrent)	(73,307)	(73,790)
Net funded status	(73,869)	(74,111)
Other Benefits [Member]
Amounts recognized in the balance sheets:
Prepaid benefit cost	0	0
Accrued benefit liability (current)	(1,555)	(1,778)
Liabilities held for sale	0	0
Accrued benefit liability (noncurrent)	(28,778)	(30,260)
Net funded status	$ (30,333)	$ (32,038)

Pension and Other Postretire101

Pension and Other Postretirement Benefits - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits [Member]
Components of net periodic benefit cost:
Service cost	$ 4,978	$ 4,981	$ 5,505
Interest cost	7,671	8,909	9,116
Expected return on plan assets	(10,644)	(12,013)	(12,518)
Amortization of prior service credit	(41)	(42)	(44)
Curtailment gain	0	(227)	(128)
Settlement loss (gain)	(8)	7,630	128
Net loss recognition	2,597	2,670	5,082
Net periodic benefit cost	4,553	11,908	7,141
Other Benefits [Member]
Components of net periodic benefit cost:
Service cost	49	46	52
Interest cost	1,139	1,259	1,301
Expected return on plan assets	0	0	0
Amortization of prior service credit	0	(42)	(87)
Curtailment gain	0	0	0
Settlement loss (gain)	0	0	0
Net loss recognition	0	86	328
Net periodic benefit cost	$ 1,188	$ 1,349	$ 1,594

Pension and Other Postretire102

Pension and Other Postretirement Benefits - Assumptions Used in Determining Benefit Obligations and Net Periodic Benefit Cost Amounts (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits [Member]
Weighted average assumptions for benefit obligations at year end:
Discount rate	2.80%	3.00%
Salary increase	3.60%	3.30%
Weighted average assumptions for net periodic cost for the year:
Discount rate	3.10%	3.60%
Salary increase	3.60%	3.50%
Expected return on assets	6.00%	6.20%
Other Benefits [Member]
Weighted average assumptions for benefit obligations at year end:
Discount rate	3.30%	3.70%
Weighted average assumptions for net periodic cost for the year:
Discount rate	3.70%	4.00%
Assumed health care cost trend rates:
Health care cost trend rate assumed for next year	6.20%	6.20%
Rate that the cost trend rate gradually declines to	5.00%	5.00%

Pension and Other Postretire103

Pension and Other Postretirement Benefits - Effect of One Percentage - Point Change in Assumed Health Care Cost Trend Rates (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Postemployment Benefits [Abstract]
Effect on total of service and interest cost components, 1% Increase	$ 127
Effect on postretirement benefit obligation, 1% Increase	2,306
Effect on total of service and interest cost components, 1% Decrease	(103)
Effect on postretirement benefit obligation, 1% Decrease	$ (1,943)

Pension and Other Postretire104

Pension and Other Postretirement Benefits - Fair Values of Pension Plan Assets by Asset Category (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	$ 198,156	$ 182,370
Large-Cap Fund [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	75,165	65,495
Mid-Cap Fund [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	13,046	11,419
Small-Cap Fund [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	18,785	17,184
Government Bond Fund [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	28,429	26,151
Corporate Bond Fund [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	24,421	20,971
Fixed Income Fund [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	38,072	40,958
Cash & Equivalents [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	238	192
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	238	192
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Large-Cap Fund [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mid-Cap Fund [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Small-Cap Fund [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Government Bond Fund [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Corporate Bond Fund [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Cash & Equivalents [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	238	192
Significant Observable Inputs (Level 2) [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	38,072	40,958
Significant Observable Inputs (Level 2) [Member] | Fixed Income Fund [Member]
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	$ 38,072	$ 40,958

Pension and Other Postretire105

Pension and Other Postretirement Benefits - Benefits Expected to be Paid in Subsequent Years from Our Pension and Other Postretirement as Well as Medicare Subsidy Receipts (Details) $ in Thousands	Dec. 31, 2017USD ($)
Pension Benefits [Member]
Pension And Other Employee Benefit Plans [Line Items]
2,018	$ 16,562
2,019	16,923
2,020	17,937
2,021	17,688
2,022	15,787
2023-2027	83,382
Total	168,279
Other Benefits [Member]
Pension And Other Employee Benefit Plans [Line Items]
2,018	1,580
2,019	1,568
2,020	1,562
2,021	1,557
2,022	1,553
2023-2027	7,753
Total	$ 15,573

