Belden (BDC) 10-K 20 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 15, 2019	Jul. 01, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
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		39,399,412
Entity Public Float			$ 1,874,027,335

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 420,610	$ 561,108
Receivables, net	465,939	473,570
Inventories, net	316,418	297,226
Other current assets	55,757	40,167
Total current assets	1,258,724	1,372,071
Property, plant and equipment, less accumulated depreciation	365,970	337,322
Goodwill	1,557,653	1,478,257
Intangible assets, less accumulated amortization	511,093	545,207
Deferred income taxes	56,018	42,549
Other long-lived assets	29,863	65,207
Total assets	3,779,321	3,840,613
Current liabilities:
Accounts payable	352,646	376,277
Accrued liabilities	364,276	302,651
Total current liabilities	716,922	678,928
Long-term debt	1,463,200	1,560,748
Postretirement benefits	132,791	102,085
Deferred income taxes	39,943	27,713
Other long-term liabilities	38,877	36,273
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; 39,396 and 42,019 shares outstanding at 2018 and 2017, respectively	503	503
Additional paid-in capital	1,139,395	1,123,832
Retained earnings	922,000	833,610
Accumulated other comprehensive loss	(74,907)	(98,026)
Treasury stock, at cost— 10,939 and 8,316 shares at 2018 and 2017, respectively	(599,845)	(425,685)
Total Belden stockholders’ equity	1,387,147	1,434,235
Noncontrolling interest	441	631
Total stockholders’ equity	1,387,588	1,434,866
Total liabilities and stockholders' equity	$ 3,779,321	$ 3,840,613

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
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)	39,396,000	42,019,000
Treasury stock, shares (in shares)	10,939,000	8,316,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenues	$ 2,585,368	$ 2,388,643	$ 2,356,672
Cost of sales	(1,576,956)	(1,453,890)	(1,375,351)
Gross profit	1,008,412	934,753	981,321
Selling, general and administrative expenses	(525,918)	(461,022)	(486,403)
Research and development expenses	(140,585)	(134,330)	(140,519)
Amortization of intangibles	(98,829)	(103,997)	(98,385)
Gain from patent litigation	62,141	0	0
Impairment of assets held for sale	0	0	(23,931)
Operating income	305,221	235,404	232,083
Interest expense, net	(61,559)	(82,901)	(95,050)
Non-operating pension cost	(342)	(714)	(8,230)
Loss on debt extinguishment	(22,990)	(52,441)	(2,342)
Income before taxes	220,330	99,348	126,461
Income tax benefit (expense)	(59,619)	(6,495)	1,185
Net income	160,711	92,853	127,646
Less: Net loss attributable to noncontrolling interest	(183)	(357)	(357)
Net income attributable to Belden	160,894	93,210	128,003
Less: Preferred stock dividends	34,931	34,931	15,428
Net income attributable to Belden common stockholders	$ 125,963	$ 58,279	$ 112,575
Weighted average number of common shares and equivalents:
Basic (in shares)	40,675	42,220	42,093
Diluted (in shares)	40,956	42,643	42,557
Basic income per share attributable to Belden common stockholders (in dollars per share)	$ 3.10	$ 1.38	$ 2.67
Diluted income per share attributable to Belden common stockholders (in dollars per share)	$ 3.08	$ 1.37	$ 2.65

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 160,711	$ 92,853	$ 127,646
Foreign currency translation, net of tax of $1.7 million, $1.3 million, and $1.2 million, respectively	27,802	(65,046)	18,687
Adjustments to pension and postretirement liability, net of tax of $1.0 million, $2.2 million, and $1.9 million, respectively	(4,690)	6,071	1,170
Other comprehensive income (loss), net of tax	23,112	(58,975)	19,857
Comprehensive income	183,823	33,878	147,503
Less: Comprehensive loss attributable to noncontrolling interest	(190)	(373)	(420)
Comprehensive income attributable to Belden	$ 184,013	$ 34,251	$ 147,923

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Foreign currency translation, tax expense (benefit)	$ 1.7	$ 1.3	$ 1.2
Adjustments to pension and postretirement liability, tax	$ 0.9	$ 2.2	$ 1.9

Consolidated Cash Flow Statemen

Consolidated Cash Flow Statements - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 160,711	$ 92,853	$ 127,646
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	148,632	149,650	145,593
Impairment of assets held for sale	0	0	23,931
Share-based compensation	18,497	14,647	18,178
Loss on debt extinguishment	22,990	52,441	2,342
Deferred income tax expense (benefit)	11,300	(24,098)	(30,034)
Changes in operating assets and liabilities, net of the effects of currency exchange rate changes and acquired businesses:
Receivables	(21,748)	(24,931)	(10,115)
Inventories	(14,779)	(84,088)	2,677
Accounts payable	(29,401)	100,752	39,298
Accrued liabilities	17,238	(25,076)	(13,181)
Income taxes	(4,390)	5,001	11,722
Other assets	(18,748)	(13,255)	760
Other liabilities	(1,082)	11,404	(4,023)
Net cash provided by operating activities	289,220	255,300	314,794
Cash flows from investing activities:
Capital expenditures	(97,847)	(64,261)	(53,974)
Cash used to acquire businesses, net of cash acquired	(84,580)	(166,896)	(18,848)
Other	0	0	(827)
Proceeds from disposal of tangible assets	1,580	1,039	392
Proceeds from disposal of business	40,171	0	0
Net cash used for investing activities	(140,676)	(230,118)	(73,257)
Cash flows from financing activities:
Payments under borrowing arrangements	(484,757)	(1,105,892)	(294,375)
Payments under share repurchase program	(175,000)	(25,000)	0
Cash dividends paid	(43,169)	(43,376)	(16,079)
Debt issuance costs paid	(7,609)	(17,316)	(3,910)
Withholding tax payments for share based-payment awards	(2,094)	(6,564)	(7,480)
Redemption of stockholders' rights agreement	(411)	0	0
Proceeds from the issuance of preferred stock, net	0	0	501,498
Borrowings under credit arrangements	431,270	866,700	222,050
Net cash provided by (used for) financing activities	(281,770)	(331,448)	401,704
Effect of foreign currency exchange rate changes on cash and cash equivalents	(7,272)	19,258	(11,876)
Increase (decrease) in cash and cash equivalents	(140,498)	(287,008)	631,365
Cash and cash equivalents, beginning of period	561,108	848,116	216,751
Cash and cash equivalents, end of period	$ 420,610	$ 561,108	$ 848,116

Consolidated Stockholders' Equi

Consolidated Stockholders' Equity Statements - USD ($) shares in Thousands, $ in Thousands	Total	Mandatory Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Non-controlling Interest
Beginning balance (in shares) at Dec. 31, 2015		0	50,335			8,354
Beginning balance at Dec. 31, 2015	$ 825,523	$ 0	$ 503	$ 605,660	$ 679,716	$ (402,793)	$ (58,987)	$ 1,424
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	127,646				128,003			(357)
Other comprehensive income (loss), net of tax	19,857						19,920	(63)
Preferred stock issuance, net, (in 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 (in 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 (in shares)						123
Share-based compensation	18,178			18,178
Preferred stock dividends	(15,428)				(15,428)
Common stock dividends ($0.20 per share)	(8,479)				(8,479)
Ending balance (in shares) at Dec. 31, 2016		52	50,335			8,155
Ending balance at Dec. 31, 2016	1,461,317	$ 1	$ 503	1,116,090	783,812	$ (401,026)	(39,067)	1,004
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	92,853				93,210			(357)
Other comprehensive income (loss), net of tax	(58,975)						(58,959)	(16)
Exercise of stock options, net of tax withholding forfeitures	(2,838)			(2,635)		$ (203)
Exercise of stock options, net of tax withholding forfeitures (in 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 (in shares)						97
Share repurchase program	(25,000)					$ (25,000)
Share repurchase program (in shares)						(313)
Share-based compensation	14,647			14,647
Preferred stock dividends	(34,931)				(34,931)
Common stock dividends ($0.20 per share)	(8,481)				(8,481)
Ending balance (in shares) at Dec. 31, 2017		52	50,335			8,316
Ending balance at Dec. 31, 2017	1,434,866	$ 1	$ 503	1,123,832	833,610	$ (425,685)	(98,026)	631
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principles	(29,041)				(29,041)
Net income (loss)	160,711				160,894			(183)
Other comprehensive income (loss), net of tax	23,112						23,119	(7)
Exercise of stock options, net of tax withholding forfeitures	(765)			(883)		$ 118
Exercise of stock options, net of tax withholding forfeitures (in shares)						20
Conversion of restricted stock units into common stock, net of tax withholding forfeitures	(1,329)			(2,051)		$ 722
Conversion of restricted stock units into common stock, net of tax withholding forfeitures (in shares)						51
Share repurchase program	(175,000)					$ (175,000)
Share repurchase program (in shares)						(2,694)
Share-based compensation	18,497			18,497
Redemption of stockholders' rights agreement	(411)				(411)
Preferred stock dividends	(34,931)				(34,931)
Common stock dividends ($0.20 per share)	(8,121)				(8,121)
Ending balance (in shares) at Dec. 31, 2018		52	50,335			10,939
Ending balance at Dec. 31, 2018	$ 1,387,588	$ 1	$ 503	$ 1,139,395	$ 922,000	$ (599,845)	$ (74,907)	$ 441

Consolidated Stockholders' Eq_2

Consolidated Stockholders' Equity Statements (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Dividends declared per share	$ 0.2	$ 0.20	$ 0.20

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2018
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 a signal transmission solutions company built around two global business platforms – Enterprise Solutions and Industrial 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 reclassifications to the 2017 and 2016 Condensed Consolidated Financial Statements, including those related to the adoption of 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) and our segment change, with no impact to reported net income in order to conform to the 2018 presentation. See Note 5.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
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. During 2018, 2017 , and 2016 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 4) and for our annual impairment testing (see Note 10). We did not have any transfers between Level 1 and Level 2 fair value measurements during 2018 . 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, 2018 and 2017 , 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 and from other business activities, 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, 2018 and 2017 totaled $25.7 million and $35.7 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 $1.0 million , $0.0 million , and $1.5 million in 2018 , 2017 , and 2016 , respectively. The allowance for doubtful accounts at December 31, 2018 and 2017 totaled $8.2 million and $7.8 million , respectively. Inventories and Related Reserves Inventories are stated at the lower of cost or net realizable value. 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, 2018 and 2017 totaled $28.9 million and $25.3 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 as of our fiscal November month-end 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 2018 , we performed a qualitative assessment for seven of our reporting units, which collectively represented approximately $383.4 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 2018 , we performed a quantitative assessment for four of our reporting units, which collectively represented approximately $1,174.3 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 four 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 2018 , 2017 , or 2016 . 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 2018 , 2017 , or 2016 . See Note 10 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 2018 , 2017 , or 2016 . Disposals During 2018, we sold a previously closed operating facility for net proceeds of $1.5 million and recognized a $0.6 million gain on the sale. During the fourth quarter of 2016, we committed to a plan to sell our MCS business and 50% ownership interest in Xuzhou Hirschmann Electronics Co. Ltd (the 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. In 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 was included in selling, general and administrative expenses. This loss included $2.8 million of accumulated other comprehensive losses that were recognized as a result of the sale. We collected the $40.2 million proceeds from the sale during 2018. 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, 2018 and 2017 totaled $41.3 million and $38.0 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 consideration of an acquired business to its identifiable assets and liabilities based on estimated fair values. The excess of the consideration 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 acquisition accounting, 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 consistent with the principles as outlined in the following five step model: (1) identify the contract with the customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when (or as) each performance obligation is satisfied. See Note 3. Gain from Patent Litigation On July 5, 2011, the Company’s wholly-owned subsidiary, PPC, filed an action for patent infringement against Corning alleging that Corning infringed two of PPC’s patents. In July 2015, a jury found that Corning willfully infringed both patents. Following a series of appeals, we received a pre-tax amount of approximately $62.1 million from Corning on July 19, 2018. We recorded the $62.1 million of cash received as a pre-tax gain from patent litigation during 2018. Prior to 2018, we had not recognized any amounts in our consolidated financial statements related to this matter. On September 27, 2018, Corning filed a petition for certiorari review by the U.S. Supreme Court. On December 10, 2018, Corning’s certiorari review by the Supreme Court was denied, thus exhausting their opportunities for further appellate relief. 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 $23.5 million , $25.0 million , and $27.2 million for 2018 , 2017 , and 2016 , 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. 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. At December 31, 2018 the valuation allowance of $90.9 million was primarily related to net operating losses and foreign tax credits that we are not expected to realize. 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. 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. In accordance with the Act, we recorded $28.4 million as additional income tax expense in the fourth quarter of 2017, the period in which the legislation was enacted. The total income tax expense 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, 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. Additionally, Staff Accounting Bulletin No. 118 (“SAB 118”) was issued to address the application of U.S. 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. December 22, 2018 marked the end of the measurement period for purposes of SAB 118. As such, we have completed our analysis based on legislative updates relating to the Act currently available which resulted in an additional SAB 118 tax expense of $10.0 million for the year ended December 31, 2018. The total tax expense included an $8.0 million tax expense associated with an increase to the valuation allowance against foreign tax credit carryovers that we no longer expect to be able to realize based upon the new tax law, a $1.3 million tax expense adjustment to the transition tax on the deemed repatriation of cumulative foreign earnings, a $1.1 million tax expense resulting from a valuation allowance established on the deferred tax assets associated with stock options of covered employees, and a $0.4 million income tax benefit associated with an adjustment to the remeasurement of certain deferred tax assets and liabilities. See Note 15, Income Taxes, in the accompanying notes to our consolidated financial statements. Current-Year Adoption of Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (ASU 2014-09), which replaced 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 adopted ASU 2014-09 on January 1, 2018, using the modified retrospective method of adoption. Adoption resulted in a $2.6 million , net of tax increase to retained earnings. 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 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 (ASU 2016-15). 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. We adopted ASU 2016-15 on January 1, 2018. The adoption had no material impact on our statement of cash flows for the year ended December 31, 2018 . 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. We adopted ASU 2016-16 on January 1, 2018. The adoption resulted in a $3.0 million and $46.9 million decrease to other current assets and other long-lived assets, respectively, as well as an $18.2 million increase in deferred income tax assets and a $31.7 million decrease to retained earnings on January 1, 2018. The adoption had no material impact on our results of operations. In March 2017, the FASB issued 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

Revenues

Revenues	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenues	Revenues On January 1, 2018, we adopted Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts are not adjusted and continue to be reported in accordance with the accounting standards in effect for those periods. We recorded a net increase to retained earnings of $2.6 million as of January 1, 2018 due to the cumulative impact of adopting Topic 606, with the impact primarily related to sales commissions and software revenues within our Industrial Solutions segment. There was no significant impact to revenues for the year ended December 31, 2018 as a result of applying Topic 606. Revenues are recognized when control of the promised goods or services is transferred to our customers and in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Taxes collected from customers and remitted to governmental authorities are not included in our revenues. We do not evaluate a contract for a significant financing component when the time between cash collection and performance is less than one year. The following tables present our revenues disaggregated by major product category. Cable & Connectivity Networking, Software & Security Total Revenues Year Ended December 31, 2018 Enterprise Solutions $ 1,046,744 $ 468,822 $ 1,515,566 Industrial Solutions 662,742 407,060 1,069,802 Total $ 1,709,486 $ 875,882 $ 2,585,368 Year Ended December 31, 2017 Enterprise Solutions $ 1,024,090 $ 332,215 $ 1,356,305 Industrial Solutions 628,889 403,449 1,032,338 Total $ 1,652,979 $ 735,664 $ 2,388,643 Year Ended December 31, 2016 Enterprise Solutions $ 1,003,799 $ 368,009 $ 1,371,808 Industrial Solutions 590,462 394,402 984,864 Total $ 1,594,261 $ 762,411 $ 2,356,672 The following tables present our revenues disaggregated by geography, based on the location of the customer purchasing the product. Americas EMEA APAC Total Revenues Year Ended December 31, 2018 Enterprise Solutions $ 981,822 $ 294,129 $ 239,615 $ 1,515,566 Industrial Solutions 619,721 290,607 159,474 1,069,802 Total $ 1,601,543 $ 584,736 $ 399,089 $ 2,585,368 Year Ended December 31, 2017 Enterprise Solutions $ 925,647 $ 214,763 $ 215,895 $ 1,356,305 Industrial Solutions 606,331 280,890 145,117 1,032,338 Total $ 1,531,978 $ 495,653 $ 361,012 $ 2,388,643 Year Ended December 31, 2016 Enterprise Solutions $ 937,741 $ 220,511 $ 213,556 $ 1,371,808 Industrial Solutions 596,032 261,055 127,777 984,864 Total $ 1,533,773 $ 481,566 $ 341,333 $ 2,356,672 The following tables present our revenues disaggregated by products, including software products, and support and services. Products Support & Services Total Revenues Year Ended December 31, 2018 Enterprise Solutions $ 1,441,757 $ 73,809 $ 1,515,566 Industrial Solutions 974,029 95,773 1,069,802 Total $ 2,415,786 $ 169,582 $ 2,585,368 Year Ended December 31, 2017 Enterprise Solutions $ 1,281,960 $ 74,345 $ 1,356,305 Industrial Solutions 929,263 103,075 1,032,338 Total $ 2,211,223 $ 177,420 $ 2,388,643 Year Ended December 31, 2016 Enterprise Solutions $ 1,293,392 $ 78,416 $ 1,371,808 Industrial Solutions 885,208 99,656 984,864 Total $ 2,178,600 $ 178,072 $ 2,356,672 We generate revenues primarily by selling products that provide secure and reliable transmission of data, sound, and video for mission critical applications. We also generate revenues from providing support and professional services. We sell our products to distributors, end-users, installers, and directly to original equipment manufacturers. At times, we enter into arrangements that involve the delivery of multiple performance obligations. For these arrangements, revenue is allocated to each performance obligation based on its relative standalone selling price and recognized when or as each performance obligation is satisfied. Most of our performance obligations related to the sale of products are satisfied at a point in time when control of the product is transferred based on the shipping terms of the arrangement. Generally, we determine standalone selling price using the prices charged to customers on a standalone basis. The amount of consideration we receive and revenue we recognize varies due to rebates, returns, and price adjustments. We estimate the expected rebates, returns, and price adjustments based on an analysis of historical experience, anticipated sales demand, and trends in product pricing. We adjust our estimate of revenue at the earlier of when the most likely amount of consideration we expect to receive changes or when the consideration becomes fixed. Adjustments to revenue for performance obligations satisfied in prior periods was not significant during the year ended December 31, 2018 . Accrued rebates and accrued returns as of December 31, 2018 totaled $41.3 million and $11.9 million , respectively. Estimated price adjustments recognized against our gross accounts receivable balance as of December 31, 2018 totaled $25.1 million . Depending on the terms of an arrangement, we may defer the recognition of a portion of the consideration received because we have to satisfy a future obligation. Consideration allocated to support services under a support and maintenance contract is typically paid in advance and recognized ratably over the term of the service. Consideration allocated to professional services is recognized when or as the services are performed depending on the terms of the arrangement. As of January 1, 2018, total deferred revenue was $104.4 million , and during 2018, $202.1 million of revenue was deferred and $193.2 million of revenue was recognized. Thus, as of December 31, 2018 , total deferred revenue was $113.3 million , and of this amount, $101.2 million will be recognized within the next twelve months, and the remaining $12.1 million is long-term and will be recognized over a period greater than twelve months. We expense sales commissions as incurred when the duration of the related revenue arrangement is one year or less. We capitalize sales commissions in other current and long-lived assets on our balance sheet when the duration of the related revenue arrangement is longer than one year, and we amortize it over the related revenue arrangement period. Total capitalized sales commissions was $2.9 million as of December 31, 2018 . Total sales commissions costs were $23.3 million during the year ended December 31, 2018 . Sales commissions are recorded within selling, general and administrative expenses.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Acquisitions	Acquisitions Net-Tech Technology, Inc. We acquired 100% of the shares of NT2 on April 25, 2018 for a purchase price of $8.5 million that was funded with cash on hand. NT2 is an integrator of optical passive components and network optimization products used within broadband network applications where optical backhaul is used. NT2 is located in the United States. The results of NT2 have been included in our Consolidated Financial Statements from April 25, 2018, and are reported within the Enterprise Solutions segment. The NT2 acquisition was not material to our financial position or results of operations. Snell Advanced Media We acquired 100% of the outstanding ownership interest in SAM on February 8, 2018 for a purchase price, net of cash acquired, of $104.5 million . Of the $104.5 million purchase price, $75.2 million was paid on February 8, 2018 and was funded with cash on hand. The acquisition included a potential earnout, which was based upon future combined earnings of SAM and Grass Valley through December 31, 2019. The maximum earnout consideration is $31.4 million , but based upon a third party valuation specialist using certain assumptions in a discounted cash flow model, the preliminary estimated fair value of the earnout included in the purchase price was $29.3 million . We assumed debt of $19.3 million and paid it off during the first quarter of 2018. SAM designs, manufactures, and sells innovative content production and distribution systems for the broadcast and media markets. SAM is headquartered in the United Kingdom. The results of SAM have been included in our Consolidated Financial Statements from February 8, 2018, and are reported within the Enterprise Solutions segment. The following table summarizes the estimated, preliminary fair value of the assets acquired and the liabilities assumed as of February 8, 2018 (in thousands): Receivables $ 16,551 Inventory 15,084 Prepaid and other current assets 3,799 Property, plant, and equipment 7,716 Intangible assets 51,000 Goodwill 102,715 Deferred income taxes 1,388 Other long-lived assets 3,046 Total assets acquired $ 201,299 Accounts payable $ 11,825 Accrued liabilities 24,405 Deferred revenue 8,860 Long-term debt 19,315 Postretirement benefits 31,774 Other long-term liabilities 591 Total liabilities assumed $ 96,770 Net assets $ 104,529 The above acquisition accounting is preliminary, and is subject to revision as additional information about the fair value of individual assets and liabilities becomes available. The preliminary measurement of receivables; inventories; property, plant and equipment; intangible assets; goodwill; deferred income taxes; deferred revenue; and other assets and liabilities are subject to change. A change in the estimated fair value of the net assets acquired will change the amount of the purchase price allocable to goodwill. During the fourth quarter 2018, we recorded measurement-period adjustments that increased goodwill by approximately $15 million primarily for changes in the fair value of intangible assets and deferred revenue. The impact of these adjustments to the consolidated statement of operations was immaterial. 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 $16.6 million , which is equivalent to its gross contractual amount. For purposes of the above allocation, we based our estimates of the preliminary fair values for the acquired inventory; property, plant, and equipment; intangible assets; and deferred revenue on preliminary valuation studies 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. 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). 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). Goodwill and other intangible assets reflected above were determined to meet the criteria 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 SAM acquisition may be gained from cost synergies and helping broadcast and media content creators, aggregators and distributors significantly improve their effectiveness and efficiency during a period of rapid change in technology, viewer and advertiser behavior and business models. Our tax basis in the acquired goodwill is zero . The intangible assets related to the acquisition consisted of the following: Preliminary Fair Value Amortization Period (In thousands) (In years) Intangible assets subject to amortization: Developed technologies $ 36,500 5.0 Customer relationships 11,000 12.0 Sales backlog 1,900 0.3 Trademarks 1,600 0.9 Total intangible assets subject to amortization $ 51,000 Intangible assets not subject to amortization: Goodwill $ 102,715 n/a Total intangible assets not subject to amortization $ 102,715 Total intangible assets $ 153,715 Weighted average amortization period 6.2 years 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 of the backlog intangible asset was based on our estimate of when the ordered items would ship. The useful life for the trademarks was based on the period of time we expect to continue to go to market using the trademarks. Our consolidated revenues for the year ended December 31, 2018 included an estimated $106.3 million from SAM. Due to the integration of SAM into our existing business, we are unable to reasonably estimate the amount of income before taxes from SAM included in our consolidated financial statements. Our consolidated income before taxes for the year ended December 31, 2018 included $46.1 million of severance and other restructuring costs, $10.6 million of amortization of intangible assets, and $1.8 million of cost of sales related to the adjustment of acquired inventory to fair value from SAM. The following table illustrates the unaudited pro forma effect on operating results as if the SAM acquisition had been completed as of January 1, 2017. Years Ended December 31, 2018 2017 (In thousands, except per share data) (Unaudited) Revenues $ 2,598,741 $ 2,500,779 Net income (loss) attributable to Belden common stockholders 168,819 (8,581 ) Diluted income (loss) per share attributable to Belden common stockholders $ 4.12 $ (0.20 ) For purposes of the pro forma disclosures, the year ended December 31, 2017 includes nonrecurring expenses related to the acquisition, including severance, restructuring, and acquisition integration costs; amortization of the sales backlog intangible asset; and cost of sales arising from the adjustment of inventory to fair value of $46.1 million , $1.9 million , and $1.7 million , respectively. 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. Thinklogical Holdings, LLC We acquired 100% of the outstanding ownership interest in Thinklogical on May 31, 2017 for cash of $165.8 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 Enterprise Solutions segment. The following table summarizes the estimated fair values of the assets acquired and the liabilities assumed as of May 31, 2017 (in thousands): Receivables $ 4,355 Inventory 16,424 Prepaid and other current assets 320 Property, plant, and equipment 4,289 Intangible assets 73,400 Goodwill 70,654 Deferred income taxes 598 Total assets acquired $ 170,040 Accounts payable $ 1,231 Accrued liabilities 1,353 Deferred revenue 1,702 Total liabilities assumed $ 4,286 Net assets $ 165,754 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 $4.4 million , which is equivalent to its gross contractual amount. For purposes of the above allocation, we based our estimate of the fair value for the acquired inventory, intangible assets, and deferred revenue on a valuation study performed by a third party valuation firm. 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 complete. 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 $43.3 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 $ 70,654 n/a Total intangible assets not subject to amortization $ 70,654 Total intangible assets $ 144,054 Weighted average amortization period 9.6 years The amortizable intangible assets reflected in the table above were determined by us to have finite lives. 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 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 of the backlog intangible asset was based on our estimate of when the ordered items would ship. Our consolidated revenues and consolidated income 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 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 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 Enterprise 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 Enterprise Solutions segment.