Pension and Other Postretire106

Pension and Other Postretirement Benefits - Summary of Accumulated Other Comprehensive Loss That Have Not Been Recognized as Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	$ 44,359	$ 49,260
Net prior service cost	11	(44)
Total	44,370
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	(1,545)	1,842
Net prior service cost	0	$ 0
Total	$ (1,545)

Pension and Other Postretire107

Pension and Other Postretirement Benefits - Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits [Member]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Net actuarial loss, beginning of year	$ 49,260
Amortization of actuarial loss	(2,597)
Actuarial loss (gain)	3,291
Asset gain	(8,102)
Curtailment gain recognized	0
Settlement gain recognized	8	$ (7,630)	$ (128)
Divestiture	(180)
Currency impact	2,679
Net actuarial loss (gain), end of year	44,359	49,260
Prior service credit, beginning of year	(44)
Amortization of prior service credit	41
Divestiture	(10)
Currency impact	24
Prior service cost, end of year	11	(44)
Other Benefits [Member]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Net actuarial loss, beginning of year	1,842
Amortization of actuarial loss	0
Actuarial loss (gain)	(3,370)
Asset gain	0
Curtailment gain recognized	0
Settlement gain recognized	0	0	$ 0
Divestiture	0
Currency impact	(17)
Net actuarial loss (gain), end of year	(1,545)	1,842
Prior service credit, beginning of year	0
Amortization of prior service credit	0
Divestiture	0
Currency impact	0
Prior service cost, end of year	$ 0	$ 0

Pension and Other Postretire108

Pension and Other Postretirement Benefits - Expected Amortization of Accumulated Other Comprehensive Loss as Components of Net Periodic Benefit Cost (Details) $ in Thousands	Dec. 31, 2017USD ($)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service credit	$ (41)
Amortization of actuarial loss	2,758
Total	2,717
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service credit	0
Amortization of actuarial loss	0
Total	$ 0

Comprehensive Income and Acc109

Comprehensive Income and Accumulated Other Comprehensive Income (Loss) - Components of Other Comprehensive Income (Loss), Net of Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ (39,067)	$ (58,987)
Other comprehensive gain (loss) loss attributable to Belden before reclassifications	(60,526)	13,584
Amounts reclassified from accumulated other comprehensive loss	1,567	6,336
Other comprehensive income (loss), net of tax	(58,959)	19,920
Ending balance	(98,026)	(39,067)
Foreign Currency Translation Component [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(4,661)	(23,411)
Other comprehensive gain (loss) loss attributable to Belden before reclassifications	(65,030)	18,750
Amounts reclassified from accumulated other comprehensive loss	0	0
Other comprehensive income (loss), net of tax	(65,030)	18,750
Ending balance	(69,691)	(4,661)
Pension and Other Postretirement Benefit Plans [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(34,406)	(35,576)
Other comprehensive gain (loss) loss attributable to Belden before reclassifications	4,504	(5,166)
Amounts reclassified from accumulated other comprehensive loss	1,567	6,336
Other comprehensive income (loss), net of tax	6,071	1,170
Ending balance	$ (28,335)	$ (34,406)

Comprehensive Income and Acc110

Comprehensive Income and Accumulated Other Comprehensive Income (Loss) - Summary of Effects of Reclassifications from Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Amortization of pension and other postretirement benefit plan items:
Total net of tax	$ 1,567	$ 6,336
Settlement gain [Member]
Amortization of pension and other postretirement benefit plan items:
Total before tax	(8)
Actuarial losses [Member]
Amortization of pension and other postretirement benefit plan items:
Total before tax	2,597
Prior service credit [Member]
Amortization of pension and other postretirement benefit plan items:
Total before tax	(41)
Pension and Other Postretirement Benefit Plans [Member]
Amortization of pension and other postretirement benefit plan items:
Total before tax	2,548
Tax benefit	(981)
Total net of tax	$ 1,567	$ 6,336

Share-Based Compensation - Inco

Share-Based Compensation - Income Tax Benefit Recognized for our Share-Based Compensation Arrangements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Total share-based compensation cost	$ 14,647	$ 18,178	$ 17,745
Income tax benefit	$ 5,566	$ 7,069	$ 6,867