Operating Segments and Geograph

Operating Segments and Geographic Information	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Operating Segments and Geographic Information	Operating Segments and Geographic Information Effective January 1, 2018, we changed our organizational structure and, as a result, now are reporting two segments. The segments formerly known as Broadcast Solutions and Enterprise Solutions now are presented as the Enterprise Solutions segment, and the segments formerly known as Industrial Solutions and Network Solutions now are presented as the Industrial Solutions segment. The reorganization allows us to further accelerate progress in key strategic areas, and the segment consolidation properly aligns our external reporting with the way the businesses are now managed. We have recast the prior period segment information to conform to the change in the composition of these reportable segments. This change 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, were not included in the corporate expense allocation. Operating Segment Information Enterprise Solutions Years ended December 31, 2018 2017 2016 (In thousands) Segment revenues $ 1,522,178 $ 1,356,305 $ 1,372,941 Affiliate revenues 6,085 5,091 2,799 Segment EBITDA 267,656 216,558 239,978 Depreciation expense 28,861 26,272 29,455 Amortization of intangibles 45,944 51,054 48,966 Amortization of software development intangible assets 2,180 56 — Severance, restructuring, and acquisition integration costs 57,563 29,043 18,561 Purchase accounting effects of acquisitions 3,497 6,133 (2,079 ) Deferred revenue adjustments 6,612 — 1,774 Patent settlement — — (5,554 ) Acquisition of property, plant and equipment 65,619 49,440 38,392 Segment assets 761,309 687,914 571,960 Industrial Solutions Years ended December 31, 2018 2017 2016 (In thousands) Segment revenues $ 1,069,802 $ 1,032,338 $ 984,864 Affiliate revenues 81 67 71 Segment EBITDA 207,724 214,190 193,811 Depreciation expense 18,754 19,325 17,753 Amortization of intangibles 52,885 52,943 49,419 Amortization of software development intangible assets 8 — — Severance, restructuring, and acquisition integration costs 11,050 13,747 12,579 Deferred revenue adjustments — — 4,913 Acquisition of property, plant and equipment 29,215 13,319 15,190 Segment assets 458,801 458,481 342,038 Total Segments Years ended December 31, 2018 2017 2016 (In thousands) Segment revenues $ 2,591,980 $ 2,388,643 $ 2,357,805 Affiliate revenues 6,166 5,158 2,870 Segment EBITDA 475,380 430,748 433,789 Depreciation expense 47,615 45,597 47,208 Amortization of intangibles 98,829 103,997 98,385 Amortization of software development intangible assets 2,188 56 — Severance, restructuring, and acquisition integration costs 68,613 42,790 31,140 Purchase accounting effects of acquisitions 3,497 6,133 (2,079 ) Deferred revenue adjustments 6,612 — 6,687 Patent settlement — — (5,554 ) Acquisition of property, plant and equipment 94,834 62,759 53,582 Segment assets 1,220,110 1,146,395 913,998 The following table is a reconciliation of the total of the reportable segments’ Revenues and EBITDA to consolidated revenues and consolidated income before taxes, respectively. Years Ended December 31, 2018 2017 2016 (In thousands) Total Segment Revenues $ 2,591,980 $ 2,388,643 $ 2,357,805 Deferred revenue adjustments (1) (6,612 ) — (6,687 ) Patent settlement (2) — — 5,554 Consolidated Revenues $ 2,585,368 $ 2,388,643 $ 2,356,672 Total Segment EBITDA $ 475,380 $ 430,748 $ 433,789 Amortization of intangibles (98,829 ) (103,997 ) (98,385 ) Severance, restructuring, and acquisition integration costs (3) (68,613 ) (42,790 ) (31,140 ) Depreciation expense (47,615 ) (45,597 ) (47,208 ) Deferred revenue adjustments (1) (6,612 ) — (6,687 ) Purchase accounting effects related to acquisitions (4) (3,497 ) (6,133 ) 2,079 Costs related to patent litigation (2,634 ) — — Amortization of software development intangible assets (2,188 ) (56 ) — Loss on sale of assets (5) (94 ) (1,013 ) — Impairment of assets held for sale (5) — — (23,931 ) Patent settlement (2) — — 5,554 Income from equity method investment — 7,502 1,793 Gain from patent litigation 62,141 — — Eliminations (2,218 ) (3,260 ) (3,781 ) Consolidated operating income 305,221 235,404 232,083 Interest expense, net (61,559 ) (82,901 ) (95,050 ) Non-operating pension cost (342 ) (714 ) (8,230 ) Loss on debt extinguishment (22,990 ) (52,441 ) (2,342 ) Consolidated income before taxes $ 220,330 $ 99,348 $ 126,461 (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 4, 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 12, Severance, Restructuring, and Acquisition Integration Activities, for details . (4) In 2018, we recognized $3.5 million of cost of sales related to purchase accounting adjustments, most of which was for the adjustment of acquired inventory to fair value for our SAM and NT2 acquisitions. 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 segment and M2FX acquisition, respectively. (5) In 2018, 2017, and 2016, we recognized a $0.1 million loss on sale of assets, $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. Below are reconciliations of other segment measures to the consolidated totals. Years Ended December 31, 2018 2017 2016 (In thousands) Total segment assets $ 1,220,110 $ 1,146,395 $ 913,998 Cash and cash equivalents 420,610 561,108 848,116 Goodwill 1,557,653 1,478,257 1,385,995 Intangible assets, less accumulated amortization 511,093 545,207 560,082 Deferred income taxes 56,018 42,549 33,706 Corporate assets 13,837 67,097 64,906 Total assets $ 3,779,321 $ 3,840,613 $ 3,806,803 Total segment acquisition of property, plant and equipment $ 94,834 $ 62,759 $ 53,582 Corporate acquisition of property, plant and equipment 3,013 1,502 392 Total acquisition of property, plant and equipment $ 97,847 $ 64,261 $ 53,974 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, 2018 , 2017 and 2016 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, 2018 Revenues $ 1,324,653 $ 174,727 $ 132,544 $ 117,598 $ 835,846 $ 2,585,368 Percent of total revenues 51 % 7 % 5 % 5 % 32 % 100 % Long-lived assets $ 189,211 $ 32,312 $ 37,227 $ 39,870 $ 97,213 $ 395,833 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 Major Customer Revenues generated from sales to the distributor Anixter International Inc., in both the Enterprise Solutions and Industrial Solutions segments, were $309.0 million ( 12% of revenues), $292.2 million ( 12% of revenues), and $286.2 million ( 12% of revenues) for 2018 , 2017 , and 2016 , respectively. At December 31, 2018 , we had $37.0 million in accounts receivable outstanding from Anixter International Inc. This represented approximately 8% of our total accounts receivable outstanding at December 31, 2018 .

Noncontrolling Interest

Noncontrolling Interest	12 Months Ended
	Dec. 31, 2018
Noncontrolling Interest [Abstract]
Noncontrolling Interest	Noncontrolling Interest We have a 51% ownership percentage in a joint venture with Shanghai Hi-Tech Control System Co, Ltd (Hite). The purpose of the joint venture is to develop and provide certain Industrial Solutions products and integrated solutions to customers in China. Belden and Hite are committed to fund $1.53 million and $1.47 million , respectively, to the joint venture in the future. The joint venture is determined to not have sufficient equity at risk; therefore, it is considered a variable interest entity. We have determined that Belden is the primary beneficiary of the joint venture, due to both our ownership percentage and our control over the activities of the joint venture that most significantly impact its economic performance based on the terms of the joint venture agreement with Hite. Because Belden is the primary beneficiary of the joint venture, we have consolidated the joint venture in our financial statements. The results of the joint venture attributable to Hite’s ownership are presented as net 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, 2018 , 2017 , or 2016.

Income Per Share

Income Per Share	12 Months Ended
	Dec. 31, 2018
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, 2018 2017 2016 (In thousands) Numerator: Net income $ 160,711 $ 92,853 $ 127,646 Less: Net loss attributable to noncontrolling interest (183 ) (357 ) (357 ) Less: Preferred stock dividends 34,931 34,931 15,428 Net income attributable to Belden common stockholders $ 125,963 $ 58,279 $ 112,575 Denominator: Weighted average shares outstanding, basic 40,675 42,220 42,093 Effect of dilutive common stock equivalents 281 423 464 Weighted average shares outstanding, diluted 40,956 42,643 42,557 For the years ended December 31, 2018 , 2017 , and 2016 , diluted weighted average shares outstanding do not include outstanding equity awards of 0.9 million , 0.5 million , and 0.6 million , respectively, because to do so would have been anti-dilutive. In addition, for the years ended December 31, 2018 , 2017 , and 2016 , diluted weighted average shares outstanding do not include outstanding equity awards of 0.3 million , 0.2 million , and 0.1 million , respectively, because the related performance conditions have not been satisfied. Furthermore, for the years ended December 31, 2018 , 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 , 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, 2018
Inventory Disclosure [Abstract]
Inventories	Inventories The major classes of inventories were as follows: December 31, 2018 2017 (In thousands) Raw materials $ 146,803 $ 133,311 Work-in-process 45,939 35,807 Finished goods 152,572 153,377 Gross inventories 345,314 322,495 Excess and obsolete reserves (28,896 ) (25,269 ) Net inventories $ 316,418 $ 297,226

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2018
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, 2018 2017 (In thousands) Land and land improvements $ 30,173 $ 31,963 Buildings and leasehold improvements 141,009 148,598 Machinery and equipment 569,359 543,594 Computer equipment and software 139,773 136,509 Construction in process 64,145 46,898 Gross property, plant and equipment 944,459 907,562 Accumulated depreciation (578,489 ) (570,240 ) Net property, plant and equipment $ 365,970 $ 337,322 Depreciation Expense We recognized depreciation expense of $47.6 million , $45.6 million , and $47.2 million in 2018 , 2017 , and 2016 , respectively.

Intangible Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Intangible Assets The carrying values of intangible assets were as follows: December 31, 2018 December 31, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount (In thousands) (In thousands) Goodwill $ 1,557,653 $ — $ 1,557,653 $ 1,478,257 $ — $ 1,478,257 Definite-lived intangible assets subject to amortization: Developed technology $ 545,982 $ (379,896 ) $ 166,086 $ 498,649 $ (318,366 ) $ 180,283 Customer relationships 331,643 (115,943 ) 215,700 320,550 (98,175 ) 222,375 Trademarks 57,860 (27,106 ) 30,754 56,794 (18,648 ) 38,146 In-service research and development 23,833 (16,471 ) 7,362 23,428 (13,483 ) 9,945 Backlog 15,885 (15,885 ) — 14,535 (14,535 ) — Total intangible assets subject to amortization 975,203 (555,301 ) 419,902 913,956 (463,207 ) 450,749 Indefinite-lived intangible assets not subject to amortization: Trademarks 90,391 — 90,391 92,758 — 92,758 In-process research and development 800 — 800 1,700 — 1,700 Total intangible assets not subject to amortization 91,191 — 91,191 94,458 — 94,458 Intangible assets $ 1,066,394 $ (555,301 ) $ 511,093 $ 1,008,414 $ (463,207 ) $ 545,207 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: Enterprise Solutions Industrial Solutions Consolidated (In thousands) Balance at December 31, 2016 $ 617,320 $ 768,675 $ 1,385,995 Acquisitions and purchase accounting adjustments 71,394 — 71,394 Translation impact 13,557 7,311 20,868 Balance at December 31, 2017 $ 702,271 $ 775,986 $ 1,478,257 Acquisitions and purchase accounting adjustments 105,899 — 105,899 Translation impact (22,812 ) (3,691 ) (26,503 ) Balance at December 31, 2018 $ 785,358 $ 772,295 $ 1,557,653 The changes in the carrying amount of indefinite-lived trademarks are as follows: Enterprise Solutions Industrial Solutions Consolidated (In thousands) Balance at December 31, 2016 $ 80,350 $ 41,622 $ 121,972 Translation impact 2,727 1,260 3,987 Reclassify to definite-lived — (33,201 ) (33,201 ) Balance at December 31, 2017 $ 83,077 $ 9,681 $ 92,758 Translation impact (1,893 ) (474 ) (2,367 ) Balance at December 31, 2018 $ 81,184 $ 9,207 $ 90,391 Impairment The annual measurement date for our goodwill and indefinite-lived intangible assets impairment test is our fiscal November month-end. For our 2018 goodwill impairment test, we performed a quantitative assessment for four 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 four 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 2017 or 2016 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 2018 , 2017 , or 2016 . Amortization Expense We recognized amortization expense in income from continuing operations of $101.0 million , $104.0 million , and $98.4 million in 2018 , 2017 , and 2016 , respectively. We expect to recognize annual amortization expense of $90.4 million in 2019 , $74.4 million in 2020 , $42.1 million in 2021 , $38.2 million in 2022 , and $29.3 million in 2023 related to our intangible assets balance as of December 31, 2018 . The weighted-average amortization period for our customer relationships, trademarks, developed technology, and in-service research and development is 18.4 years , 7.9 years , 6.5 years , and 5.0 years , respectively. In connection with a segment change in 2017, we re-evaluated the useful life of the Tripwire trademark and concluded that an indefinite life was no longer appropriate. We 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 2017, which resulted in amortization expense of $3.1 million for each of the years ended December 31, 2018 and 2017. As of December 31, 2018 , the net book value of the Tripwire trademark was $24.8 million .

Accrued Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2018
Accrued Liabilities [Abstract]
Accrued Liabilities	Accrued Liabilities The carrying values of accrued liabilities were as follows: December 31, 2018 2017 (In thousands) Current deferred revenue $ 101,194 $ 90,639 Wages, severance and related taxes 56,129 57,633 Accrued rebates 41,312 38,025 Employee benefits 25,670 25,406 Accrued interest 18,530 22,019 Other (individual items less than 5% of total current liabilities) 121,441 68,929 Accrued liabilities $ 364,276 $ 302,651

Severance, Restructuring, and A

Severance, Restructuring, and Acquisition Integration Activities	12 Months Ended
	Dec. 31, 2018
Restructuring and Related Activities [Abstract]
Severance, Restructuring, and Acquisition Integration Activities	Severance, Restructuring, and Acquisition Integration Activities Grass Valley and SAM Integration Program: 2018 During the first quarter of 2018, we began a restructuring program to integrate SAM with Grass Valley. The restructuring and integration activities are focused on achieving desired cost savings by consolidating existing and acquired facilities and other support functions. We recognized $42.3 million of severance and other restructuring costs for this program during 2018 . The costs were incurred by the Enterprise Solutions segment. We expect to incur approximately $3 million of additional severance and restructuring costs for this program, which will be incurred during the first quarter of 2019. Industrial Manufacturing Footprint Program: 2016-2018 In 2016, we began a program to consolidate our manufacturing footprint. The manufacturing consolidation is complete. We recognized $17.7 million , $30.6 million , and $17.8 million of severance and other restructuring costs for this program during 2018 , 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 $66.1 million in severance and other restructuring costs, including manufacturing inefficiencies for this program. 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, 2018 Enterprise Solutions $ 9,945 $ 47,618 $ 57,563 Industrial Solutions 378 10,672 11,050 Total $ 10,323 $ 58,290 $ 68,613 Year Ended December 31, 2017 Enterprise Solutions $ 4,535 $ 24,508 $ 29,043 Industrial Solutions 676 13,071 13,747 Total $ 5,211 $ 37,579 $ 42,790 Year Ended December 31, 2016 Enterprise Solutions $ 520 $ 18,041 $ 18,561 Industrial Solutions 6,562 6,017 12,579 Total $ 7,082 $ 24,058 $ 31,140 The other restructuring and integration costs primarily consisted of equipment transfers, costs to consolidate operating and support facilities, retention bonuses, relocation, travel, legal, 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 2018 , $28.1 million , $35.0 million , and $5.5 million were included in cost of sales; selling, general and administrative expenses; and research and development expenses, respectively. 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 expenses, respectively. Of the total severance and other restructuring costs recognized during 2016 , $12.3 million , $18.0 million , and $0.8 million were included in cost of sales; selling, general and administrative expenses; and research and development expenses, respectively. There were no significant severance accrual balances as of December 31, 2018 or 2017.

Long-Term Debt and Other Borrow

Long-Term Debt and Other Borrowing Arrangements	12 Months Ended
	Dec. 31, 2018
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, 2018 2017 (In thousands) Revolving credit agreement due 2022 $ — $ — Senior subordinated notes: 3.875% Senior subordinated notes due 2028 400,050 — 3.375% Senior subordinated notes due 2027 514,350 540,810 4.125% Senior subordinated notes due 2026 228,600 240,360 2.875% Senior subordinated notes due 2025 342,900 360,540 5.25% Senior subordinated notes due 2024 — 200,000 5.50% Senior subordinated notes due 2023 — 242,522 Total senior subordinated notes 1,485,900 1,584,232 Less unamortized debt issuance costs (22,700 ) (23,484 ) Long-term debt $ 1,463,200 $ 1,560,748 Revolving Credit Agreement due 2022 In 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, 2018 , we had no borrowings outstanding on the Revolver, and our available borrowing capacity was $359.1 million . Senior Subordinated Notes In March 2018, we completed an offering for €350.0 million ( $431.3 million at issuance) aggregate principal amount of 3.875% senior subordinated notes due 2028 (the 2028 Notes). The carrying value of the 2028 Notes as of December 31, 2018 is $400.1 million . The 2028 Notes are guaranteed on a senior subordinated basis by our current and future domestic subsidiaries. The 2028 Notes rank equal in right of payment with our senior subordinated notes due 2027, 2026, and 2025 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, which commenced on September 15, 2018. We paid approximately $7.5 million of fees associated with the issuance of the 2028 Notes, which are being amortized over the life of the 2028 Notes using the effective interest method. We used the net proceeds from this offering and cash on hand to repurchase the 2023 and 2024 Notes - see further discussion below. 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, 2018 is $514.4 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 2028, 2026, and 2025 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, which commenced on January 15, 2018. We paid approximately $8.8 million of fees associated with the issuance of the 2027 Notes, which are being amortized over the life of the 2027 Notes using the effective interest method. 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, 2018 is $228.6 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 2028, 2027, and 2025 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, which commenced 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, 2018 is $342.9 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 2028, 2027, and 2026 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, which commenced on March 15, 2018. We paid approximately $6.2 million of fees associated with the issuance of the 2025 Notes, which are being amortized over the life of the 2025 Notes using the effective interest method. We had outstanding $200 million aggregate principal amount of 5.25% senior subordinated notes due 2024 (the 2024 Notes). In March 2018, we repurchased $188.7 million of the 2024 Notes outstanding for cash consideration of $199.8 million , including a prepayment penalty and recognized a $13.8 million loss on debt extinguishment including the write-off of unamortized debt issuance costs. In April 2018, we repurchased the remaining 2024 Notes outstanding for cash consideration of $11.9 million , including a prepayment penalty, and recognized a $0.8 million loss on debt extinguishment including the write-off of unamortized debt issuance costs. We had outstanding €200.0 million aggregate principal amount of 5.5% senior subordinated notes due 2023 (the 2023 Notes). In March 2018, we repurchased €143.1 million of the €200.0 million 2023 Notes outstanding for cash consideration of €147.8 million ( $182.1 million ), including a prepayment penalty and recognized a $6.2 million loss on debt extinguishment including the write-off of unamortized debt issuance costs. In April 2018, we repurchased the remaining 2023 Notes outstanding for cash consideration of €58.5 million ( $71.6 million ), including a prepayment penalty, and recognized a $2.2 million loss on debt extinguishment including the write-off of unamortized debt issuance costs. The senior subordinated notes due 2025, 2026, 2027 and 2028 are redeemable after September 15, 2020, October 15, 2021, July 15, 2022, and March 15, 2023, respectively, at the following redemption prices as a percentage of the face amount of the notes: Senior Subordinated Notes due 2025 2026 2027 2028 Year Percentage Year Percentage Year Percentage Year Percentage 2020 101.438 % 2021 102.063 % 2022 101.688 % 2023 101.9375 % 2021 100.719 % 2022 101.375 % 2023 101.125 % 2024 101.2916 % 2022 and thereafter 100.000 % 2023 100.688 % 2024 100.563 % 2025 100.6458 % 2024 and thereafter 100.000 % 2025 and thereafter 100.000 % 2026 and thereafter 100.0000 % Fair Value of Long-Term Debt The fair value of our senior subordinated notes as of December 31, 2018 was approximately $1,485.0 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 $1,485.9 million as of December 31, 2018 . Maturities Maturities on outstanding long-term debt and other borrowings during each of the five years subsequent to December 31, 2018 are as follows (in thousands): 2019 $ — 2020 — 2021 — 2022 — 2023 — Thereafter 1,485,900 $ 1,485,900

Net Investment Hedge

Net Investment Hedge	12 Months Ended
	Dec. 31, 2018
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 entity. As of December 31, 2018 , 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 operations against adverse changes in the euro exchange rate. 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, 2018 and 2017 was a gain of $87.5 million and a loss of $56.2 million , respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Years ended December 31, 2018 2017 2016 (In thousands) Income (loss) before taxes: United States operations $ 126,385 $ 2,177 $ (25,615 ) Foreign operations 93,945 97,171 152,076 Income before taxes $ 220,330 $ 99,348 $ 126,461 Income tax expense (benefit): Currently payable United States federal $ 27,529 $ — $ 2,981 United States state and local 3,274 2,392 (1,038 ) Foreign 17,516 28,201 26,906 48,319 30,593 28,849 Deferred United States federal 10,942 (11,028 ) (27,677 ) United States state and local 703 (8,758 ) (3,139 ) Foreign (345 ) (4,312 ) 782 11,300 (24,098 ) (30,034 ) Income tax expense (benefit) $ 59,619 $ 6,495 $ (1,185 ) Years Ended December 31, 2018 2017 2016 Effective income tax rate reconciliation from continuing operations: United States federal statutory rate 21.0 % 35.0 % 35.0 % State and local income taxes 1.7 % 0.8 % (0.9 )% Impact of change in tax contingencies (1.0 )% 2.2 % 2.4 % Foreign income tax rate differences (1.8 )% (13.1 )% (14.0 )% Impact of change in deferred tax asset valuation allowance 2.0 % 1.5 % (7.3 )% 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 )% Domestic permanent differences and tax credits 0.7 % (15.7 )% (5.7 )% Impact of tax reform 4.5 % 28.6 % — % 27.1 % 6.5 % (0.9 )% 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. In accordance with the Act, we recorded $28.4 million as an additional income tax expense in the fourth quarter of 2017, the period in which the legislation was enacted. The total income tax expense 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, 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. Additionally, 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. December 22, 2018 marked the end of the measurement period for purposes of SAB 118. As such, we have completed our analysis based on legislative updates relating to the Act currently available which resulted in an additional SAB 118 tax expense of $2.9 million in the fourth quarter of 2018 and a total tax expense of $10.0 million for the year ended December 31, 2018. The total tax provision expense included an $8.0 million tax expense associated with an increase to the valuation allowance against foreign tax credit carryovers that we no longer expect to be able to realize based upon the new tax law, a $1.3 million tax expense adjustment to the transition tax on the deemed repatriation of cumulative foreign earnings, a $1.1 million tax expense resulting from a valuation allowance established on the deferred tax assets associated with stock options of covered employees, and a $0.4 million income tax benefit associated with an adjustment to the remeasurement of certain deferred tax assets and liabilities. If we were to repatriate foreign cash to the U.S., we may be required to accrue and pay U.S. taxes in accordance with applicable U.S. tax rules and regulations as a result of the repatriation. However, it is our practice and intention to reinvest the earnings of our non-U.S. subsidiaries in those operations. As a result, as of December 31, 2018, we have not made a provision for U.S. or additional foreign withholding taxes. Foreign tax rate differences resulted in an income tax benefit of $4.0 million , $13.0 million , and $17.7 million in 2018, 2017, and 2016, respectively. Additionally, in 2018 and 2017, our income tax expense was reduced by $3.0 million and $3.5 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, 2018 2017 (In thousands) Components of deferred income tax balances: Deferred income tax liabilities: Plant, equipment, and intangibles $ (114,413 ) $ (120,171 ) Deferred income tax assets: Postretirement, pensions, and stock compensation 30,896 28,736 Reserves and accruals 25,641 29,297 Net operating loss and tax credit carryforwards 164,823 228,815 Valuation allowances (90,872 ) (151,841 ) 130,488 135,007 Net deferred income tax asset $ 16,075 $ 14,836 The decrease in deferred income tax liabilities associated with plant, equipment and intangibles during 2018 is primarily due to the adoption of ASU 2016-16 in the first quarter of 2018 in which deferred tax assets associated with prior intercompany sales of intangible assets were recorded onto the Company’s balance sheet. The decrease in our net operating loss carryforwards and deferred tax valuation allowances is primarily due to the write-off of certain foreign net operating loss carryforwards and the corresponding valuation allowance associated with those foreign net operating losses. The Company has determined these net operating losses are not realizable as a result of a significant change in business operations that occurred in a prior year. As of December 31, 2018 , we had $537.3 million of gross net operating loss carryforwards and $71.0 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: $0.2 million in 2018, $8.0 million in 2019, $29.4 million between 2020 and 2022, and $167.8 million between 2023 and 2038. Net operating losses with an indefinite carryforward period total $331.9 million . Of the $537.3 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 $172.5 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 $71.0 million will expire as follows: $1.6 million between 2020 and 2022, $64.2 million between 2023 and 2038. Tax credit carryforwards with an indefinite carryforward period total $5.2 million . We have determined, based on the weight of all available evidence, both positive and negative, that we will utilize $42.7 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, 2018 by jurisdiction: Net Operating Loss Carryforwards (In thousands) Australia $ 12,064 France 15,538 Germany 13,436 Japan 20,203 Luxembourg 24,252 Netherlands 23,889 Other 45,171 United Kingdom 258,423 United States - Federal and various states 124,349 Total $ 537,325 Tax Credit Carryforwards (In thousands) United States $ 48,859 Canada 22,181 Total $ 71,040 In 2018, we recognized a net $1.2 million decrease to reserves for uncertain tax positions. A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows: 2018 2017 (In thousands) Balance at beginning of year $ 8,579 $ 10,474 Additions based on tax positions related to the current year 866 981 Additions for tax positions of prior years 1,292 2,549 Reductions for tax positions of prior years - Settlement (1,689 ) (5,425 ) Reduction for tax positions of prior years - Statute of limitations (1,631 ) — Balance at end of year $ 7,417 $ 8,579 The additions for tax positions of prior years relates to transition tax. The balance of $7.4 million at December 31, 2018 , reflects tax positions that, if recognized, would impact our effective tax rate. As of December 31, 2018 , we believe it is reasonably possible that $0.9 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 2016, we recognized reductions of interest expense of $0.2 million related to uncertain tax positions. We do not have any material amounts accrued for the payment of interest and penalties as of December 31, 2018 and 2017 . Our federal tax return for the tax years 2015 and later remain subject to examination by the Internal Revenue Service. Belden reached agreement with the Internal Revenue Service for the 2013 and 2014 tax years in December 2018. Our state and foreign income tax returns for the tax years 2010 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, 2018
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 and Japan. Our plans in the United Kingdom include SAM's defined contribution and defined benefit plans which we acquired during 2018 (see Note 4). The SAM defined benefit plans are frozen and additional benefits are not being earned by the participants. 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. 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 2018 , 2017 , and 2016 was $15.2 million , $13.9 million , and $13.5 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, 2018 2017 2018 2017 (In thousands) Change in benefit obligation: Benefit obligation, beginning of year $ (272,025 ) $ (256,481 ) $ (30,333 ) $ (32,038 ) Service cost (4,705 ) (4,978 ) (47 ) (49 ) Interest cost (11,690 ) (7,671 ) (945 ) (1,139 ) Participant contributions (85 ) (91 ) (6 ) (7 ) Actuarial gain (loss) 15,032 (3,291 ) 1,681 3,370 Divestitures (acquisitions) (185,692 ) 794 — — Settlements 7,437 49 — — Plan amendments (2,822 ) — — — Foreign currency exchange rate changes 23,454 (14,299 ) 2,020 (2,022 ) Benefits paid 12,849 13,943 1,487 1,552 Benefit obligation, end of year $ (418,247 ) $ (272,025 ) $ (26,143 ) $ (30,333 ) Pension Benefits Other Benefits Years Ended December 31, 2018 2017 2018 2017 (In thousands) Change in plan assets: Fair value of plan assets, beginning of year $ 198,156 $ 182,370 $ — $ — Actual return on plan assets (8,364 ) 18,746 — — Employer contributions 5,397 4,425 1,481 1,545 Plan participant contributions 85 91 6 7 Acquisitions 153,919 — — — Settlements (7,054 ) — — — Foreign currency exchange rate changes (17,616 ) 6,467 — — Benefits paid (12,849 ) (13,943 ) (1,487 ) (1,552 ) Fair value of plan assets, end of year $ 311,674 $ 198,156 $ — $ — Funded status, end of year $ (106,573 ) $ (73,869 ) $ (26,143 ) $ (30,333 ) Amounts recognized in the balance sheets: Prepaid benefit cost $ 4,801 $ 3,174 $ — $ — Accrued benefit liability (current) (3,320 ) (3,736 ) (1,405 ) (1,555 ) Accrued benefit liability (noncurrent) (108,054 ) (73,307 ) (24,738 ) (28,778 ) Net funded status $ (106,573 ) $ (73,869 ) $ (26,143 ) $ (30,333 ) The accumulated benefit obligation for all defined benefit pension plans was $412.4 million and $269.2 million at December 31, 2018 and 2017 , respectively. The projected benefit obligation, accumulated benefit obligation, and fair value of plan assets for the pension plans with a projected benefit obligation in excess of plan assets were $368.5 million , $362.6 million , and $257.1 million , respectively, as of December 31, 2018 and were $215.6 million , $212.7 million , and $138.5 million , respectively, as of December 31, 2017. The accumulated benefit obligation and fair value of plan assets for other postretirement benefit plans with an accumulated benefit obligation in excess of plan assets were $26.1 million and $0.0 million , respectively, as of December 31, 2018 and were $30.3 million and $0.0 million , respectively, as of December 31, 2017. The following table provides the components of net periodic benefit costs for the plans. Pension Benefits Other Benefits Years Ended December 31, 2018 2017 2016 2018 2017 2016 (In thousands) Components of net periodic benefit cost: Service cost $ 4,705 $ 4,978 $ 4,981 $ 47 $ 49 $ 46 Interest cost 11,690 7,671 8,909 945 1,139 1,259 Expected return on plan assets (16,391 ) (10,644 ) (12,013 ) — — — Amortization of prior service credit (42 ) (41 ) (42 ) — — (42 ) Curtailment gain — — (227 ) — — — Settlement loss (gain) 1,342 (8 ) 7,630 — — — Net loss (gain) recognition 2,810 2,597 2,670 (12 ) — 86 Net periodic benefit cost $ 4,114 $ 4,553 $ 11,908 $ 980 $ 1,188 $ 1,349 We recorded settlement losses totaling $1.3 million and $7.6 million during 2018 and 2016, respectively. These settlement losses were the result of lump-sum payments to participants that exceeded the sum of the pension plan's 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, 2018 2017 2018 2017 Weighted average assumptions for benefit obligations at year end: Discount rate 3.1 % 2.8 % 3.7 % 3.3 % Salary increase 3.6 % 3.6 % N/A N/A Cash balance interest credit rate 4.7 % 4.7 % N/A N/A Weighted average assumptions for net periodic cost for the year: Discount rate 2.8 % 3.1 % 3.3 % 3.7 % Salary increase 3.6 % 3.6 % N/A N/A Cash balance interest credit rate 4.7 % 4.7 % N/A N/A Expected return on assets 5.5 % 6.0 % N/A N/A Assumed health care cost trend rates: Health care cost trend rate assumed for next year N/A N/A 5.8 % 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 2025 2024 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 asset growth portion and an asset protection portion. The expected role of asset growth investments is to maximize the long-term real growth of assets, while the role of asset protection investments is to generate current income, provide for more stable periodic returns, and provide some protection against a permanent loss of capital. Absent regulatory or statutory limitations, the target asset allocation for the investment of the assets for our ongoing pension plans is 30 - 40% in asset protection investments and 60 - 70% in asset growth investments and for our pension plans where the majority of the participants are in payment or terminated vested status is 55 - 90% in asset protection investments and 10 - 45% in asset growth investments. Asset growth investments include a diversified mix of U.S. and international equity, primarily invested through investment funds. Asset protection investments 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 securities and instruments 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, 2018 December 31, 2017 Fair Market Value at December 31, 2018 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, 2017 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) U.S. equities fund $ 96,417 $ 1,465 $ — $ — $ 95,425 $ — $ — $ — Non-U.S. equities fund 47,274 5,755 — — 11,571 — — — Debt securities(b) Government bond fund 66,439 — 1,253 — 28,429 — — — Corporate bond fund 39,366 — 7,116 — 24,421 — — — Fixed income fund(c) 41,167 — 39,340 — 38,072 — 38,072 — Other investments(d) 17,274 — — — — — — — Cash & equivalents 3,737 301 — — 238 238 — — Total $ 311,674 $ 7,521 $ 47,709 $ — $ 198,156 $ 238 $ 38,072 $ — (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. Equity securities held in separate accounts are valued based on observable quoted prices on active exchanges. Funds which are 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 and annuity policies. (d) This category includes investments in hedge funds that pursue multiple strategies in order to provide diversification and balance risk/return objectives, real estate funds, and private equity funds. Funds valued using the net asset method are not included in the fair value hierarchy. 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, 2018 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) 2019 $ 21,667 $ 1,432 2020 22,965 1,436 2021 22,199 1,438 2022 23,157 1,438 2023 22,081 1,432 2024-2028 111,338 7,196 Total $ 223,407 $ 14,372 We anticipate contributing $6.3 million and $1.4 million to our pension and other postretirement plans, respectively, during 2019. 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, 2018 and the changes in these amounts during the year ended December 31, 2018 are as follows. Pension Benefits Other Benefits (In thousands) Components of accumulated other comprehensive loss: Net actuarial loss (gain) $ 48,466 $ (3,047 ) Net prior service cost 2,734 — $ 51,200 $ (3,047 ) Pension Benefits Other Benefits (In thousands) Changes in accumulated other comprehensive loss: Net actuarial loss (gain), beginning of year $ 44,359 $ (1,545 ) Amortization of actuarial gain (loss) (2,810 ) 12 Actuarial gain (15,032 ) (1,681 ) Asset loss 24,755 — Settlement loss recognized (1,342 ) — Currency impact (1,464 ) 167 Net actuarial loss (gain), end of year $ 48,466 $ (3,047 ) Prior service cost, beginning of year $ 11 $ — Amortization of prior service credit 42 — Prior service cost occurring during the year 2,822 — Currency impact (141 ) — Prior service cost, end of year $ 2,734 $ —

Comprehensive Income and Accumu

Comprehensive Income and Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2018
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, 2016 $ (4,661 ) $ (34,406 ) $ (39,067 ) Other comprehensive gain (loss) 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 ) Other comprehensive gain (loss) attributable to Belden before reclassifications 27,809 (7,813 ) 19,996 Amounts reclassified from accumulated other comprehensive income — 3,123 3,123 Net current period other comprehensive gain (loss) attributable to Belden 27,809 (4,690 ) 23,119 Balance at December 31, 2018 $ (41,882 ) $ (33,025 ) $ (74,907 ) The following table summarizes the effects of reclassifications from accumulated other comprehensive income (loss): Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Consolidated Statements of Operations and Comprehensive Income (In thousands) Amortization of pension and other postretirement benefit plan items: Settlement loss $ 1,342 (1 ) Actuarial losses 2,798 (1 ) Prior service credit (42 ) (1 ) Total before tax 4,098 Tax benefit (975 ) Total net of tax $ 3,123 (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, 2018
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, 2018 2017 2016 (In thousands) Total share-based compensation cost $ 18,497 $ 14,647 $ 18,178 Income tax benefit 4,402 5,566 7,069 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, 2018 2017 2016 (In thousands, except weighted average fair value and assumptions) Weighted-average fair value of SARs and options granted $ 25.19 $ 27.31 $ 18.79 Total intrinsic value of SARs converted and options exercised 2,263 7,156 9,678 Tax benefit related to share-based compensation 113 967 1,171 Weighted-average fair value of restricted stock shares and units granted 72.54 79.96 54.52 Total fair value of restricted stock shares and units vested 5,740 10,355 8,171 Expected volatility 33.16 % 36.89 % 37.47 % Expected term (in years) 5.6 5.6 5.7 Risk-free rate 2.70 % 2.01 % 1.32 % Dividend yield 0.27 % 0.27 % 0.38 % 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, 2018 1,132 $ 62.75 496 $ 78.03 Granted 265 72.34 338 72.54 Exercised or converted (62 ) 36.70 (71 ) 81.48 Forfeited or expired (46 ) 73.76 (136 ) 91.97 Outstanding at December 31, 2018 1,289 $ 65.58 6.6 $ — 627 $ 71.66 Vested or expected to vest at December 31, 2018 1,237 $ 65.33 6.5 $ — Exercisable or convertible at December 31, 2018 801 62.88 5.4 — At December 31, 2018 , the total unrecognized compensation cost related to all nonvested awards was $27.8 million . That cost is expected to be recognized over a weighted-average period of 2.1 years . Historically, we have issued treasury shares, if available, to satisfy award conversions and exercises.

Preferred Stock

Preferred Stock	12 Months Ended
	Dec. 31, 2018
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, 2018
Equity [Abstract]
Stockholder Rights Plan	Stockholder Rights Plan On March 27, 2018, our Board of Directors authorized the redemption of all outstanding preferred share purchase rights issued pursuant to the then existing Rights Agreement. Under the former Rights Agreement, one right was attached to each outstanding share of common stock. The rights were redeemed at a redemption price of $0.01 per right, resulting in a total payment of $0.4 million to the holders of the rights as of the close of business on March 27, 2018.

Share Repurchases

Share Repurchases	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Share Repurchases	Share Repurchases On May 25, 2017, our Board of Directors authorized a share repurchase program, which allowed 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 was funded with cash on hand and cash flows from operating activities. During 2018, we repurchased 2.7 million shares of our common stock under the program for an aggregate cost of $175.0 million and an average price per share of $64.94 . 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 . We have utilized all of the $200.0 million authorized under this share repurchase program. On November 29, 2018, our Board of Directors authorized a share repurchase program, which allows us to purchase up to $300.0 million of our common stock through open market repurchases, negotiated transactions, or other means, in accordance with applicable securities laws and other restrictions. During 2018, we did not repurchase any shares of our common stock under this program.

Operating Leases

Operating Leases	12 Months Ended
	Dec. 31, 2018
Leases [Abstract]
Operating Leases	Operating Leases Operating lease expense incurred primarily for manufacturing and office space, machinery, and equipment was $31.7 million , $38.6 million , and $40.3 million in 2018 , 2017 , and 2016 , respectively. Minimum annual lease payments for noncancelable operating leases in effect at December 31, 2018 are as follows (in thousands): 2019 $ 19,877 2020 17,531 2021 14,776 2022 12,317 2023 7,654 Thereafter 28,771 $ 100,926 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, 2018
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 34% , 35% , and 33% of revenues in 2018 , 2017 , and 2016 , respectively. Unconditional Commodity Purchase Obligations At December 31, 2018 , we were committed to purchase approximately 1.8 million pounds of copper at an aggregate fixed cost of $5.0 million . At December 31, 2018 , this fixed cost was $0.2 million more 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 15% of our labor force is covered by collective bargaining agreements that we expect to renegotiate during 2019. 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, 2018 are considered representative of their respective fair values. The fair value of our senior subordinated notes at December 31, 2018 and 2017 was approximately $1,485.0 million and $1,619.3 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 $1,485.9 million and $1,584.2 million as of December 31, 2018 and 2017 , respectively.