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to all nonvested awards	$ 21.1
Unrecognized compensation cost is expected to be recognized over a weighted-average period	1 year 10 months
SARs and Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
SAR's and stock options expiration period	10 years
Restricted Shares and Units [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Restricted Shares and Units [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	5 years

Share-Based Compensation - Fair

Share-Based Compensation - Fair Values for SARs and Stock Options Estimated on Grant Date Using Black-Scholes-Merton Option-Pricing Formula Which Incorporates Assumptions (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted-average fair value of SARs and options granted (in usd per share)	$ 27.31	$ 18.79	$ 31.22
Total intrinsic value of SARs converted and options exercised	$ 7,156	$ 9,678	$ 14,697
Cash received for options exercised	0	0	30
Tax benefit related to share-based compensation	$ 967	$ 1,171	$ 5,050
Weighted-average fair value of restricted stock shares and units granted (in usd per share)	$ 79.96	$ 54.52	$ 96.52
Total fair value of restricted stock shares and units vested	$ 10,355	$ 8,171	$ 7,696
Expected volatility	36.89%	37.47%	35.66%
Expected term (in years)	5 years 7 months 2 days	5 years 8 months 12 days	5 years 8 months 12 days
Risk-free rate	2.01%	1.32%	1.59%
Dividend yield	0.27%	0.38%	0.22%

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Share Based Compensation Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Granted, Weighted-Average Grant-Date Fair Value (in dollars per share)	$ 79.96	$ 54.52	$ 96.52
SARs and Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at Beginning, Number (in shares)	1,124
Granted, Number (in shares)	254
Exercised or converted, Number (in shares)	(210)
Forfeited or expired, Number (in shares)	(36)
Outstanding at Ending, Number (in shares)	1,132	1,124
Vested or expected to vest at End, Number (in shares)	1,118
Exercisable or convertible at End, Number (in shares)	623
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding at Beginning, Weighted-Average Exercise Price (in dollars per share)	$ 56.79
Granted, Weighted-Average Exercise Price (in dollars per share)	74.91
Exercised or converted, Weighted-Average Exercise Price (in dollars per share)	44.08
Forfeited or expired, Weighted-Average Exercise Price (in dollars per share)	71.02
Outstanding at End, Weighted-Average Exercise Price (in dollars per share)	62.75	$ 56.79
Vested or expected to vest at End, Weighted-Average Exercise Price	62.65
Exercisable or convertible at End, Weighted-Average Exercise Price	$ 58.57
Outstanding at End, Weighted-Average Remaining Contractual Term	6 years 10 months 18 days
Vested or expected to vest at End, Weighted-Average Remaining Contractual Term	6 years 9 months 18 days
Exercisable or convertible at End, Weighted-Average Remaining Contractual Term	5 years 7 months 2 days
Outstanding at End, Aggregate Intrinsic Value	$ 16,327
Vested or expected to vest at End, Aggregate Intrinsic Value	16,234
Exercisable or convertible at End, Aggregate Intrinsic Value	$ 11,585
Restricted Shares and Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at Beginning, Number (in shares)	454
Granted, Number (in shares)	222
Exercised or converted, Number (in shares)	(145)
Forfeited or expired, Number (in shares)	(35)
Outstanding at End, Number (in shares)	496	454
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at Beginning, Weighted-Average Grant-Date Fair Value (in dollars per share)	$ 69.55
Granted, Weighted-Average Grant-Date Fair Value (in dollars per share)	79.96
Exercised or converted, Weighted-Average Grant-Date Fair Value (in dollars per share)	71.27
Forfeited or expired, Weighted-Average Grant-Date Fair Value (in dollars per share)	75.56
Outstanding at End, Weighted-Average Grant-Date Fair Value (in dollars per share)	$ 78.03	$ 69.55

Preferred Stock (Details)