Contingent Liabilities

Contingent Liabilities	12 Months Ended
	Dec. 31, 2018
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, 2018 , we were party to unused standby letters of credit, bank guarantees, and surety bonds totaling $7.5 million , $3.9 million , and $2.4 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, 2018
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information Supplemental cash flow information is as follows: Years Ended December 31, 2018 2017 2016 (In thousands) Income tax refunds received $ 4,782 $ 5,031 $ 3,838 Income taxes paid (54,109 ) (35,893 ) (26,587 ) Interest paid (48,519 ) (79,047 ) (87,076 )

Quarterly Operating Results (Un

Quarterly Operating Results (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly Operating Results (Unaudited)	Quarterly Operating Results (Unaudited) 2018 1st 2nd 3rd 4th Year (In thousands, except days and per share amounts) Number of days in quarter 91 91 91 92 365 Revenues $ 605,565 $ 668,639 $ 655,774 $ 655,390 $ 2,585,368 Gross profit 230,594 257,596 260,857 259,365 1,008,412 Operating income 44,203 56,506 131,278 73,234 305,221 Net income 2,570 28,792 85,858 43,491 160,711 Less: Net loss attributable to noncontrolling interest (48 ) (77 ) (23 ) (35 ) (183 ) Net income attributable to Belden 2,618 28,869 85,881 43,526 160,894 Less: Preferred stock dividends 8,733 8,733 8,732 8,733 34,931 Net income (loss) attributable to Belden common stockholders (6,115 ) 20,136 77,149 34,793 125,963 Basic income (loss) per share attributable to Belden common stockholders: $ (0.15 ) $ 0.49 $ 1.90 $ 0.87 $ 3.10 Diluted income (loss) per share attributable to Belden stockholders: $ (0.15 ) $ 0.49 $ 1.80 $ 0.87 $ 3.08 Included in the first, second, third, and fourth quarters of 2018 are severance, restructuring, and integration costs of $20.4 million , $24.9 million , $11.7 million , and $11.6 million , respectively. 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 222,374 243,104 239,849 229,426 934,753 Operating income 51,597 62,776 61,116 59,915 235,404 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 common 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 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 Enterprise 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 were 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.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events We signed a settlement agreement with the sellers ("Claimant") of SAM on January 30, 2019 for claims arising over the timing of the earnout consideration outlined in the purchase agreement. As part of the settlement, the parties agreed that the earnout consideration would be payable during the first quarter 2020, unless earlier payment is required as per the terms of the purchase agreement, and Belden would immediately pay the Claimant $0.9 million for interest and fees incurred, which we recognized in selling, general, and administrative expenses in our 2018 financial statements.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2018
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: 2018 $ 7,766 $ 1,273 $ 1,168 $ (1,389 ) $ (293 ) $ (294 ) $ 8,231 2017 8,104 950 38 (905 ) (995 ) 574 7,766 2016 8,281 2,517 (1 ) (1,336 ) (1,046 ) (311 ) 8,104 Inventories— Excess and Obsolete Allowances: 2018 $ 25,269 $ 3,659 $ 6,204 $ (3,328 ) $ (2,709 ) $ (199 ) $ 28,896 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 Deferred Income Tax Asset— Valuation Allowance: 2018 $ 151,841 $ 20,274 $ 33,870 $ (93,432 ) $ (17,930 ) $ (3,751 ) $ 90,872 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

Basis of Presentation (Policies

Basis of Presentation (Policies)	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business Description	Business Description Belden Inc. (the Company, us, we, or our) is a signal transmission solutions company built around two global business platforms – Enterprise Solutions and Industrial 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 reclassifications to the 2017 and 2016 Condensed Consolidated Financial Statements, including those related to the adoption of 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) and our segment change, with no impact to reported net income in order to conform to the 2018 presentation. See Note 5.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
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. During 2018, 2017 , and 2016 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 4) and for our annual impairment testing (see Note 10). We did not have any transfers between Level 1 and Level 2 fair value measurements during 2018 .
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, 2018 and 2017 , 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	Accounts Receivable We classify amounts owed to us and due within twelve months, arising from the sale of goods or services and from other business activities, 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, 2018 and 2017 totaled $25.7 million and $35.7 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 net realizable value. 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 as of our fiscal November month-end 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 2018 , we performed a qualitative assessment for seven of our reporting units, which collectively represented approximately $383.4 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 2018 , we performed a quantitative assessment for four of our reporting units, which collectively represented approximately $1,174.3 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 four 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 2018 , 2017 , or 2016 . 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 2018 , 2017 , or 2016 . See Note 10 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 2018 , 2017 , or 2016 .
Disposals	Disposals During 2018, we sold a previously closed operating facility for net proceeds of $1.5 million and recognized a $0.6 million gain on the sale. During the fourth quarter of 2016, we committed to a plan to sell our MCS business and 50% ownership interest in Xuzhou Hirschmann Electronics Co. Ltd (the 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. In 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 was included in selling, general and administrative expenses. This loss included $2.8 million of accumulated other comprehensive losses that were recognized as a result of the sale. We collected the $40.2 million proceeds from the sale during 2018.
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 consideration of an acquired business to its identifiable assets and liabilities based on estimated fair values. The excess of the consideration 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 acquisition accounting, 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 consistent with the principles as outlined in the following five step model: (1) identify the contract with the customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when (or as) each performance obligation is satisfied. See Note 3.
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. 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. At December 31, 2018 the valuation allowance of $90.9 million was primarily related to net operating losses and foreign tax credits that we are not expected to realize. 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. 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. In accordance with the Act, we recorded $28.4 million as additional income tax expense in the fourth quarter of 2017, the period in which the legislation was enacted. The total income tax expense 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, 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. Additionally, Staff Accounting Bulletin No. 118 (“SAB 118”) was issued to address the application of U.S. 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. December 22, 2018 marked the end of the measurement period for purposes of SAB 118. As such, we have completed our analysis based on legislative updates relating to the Act currently available which resulted in an additional SAB 118 tax expense of $10.0 million for the year ended December 31, 2018. The total tax expense included an $8.0 million tax expense associated with an increase to the valuation allowance against foreign tax credit carryovers that we no longer expect to be able to realize based upon the new tax law, a $1.3 million tax expense adjustment to the transition tax on the deemed repatriation of cumulative foreign earnings, a $1.1 million tax expense resulting from a valuation allowance established on the deferred tax assets associated with stock options of covered employees, and a $0.4 million income tax benefit associated with an adjustment to the remeasurement of certain deferred tax assets and liabilities. See Note 15, Income Taxes, in the accompanying notes to our consolidated financial statements.
Recent Accounting Pronouncements	Current-Year Adoption of Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (ASU 2014-09), which replaced 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 adopted ASU 2014-09 on January 1, 2018, using the modified retrospective method of adoption. Adoption resulted in a $2.6 million , net of tax increase to retained earnings. 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 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 (ASU 2016-15). 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. We adopted ASU 2016-15 on January 1, 2018. The adoption had no material impact on our statement of cash flows for the year ended December 31, 2018 . 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. We adopted ASU 2016-16 on January 1, 2018. The adoption resulted in a $3.0 million and $46.9 million decrease to other current assets and other long-lived assets, respectively, as well as an $18.2 million increase in deferred income tax assets and a $31.7 million decrease to retained earnings on January 1, 2018. The adoption had no material impact on our results of operations. In March 2017, the FASB issued 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 is 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. We adopted ASU 2017-07 on January 1, 2018, and elected to use the practical expedient related to the retrospective presentation requirements. Adoption resulted in a $0.7 million and $8.2 million increase to operating income for the years ended December 31, 2017 and 2016, respectively, but no changes to net income. 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. In the fourth quarter of 2018, the Company elected to treat any potential GILTI inclusions as a period cost. In August 2018, the FASB issued ASU No. 2018-14 (“ASU 2018-14”), Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans. The amendments in ASU 2018-14 remove certain disclosures, clarify the specific requirements of disclosures, and add new disclosure requirements, including (1) the weighted-average interest crediting rates for cash balance plans and other plans with promised interest crediting rates and (2) an explanation of the reasons for significant gains and losses related to changes in the benefit obligation for the period. The amendments are effective for fiscal years ending after December 15, 2020, and early adoption is permitted. We early adopted ASU 2018-14 in 2018. The adoption had no impact on our financial statements; only our disclosures. See Note 16. Pending Adoption of Recent Accounting Pronouncements In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (ASU 2016-02), a leasing standard for both lessees and lessors that supersedes the lease requirements in Accounting Standards Codification (ASC) Topic 840, " Leases ." Under its core principle, a lessee will recognize a right-of-use asset and lease liability on the balance sheet for nearly all leased assets. Lessor accounting remains largely consistent with existing U.S. generally accepted accounting principles. We plan to adopt ASU 2016-02 on January 1, 2019 using the newly permitted transition method issued in July 2018, under ASU No. 2018-11 (“ASU 2018-11”), Leases: Targeted Improvements , which provides an additional (and optional) transition method for adopting the new lease standard. Under this transition method, an entity initially applies the new lease standard at the adoption date and recognizes a cumulative effect adjustment to opening retained earnings in the period of adoption. Furthermore, we plan to elect the following practical expedients and accounting policy elections upon adoption: (i) the package of practical expedients as defined in ASU 2016-02, (ii) the short-term lease accounting policy election, (iii) the practical expedient to not separate non-lease components from lease components, and (iv) the easement practical expedient, which permits an entity to continue applying its current policy for accounting for land easements that existed as of the effective date of ASU 2016-02. We are implementing changes to our systems and processes in response to the new standard. We expect the adoption will result in an increase to our total assets and liabilities on our consolidated balance sheet between $68 million and $78 million , before considering deferred taxes. The adoption is not expected to have a material impact on our results of operations. 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 February 2018, the FASB issued ASU No. 2018-02 (“ASU 2018-02”), Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . ASU 2018-02 provides an option to allow reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017. The new guidance is effective for annual and interim periods beginning after December 15, 2018, and early adoption is permitted. We are currently evaluating the impact this update will have on our condensed consolidated financial statements and related disclosures. In June 2018, the FASB issued ASU No. 2018-07 (“ASU 2018-07”), Improvements to Nonemployee Share-Based Payment Accounting . The amendments in ASU 2018-07 expand the scope of Topic 718, Compensation - Stock Compensation, to include share-based payment transactions for acquiring goods and services from non-employees, and provide that non-employee share-based payment awards be measured at their grant-date fair value and the probability of satisfying performance conditions be taken into account when non-employee share-based payment awards contain such conditions. The standard is effective for fiscal years beginning after December 15, 2018, and early adoption is permitted. We are currently evaluating the impact this update will have on our condensed consolidated financial statements and related disclosures. In August 2018, the Securities and Exchange Commission (“SEC”) adopted the final rule under SEC Release No. 33-10532, Disclosure Update and Simplification , amending certain disclosure requirements that were redundant, duplicative, overlapping, outdated or superseded. Additionally, the amendments expanded the disclosure requirements on the analysis of stockholders' equity for interim financial statements. Under the amendments, an analysis of changes in each caption of stockholders' equity presented in the balance sheet must be provided in a note or separate statement. The analysis should present a reconciliation of the beginning balance to the ending balance of each period presented. The amendments were effective on November 5, 2018, however, the SEC staff recently clarified in a Compliance and Disclosure Interpretation (C&DI) that it would not object if a registrant waits until it files Form 10-Q for the quarter that begins after the effective date to comply with the new requirements pertaining to the equity reconciliation but can adopt the other amendments upon effectiveness. We are in the process of evaluating the impact of the final rule on its consolidated financial statements.

Revenues (Tables)

Revenues (Tables)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables present our revenues disaggregated by major product category. Cable & Connectivity Networking, Software & Security Total Revenues Year Ended December 31, 2018 Enterprise Solutions $ 1,046,744 $ 468,822 $ 1,515,566 Industrial Solutions 662,742 407,060 1,069,802 Total $ 1,709,486 $ 875,882 $ 2,585,368 Year Ended December 31, 2017 Enterprise Solutions $ 1,024,090 $ 332,215 $ 1,356,305 Industrial Solutions 628,889 403,449 1,032,338 Total $ 1,652,979 $ 735,664 $ 2,388,643 Year Ended December 31, 2016 Enterprise Solutions $ 1,003,799 $ 368,009 $ 1,371,808 Industrial Solutions 590,462 394,402 984,864 Total $ 1,594,261 $ 762,411 $ 2,356,672 The following tables present our revenues disaggregated by geography, based on the location of the customer purchasing the product. Americas EMEA APAC Total Revenues Year Ended December 31, 2018 Enterprise Solutions $ 981,822 $ 294,129 $ 239,615 $ 1,515,566 Industrial Solutions 619,721 290,607 159,474 1,069,802 Total $ 1,601,543 $ 584,736 $ 399,089 $ 2,585,368 Year Ended December 31, 2017 Enterprise Solutions $ 925,647 $ 214,763 $ 215,895 $ 1,356,305 Industrial Solutions 606,331 280,890 145,117 1,032,338 Total $ 1,531,978 $ 495,653 $ 361,012 $ 2,388,643 Year Ended December 31, 2016 Enterprise Solutions $ 937,741 $ 220,511 $ 213,556 $ 1,371,808 Industrial Solutions 596,032 261,055 127,777 984,864 Total $ 1,533,773 $ 481,566 $ 341,333 $ 2,356,672 The following tables present our revenues disaggregated by products, including software products, and support and services. Products Support & Services Total Revenues Year Ended December 31, 2018 Enterprise Solutions $ 1,441,757 $ 73,809 $ 1,515,566 Industrial Solutions 974,029 95,773 1,069,802 Total $ 2,415,786 $ 169,582 $ 2,585,368 Year Ended December 31, 2017 Enterprise Solutions $ 1,281,960 $ 74,345 $ 1,356,305 Industrial Solutions 929,263 103,075 1,032,338 Total $ 2,211,223 $ 177,420 $ 2,388,643 Year Ended December 31, 2016 Enterprise Solutions $ 1,293,392 $ 78,416 $ 1,371,808 Industrial Solutions 885,208 99,656 984,864 Total $ 2,178,600 $ 178,072 $ 2,356,672

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table summarizes the estimated, preliminary fair value of the assets acquired and the liabilities assumed as of February 8, 2018 (in thousands): Receivables $ 16,551 Inventory 15,084 Prepaid and other current assets 3,799 Property, plant, and equipment 7,716 Intangible assets 51,000 Goodwill 102,715 Deferred income taxes 1,388 Other long-lived assets 3,046 Total assets acquired $ 201,299 Accounts payable $ 11,825 Accrued liabilities 24,405 Deferred revenue 8,860 Long-term debt 19,315 Postretirement benefits 31,774 Other long-term liabilities 591 Total liabilities assumed $ 96,770 Net assets $ 104,529 The following table summarizes the estimated fair values of the assets acquired and the liabilities assumed as of May 31, 2017 (in thousands): Receivables $ 4,355 Inventory 16,424 Prepaid and other current assets 320 Property, plant, and equipment 4,289 Intangible assets 73,400 Goodwill 70,654 Deferred income taxes 598 Total assets acquired $ 170,040 Accounts payable $ 1,231 Accrued liabilities 1,353 Deferred revenue 1,702 Total liabilities assumed $ 4,286 Net assets $ 165,754
Schedule of Acquired Intangible Assets	The intangible assets related to the acquisition consisted of the following: Preliminary Fair Value Amortization Period (In thousands) (In years) Intangible assets subject to amortization: Developed technologies $ 36,500 5.0 Customer relationships 11,000 12.0 Sales backlog 1,900 0.3 Trademarks 1,600 0.9 Total intangible assets subject to amortization $ 51,000 Intangible assets not subject to amortization: Goodwill $ 102,715 n/a Total intangible assets not subject to amortization $ 102,715 Total intangible assets $ 153,715 Weighted average amortization period 6.2 years 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 $ 70,654 n/a Total intangible assets not subject to amortization $ 70,654 Total intangible assets $ 144,054 Weighted average amortization period 9.6 years
Schedule of Pro Forma Information	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 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 The following table illustrates the unaudited pro forma effect on operating results as if the SAM acquisition had been completed as of January 1, 2017. Years Ended December 31, 2018 2017 (In thousands, except per share data) (Unaudited) Revenues $ 2,598,741 $ 2,500,779 Net income (loss) attributable to Belden common stockholders 168,819 (8,581 ) Diluted income (loss) per share attributable to Belden common stockholders $ 4.12 $ (0.20 )

Operating Segments and Geogra_2

Operating Segments and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Operating Segment Information	Operating Segment Information Enterprise Solutions Years ended December 31, 2018 2017 2016 (In thousands) Segment revenues $ 1,522,178 $ 1,356,305 $ 1,372,941 Affiliate revenues 6,085 5,091 2,799 Segment EBITDA 267,656 216,558 239,978 Depreciation expense 28,861 26,272 29,455 Amortization of intangibles 45,944 51,054 48,966 Amortization of software development intangible assets 2,180 56 — Severance, restructuring, and acquisition integration costs 57,563 29,043 18,561 Purchase accounting effects of acquisitions 3,497 6,133 (2,079 ) Deferred revenue adjustments 6,612 — 1,774 Patent settlement — — (5,554 ) Acquisition of property, plant and equipment 65,619 49,440 38,392 Segment assets 761,309 687,914 571,960 Industrial Solutions Years ended December 31, 2018 2017 2016 (In thousands) Segment revenues $ 1,069,802 $ 1,032,338 $ 984,864 Affiliate revenues 81 67 71 Segment EBITDA 207,724 214,190 193,811 Depreciation expense 18,754 19,325 17,753 Amortization of intangibles 52,885 52,943 49,419 Amortization of software development intangible assets 8 — — Severance, restructuring, and acquisition integration costs 11,050 13,747 12,579 Deferred revenue adjustments — — 4,913 Acquisition of property, plant and equipment 29,215 13,319 15,190 Segment assets 458,801 458,481 342,038 Total Segments Years ended December 31, 2018 2017 2016 (In thousands) Segment revenues $ 2,591,980 $ 2,388,643 $ 2,357,805 Affiliate revenues 6,166 5,158 2,870 Segment EBITDA 475,380 430,748 433,789 Depreciation expense 47,615 45,597 47,208 Amortization of intangibles 98,829 103,997 98,385 Amortization of software development intangible assets 2,188 56 — Severance, restructuring, and acquisition integration costs 68,613 42,790 31,140 Purchase accounting effects of acquisitions 3,497 6,133 (2,079 ) Deferred revenue adjustments 6,612 — 6,687 Patent settlement — — (5,554 ) Acquisition of property, plant and equipment 94,834 62,759 53,582 Segment assets 1,220,110 1,146,395 913,998
Reconciliation of Total Reportable Segments' Revenues and EBITDA to Consolidated Revenues and Consolidated Income Before Taxes	The following table is a reconciliation of the total of the reportable segments’ Revenues and EBITDA to consolidated revenues and consolidated income before taxes, respectively. Years Ended December 31, 2018 2017 2016 (In thousands) Total Segment Revenues $ 2,591,980 $ 2,388,643 $ 2,357,805 Deferred revenue adjustments (1) (6,612 ) — (6,687 ) Patent settlement (2) — — 5,554 Consolidated Revenues $ 2,585,368 $ 2,388,643 $ 2,356,672 Total Segment EBITDA $ 475,380 $ 430,748 $ 433,789 Amortization of intangibles (98,829 ) (103,997 ) (98,385 ) Severance, restructuring, and acquisition integration costs (3) (68,613 ) (42,790 ) (31,140 ) Depreciation expense (47,615 ) (45,597 ) (47,208 ) Deferred revenue adjustments (1) (6,612 ) — (6,687 ) Purchase accounting effects related to acquisitions (4) (3,497 ) (6,133 ) 2,079 Costs related to patent litigation (2,634 ) — — Amortization of software development intangible assets (2,188 ) (56 ) — Loss on sale of assets (5) (94 ) (1,013 ) — Impairment of assets held for sale (5) — — (23,931 ) Patent settlement (2) — — 5,554 Income from equity method investment — 7,502 1,793 Gain from patent litigation 62,141 — — Eliminations (2,218 ) (3,260 ) (3,781 ) Consolidated operating income 305,221 235,404 232,083 Interest expense, net (61,559 ) (82,901 ) (95,050 ) Non-operating pension cost (342 ) (714 ) (8,230 ) Loss on debt extinguishment (22,990 ) (52,441 ) (2,342 ) Consolidated income before taxes $ 220,330 $ 99,348 $ 126,461 (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 4, 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 12, Severance, Restructuring, and Acquisition Integration Activities, for details . (4) In 2018, we recognized $3.5 million of cost of sales related to purchase accounting adjustments, most of which was for the adjustment of acquired inventory to fair value for our SAM and NT2 acquisitions. 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 segment and M2FX acquisition, respectively. (5) In 2018, 2017, and 2016, we recognized a $0.1 million loss on sale of assets, $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.
Reconciliations of Other Segment Measures to Consolidated Totals	Below are reconciliations of other segment measures to the consolidated totals. Years Ended December 31, 2018 2017 2016 (In thousands) Total segment assets $ 1,220,110 $ 1,146,395 $ 913,998 Cash and cash equivalents 420,610 561,108 848,116 Goodwill 1,557,653 1,478,257 1,385,995 Intangible assets, less accumulated amortization 511,093 545,207 560,082 Deferred income taxes 56,018 42,549 33,706 Corporate assets 13,837 67,097 64,906 Total assets $ 3,779,321 $ 3,840,613 $ 3,806,803 Total segment acquisition of property, plant and equipment $ 94,834 $ 62,759 $ 53,582 Corporate acquisition of property, plant and equipment 3,013 1,502 392 Total acquisition of property, plant and equipment $ 97,847 $ 64,261 $ 53,974
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, 2018 , 2017 and 2016 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, 2018 Revenues $ 1,324,653 $ 174,727 $ 132,544 $ 117,598 $ 835,846 $ 2,585,368 Percent of total revenues 51 % 7 % 5 % 5 % 32 % 100 % Long-lived assets $ 189,211 $ 32,312 $ 37,227 $ 39,870 $ 97,213 $ 395,833 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

Income Per Share (Tables)

Income Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 2017 2016 (In thousands) Numerator: Net income $ 160,711 $ 92,853 $ 127,646 Less: Net loss attributable to noncontrolling interest (183 ) (357 ) (357 ) Less: Preferred stock dividends 34,931 34,931 15,428 Net income attributable to Belden common stockholders $ 125,963 $ 58,279 $ 112,575 Denominator: Weighted average shares outstanding, basic 40,675 42,220 42,093 Effect of dilutive common stock equivalents 281 423 464 Weighted average shares outstanding, diluted 40,956 42,643 42,557

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Major Classes of Inventories	The major classes of inventories were as follows: December 31, 2018 2017 (In thousands) Raw materials $ 146,803 $ 133,311 Work-in-process 45,939 35,807 Finished goods 152,572 153,377 Gross inventories 345,314 322,495 Excess and obsolete reserves (28,896 ) (25,269 ) Net inventories $ 316,418 $ 297,226

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 2017 (In thousands) Land and land improvements $ 30,173 $ 31,963 Buildings and leasehold improvements 141,009 148,598 Machinery and equipment 569,359 543,594 Computer equipment and software 139,773 136,509 Construction in process 64,145 46,898 Gross property, plant and equipment 944,459 907,562 Accumulated depreciation (578,489 ) (570,240 ) Net property, plant and equipment $ 365,970 $ 337,322

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Carrying Value of Intangible Assets	The carrying values of intangible assets were as follows: December 31, 2018 December 31, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount (In thousands) (In thousands) Goodwill $ 1,557,653 $ — $ 1,557,653 $ 1,478,257 $ — $ 1,478,257 Definite-lived intangible assets subject to amortization: Developed technology $ 545,982 $ (379,896 ) $ 166,086 $ 498,649 $ (318,366 ) $ 180,283 Customer relationships 331,643 (115,943 ) 215,700 320,550 (98,175 ) 222,375 Trademarks 57,860 (27,106 ) 30,754 56,794 (18,648 ) 38,146 In-service research and development 23,833 (16,471 ) 7,362 23,428 (13,483 ) 9,945 Backlog 15,885 (15,885 ) — 14,535 (14,535 ) — Total intangible assets subject to amortization 975,203 (555,301 ) 419,902 913,956 (463,207 ) 450,749 Indefinite-lived intangible assets not subject to amortization: Trademarks 90,391 — 90,391 92,758 — 92,758 In-process research and development 800 — 800 1,700 — 1,700 Total intangible assets not subject to amortization 91,191 — 91,191 94,458 — 94,458 Intangible assets $ 1,066,394 $ (555,301 ) $ 511,093 $ 1,008,414 $ (463,207 ) $ 545,207
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: Enterprise Solutions Industrial Solutions Consolidated (In thousands) Balance at December 31, 2016 $ 617,320 $ 768,675 $ 1,385,995 Acquisitions and purchase accounting adjustments 71,394 — 71,394 Translation impact 13,557 7,311 20,868 Balance at December 31, 2017 $ 702,271 $ 775,986 $ 1,478,257 Acquisitions and purchase accounting adjustments 105,899 — 105,899 Translation impact (22,812 ) (3,691 ) (26,503 ) Balance at December 31, 2018 $ 785,358 $ 772,295 $ 1,557,653
Changes in Carrying Amount of Trademarks	The changes in the carrying amount of indefinite-lived trademarks are as follows: Enterprise Solutions Industrial Solutions Consolidated (In thousands) Balance at December 31, 2016 $ 80,350 $ 41,622 $ 121,972 Translation impact 2,727 1,260 3,987 Reclassify to definite-lived — (33,201 ) (33,201 ) Balance at December 31, 2017 $ 83,077 $ 9,681 $ 92,758 Translation impact (1,893 ) (474 ) (2,367 ) Balance at December 31, 2018 $ 81,184 $ 9,207 $ 90,391

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
Accrued Liabilities [Abstract]
Carrying Value of Accrued Liabilities	The carrying values of accrued liabilities were as follows: December 31, 2018 2017 (In thousands) Current deferred revenue $ 101,194 $ 90,639 Wages, severance and related taxes 56,129 57,633 Accrued rebates 41,312 38,025 Employee benefits 25,670 25,406 Accrued interest 18,530 22,019 Other (individual items less than 5% of total current liabilities) 121,441 68,929 Accrued liabilities $ 364,276 $ 302,651

Severance, Restructuring, and_2

Severance, Restructuring, and Acquisition Integration Activities (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 Enterprise Solutions $ 9,945 $ 47,618 $ 57,563 Industrial Solutions 378 10,672 11,050 Total $ 10,323 $ 58,290 $ 68,613 Year Ended December 31, 2017 Enterprise Solutions $ 4,535 $ 24,508 $ 29,043 Industrial Solutions 676 13,071 13,747 Total $ 5,211 $ 37,579 $ 42,790 Year Ended December 31, 2016 Enterprise Solutions $ 520 $ 18,041 $ 18,561 Industrial Solutions 6,562 6,017 12,579 Total $ 7,082 $ 24,058 $ 31,140

Long-Term Debt and Other Borr_2

Long-Term Debt and Other Borrowing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 2017 (In thousands) Revolving credit agreement due 2022 $ — $ — Senior subordinated notes: 3.875% Senior subordinated notes due 2028 400,050 — 3.375% Senior subordinated notes due 2027 514,350 540,810 4.125% Senior subordinated notes due 2026 228,600 240,360 2.875% Senior subordinated notes due 2025 342,900 360,540 5.25% Senior subordinated notes due 2024 — 200,000 5.50% Senior subordinated notes due 2023 — 242,522 Total senior subordinated notes 1,485,900 1,584,232 Less unamortized debt issuance costs (22,700 ) (23,484 ) Long-term debt $ 1,463,200 $ 1,560,748
Schedule of Senior Subordinated Notes	The senior subordinated notes due 2025, 2026, 2027 and 2028 are redeemable after September 15, 2020, October 15, 2021, July 15, 2022, and March 15, 2023, respectively, at the following redemption prices as a percentage of the face amount of the notes: Senior Subordinated Notes due 2025 2026 2027 2028 Year Percentage Year Percentage Year Percentage Year Percentage 2020 101.438 % 2021 102.063 % 2022 101.688 % 2023 101.9375 % 2021 100.719 % 2022 101.375 % 2023 101.125 % 2024 101.2916 % 2022 and thereafter 100.000 % 2023 100.688 % 2024 100.563 % 2025 100.6458 % 2024 and thereafter 100.000 % 2025 and thereafter 100.000 % 2026 and thereafter 100.0000 %
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, 2018 are as follows (in thousands): 2019 $ — 2020 — 2021 — 2022 — 2023 — Thereafter 1,485,900 $ 1,485,900

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Components of Income Tax Expense	Years ended December 31, 2018 2017 2016 (In thousands) Income (loss) before taxes: United States operations $ 126,385 $ 2,177 $ (25,615 ) Foreign operations 93,945 97,171 152,076 Income before taxes $ 220,330 $ 99,348 $ 126,461 Income tax expense (benefit): Currently payable United States federal $ 27,529 $ — $ 2,981 United States state and local 3,274 2,392 (1,038 ) Foreign 17,516 28,201 26,906 48,319 30,593 28,849 Deferred United States federal 10,942 (11,028 ) (27,677 ) United States state and local 703 (8,758 ) (3,139 ) Foreign (345 ) (4,312 ) 782 11,300 (24,098 ) (30,034 ) Income tax expense (benefit) $ 59,619 $ 6,495 $ (1,185 )
Effective Income Tax Rate Reconciliation from Continuing Operations	Years Ended December 31, 2018 2017 2016 Effective income tax rate reconciliation from continuing operations: United States federal statutory rate 21.0 % 35.0 % 35.0 % State and local income taxes 1.7 % 0.8 % (0.9 )% Impact of change in tax contingencies (1.0 )% 2.2 % 2.4 % Foreign income tax rate differences (1.8 )% (13.1 )% (14.0 )% Impact of change in deferred tax asset valuation allowance 2.0 % 1.5 % (7.3 )% 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 )% Domestic permanent differences and tax credits 0.7 % (15.7 )% (5.7 )% Impact of tax reform 4.5 % 28.6 % — % 27.1 % 6.5 % (0.9 )%
Components of Deferred Income Tax Balances	December 31, 2018 2017 (In thousands) Components of deferred income tax balances: Deferred income tax liabilities: Plant, equipment, and intangibles $ (114,413 ) $ (120,171 ) Deferred income tax assets: Postretirement, pensions, and stock compensation 30,896 28,736 Reserves and accruals 25,641 29,297 Net operating loss and tax credit carryforwards 164,823 228,815 Valuation allowances (90,872 ) (151,841 ) 130,488 135,007 Net deferred income tax asset $ 16,075 $ 14,836
Summary of Net Operating Loss Carryforwards	The following tables summarize our net operating loss carryforwards and tax credit carryforwards as of December 31, 2018 by jurisdiction: Net Operating Loss Carryforwards (In thousands) Australia $ 12,064 France 15,538 Germany 13,436 Japan 20,203 Luxembourg 24,252 Netherlands 23,889 Other 45,171 United Kingdom 258,423 United States - Federal and various states 124,349 Total $ 537,325
Summary of Tax Credit Carryforwards	Tax Credit Carryforwards (In thousands) United States $ 48,859 Canada 22,181 Total $ 71,040
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: 2018 2017 (In thousands) Balance at beginning of year $ 8,579 $ 10,474 Additions based on tax positions related to the current year 866 981 Additions for tax positions of prior years 1,292 2,549 Reductions for tax positions of prior years - Settlement (1,689 ) (5,425 ) Reduction for tax positions of prior years - Statute of limitations (1,631 ) — Balance at end of year $ 7,417 $ 8,579

Pension and Other Postretirem_2

Pension and Other Postretirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 2017 2018 2017 (In thousands) Change in benefit obligation: Benefit obligation, beginning of year $ (272,025 ) $ (256,481 ) $ (30,333 ) $ (32,038 ) Service cost (4,705 ) (4,978 ) (47 ) (49 ) Interest cost (11,690 ) (7,671 ) (945 ) (1,139 ) Participant contributions (85 ) (91 ) (6 ) (7 ) Actuarial gain (loss) 15,032 (3,291 ) 1,681 3,370 Divestitures (acquisitions) (185,692 ) 794 — — Settlements 7,437 49 — — Plan amendments (2,822 ) — — — Foreign currency exchange rate changes 23,454 (14,299 ) 2,020 (2,022 ) Benefits paid 12,849 13,943 1,487 1,552 Benefit obligation, end of year $ (418,247 ) $ (272,025 ) $ (26,143 ) $ (30,333 )
Change in Plan Assets	Pension Benefits Other Benefits Years Ended December 31, 2018 2017 2018 2017 (In thousands) Change in plan assets: Fair value of plan assets, beginning of year $ 198,156 $ 182,370 $ — $ — Actual return on plan assets (8,364 ) 18,746 — — Employer contributions 5,397 4,425 1,481 1,545 Plan participant contributions 85 91 6 7 Acquisitions 153,919 — — — Settlements (7,054 ) — — — Foreign currency exchange rate changes (17,616 ) 6,467 — — Benefits paid (12,849 ) (13,943 ) (1,487 ) (1,552 ) Fair value of plan assets, end of year $ 311,674 $ 198,156 $ — $ —
Amounts Recognized in Balance Sheets	Funded status, end of year $ (106,573 ) $ (73,869 ) $ (26,143 ) $ (30,333 ) Amounts recognized in the balance sheets: Prepaid benefit cost $ 4,801 $ 3,174 $ — $ — Accrued benefit liability (current) (3,320 ) (3,736 ) (1,405 ) (1,555 ) Accrued benefit liability (noncurrent) (108,054 ) (73,307 ) (24,738 ) (28,778 ) Net funded status $ (106,573 ) $ (73,869 ) $ (26,143 ) $ (30,333 )
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, 2018 2017 2016 2018 2017 2016 (In thousands) Components of net periodic benefit cost: Service cost $ 4,705 $ 4,978 $ 4,981 $ 47 $ 49 $ 46 Interest cost 11,690 7,671 8,909 945 1,139 1,259 Expected return on plan assets (16,391 ) (10,644 ) (12,013 ) — — — Amortization of prior service credit (42 ) (41 ) (42 ) — — (42 ) Curtailment gain — — (227 ) — — — Settlement loss (gain) 1,342 (8 ) 7,630 — — — Net loss (gain) recognition 2,810 2,597 2,670 (12 ) — 86 Net periodic benefit cost $ 4,114 $ 4,553 $ 11,908 $ 980 $ 1,188 $ 1,349
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, 2018 2017 2018 2017 Weighted average assumptions for benefit obligations at year end: Discount rate 3.1 % 2.8 % 3.7 % 3.3 % Salary increase 3.6 % 3.6 % N/A N/A Cash balance interest credit rate 4.7 % 4.7 % N/A N/A Weighted average assumptions for net periodic cost for the year: Discount rate 2.8 % 3.1 % 3.3 % 3.7 % Salary increase 3.6 % 3.6 % N/A N/A Cash balance interest credit rate 4.7 % 4.7 % N/A N/A Expected return on assets 5.5 % 6.0 % N/A N/A Assumed health care cost trend rates: Health care cost trend rate assumed for next year N/A N/A 5.8 % 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 2025 2024
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, 2018 December 31, 2017 Fair Market Value at December 31, 2018 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, 2017 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) U.S. equities fund $ 96,417 $ 1,465 $ — $ — $ 95,425 $ — $ — $ — Non-U.S. equities fund 47,274 5,755 — — 11,571 — — — Debt securities(b) Government bond fund 66,439 — 1,253 — 28,429 — — — Corporate bond fund 39,366 — 7,116 — 24,421 — — — Fixed income fund(c) 41,167 — 39,340 — 38,072 — 38,072 — Other investments(d) 17,274 — — — — — — — Cash & equivalents 3,737 301 — — 238 238 — — Total $ 311,674 $ 7,521 $ 47,709 $ — $ 198,156 $ 238 $ 38,072 $ — (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. Equity securities held in separate accounts are valued based on observable quoted prices on active exchanges. Funds which are 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 and annuity policies. (d) This category includes investments in hedge funds that pursue multiple strategies in order to provide diversification and balance risk/return objectives, real estate funds, and private equity funds. Funds valued using the net asset method are not included in the fair value hierarchy.
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, 2018 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) 2019 $ 21,667 $ 1,432 2020 22,965 1,436 2021 22,199 1,438 2022 23,157 1,438 2023 22,081 1,432 2024-2028 111,338 7,196 Total $ 223,407 $ 14,372
Summary of Accumulated Other Comprehensive Loss and Changes in these Amounts	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, 2018 and the changes in these amounts during the year ended December 31, 2018 are as follows. Pension Benefits Other Benefits (In thousands) Components of accumulated other comprehensive loss: Net actuarial loss (gain) $ 48,466 $ (3,047 ) Net prior service cost 2,734 — $ 51,200 $ (3,047 ) Pension Benefits Other Benefits (In thousands) Changes in accumulated other comprehensive loss: Net actuarial loss (gain), beginning of year $ 44,359 $ (1,545 ) Amortization of actuarial gain (loss) (2,810 ) 12 Actuarial gain (15,032 ) (1,681 ) Asset loss 24,755 — Settlement loss recognized (1,342 ) — Currency impact (1,464 ) 167 Net actuarial loss (gain), end of year $ 48,466 $ (3,047 ) Prior service cost, beginning of year $ 11 $ — Amortization of prior service credit 42 — Prior service cost occurring during the year 2,822 — Currency impact (141 ) — Prior service cost, end of year $ 2,734 $ —

Comprehensive Income and Accu_2

Comprehensive Income and Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2016 $ (4,661 ) $ (34,406 ) $ (39,067 ) Other comprehensive gain (loss) 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 ) Other comprehensive gain (loss) attributable to Belden before reclassifications 27,809 (7,813 ) 19,996 Amounts reclassified from accumulated other comprehensive income — 3,123 3,123 Net current period other comprehensive gain (loss) attributable to Belden 27,809 (4,690 ) 23,119 Balance at December 31, 2018 $ (41,882 ) $ (33,025 ) $ (74,907 )
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 Affected Line Item in the Consolidated Statements of Operations and Comprehensive Income (In thousands) Amortization of pension and other postretirement benefit plan items: Settlement loss $ 1,342 (1 ) Actuarial losses 2,798 (1 ) Prior service credit (42 ) (1 ) Total before tax 4,098 Tax benefit (975 ) Total net of tax $ 3,123 (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, 2018
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, 2018 2017 2016 (In thousands) Total share-based compensation cost $ 18,497 $ 14,647 $ 18,178 Income tax benefit 4,402 5,566 7,069
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, 2018 2017 2016 (In thousands, except weighted average fair value and assumptions) Weighted-average fair value of SARs and options granted $ 25.19 $ 27.31 $ 18.79 Total intrinsic value of SARs converted and options exercised 2,263 7,156 9,678 Tax benefit related to share-based compensation 113 967 1,171 Weighted-average fair value of restricted stock shares and units granted 72.54 79.96 54.52 Total fair value of restricted stock shares and units vested 5,740 10,355 8,171 Expected volatility 33.16 % 36.89 % 37.47 % Expected term (in years) 5.6 5.6 5.7 Risk-free rate 2.70 % 2.01 % 1.32 % Dividend yield 0.27 % 0.27 % 0.38 %
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, 2018 1,132 $ 62.75 496 $ 78.03 Granted 265 72.34 338 72.54 Exercised or converted (62 ) 36.70 (71 ) 81.48 Forfeited or expired (46 ) 73.76 (136 ) 91.97 Outstanding at December 31, 2018 1,289 $ 65.58 6.6 $ — 627 $ 71.66 Vested or expected to vest at December 31, 2018 1,237 $ 65.33 6.5 $ — Exercisable or convertible at December 31, 2018 801 62.88 5.4 —

Operating Leases (Tables)

Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 are as follows (in thousands): 2019 $ 19,877 2020 17,531 2021 14,776 2022 12,317 2023 7,654 Thereafter 28,771 $ 100,926

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental cash flow information is as follows: Years Ended December 31, 2018 2017 2016 (In thousands) Income tax refunds received $ 4,782 $ 5,031 $ 3,838 Income taxes paid (54,109 ) (35,893 ) (26,587 ) Interest paid (48,519 ) (79,047 ) (87,076 )

Quarterly Operating Results (_2

Quarterly Operating Results (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly Operating Results (Unaudited)	2018 1st 2nd 3rd 4th Year (In thousands, except days and per share amounts) Number of days in quarter 91 91 91 92 365 Revenues $ 605,565 $ 668,639 $ 655,774 $ 655,390 $ 2,585,368 Gross profit 230,594 257,596 260,857 259,365 1,008,412 Operating income 44,203 56,506 131,278 73,234 305,221 Net income 2,570 28,792 85,858 43,491 160,711 Less: Net loss attributable to noncontrolling interest (48 ) (77 ) (23 ) (35 ) (183 ) Net income attributable to Belden 2,618 28,869 85,881 43,526 160,894 Less: Preferred stock dividends 8,733 8,733 8,732 8,733 34,931 Net income (loss) attributable to Belden common stockholders (6,115 ) 20,136 77,149 34,793 125,963 Basic income (loss) per share attributable to Belden common stockholders: $ (0.15 ) $ 0.49 $ 1.90 $ 0.87 $ 3.10 Diluted income (loss) per share attributable to Belden stockholders: $ (0.15 ) $ 0.49 $ 1.80 $ 0.87 $ 3.08 Included in the first, second, third, and fourth quarters of 2018 are severance, restructuring, and integration costs of $20.4 million , $24.9 million , $11.7 million , and $11.6 million , respectively. 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 222,374 243,104 239,849 229,426 934,753 Operating income 51,597 62,776 61,116 59,915 235,404 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 common stockholders: $ 0.40 $ 0.64 $ (0.18 ) $ 0.51 $ 1.37

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Details)	12 Months Ended
	Dec. 31, 2018Segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	2

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details)	Jul. 19, 2018USD ($)	Jul. 05, 2011patent	Jul. 31, 2015patent	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jul. 01, 2018USD ($)	Apr. 01, 2018USD ($)	Dec. 31, 2017USD ($)	Oct. 01, 2017USD ($)	Jul. 02, 2017USD ($)	Apr. 02, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2018USD ($)Reporting_Unit	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Mar. 31, 2019USD ($)	Jan. 01, 2018USD ($)
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													$ 25,700,000	$ 35,700,000
Bad debt expense, net of recoveries													1,000,000	0	$ 1,500,000
Allowance for doubtful accounts				$ 8,200,000				$ 7,800,000					8,200,000	7,800,000
Obsolescence and other reserves				28,896,000				25,269,000					$ 28,896,000	25,269,000
Number of reporting units used in qualitative assessment | Reporting_Unit													7
Goodwill qualitative assessment				383,400,000									$ 383,400,000
Number of reporting units used in quantitative assessment | Reporting_Unit													4
Goodwill quantitative assessment				1,174,300,000									$ 1,174,300,000
Impairment of assets held for sale													0	0	23,931,000
Accumulated other comprehensive losses recognized as result of sale of equity method investment				74,907,000				98,026,000					74,907,000	98,026,000
Proceeds from disposal of business													40,171,000	0	0
Accrued sales rebates				41,312,000				38,025,000					41,312,000	38,025,000
Gain from patent litigation													62,141,000	0	0
Advertising costs													23,500,000	25,000,000	27,200,000
Valuation allowances				90,872,000				151,841,000					90,872,000	151,841,000
Tax Cuts and Jobs Act of 2017, income tax expense								28,400,000
Tax Cuts and Jobs Act of 2017, remeasurement of deferred tax assets and liabilities								36,000,000					400,000
Tax Cuts and Jobs Act of 2017, transition tax for accumulated foreign earnings, income tax expense								29,100,000					1,300,000
Tax Cuts and Jobs Act of 2017, valuation allowance against foreign tax credit carryforward								35,300,000					8,000,000
SAB 118 Tax Expense				2,900,000									10,000,000
Tax Cuts and Jobs Act of 2017, income tax expense related to employee compensation													1,100,000
Increase (decrease) in retained earnings				922,000,000				833,610,000					922,000,000	833,610,000
Other current assets				(55,757,000)				(40,167,000)					(55,757,000)	(40,167,000)
Other long-lived assets				(29,863,000)				(65,207,000)					(29,863,000)	(65,207,000)
Deferred income taxes				56,018,000				42,549,000				$ 33,706,000	56,018,000	42,549,000	33,706,000
Operating income				73,234,000	$ 131,278,000	$ 56,506,000	$ 44,203,000	59,915,000	$ 61,116,000	$ 62,776,000	$ 51,597,000		305,221,000	235,404,000	232,083,000
Goodwill impairment													0	0	0
Indefinite lived intangible asset impairment													0	0	0
Amortizable intangible asset impairment													0	0	0
Reportable Segment
Significant Accounting Policies [Line Items]
Impairment of assets held for sale													0	0	23,931,000
Gain from patent litigation													(62,141,000)	0	0
Subsidiaries | Corning
Significant Accounting Policies [Line Items]
Number of patents allegedly infringed upon | patent		2
Proceeds from settlement	$ 62,100,000
Number of patents found infringed upon | patent			2
Previously Closed Operating Facility | Discontinued Operations, Disposed of by Sale
Significant Accounting Policies [Line Items]
Disposition, sales price				$ 1,500,000									1,500,000
Gain on disposal													600,000
Hirschmann Jv | Discontinued Operations, Held-for-sale
Significant Accounting Policies [Line Items]
Disposition, sales price								40,200,000				39,000,000		40,200,000	39,000,000
Impairment of assets held for sale												$ 23,900,000
Equity method investment, realized loss on disposal														1,000,000
Accumulated other comprehensive losses recognized as result of sale of equity method investment								$ 2,800,000						$ 2,800,000
Proceeds from disposal of business													$ 40,200,000
Hirschmann Jv
Significant Accounting Policies [Line Items]
Equity method investment, ownership percentage								50.00%						50.00%
Minimum
Significant Accounting Policies [Line Items]
Estimated useful life of definite-lived intangible assets													1 year
Maximum
Significant Accounting Policies [Line Items]
Estimated useful life of definite-lived intangible assets													25 years
Buildings | Minimum
Significant Accounting Policies [Line Items]
Estimated useful life of property, plant, and equipment													P10Y
Buildings | Maximum
Significant Accounting Policies [Line Items]
Estimated useful life of property, plant, and equipment													P40Y
Machinery and equipment | Minimum
Significant Accounting Policies [Line Items]
Estimated useful life of property, plant, and equipment													P5Y
Machinery and equipment | Maximum
Significant Accounting Policies [Line Items]
Estimated useful life of property, plant, and equipment													P12Y
Computer Equipment and Software | Minimum
Significant Accounting Policies [Line Items]
Estimated useful life of property, plant, and equipment													P5Y
Computer Equipment and Software | Maximum
Significant Accounting Policies [Line Items]
Estimated useful life of property, plant, and equipment													P10Y
Accounting Standards Update 2014-09
Significant Accounting Policies [Line Items]
Increase (decrease) in retained earnings																	$ 2,600,000
Accounting Standards Update 2016-16
Significant Accounting Policies [Line Items]
Increase (decrease) in retained earnings																	(31,700,000)
Other current assets																	3,000,000
Other long-lived assets																	46,900,000
Deferred income taxes																	$ 18,200,000
Accounting Standards Update 2017-07
Significant Accounting Policies [Line Items]
Operating income														$ 700,000	$ 8,200,000
Scenario, Forecast | Accounting Standards Update 2016-02 | Minimum
Significant Accounting Policies [Line Items]
Operating lease, asset																$ 68,000,000
Operating lease, liability																68,000,000
Scenario, Forecast | Accounting Standards Update 2016-02 | Maximum
Significant Accounting Policies [Line Items]
Operating lease, asset																78,000,000
Operating lease, liability																$ 78,000,000