Preferred Stock (Details) $ / shares in Units, $ in Millions	Jul. 15, 2019shares	Jul. 26, 2016USD ($)trading_day$ / sharesshares
Depository Shares [Member]
Class of Stock [Line Items]
Depository shares issued		5,200,000
Preferred stock ownership interest		0.01
6.75% Series B Mandatory Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Percentage of issued shares		6.75%
Offering price (in usd per share) | $ / shares		$ 100
Threshold trading days | trading_day		20
Proceeds from offering, net | $		$ 501
6.75% Series B Mandatory Convertible Preferred Stock [Member] | Scenario, Forecast [Member] | Minimum [Member]
Class of Stock [Line Items]
Preferred stock converted in to common stock (in shares)	120.46
Number of common stock issued upon conversion (in shares)	6,200,000
6.75% Series B Mandatory Convertible Preferred Stock [Member] | Scenario, Forecast [Member] | Maximum [Member]
Class of Stock [Line Items]
Preferred stock converted in to common stock (in shares)	132.50
Number of common stock issued upon conversion (in shares)	6,900,000

Stockholder Rights Plan (Detail

Stockholder Rights Plan (Details)	12 Months Ended
	Dec. 31, 2017vote / sharespurchase_right / shares$ / shares$ / Warrantshares
Equity [Abstract]
Common stock, number of preferred stock purchase rights per share of common stock held | purchase_right / shares	1
Portion of preferred share purchase right entitled to holder (in shares) | shares	0.0001
Purchase price of Preferred Stock as per plan (in dollars per share)	$ 325
Common stock, number of voting rights per share of common stock held | vote / shares	1
Percentage common stock to acquired to exercise stock rights	20.00%
Price worth of surviving company common stock | $ / Warrant	300
Purchase price of Preferred Stock as per plan if acquired	$ 150
Redemption price of stock holder rights plan	$ 0.01
Percentage of beneficial ownership	20.00%

Share Repurchases (Details)

Share Repurchases (Details) - USD ($) $ / shares in Units, shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	May 25, 2017
Equity, Class of Treasury Stock [Line Items]
Payments under share repurchase program	$ 25,000,000	$ 0	$ 39,053,000
Share Repurchase Plan 2017 [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares authorized to be repurchased				$ 200,000,000
Number of shares repurchased	0.3
Payments under share repurchase program	$ 25,000,000
Average price per share of shares repurchased (in dollars per share)	$ 79.75

Operating Leases - Additional I

Operating Leases - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases [Abstract]
Operating lease expense incurred	$ 38.6	$ 40.3	$ 40.6

Operating Leases - Summary of M

Operating Leases - Summary of Minimum Annual Lease Payments for Noncancelable Operating Leases (Details) $ in Thousands	Dec. 31, 2017USD ($)
Leases [Abstract]
2,018	$ 22,440
2,019	18,006
2,020	13,787
2,021	11,001
2,022	8,561
Thereafter	23,494
Total	$ 97,289

Market Concentrations and Ri120

Market Concentrations and Risks (Details) $ in Thousands, lb in Millions	12 Months Ended
	Dec. 31, 2017USD ($)lbCustomerDistributor	Dec. 31, 2016USD ($)CustomerDistributor	Dec. 31, 2015CustomerDistributor
Concentration Risk [Line Items]
Number of customers | Customer	10	10	10
Number of distributors | Distributor	6	6	6
Senior Subordinated Notes [Member]
Concentration Risk [Line Items]
Fair value of debt instrument	$ 1,619,300	$ 1,693,200
Total senior subordinated notes	$ 1,584,232	$ 1,643,448
Copper [Member]
Concentration Risk [Line Items]
Committed amounts to purchase | lb	2.3
Aggregate cost	$ 7,000
Recorded unconditional purchase obligation fixed cost	$ (500)
Customer Concentration Risk [Member] | Consolidated Revenues [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	35.00%	33.00%	33.00%
Labor Force Concentration Risk [Member] | Workforce Subject to Collective Bargaining Arrangements [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	21.00%
Labor Force Concentration Risk [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring within One Year [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	16.00%

Contingent Liabilities (Details

Contingent Liabilities (Details) $ in Millions	Dec. 31, 2017USD ($)
Standby Letters of Credit [Member]
Line of Credit Facility [Line Items]
Loss contingency, range of possible loss, portion not accrued	$ 7.5
Surety Bonds [Member]
Line of Credit Facility [Line Items]
Loss contingency, range of possible loss, portion not accrued	2.3
Bank Guaranties [Member]
Line of Credit Facility [Line Items]
Loss contingency, range of possible loss, portion not accrued	$ 1.7