Revenues - Narrative (Details)

Revenues - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Increase (decrease) in retained earnings	$ 922,000				$ 833,610				$ 922,000	$ 833,610
Decrease in revenues	(655,390)	$ (655,774)	$ (668,639)	$ (605,565)	(604,884)	$ (621,745)	$ (610,633)	$ (551,381)	(2,585,368)	(2,388,643)	$ (2,356,672)
Accrued rebates	41,312				$ 38,025				41,312	$ 38,025
Accrued returns	11,900								11,900
Estimated price adjustments, accounts receivable									25,100
Contract with customer, deferred revenues	113,300								113,300			$ 104,400
Deferred Revenue, Additions									202,100
Contract with customer, revenue recognized									193,200
Contract with customer, deferred revenues, current	101,200								101,200
Contract with customer, deferred revenues, noncurrent	12,100								12,100
Deferred sales commission	$ 2,900								2,900
Sales commissions									23,300
Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Increase (decrease) in retained earnings												$ 2,600
Decrease in revenues									$ 0

Revenues - Major Product Catego

Revenues - Major Product Category (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenues	$ 2,585,368	$ 2,388,643	$ 2,356,672
Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	1,515,566	1,356,305	1,371,808
Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	1,069,802	1,032,338	984,864
Cable And Connectivity
Disaggregation of Revenue [Line Items]
Revenues	1,709,486	1,652,979	1,594,261
Cable And Connectivity | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	1,046,744	1,024,090	1,003,799
Cable And Connectivity | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	662,742	628,889	590,462
Networking, Software & Security
Disaggregation of Revenue [Line Items]
Revenues	875,882	735,664	762,411
Networking, Software & Security | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	468,822	332,215	368,009
Networking, Software & Security | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	$ 407,060	$ 403,449	$ 394,402

Revenues - Location of Customer

Revenues - Location of Customer (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenues	$ 2,585,368	$ 2,388,643	$ 2,356,672
Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	1,515,566	1,356,305	1,371,808
Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	1,069,802	1,032,338	984,864
Americas
Disaggregation of Revenue [Line Items]
Revenues	1,601,543	1,531,978	1,533,773
Americas | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	981,822	925,647	937,741
Americas | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	619,721	606,331	596,032
EMEA
Disaggregation of Revenue [Line Items]
Revenues	584,736	495,653	481,566
EMEA | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	294,129	214,763	220,511
EMEA | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	290,607	280,890	261,055
APAC
Disaggregation of Revenue [Line Items]
Revenues	399,089	361,012	341,333
APAC | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	239,615	215,895	213,556
APAC | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	$ 159,474	$ 145,117	$ 127,777

Revenues - Products and Service

Revenues - Products and Services (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenues	$ 2,585,368	$ 2,388,643	$ 2,356,672
Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	1,515,566	1,356,305	1,371,808
Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	1,069,802	1,032,338	984,864
Products
Disaggregation of Revenue [Line Items]
Revenues	2,415,786	2,211,223	2,178,600
Products | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	1,441,757	1,281,960	1,293,392
Products | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	974,029	929,263	885,208
Support And Services
Disaggregation of Revenue [Line Items]
Revenues	169,582	177,420	178,072
Support And Services | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	73,809	74,345	78,416
Support And Services | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	$ 95,773	$ 103,075	$ 99,656

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details) - USD ($)	Apr. 25, 2018	Feb. 08, 2018	May 31, 2017	Dec. 31, 2016	Jan. 07, 2016	Dec. 31, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Severance, restructuring, and acquisition integration costs						$ 11,600,000	$ 11,700,000	$ 24,900,000	$ 20,400,000	$ 9,900,000	$ 16,700,000	$ 9,600,000	$ 6,600,000	$ 68,613,000	$ 42,790,000	$ 31,140,000
Amortization of intangibles														98,829,000	103,997,000	98,385,000
Net-Tech Technology, Inc.
Business Acquisition [Line Items]
Percentage of outstanding shares acquired	100.00%
Acquisition price paid	$ 8,500,000
Snell Advanced Media
Business Acquisition [Line Items]
Percentage of outstanding shares acquired		100.00%
Acquisition price		$ 104,500,000
Acquisition price paid		75,200,000
Maximum earnout consideration		31,400,000
Estimated earnout consideration		29,300,000
Long-term debt acquired		19,315,000
Goodwill, Purchase Accounting Adjustments						$ 15,000,000
Fair value of acquired receivables		16,551,000
Tax Basis In Acquired Goodwill		$ 0
Post acquisition revenue of acquiree														106,300,000
Severance, restructuring, and acquisition integration costs														46,100,000
Amortization of intangibles														10,600,000
Inventory adjustment														$ 1,800,000
Snell Advanced Media | Acquisition-related Costs
Business Acquisition [Line Items]
Severance, restructuring, and acquisition integration costs															46,100,000
Amortization of intangibles															1,900,000
Inventory adjustment															1,700,000
Thinklogical Holdings LLC
Business Acquisition [Line Items]
Percentage of outstanding shares acquired			100.00%
Acquisition price paid			$ 165,800,000
Fair value of acquired receivables			4,355,000
Tax Basis In Acquired Goodwill			$ 43,300,000
Post acquisition revenue of acquiree															30,800,000
Amortization of intangibles															11,900,000
Inventory adjustment															6,100,000
Goodwill tax basis, tax deductible period														15 years
Post acquisition income (loss) before taxes of acquiree															$ (8,900,000)
Thinklogical Holdings LLC | Acquisition-related Costs
Business Acquisition [Line Items]
Amortization of intangibles																1,400,000
Inventory adjustment																6,100,000
M2 FX Limited
Business Acquisition [Line Items]
Percentage of outstanding shares acquired					100.00%
Acquisition price paid					$ 19,000,000
Estimated earnout consideration				$ 0	$ 3,200,000											3,200,000
Inventory adjustment																200,000
Benefit included in selling, general, and administrative expense																$ 3,200,000

Acquisitions - Schedule of Reco

Acquisitions - Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Feb. 08, 2018	Dec. 31, 2017	May 31, 2017	Dec. 31, 2016
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Goodwill	$ 1,557,653		$ 1,478,257		$ 1,385,995
Snell Advanced Media
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Receivables		$ 16,551
Inventory		15,084
Prepaid and other current assets		3,799
Property, plant, and equipment		7,716
Intangible assets		51,000
Goodwill		102,715
Deferred income taxes		1,388
Other long-lived assets		3,046
Total assets acquired		201,299
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]
Accounts payable		11,825
Accrued liabilities		24,405
Deferred revenue		8,860
Long-term debt		19,315
Postretirement benefits		31,774
Other long-term liabilities		591
Total liabilities assumed		96,770
Net assets		$ 104,529
Thinklogical Holdings LLC
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Receivables				$ 4,355
Inventory				16,424
Prepaid and other current assets				320
Property, plant, and equipment				4,289
Intangible assets				73,400
Goodwill				70,654
Deferred income taxes				598
Total assets acquired				170,040
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]
Accounts payable				1,231
Accrued liabilities				1,353
Deferred revenue				1,702
Total liabilities assumed				4,286
Net assets				$ 165,754

Acquisitions - Schedule of Acq

Acquisitions - Schedule of Acquired Intangible Assets (Details) - USD ($) $ in Thousands	Feb. 08, 2018	May 31, 2017	Dec. 31, 2018
Developed technology
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Amortization Period			6 years 6 months
Customer relationships
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Amortization Period			18 years 5 months
Trademarks
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Amortization Period			7 years 11 months
Snell Advanced Media
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total intangible assets subject to amortization	$ 51,000
Total intangible assets not subject to amortization	102,715
Total intangible assets	$ 153,715
Amortization Period	6 years 2 months
Snell Advanced Media | Goodwill
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total intangible assets not subject to amortization	$ 102,715
Snell Advanced Media | Developed technology
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total intangible assets subject to amortization	$ 36,500
Amortization Period	5 years
Snell Advanced Media | Customer relationships
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total intangible assets subject to amortization	$ 11,000
Amortization Period	12 years
Snell Advanced Media | Trademarks
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total intangible assets subject to amortization	$ 1,600
Amortization Period	11 months
Snell Advanced Media | Sales backlog
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total intangible assets subject to amortization	$ 1,900
Amortization Period	3 months 18 days
Thinklogical Holdings LLC
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total intangible assets subject to amortization		$ 73,400
Total intangible assets not subject to amortization		70,654
Total intangible assets		$ 144,054
Amortization Period		9 years 7 months 6 days
Thinklogical Holdings LLC | Goodwill
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total intangible assets not subject to amortization		$ 70,654
Thinklogical Holdings LLC | Developed technology
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total intangible assets subject to amortization		$ 62,600
Amortization Period		10 years
Thinklogical Holdings LLC | Customer relationships
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total intangible assets subject to amortization		$ 6,500
Amortization Period		8 years
Thinklogical Holdings LLC | Trademarks
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total intangible assets subject to amortization		$ 2,900
Amortization Period		10 years
Thinklogical Holdings LLC | Sales backlog
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total intangible assets subject to amortization		$ 1,400
Amortization Period		3 months 19 days

Acquisitions - Schedule of Pro

Acquisitions - Schedule of Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Snell Advanced Media
Business Acquisition [Line Items]
Revenues	$ 2,598,741	$ 2,500,779
Net income attributable to Belden common stockholders	$ 168,819	$ (8,581)
Diluted income per share attributable to Belden common stockholders	$ 4.12	$ (0.20)
Thinklogical Holdings LLC
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

Operating Segments and Geogra_3

Operating Segments and Geographic Information - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)Segment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment	2
Anixter International Inc.
Segment Reporting Information [Line Items]
Revenues generated from sales	$ 309	$ 292.2	$ 286.2
Accounts receivable outstanding	$ 37
Anixter International Inc. | Customer Concentration Risk
Segment Reporting Information [Line Items]
Percentage of total accounts receivable outstanding	8.00%
Anixter International Inc. | Customer Concentration Risk | Revenues
Segment Reporting Information [Line Items]
Percent of total revenues	12.00%	12.00%	12.00%

Operating Segments and Geogra_4

Operating Segments and Geographic Information - Operating Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 655,390	$ 655,774	$ 668,639	$ 605,565	$ 604,884	$ 621,745	$ 610,633	$ 551,381	$ 2,585,368	$ 2,388,643	$ 2,356,672
Depreciation expense									47,600	45,600	47,200
Amortization of intangibles									98,829	103,997	98,385
Severance, restructuring, and acquisition integration costs	11,600	$ 11,700	$ 24,900	$ 20,400	9,900	$ 16,700	$ 9,600	$ 6,600	68,613	42,790	31,140
Acquisition of property, plant and equipment									97,847	64,261	53,974
Segment assets	3,779,321				3,840,613				3,779,321	3,840,613	3,806,803
Enterprise Solutions
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs									57,563	29,043	18,561
Industrial Solutions
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs									11,050	13,747	12,579
Reportable Segment
Segment Reporting Information [Line Items]
Revenues									2,585,368	2,388,643	2,356,672
Segment EBITDA									475,380	430,748	433,789
Depreciation expense									47,615	45,597	47,208
Amortization of intangibles									98,829	103,997	98,385
Amortization of software development intangible assets									2,188	56	0
Severance, restructuring, and acquisition integration costs									68,613	42,790	31,140
Purchase accounting effects of acquisitions									3,497	6,133	(2,079)
Deferred Revenue Adjustments									6,612	0	6,687
Acquisition of property, plant and equipment									94,834	62,759	53,582
Segment assets	1,220,110				1,146,395				1,220,110	1,146,395	913,998
Reportable Segment | Enterprise Solutions
Segment Reporting Information [Line Items]
Segment EBITDA									267,656	216,558	239,978
Depreciation expense									28,861	26,272	29,455
Amortization of intangibles									45,944	51,054	48,966
Amortization of software development intangible assets									2,180	56	0
Severance, restructuring, and acquisition integration costs									57,563	29,043	18,561
Purchase accounting effects of acquisitions									3,497	6,133	(2,079)
Deferred Revenue Adjustments									6,612	0	1,774
Acquisition of property, plant and equipment									65,619	49,440	38,392
Segment assets	761,309				687,914				761,309	687,914	571,960
Reportable Segment | Industrial Solutions
Segment Reporting Information [Line Items]
Segment EBITDA									207,724	214,190	193,811
Depreciation expense									18,754	19,325	17,753
Amortization of intangibles									52,885	52,943	49,419
Amortization of software development intangible assets									8	0	0
Severance, restructuring, and acquisition integration costs									11,050	13,747	12,579
Deferred Revenue Adjustments									0	0	4,913
Acquisition of property, plant and equipment									29,215	13,319	15,190
Segment assets	$ 458,801				$ 458,481				458,801	458,481	342,038
Software Development | Reportable Segment
Segment Reporting Information [Line Items]
Amortization of intangibles									2,188	56	0
Segment revenues | Reportable Segment
Segment Reporting Information [Line Items]
Revenues									2,591,980	2,388,643	2,357,805
Segment revenues | Reportable Segment | Enterprise Solutions
Segment Reporting Information [Line Items]
Revenues									1,522,178	1,356,305	1,372,941
Segment revenues | Reportable Segment | Industrial Solutions
Segment Reporting Information [Line Items]
Revenues									1,069,802	1,032,338	984,864
Affiliate revenues | Reportable Segment
Segment Reporting Information [Line Items]
Revenues									6,166	5,158	2,870
Affiliate revenues | Reportable Segment | Enterprise Solutions
Segment Reporting Information [Line Items]
Revenues									6,085	5,091	2,799
Affiliate revenues | Reportable Segment | Industrial Solutions
Segment Reporting Information [Line Items]
Revenues									81	67	71
Patent settlement | Reportable Segment
Segment Reporting Information [Line Items]
Revenues									0	0	5,554
Patent settlement | Reportable Segment | Enterprise Solutions
Segment Reporting Information [Line Items]
Revenues									$ 0	$ 0	$ 5,554

Operating Segments and Geogra_5

Operating Segments and Geographic Information - Reconciliation of Total Reportable Segments' Revenues and EBITDA to Consolidated Revenues and Consolidated Income Before Taxes (Details) - USD ($)	Dec. 31, 2016	Jan. 07, 2016	Dec. 31, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Segment Revenues			$ 655,390,000	$ 655,774,000	$ 668,639,000	$ 605,565,000	$ 604,884,000	$ 621,745,000	$ 610,633,000	$ 551,381,000	$ 2,585,368,000	$ 2,388,643,000	$ 2,356,672,000
Amortization of intangibles											(98,829,000)	(103,997,000)	(98,385,000)
Severance, restructuring, and acquisition integration costs (3)			(11,600,000)	(11,700,000)	(24,900,000)	(20,400,000)	(9,900,000)	(16,700,000)	(9,600,000)	(6,600,000)	(68,613,000)	(42,790,000)	(31,140,000)
Depreciation expense											(47,600,000)	(45,600,000)	(47,200,000)
Impairment of assets held for sale											0	0	(23,931,000)
Gain from patent litigation											(62,141,000)	0	0
Operating income			$ 73,234,000	$ 131,278,000	$ 56,506,000	$ 44,203,000	$ 59,915,000	$ 61,116,000	$ 62,776,000	$ 51,597,000	305,221,000	235,404,000	232,083,000
Interest expense, net											(61,559,000)	(82,901,000)	(95,050,000)
Non-operating pension cost											(342,000)	(714,000)	(8,230,000)
Loss on debt extinguishment											(22,990,000)	(52,441,000)	(2,342,000)
Consolidated income before taxes											220,330,000	99,348,000	126,461,000
Reportable Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Segment Revenues											2,585,368,000	2,388,643,000	2,356,672,000
Deferred revenue adjustments (1)											(6,612,000)	0	(6,687,000)
Total Segment EBITDA											475,380,000	430,748,000	433,789,000
Amortization of intangibles											(98,829,000)	(103,997,000)	(98,385,000)
Severance, restructuring, and acquisition integration costs (3)											(68,613,000)	(42,790,000)	(31,140,000)
Depreciation expense											(47,615,000)	(45,597,000)	(47,208,000)
Purchase accounting effects related to acquisitions (4)											(3,497,000)	(6,133,000)	2,079,000
Costs related to patent litigation											(2,634,000)	0	0
Amortization of software development intangible assets											(2,188,000)	(56,000)	0
Loss on sale of assets (5)											(94,000)	(1,013,000)	0
Impairment of assets held for sale											0	0	(23,931,000)
Income from equity method investment											0	7,502,000	1,793,000
Gain from patent litigation											62,141,000	0	0
Eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income											(2,218,000)	(3,260,000)	(3,781,000)
M2 FX Limited
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
Inventory adjustment													200,000
Enterprise Solutions
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Severance, restructuring, and acquisition integration costs (3)											(57,563,000)	(29,043,000)	(18,561,000)
Inventory adjustment													800,000
Enterprise Solutions | Reportable Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Deferred revenue adjustments (1)											(6,612,000)	0	(1,774,000)
Total Segment EBITDA											267,656,000	216,558,000	239,978,000
Amortization of intangibles											(45,944,000)	(51,054,000)	(48,966,000)
Severance, restructuring, and acquisition integration costs (3)											(57,563,000)	(29,043,000)	(18,561,000)
Depreciation expense											(28,861,000)	(26,272,000)	(29,455,000)
Purchase accounting effects related to acquisitions (4)											(3,497,000)	(6,133,000)	2,079,000
Amortization of software development intangible assets											(2,180,000)	(56,000)	0
Segment revenues | Reportable Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Segment Revenues											2,591,980,000	2,388,643,000	2,357,805,000
Segment revenues | Enterprise Solutions | Reportable Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Segment Revenues											1,522,178,000	1,356,305,000	1,372,941,000
Patent settlement | Reportable Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Segment Revenues											0	0	5,554,000
Patent settlement | Enterprise Solutions | Reportable Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Segment Revenues											$ 0	$ 0	$ 5,554,000

Operating Segments and Geogra_6

Operating Segments and Geographic Information - Reconciliations of Other Segment Measures to Consolidated Totals (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment assets	$ 3,779,321	$ 3,840,613	$ 3,806,803
Cash and cash equivalents	420,610	561,108	848,116	$ 216,751
Goodwill	1,557,653	1,478,257	1,385,995
Intangible assets, less accumulated amortization	511,093	545,207	560,082
Deferred income taxes	56,018	42,549	33,706
Acquisition of property, plant and equipment	97,847	64,261	53,974
Reportable Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment assets	1,220,110	1,146,395	913,998
Acquisition of property, plant and equipment	94,834	62,759	53,582
Corporate assets
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment assets	13,837	67,097	64,906
Acquisition of property, plant and equipment	$ 3,013	$ 1,502	$ 392

Operating Segments and Geogra_7

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, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Percent of total revenues									100.00%	100.00%	100.00%
Long-lived assets	$ 395,833				$ 402,529				$ 395,833	$ 402,529	$ 348,068
Total Segment Revenues	655,390	$ 655,774	$ 668,639	$ 605,565	604,884	$ 621,745	$ 610,633	$ 551,381	$ 2,585,368	$ 2,388,643	$ 2,356,672
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Percent of total revenues									51.00%	53.00%	55.00%
Long-lived assets	189,211				231,938				$ 189,211	$ 231,938	$ 193,263
Total Segment Revenues									$ 1,324,653	$ 1,265,455	$ 1,283,925
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Percent of total revenues									7.00%	7.00%	7.00%
Long-lived assets	32,312				33,806				$ 32,312	$ 33,806	$ 31,278
Total Segment Revenues									$ 174,727	$ 167,605	$ 159,985
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Percent of total revenues									5.00%	5.00%	5.00%
Long-lived assets	37,227				34,774				$ 37,227	$ 34,774	$ 30,487
Total Segment Revenues									$ 132,544	$ 121,600	$ 114,605
Germany
Revenues from External Customers and Long-Lived Assets [Line Items]
Percent of total revenues									5.00%	5.00%	4.00%
Long-lived assets	39,870				38,029				$ 39,870	$ 38,029	$ 32,386
Total Segment Revenues									$ 117,598	$ 113,990	$ 104,214
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Percent of total revenues									32.00%	30.00%	29.00%
Long-lived assets	$ 97,213				$ 63,982				$ 97,213	$ 63,982	$ 60,654
Total Segment Revenues									$ 835,846	$ 719,993	$ 693,943

Noncontrolling Interest - Addit

Noncontrolling Interest - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2015
Variable Interest Entity, primary beneficiary Belden
Noncontrolling Interest [Line Items]
Additional contribution commitments to joint venture	$ 1,530
Hite
Noncontrolling Interest [Line Items]
Additional contribution commitments to joint venture	$ 1,470
Hite | Variable Interest Entity, primary beneficiary Belden
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, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Numerator:
Net income	$ 43,491	$ 85,858	$ 28,792	$ 2,570	$ 30,436	$ 945	$ 35,891	$ 25,581	$ 160,711	$ 92,853	$ 127,646
Less: Net loss attributable to noncontrolling interest	(35)	(23)	(77)	(48)	(83)	(82)	(86)	(106)	(183)	(357)	(357)
Less: Preferred stock dividends	8,733	8,732	8,733	8,733	8,733	8,732	8,733	8,733	34,931	34,931	15,428
Net income attributable to Belden common stockholders	$ 34,793	$ 77,149	$ 20,136	$ (6,115)	$ 21,786	$ (7,705)	$ 27,244	$ 16,954	$ 125,963	$ 58,279	$ 112,575
Denominator:
Weighted average shares outstanding, basic (in shares)									40,675	42,220	42,093
Effect of dilutive common stock equivalents (in shares)									281	423	464
Weighted average shares outstanding, diluted (in shares)									40,956	42,643	42,557

Income Per Share - Additional I

Income Per Share - Additional Information (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from diluted weighted average shares outstanding (in shares)	0.9	0.5	0.6
Anti-dilutive shares excluded form diluted weighted average shares outstanding due to performance conditions not met (in shares)	0.3	0.2	0.1
Convertible Preferred Stock
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	6.9	3

Inventories - Major Classes of

Inventories - Major Classes of Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 146,803	$ 133,311
Work-in-process	45,939	35,807
Finished goods	152,572	153,377
Gross inventories	345,314	322,495
Excess and obsolete reserves	(28,896)	(25,269)
Net inventories	$ 316,418	$ 297,226

Property, Plant and Equipment -

Property, Plant and Equipment - Summary of Carrying Values of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 944,459	$ 907,562
Accumulated depreciation	(578,489)	(570,240)
Net property, plant and equipment	365,970	337,322
Land and land improvements
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	30,173	31,963
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	141,009	148,598
Machinery and equipment
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	569,359	543,594
Computer equipment and software
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	139,773	136,509
Construction in process
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 64,145	$ 46,898

Property, Plant and Equipment_2

Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 47.6	$ 45.6	$ 47.2

Intangible Assets - Carrying Va

Intangible Assets - Carrying Value of Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Intangible Assets [Line Items]
Goodwill, Gross carrying amount	$ 1,557,653	$ 1,478,257
Goodwill, Accumulated Amortization	0	0
Goodwill, Net Carrying Amount	1,557,653	1,478,257	$ 1,385,995
Finite-lived intangible assets, Gross Carrying Amount	975,203	913,956
Finite-lived intangible assets, Accumulated Amortization	(555,301)	(463,207)
Finite-lived intangible assets, Net Carrying Amount	419,902	450,749
Indefinite-lived intangible assets, Carrying Amount	91,191	94,458
Intangible assets, Gross Carrying Amount	1,066,394	1,008,414
Intangible assets, Net Carrying Amount	511,093	545,207	$ 560,082
Trademarks
Intangible Assets [Line Items]
Indefinite-lived intangible assets, Carrying Amount	90,391	92,758
In-process research and development
Intangible Assets [Line Items]
Indefinite-lived intangible assets, Carrying Amount	800	1,700
Developed technology
Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	545,982	498,649
Finite-lived intangible assets, Accumulated Amortization	(379,896)	(318,366)
Finite-lived intangible assets, Net Carrying Amount	166,086	180,283
Customer relationships
Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	331,643	320,550
Finite-lived intangible assets, Accumulated Amortization	(115,943)	(98,175)
Finite-lived intangible assets, Net Carrying Amount	215,700	222,375
Trademarks
Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	57,860	56,794
Finite-lived intangible assets, Accumulated Amortization	(27,106)	(18,648)
Finite-lived intangible assets, Net Carrying Amount	30,754	38,146
In-process research and development
Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	23,833	23,428
Finite-lived intangible assets, Accumulated Amortization	(16,471)	(13,483)
Finite-lived intangible assets, Net Carrying Amount	7,362	9,945
Backlog
Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	15,885	14,535
Finite-lived intangible assets, Accumulated Amortization	(15,885)	(14,535)
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, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 1,478,257	$ 1,385,995
Acquisitions and purchase accounting adjustments	105,899	71,394
Translation impact	(26,503)	20,868
Goodwill, Ending Balance	1,557,653	1,478,257
Enterprise Solutions
Goodwill [Roll Forward]
Goodwill, Beginning Balance	702,271	617,320
Acquisitions and purchase accounting adjustments	105,899	71,394
Translation impact	(22,812)	13,557
Goodwill, Ending Balance	785,358	702,271
Industrial Solutions
Goodwill [Roll Forward]
Goodwill, Beginning Balance	775,986	768,675
Acquisitions and purchase accounting adjustments	0	0
Translation impact	(3,691)	7,311
Goodwill, Ending Balance	$ 772,295	$ 775,986

Intangible Assets - Changes i_2

Intangible Assets - Changes in Carrying Amount of Trademarks (Details) - Trademarks - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Indefinite-lived Intangible Assets [Roll Forward]
Trademarks, Beginning Balance	$ 92,758	$ 121,972
Translation impact	(2,367)	3,987
Reclassify to definite-lived		(33,201)
Trademarks, Ending Balance	90,391	92,758
Enterprise Solutions
Indefinite-lived Intangible Assets [Roll Forward]
Trademarks, Beginning Balance	83,077	80,350
Translation impact	(1,893)	2,727
Reclassify to definite-lived		0
Trademarks, Ending Balance	81,184	83,077
Industrial Solutions
Indefinite-lived Intangible Assets [Roll Forward]
Trademarks, Beginning Balance	9,681	41,622
Translation impact	(474)	1,260
Reclassify to definite-lived		(33,201)
Trademarks, Ending Balance	$ 9,207	$ 9,681

Intangible Assets - Additional

Intangible Assets - Additional Information (Details)	12 Months Ended
	Dec. 31, 2018USD ($)Reporting_Unit	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Finite And Indefinite Intangible Assets [Line Items]
Number of reporting units used in quantitative assessment | Reporting_Unit	4
Number of reporting units used in qualitative assessment | Reporting_Unit	7
Amortization expense in income from continuing operations	$ 101,000,000	$ 104,000,000	$ 98,400,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Estimated amortization expense in 2019	90,400,000
Estimated amortization expense in 2020	74,400,000
Estimated amortization expense in 2021	42,100,000
Estimated amortization expense in 2022	38,200,000
Estimated amortization expense in 2023	29,300,000
Goodwill impairment charges	0	0	0
Impairment charges	0	0	0
Recognized trademark amortization expense	98,829,000	103,997,000	98,385,000
Trademark, net carrying amount	$ 419,902,000	450,749,000
Customer relationships
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Weighted-average amortization period	18 years 5 months
Trademark, net carrying amount	$ 215,700,000	222,375,000
Trademarks
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Weighted-average amortization period	7 years 11 months
Impairment charges	$ 0	0	$ 0
Trademark, net carrying amount	$ 30,754,000	38,146,000
Developed technology
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Weighted-average amortization period	6 years 6 months
Trademark, net carrying amount	$ 166,086,000	180,283,000
In-process research and development
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Weighted-average amortization period	5 years
Trademark, net carrying amount	$ 7,362,000	9,945,000
Tripwire | Trademarks
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Estimated intangible asset useful life	10 years
Recognized trademark amortization expense	$ 3,100,000	$ 3,100,000
Trademark, net carrying amount	$ 24,800,000

Accrued Liabilities - Carrying

Accrued Liabilities - Carrying Value of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accrued Liabilities and Other Liabilities [Abstract]
Current deferred revenue	$ 101,194	$ 90,639
Wages, severance and related taxes	56,129	57,633
Accrued rebates	41,312	38,025
Employee benefits	25,670	25,406
Accrued interest	18,530	22,019
Other (individual items less than 5% of total current liabilities)	121,441	68,929
Accrued liabilities	$ 364,276	$ 302,651

Severance, Restructuring, and_3

Severance, Restructuring, and Acquisition Integration Activities Severance, Restructuring, and Acquisition Integration Activities - Additional Information (Details) - USD ($) $ in Thousands

3 Months Ended

12 Months Ended

31 Months Ended

Dec. 31, 2018

Sep. 30, 2018

Jul. 01, 2018

Apr. 01, 2018

Dec. 31, 2017

Oct. 01, 2017

Jul. 02, 2017

Apr. 02, 2017

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2018

Mar. 31, 2019

Restructuring Cost and Reserve [Line Items]

Severance, restructuring, and acquisition integration costs

$ 11,600

$ 11,700

$ 24,900

$ 20,400

$ 9,900

$ 16,700

$ 9,600

$ 6,600

$ 68,613

$ 42,790

$ 31,140

Cost of Sales

Restructuring Cost and Reserve [Line Items]

Severance, restructuring, and acquisition integration costs

28,100

32,600

12,300

Selling, General and Administrative Expenses

Restructuring Cost and Reserve [Line Items]

Severance, restructuring, and acquisition integration costs

35,000

10,000

18,000

Research and Development

Restructuring Cost and Reserve [Line Items]

Severance, restructuring, and acquisition integration costs

$ 5,500

200

800

Maximum

Restructuring Cost and Reserve [Line Items]

Restructuring and integration cost payable period

60 days

Grass Valley And SAM Integration Program

Restructuring Cost and Reserve [Line Items]

Severance, restructuring, and acquisition integration costs

$ 42,300

Industrial Manufacturing Footprint Program

Restructuring Cost and Reserve [Line Items]

Severance, restructuring, and acquisition integration costs

$ 17,700

$ 30,600

$ 17,800

$ 66,100

Scenario, Forecast | Grass Valley And SAM Integration Program

Restructuring Cost and Reserve [Line Items]

Expected restructuring cost remaining

$ 3,000

Severance, Restructuring, and_4

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, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Severance									$ 10,323	$ 5,211	$ 7,082
Other Restructuring and Integration Costs									58,290	37,579	24,058
Total Costs	$ 11,600	$ 11,700	$ 24,900	$ 20,400	$ 9,900	$ 16,700	$ 9,600	$ 6,600	68,613	42,790	31,140
Enterprise Solutions
Restructuring Cost and Reserve [Line Items]
Severance									9,945	4,535	520
Other Restructuring and Integration Costs									47,618	24,508	18,041
Total Costs									57,563	29,043	18,561
Industrial Solutions
Restructuring Cost and Reserve [Line Items]
Severance									378	676	6,562
Other Restructuring and Integration Costs									10,672	13,071	6,017
Total Costs									$ 11,050	$ 13,747	$ 12,579

Long-Term Debt and Other Borr_3

Long-Term Debt and Other Borrowing Arrangements - Carrying Values of Long-Term Debt and Other Borrowing Arrangements (Details) - USD ($)	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jul. 31, 2017	Oct. 31, 2016
Debt Instrument [Line Items]
Total senior subordinated notes	$ 1,485,900,000		$ 1,584,232,000
Less unamortized debt issuance costs	(22,700,000)		(23,484,000)
Long-term debt	1,463,200,000		1,560,748,000
Revolving credit agreement due 2022
Debt Instrument [Line Items]
Revolving credit agreement due 2022	$ 0		$ 0
3.875% Senior subordinated notes due 2028
Debt Instrument [Line Items]
Senior subordinated notes interest rate	3.875%		3.875%
Total senior subordinated notes	$ 400,050,000		$ 0
3.375% Senior subordinated notes due 2027
Debt Instrument [Line Items]
Senior subordinated notes interest rate	3.375%		3.375%
Total senior subordinated notes	$ 514,350,000		$ 540,810,000
4.125% Senior subordinated notes due 2026
Debt Instrument [Line Items]
Senior subordinated notes interest rate	4.125%		4.125%			4.125%
Total senior subordinated notes	$ 228,600,000		$ 240,360,000
2.875% Senior subordinated notes due 2025
Debt Instrument [Line Items]
Senior subordinated notes interest rate	2.875%		2.875%
Total senior subordinated notes	$ 342,900,000		$ 360,540,000
5.25% Senior subordinated notes due 2024
Debt Instrument [Line Items]
Senior subordinated notes interest rate	5.25%		5.25%
Total senior subordinated notes	$ 0		$ 200,000,000
5.50% Senior subordinated notes due 2023
Debt Instrument [Line Items]
Senior subordinated notes interest rate	5.50%		5.50%
Total senior subordinated notes	$ 0		$ 242,522,000
Senior Subordinated Notes
Debt Instrument [Line Items]
Total senior subordinated notes	$ 1,485,900,000
Senior Subordinated Notes | 3.875% Senior subordinated notes due 2028
Debt Instrument [Line Items]
Senior subordinated notes interest rate		3.875%
Senior Subordinated Notes | 3.375% Senior subordinated notes due 2027
Debt Instrument [Line Items]
Senior subordinated notes interest rate					3.375%
Senior Subordinated Notes | 2.875% Senior subordinated notes due 2025
Debt Instrument [Line Items]
Senior subordinated notes interest rate				2.875%
Senior Subordinated Notes | 5.25% Senior subordinated notes due 2024
Debt Instrument [Line Items]
Senior subordinated notes interest rate	5.25%
Senior Subordinated Notes | 5.50% Senior subordinated notes due 2023
Debt Instrument [Line Items]
Senior subordinated notes interest rate	5.50%

Long-Term Debt and Other Borr_4

Long-Term Debt and Other Borrowing Arrangements - Additional Information (Details)	1 Months Ended				12 Months Ended
	Apr. 30, 2018USD ($)	Apr. 30, 2018EUR (€)	Mar. 31, 2018USD ($)	Mar. 31, 2018EUR (€)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Mar. 31, 2018EUR (€)	Feb. 28, 2018EUR (€)	Sep. 30, 2017USD ($)	Sep. 30, 2017EUR (€)	Jul. 31, 2017USD ($)	Jul. 31, 2017EUR (€)	Oct. 31, 2016USD ($)	Oct. 31, 2016EUR (€)
Debt Instrument [Line Items]
Loss on debt extinguishment					$ 22,990,000	$ 52,441,000	$ 2,342,000
Senior subordinated notes					1,485,900,000	1,584,232,000
Senior Subordinated Notes
Debt Instrument [Line Items]
Senior subordinated notes					1,485,900,000
Fair value of debt instrument					1,485,000,000	1,619,300,000
Revolving credit agreement due 2022
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity						$ 400,000,000
Commitment fee percentage						0.25%
Fixed charge coverage, minimum threshold (as a percent)						90.00%
Loss on debt extinguishment						$ 800,000
Revolving credit agreement due 2022, execution fees						2,300,000
Revolving credit agreement due 2022, borrowings outstanding					0	$ 0
Revolving credit agreement due 2022, available borrowing capacity					$ 359,100,000
Revolving credit agreement due 2022 | Minimum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate (as a percent)						1.25%
Revolving credit agreement due 2022 | Maximum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate (as a percent)						1.75%
3.875% Senior subordinated notes due 2028
Debt Instrument [Line Items]
Senior subordinated notes interest rate					3.875%	3.875%
Senior subordinated notes					$ 400,050,000	$ 0
3.875% Senior subordinated notes due 2028 | Senior Subordinated Notes
Debt Instrument [Line Items]
Revolving credit agreement due 2022, execution fees			$ 7,500,000											$ 3,900,000
Aggregate principal amount outstanding of senior subordinated notes			$ 431,300,000					€ 350,000,000
Senior subordinated notes interest rate			3.875%					3.875%
3.375% Senior subordinated notes due 2027
Debt Instrument [Line Items]
Senior subordinated notes interest rate					3.375%	3.375%
Senior subordinated notes					$ 514,350,000	$ 540,810,000
3.375% Senior subordinated notes due 2027 | Senior Subordinated Notes
Debt Instrument [Line Items]
Revolving credit agreement due 2022, execution fees												$ 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%
4.125% Senior subordinated notes due 2026
Debt Instrument [Line Items]
Senior subordinated notes interest rate					4.125%	4.125%								4.125%	4.125%
Senior subordinated notes					$ 228,600,000	$ 240,360,000
4.125% Senior subordinated notes due 2026 | Senior Subordinated Notes
Debt Instrument [Line Items]
Aggregate principal amount outstanding of senior subordinated notes														$ 222,200,000	€ 200,000,000
2.875% Senior subordinated notes due 2025
Debt Instrument [Line Items]
Senior subordinated notes interest rate					2.875%	2.875%
Senior subordinated notes					$ 342,900,000	$ 360,540,000
2.875% Senior subordinated notes due 2025 | Senior Subordinated Notes
Debt Instrument [Line Items]
Revolving credit agreement due 2022, execution fees										$ 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%
5.25% Senior subordinated notes due 2024
Debt Instrument [Line Items]
Senior subordinated notes interest rate					5.25%	5.25%
Senior subordinated notes					$ 0	$ 200,000,000
5.25% Senior subordinated notes due 2024 | Senior Subordinated Notes
Debt Instrument [Line Items]
Loss on debt extinguishment	$ 800,000		$ 13,800,000
Senior subordinated notes interest rate					5.25%
Repayments of debt	11,900,000		199,800,000
Debt repurchase amount			188,700,000
5.50% Senior subordinated notes due 2023
Debt Instrument [Line Items]
Senior subordinated notes interest rate					5.50%	5.50%
Senior subordinated notes					$ 0	$ 242,522,000
5.50% Senior subordinated notes due 2023 | Senior Subordinated Notes
Debt Instrument [Line Items]
Loss on debt extinguishment	2,200,000		6,200,000
Aggregate principal amount outstanding of senior subordinated notes | €									€ 200,000,000
Senior subordinated notes interest rate					5.50%
Repayments of debt	$ 71,600,000	€ 58,500,000	$ 182,100,000	€ 147,800,000
Debt repurchase amount | €								€ 143,100,000

Long-Term Debt and Other Borr_5

Long-Term Debt and Other Borrowing Arrangements - Schedule of Senior Subordinated Notes (Details)	12 Months Ended
	Dec. 31, 2018
2020 | Senior Subordinated Notes Due 2025
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	101.438%
2021 | Senior Subordinated Notes Due 2025
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.719%
2021 | Senior Subordinated Notes Due 2026
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	102.063%
2022 | Senior Subordinated Notes Due 2026
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	101.375%
2022 | Senior Subordinated Notes Due 2027
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	101.688%
2023 | Senior Subordinated Notes Due 2026
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.688%
2023 | Senior Subordinated Notes Due 2027
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	101.125%
2023 | Senior Subordinated Notes Due 2028
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	101.9375%
2024 | Senior Subordinated Notes Due 2027
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.563%
2024 | Senior Subordinated Notes Due 2028
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	101.2916%
2025 | Senior Subordinated Notes Due 2028
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.6458%
2022 And Thereafter | Senior Subordinated Notes Due 2025
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.00%
2024 and Thereafter | Senior Subordinated Notes Due 2026
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.00%
2025 and Thereafter | Senior Subordinated Notes Due 2027
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.00%
2026 and Thereafter | Senior Subordinated Notes Due 2028
Debt Instrument [Line Items]
Redemption price as a percentage of the face amount of the notes	100.00%

Long-Term Debt and Other Borr_6

Long-Term Debt and Other Borrowing Arrangements - Maturities on Outstanding Long-Term Debt and Other Borrowings (Details) $ in Thousands	Dec. 31, 2018USD ($)
Debt Disclosure [Abstract]
2,019	$ 0
2,020	0
2,021	0
2,022	0
2,023	0
Thereafter	1,485,900
Total gross debt and other borrowing arrangements	$ 1,485,900

Net Investment Hedge Net Invest

Net Investment Hedge Net Investment Hedge (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative translation adjustment	$ 27,802	$ (65,046)	$ 18,687
Senior Subordinated Notes
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative translation adjustment	$ 87,500	$ (56,200)

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income (loss) before taxes:
United States operations	$ 126,385	$ 2,177	$ (25,615)
Foreign operations	93,945	97,171	152,076
Income before taxes	220,330	99,348	126,461
Currently payable
United States federal	27,529	0	2,981
United States state and local	3,274	2,392	(1,038)
Foreign	17,516	28,201	26,906
Income tax expense (benefit)	48,319	30,593	28,849
Deferred
United States federal	10,942	(11,028)	(27,677)
United States state and local	703	(8,758)	(3,139)
Foreign	(345)	(4,312)	782
Deferred Income tax expense (benefit)	11,300	(24,098)	(30,034)
Income tax expense (benefit)	$ 59,619	$ 6,495	$ (1,185)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2038	Dec. 31, 2022
Income Taxes [Line Items]
Tax Cuts and Jobs Act of 2017, income tax expense		$ 28,400,000
Tax Cuts and Jobs Act of 2017, remeasurement of deferred tax assets and liabilities		36,000,000	$ 400,000
Tax Cuts and Jobs Act of 2017, transition tax for accumulated foreign earnings, income tax expense		29,100,000	1,300,000
Tax Cuts and Jobs Act of 2017, valuation allowance against foreign tax credit carryforward		35,300,000	8,000,000
SAB 118 Tax Expense	$ 2,900,000		10,000,000
Tax Cuts and Jobs Act of 2017, income tax expense related to employee compensation			1,100,000
Foreign tax rate differences benefit in income tax			4,000,000	$ 13,000,000	$ 17,700,000
Income tax expense reduction due to tax holiday			3,000,000	3,500,000
Net operating loss carryforwards	537,325,000		537,325,000
Net tax credit carryforwards	71,000,000		71,000,000
Operating loss carryforwards that will be used in expiration periods	172,500,000		172,500,000
Net tax credit carryforwards that will expire	71,040,000		71,040,000
Net tax credit carry forwards with indefinite carry forward period	5,200,000		5,200,000
Net tax credit carryforwards that expected to be utilized prior to expiry	42,700,000		42,700,000
Net decrease in reserve for uncertain tax positions			1,200,000
Balance at end of the year of unrecognized tax benefits	7,417,000	8,579,000	7,417,000	8,579,000	10,474,000
Estimate the range of reasonably possible changes to unrecognized tax positions	900,000		900,000
Recognized interest expense (income) and penalties of unrecognized tax benefits					$ 200,000
Accrued interest expense (income) and penalties of unrecognized tax benefits	0	$ 0	0	$ 0
Scenario, Forecast
Income Taxes [Line Items]
Net tax credit carryforwards that will expire						$ 64,200,000	$ 1,600,000
Net Operating Loss Carry Forwards Expires In 2018
Income Taxes [Line Items]
Net operating loss carryforwards	200,000		200,000
Net Operating Loss Carry Forwards Expires In 2019
Income Taxes [Line Items]
Net operating loss carryforwards	8,000,000		8,000,000
Net Operating Loss Carry Forwards Expires Between Two Thousand Twenty And Two Thousand Twenty Two
Income Taxes [Line Items]
Net operating loss carryforwards	29,400,000		29,400,000
Net Operating Loss Carry Forwards Expires Between Two Thousand Twenty Three And Two Thousand Thirty Eight
Income Taxes [Line Items]
Net operating loss carryforwards	167,800,000		167,800,000
Net Operating Loss Carry Forward Indefinite Period
Income Taxes [Line Items]
Net operating loss carryforwards	$ 331,900,000		$ 331,900,000