Supplemental Cash Flow Infor122

Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Supplemental Cash Flow Elements [Abstract]
Income tax refunds received	$ 5,031	$ 3,838	$ 4,068
Income taxes paid	(35,893)	(26,587)	(24,960)
Interest paid, net of amount capitalized	$ (79,047)	$ (87,076)	$ (91,496)

Quarterly Operating Results 123

Quarterly Operating Results (Unaudited) - Quarterly Operating Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Number of days in quarter	91 days	91 days	91 days	92 days	90 days	91 days	91 days	94 days	365 days	366 days
Revenues	$ 604,884	$ 621,745	$ 610,633	$ 551,381	$ 612,435	$ 601,109	$ 601,631	$ 541,497	$ 2,388,643	$ 2,356,672	$ 2,309,222
Gross profit	229,592	239,824	242,509	222,114	261,784	245,962	248,213	225,035	934,039	980,994	918,173
Operating income	60,081	60,791	62,481	51,337	58,668	61,980	62,241	40,964	234,690	223,853	140,553
Net income	30,436	945	35,891	25,581	33,283	36,072	41,933	16,358	92,853	127,646	66,180
Less: Net loss attributable to noncontrolling interest	(83)	(82)	(86)	(106)	(71)	(88)	(99)	(99)	(357)	(357)	(24)
Net income attributable to Belden	30,519	1,027	35,977	25,687	33,354	36,160	42,032	16,457	93,210	128,003	66,204
Less: Preferred stock dividends	8,733	8,732	8,733	8,733	8,733	6,695	0	0	34,931	15,428	0
Net income attributable to Belden common stockholders	$ 21,786	$ (7,705)	$ 27,244	$ 16,954	$ 24,621	$ 29,465	$ 42,032	$ 16,457	$ 58,279	$ 112,575	$ 66,204
Basic income (loss) per share attributable to Belden common stockholders:	$ 0.52	$ (0.18)	$ 0.64	$ 0.40	$ 0.58	$ 0.70	$ 1	$ 0.39	$ 1.38	$ 2.67	$ 1.56
Diluted income (loss) per share attributable to Belden stockholders:	$ 0.51	$ (0.18)	$ 0.64	$ 0.40	$ 0.58	$ 0.69	$ 0.99	$ 0.39	$ 1.37	$ 2.65	$ 1.54

Quarterly Operating Results 124

Quarterly Operating Results (Unaudited) - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Severance, restructuring, and acquisition integration costs	$ 9,900	$ 16,700	$ 9,600	$ 6,600	$ 11,700	$ 12,800	$ 5,900	$ 8,400	$ 42,790	$ 38,770	$ 47,170
Royalty revenues					$ 10,300
Overstatement Of Revenues [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Qualifying misstatement	27,800	11,800	10,400	6,100
Overstatement Of Net Income [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Qualifying misstatement	$ 5,200	$ 2,600	$ 1,300	$ 3,000

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event [Member] $ in Millions	Feb. 08, 2018USD ($)
Subsequent Event [Line Items]
Consideration transferred	$ 75.8
Liabilities incurred	$ 18.4

Schedule II - Valuation and 126

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts Receivable - Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	$ 8,104	$ 8,281	$ 11,503
Charged to Costs and Expenses	950	2,517	2,561
Divestitures/ Acquisitions	38	(1)	40
Charge Offs	(905)	(1,336)	(803)
Recoveries	(995)	(1,046)	(4,353)
Currency Movement	574	(311)	(667)
Ending Balance	7,766	8,104	8,281
Inventories - Excess and Obsolete Allowances [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	24,561	22,531	31,823
Charged to Costs and Expenses	2,348	3,921	3,001
Divestitures/ Acquisitions	2,628	(706)	2,755
Charge Offs	(3,219)	0	(12,744)
Recoveries	(2,205)	(1,142)	(1,407)
Currency Movement	1,156	(43)	(897)
Ending Balance	25,269	24,561	22,531
Deferred Income Tax Asset - Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	104,771	117,071	157,317
Charged to Costs and Expenses	39,307	10,782	2,840
Divestitures/ Acquisitions	0	616	(14,425)
Charge Offs	(3,322)	(8,074)	(1,823)
Recoveries	(1,712)	(10,526)	(13,988)
Currency Movement	12,797	(5,098)	(12,850)
Ending Balance	$ 151,841	$ 104,771	$ 117,071