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate Reconciliation from Continuing Operations (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective income tax rate reconciliation from continuing operations:
United States federal statutory rate	21.00%	35.00%	35.00%
State and local income taxes	1.70%	0.80%	(0.90%)
Impact of change in tax contingencies	(1.00%)	2.20%	2.40%
Foreign income tax rate differences	(1.80%)	(13.10%)	(14.00%)
Impact of change in deferred tax asset valuation allowance	2.00%	1.50%	(7.30%)
Impact of change in legal entity tax status	0.00%	0.00%	(5.50%)
Impact of non-taxable translation gain	0.00%	(27.30%)	0.00%
Impact of non-taxable interest income	0.00%	(5.50%)	(4.90%)
Domestic permanent differences and tax credits	0.70%	(15.70%)	(5.70%)
Impact of tax reform	4.50%	28.60%	0.00%
Effective income tax rate reconciliation from continuing operations	27.10%	6.50%	(0.90%)

Income Taxes - Components of De

Income Taxes - Components of Deferred Income Tax Balances (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred income tax liabilities:
Plant, equipment, and intangibles	$ (114,413)	$ (120,171)
Deferred income tax assets:
Postretirement, pensions, and stock compensation	30,896	28,736
Reserves and accruals	25,641	29,297
Net operating loss and tax credit carryforwards	164,823	228,815
Valuation allowances	(90,872)	(151,841)
Deferred tax assets	130,488	135,007
Net deferred income tax asset	$ 16,075	$ 14,836

Income Taxes - Summary of Net O

Income Taxes - Summary of Net Operating Loss Carryforwards (Details) $ in Thousands	Dec. 31, 2018USD ($)
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	$ 537,325
Australia
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	12,064
France
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	15,538
Germany
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	13,436
Japan
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	20,203
Luxembourg
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	24,252
Netherlands
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	23,889
Other
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	45,171
United Kingdom
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	258,423
United States - Federal and various states
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	$ 124,349

Income Taxes - Summary of Tax C

Income Taxes - Summary of Tax Credit Carryforwards (Details) $ in Thousands	Dec. 31, 2018USD ($)
Tax Credit Carryforward [Line Items]
Tax Credit Carryforwards	$ 71,040
United States
Tax Credit Carryforward [Line Items]
Tax Credit Carryforwards	48,859
Canada
Tax Credit Carryforward [Line Items]
Tax Credit Carryforwards	$ 22,181

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, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 8,579	$ 10,474
Additions based on tax positions related to the current year	866	981
Additions for tax positions of prior years	1,292	2,549
Reductions for tax positions of prior years - Settlement	(1,689)	(5,425)
Reduction for tax positions of prior years - Statute of limitations	(1,631)	0
Balance at end of year	$ 7,417	$ 8,579

Pension and Other Postretirem_3

Pension and Other Postretirement Benefits - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined contribution expense	$ 15,200	$ 13,900	$ 13,500
Accumulated benefit obligation	$ 412,400	269,200
Target asset allocation for the investment of the assets in fixed income securities minimum	55.00%
Target asset allocation for the investment of the assets in fixed income securities maximum	90.00%
Target asset allocation for the investment of the assets in equity securities minimum	10.00%
Target asset allocation for the investment of the assets in equity securities maximum	45.00%
Minimum
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
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
Defined Benefit Plan Disclosure [Line Items]
Defined benefit pension plans with projected benefit obligation in excess of plan assets, projected benefit obligation	$ 368,500	215,600
Defined benefit pension plans with projected benefit obligation in excess of plan assets, accumulated benefit obligation	362,600	212,700
Defined benefit pension plans with projected benefit obligation in excess of plan assets, fair value of plan assets	257,100	138,500
Settlement loss (gain)	1,342		$ 7,600
Anticipated pension and other postretirement plans contributions, next fiscal year	6,300
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined benefit other postretirement plans with accumulated benefit obligation in excess of plan assets, accumulated benefit obligation	26,100	30,300
Defined benefit other postretirement plans with accumulated benefit obligation in excess of plan assets, fair value of plan assets	0	$ 0
Settlement loss (gain)	0
Anticipated pension and other postretirement plans contributions, next fiscal year	$ 1,400

Pension and Other Postretirem_4

Pension and Other Postretirement Benefits - Change in Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits
Change in benefit obligation:
Benefit obligation, beginning of year	$ (272,025)	$ (256,481)
Service cost	(4,705)	(4,978)	$ (4,981)
Interest cost	(11,690)	(7,671)	(8,909)
Participant contributions	(85)	(91)
Actuarial gain (loss)	15,032	(3,291)
Divestitures (acquisitions)	(185,692)	794
Settlements	7,437	49
Plan amendments	(2,822)	0
Foreign currency exchange rate changes	23,454	(14,299)
Benefits paid	12,849	13,943
Benefit obligation, end of year	(418,247)	(272,025)	(256,481)
Other Benefits
Change in benefit obligation:
Benefit obligation, beginning of year	(30,333)	(32,038)
Service cost	(47)	(49)	(46)
Interest cost	(945)	(1,139)	(1,259)
Participant contributions	(6)	(7)
Actuarial gain (loss)	1,681	3,370
Divestitures (acquisitions)	0	0
Settlements	0	0
Plan amendments	0	0
Foreign currency exchange rate changes	2,020	(2,022)
Benefits paid	1,487	1,552
Benefit obligation, end of year	$ (26,143)	$ (30,333)	$ (32,038)

Pension and Other Postretirem_5

Pension and Other Postretirement Benefits - Change in Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Change in plan assets:
Fair value of plan assets, beginning of year	$ 198,156
Fair value of plan assets, end of year	311,674	$ 198,156
Pension Benefits
Change in plan assets:
Fair value of plan assets, beginning of year	198,156	182,370
Actual return on plan assets	(8,364)	18,746
Employer contributions	5,397	4,425
Plan participant contributions	85	91
Acquisitions	153,919	0
Settlements	(7,054)	0
Foreign currency exchange rate changes	(17,616)	6,467
Benefits paid	(12,849)	(13,943)
Fair value of plan assets, end of year	311,674	198,156
Other Benefits
Change in plan assets:
Fair value of plan assets, beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	1,481	1,545
Plan participant contributions	6	7
Acquisitions	0	0
Settlements	0	0
Foreign currency exchange rate changes	0	0
Benefits paid	(1,487)	(1,552)
Fair value of plan assets, end of year	$ 0	$ 0

Pension and Other Postretirem_6

Pension and Other Postretirement Benefits - Amounts Recognized in Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Amounts recognized in the balance sheets:
Accrued benefit liability (noncurrent)	$ (132,791)	$ (102,085)
Pension Benefits
Amounts recognized in the balance sheets:
Prepaid benefit cost	4,801	3,174
Accrued benefit liability (current)	(3,320)	(3,736)
Accrued benefit liability (noncurrent)	(108,054)	(73,307)
Net funded status	(106,573)	(73,869)
Other Benefits
Amounts recognized in the balance sheets:
Prepaid benefit cost	0	0
Accrued benefit liability (current)	(1,405)	(1,555)
Accrued benefit liability (noncurrent)	(24,738)	(28,778)
Net funded status	$ (26,143)	$ (30,333)

Pension and Other Postretirem_7

Pension and Other Postretirement Benefits - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits
Components of net periodic benefit cost:
Service cost	$ 4,705	$ 4,978	$ 4,981
Interest cost	11,690	7,671	8,909
Expected return on plan assets	(16,391)	(10,644)	(12,013)
Amortization of prior service credit	(42)	(41)	(42)
Curtailment gain	0	0	(227)
Settlement loss (gain)	1,342	(8)	7,630
Net loss (gain) recognition	2,810	2,597	2,670
Net periodic benefit cost	4,114	4,553	11,908
Other Benefits
Components of net periodic benefit cost:
Service cost	47	49	46
Interest cost	945	1,139	1,259
Expected return on plan assets	0	0	0
Amortization of prior service credit	0	0	(42)
Curtailment gain	0	0	0
Settlement loss (gain)	0	0	0
Net loss (gain) recognition	(12)	0	86
Net periodic benefit cost	$ 980	$ 1,188	$ 1,349

Pension and Other Postretirem_8

Pension and Other Postretirement Benefits - Assumptions Used in Determining Benefit Obligations and Net Periodic Benefit Cost Amounts (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Pension Benefits
Weighted average assumptions for benefit obligations at year end:
Discount rate	3.10%	2.80%
Salary increase	3.60%	3.60%
Weighted average assumptions for net periodic cost for the year:
Discount rate	2.80%	3.10%
Salary increase	3.60%	3.60%
Expected return on assets	5.50%	6.00%
Other Benefits
Weighted average assumptions for benefit obligations at year end:
Discount rate	3.70%	3.30%
Weighted average assumptions for net periodic cost for the year:
Discount rate	3.30%	3.70%
Assumed health care cost trend rates:
Health care cost trend rate assumed for next year	5.80%	6.20%
Rate that the cost trend rate gradually declines to	5.00%	5.00%
Cash & equivalents | Pension Benefits
Weighted average assumptions for net periodic cost for the year:
Defined Benefit Plan, Assumptions Used in Calculation, Description	0.047	0.047

Pension and Other Postretirem_9

Pension and Other Postretirement Benefits - Fair Values of Pension Plan Assets by Asset Category (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	$ 311,674	$ 198,156
U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	96,417	95,425
Non-U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	47,274	11,571
Government bond fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	66,439	28,429
Corporate bond fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	39,366	24,421
Fixed income fund(c)
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	41,167	38,072
Other investments(d)
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	17,274
Cash & equivalents
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	3,737	238
Quoted Prices in Active Markets for Identical Assets (Level 1)
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	7,521	238
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	1,465	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Non-U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	5,755	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Government bond fund
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) | Corporate bond fund
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) | Cash & equivalents
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	301	238
Significant Observable Inputs (Level 2)
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	47,709	38,072
Significant Observable Inputs (Level 2) | U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Significant Observable Inputs (Level 2) | Non-U.S. equities fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	0	0
Significant Observable Inputs (Level 2) | Government bond fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	1,253
Significant Observable Inputs (Level 2) | Corporate bond fund
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	7,116
Significant Observable Inputs (Level 2) | Fixed income fund(c)
Pension And Other Employee Benefit Plans [Line Items]
Fair values of pension plan assets by asset category	$ 39,340	$ 38,072

Pension and Other Postretire_10

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, 2018USD ($)
Pension Benefits
Pension And Other Employee Benefit Plans [Line Items]
2,019	$ 21,667
2,020	22,965
2,021	22,199
2,022	23,157
2,023	22,081
2024-2028	111,338
Total	223,407
Other Benefits
Pension And Other Employee Benefit Plans [Line Items]
2,019	1,432
2,020	1,436
2,021	1,438
2,022	1,438
2,023	1,432
2024-2028	7,196
Total	$ 14,372

Pension and Other Postretire_11

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, 2018	Dec. 31, 2017
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	$ 48,466	$ 44,359
Net prior service cost	2,734	11
Total	51,200
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	(3,047)	(1,545)
Net prior service cost	0	$ 0
Total	$ (3,047)

Pension and Other Postretire_12

Pension and Other Postretirement Benefits - Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Net actuarial loss (gain), beginning of year	$ 44,359
Amortization of actuarial gain (loss)	(2,810)
Actuarial gain	(15,032)
Asset loss	24,755
Settlement loss recognized	(1,342)		$ (7,600)
Currency impact	(1,464)
Net actuarial loss (gain), end of year	48,466	$ 44,359
Prior service cost, beginning of year	11
Amortization of prior service credit	42	41	42
Prior service cost occurring during the year	2,822
Currency impact	(141)
Prior service cost, end of year	2,734	11
Other Benefits
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Net actuarial loss (gain), beginning of year	(1,545)
Amortization of actuarial gain (loss)	12
Actuarial gain	(1,681)
Asset loss	0
Settlement loss recognized	0
Currency impact	167
Net actuarial loss (gain), end of year	(3,047)	(1,545)
Prior service cost, beginning of year	0
Amortization of prior service credit	0	0	$ 42
Prior service cost occurring during the year	0
Currency impact	0
Prior service cost, end of year	$ 0	$ 0

Comprehensive Income and Accu_3

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, 2018	Dec. 31, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 1,434,866	$ 1,461,317
Ending balance	1,387,588	1,434,866
Foreign Currency Translation Component
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(69,691)	(4,661)
Other comprehensive gain (loss) loss attributable to Belden before reclassifications	27,809	(65,030)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Net current period other comprehensive gain (loss) attributable to Belden	27,809	(65,030)
Ending balance	(41,882)	(69,691)
Pension and Other Postretirement Benefit Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(28,335)	(34,406)
Other comprehensive gain (loss) loss attributable to Belden before reclassifications	(7,813)	4,504
Amounts reclassified from accumulated other comprehensive income (loss)	3,123	1,567
Net current period other comprehensive gain (loss) attributable to Belden	(4,690)	6,071
Ending balance	(33,025)	(28,335)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(98,026)	(39,067)
Other comprehensive gain (loss) loss attributable to Belden before reclassifications	19,996	(60,526)
Amounts reclassified from accumulated other comprehensive income (loss)	3,123	1,567
Net current period other comprehensive gain (loss) attributable to Belden	23,119	(58,959)
Ending balance	$ (74,907)	$ (98,026)

Comprehensive Income and Accu_4

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, 2018	Dec. 31, 2017
Settlement loss
Amortization of pension and other postretirement benefit plan items:
Total before tax	$ 1,342
Pension and Other Postretirement Benefit Plans
Amortization of pension and other postretirement benefit plan items:
Total net of tax	(3,123)	$ (1,567)
Amount Reclassified from Accumulated Other Comprehensive Income | Actuarial losses
Amortization of pension and other postretirement benefit plan items:
Total before tax	2,798
Amount Reclassified from Accumulated Other Comprehensive Income | Prior service credit
Amortization of pension and other postretirement benefit plan items:
Total before tax	(42)
Amount Reclassified from Accumulated Other Comprehensive Income | Pension and Other Postretirement Benefit Plans
Amortization of pension and other postretirement benefit plan items:
Total before tax	4,098
Tax benefit	(975)
Total net of tax	$ 3,123

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, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Total share-based compensation cost	$ 18,497	$ 14,647	$ 18,178
Income tax benefit	$ 4,402	$ 5,566	$ 7,069

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to all nonvested awards	$ 27.8
Unrecognized compensation cost is expected to be recognized over a weighted-average period	2 years 1 month 10 days
SARs and Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
SAR's and stock options expiration period	10 years
Restricted Shares and Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Restricted Shares and Units | Maximum
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, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted-average fair value of SARs and options granted (in usd per share)	$ 25.19	$ 27.31	$ 18.79
Total intrinsic value of SARs converted and options exercised	$ 2,263	$ 7,156	$ 9,678
Tax benefit related to share-based compensation	$ 113	$ 967	$ 1,171
Weighted-average fair value of restricted stock shares and units granted (in usd per share)	$ 72.54	$ 79.96	$ 54.52
Total fair value of restricted stock shares and units vested	$ 5,740	$ 10,355	$ 8,171
Expected volatility	33.16%	36.89%	37.47%
Expected term (in years)	5 years 7 months 2 days	5 years 7 months 2 days	5 years 8 months 12 days
Risk-free rate	2.70%	2.01%	1.32%
Dividend yield	0.27%	0.27%	0.38%

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, 2018	Dec. 31, 2017	Dec. 31, 2016
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)	$ 72.54	$ 79.96	$ 54.52
SARs and Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at Beginning, Number (in shares)	1,132
Granted, Number (in shares)	265
Exercised or converted, Number (in shares)	(62)
Forfeited or expired, Number (in shares)	(46)
Outstanding at Ending, Number (in shares)	1,289	1,132
Vested or expected to vest at End, Number (in shares)	1,237
Exercisable or convertible at End, Number (in shares)	801
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)	$ 62.75
Granted, Weighted-Average Exercise Price (in dollars per share)	72.34
Exercised or converted, Weighted-Average Exercise Price (in dollars per share)	36.70
Forfeited or expired, Weighted-Average Exercise Price (in dollars per share)	73.76
Outstanding at End, Weighted-Average Exercise Price (in dollars per share)	65.58	$ 62.75
Vested or expected to vest at End, Weighted-Average Exercise Price	65.33
Exercisable or convertible at End, Weighted-Average Exercise Price	$ 62.88
Outstanding at End, Weighted-Average Remaining Contractual Term	6 years 7 months 15 days
Vested or expected to vest at End, Weighted-Average Remaining Contractual Term	6 years 6 months 15 days
Exercisable or convertible at End, Weighted-Average Remaining Contractual Term	5 years 5 months 1 day
Outstanding at End, Aggregate Intrinsic Value	$ 0
Vested or expected to vest at End, Aggregate Intrinsic Value	0
Exercisable or convertible at End, Aggregate Intrinsic Value	$ 0
Restricted Shares and Units
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)	496
Granted, Number (in shares)	338
Exercised or converted, Number (in shares)	(71)
Forfeited or expired, Number (in shares)	(136)
Outstanding at End, Number (in shares)	627	496
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)	$ 78.03
Granted, Weighted-Average Grant-Date Fair Value (in dollars per share)	72.54
Exercised or converted, Weighted-Average Grant-Date Fair Value (in dollars per share)	81.48
Forfeited or expired, Weighted-Average Grant-Date Fair Value (in dollars per share)	91.97
Outstanding at End, Weighted-Average Grant-Date Fair Value (in dollars per share)	$ 71.66	$ 78.03

Preferred Stock (Details)

Preferred Stock (Details) $ / shares in Units, $ in Millions	Jul. 15, 2019shares	Jul. 26, 2016USD ($)trading_day$ / sharesshares
Depository Shares
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
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 | Scenario, Forecast | Minimum
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 | Scenario, Forecast | Maximum
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) - USD ($) $ / shares in Units, $ in Thousands	Mar. 27, 2018	Dec. 31, 2018
Equity [Abstract]
Redemption price per share (in USD per share)	$ 0.01
Redemption of stockholders' rights agreement	$ 400	$ 411

Share Repurchases (Details)

Share Repurchases (Details) - USD ($) $ / shares in Units, shares in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Nov. 29, 2018	May 25, 2017
Equity, Class of Treasury Stock [Line Items]
Value of shares repurchased	$ 175,000,000	$ 25,000,000
5/25/2017 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount (in usd)				$ 200,000,000
Shares repurchased	2.7	0.3
Value of shares repurchased	$ 175,000,000	$ 25,000,000
Treasury stock acquired, average cost per share (in usd per share)	$ 64.94	$ 79.75
Amount remaining of authorized amount for repurchase under the share repurchase program (in usd)	$ 0
11/29/2018 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount (in usd)			$ 300,000,000
Shares repurchased	0

Operating Leases - Additional I

Operating Leases - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Leases [Abstract]
Operating lease expense incurred	$ 31.7	$ 38.6	$ 40.3

Operating Leases - Summary of M

Operating Leases - Summary of Minimum Annual Lease Payments for Noncancelable Operating Leases (Details) $ in Thousands	Dec. 31, 2018USD ($)
Leases [Abstract]
2,019	$ 19,877
2,020	17,531
2,021	14,776
2,022	12,317
2,023	7,654
Thereafter	28,771
Total	$ 100,926

Market Concentrations and Ris_2

Market Concentrations and Risks (Details) $ in Thousands, lb in Millions	12 Months Ended
	Dec. 31, 2018USD ($)lbDistributorCustomer	Dec. 31, 2017USD ($)DistributorCustomer	Dec. 31, 2016DistributorCustomer
Concentration Risk [Line Items]
Number of customers | Customer	10	10	10
Number of distributors | Distributor	6	6	6
Total senior subordinated notes	$ 1,485,900	$ 1,584,232
Senior Subordinated Notes
Concentration Risk [Line Items]
Fair value of debt instrument	1,485,000	$ 1,619,300
Total senior subordinated notes	$ 1,485,900
Copper
Concentration Risk [Line Items]
Committed amounts to purchase (in pounds) | lb	1.8
Committed amounts to purchase (in usd)	$ 5,000
Gain (loss) on unconditional purchase obligation	$ (200)
Customer Concentration Risk | Consolidated Revenues
Concentration Risk [Line Items]
Concentration risk, percentage	34.00%	35.00%	33.00%
Labor Force Concentration Risk | Workforce Subject to Collective Bargaining Arrangements
Concentration Risk [Line Items]
Concentration risk, percentage	21.00%
Labor Force Concentration Risk | Workforce Subject to Collective Bargaining Arrangements Expiring within One Year
Concentration Risk [Line Items]
Concentration risk, percentage	15.00%

Contingent Liabilities (Details

Contingent Liabilities (Details) $ in Millions	Dec. 31, 2018USD ($)
Standby Letters of Credit
Line of Credit Facility [Line Items]
Loss contingency, range of possible loss, portion not accrued	$ 7.5
Bank Guaranties
Line of Credit Facility [Line Items]
Loss contingency, range of possible loss, portion not accrued	3.9
Surety Bonds
Line of Credit Facility [Line Items]
Loss contingency, range of possible loss, portion not accrued	$ 2.4

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplemental Cash Flow Elements [Abstract]
Income tax refunds received	$ 4,782	$ 5,031	$ 3,838
Income taxes paid	(54,109)	(35,893)	(26,587)
Interest paid	$ (48,519)	$ (79,047)	$ (87,076)

Quarterly Operating Results (_3

Quarterly Operating Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Number of days in quarter	92 days	91 days	91 days	91 days	91 days	91 days	91 days	92 days	365 days	365 days
Revenues	$ 655,390	$ 655,774	$ 668,639	$ 605,565	$ 604,884	$ 621,745	$ 610,633	$ 551,381	$ 2,585,368	$ 2,388,643	$ 2,356,672
Gross profit	259,365	260,857	257,596	230,594	229,426	239,849	243,104	222,374	1,008,412	934,753	981,321
Operating income	73,234	131,278	56,506	44,203	59,915	61,116	62,776	51,597	305,221	235,404	232,083
Net income	43,491	85,858	28,792	2,570	30,436	945	35,891	25,581	160,711	92,853	127,646
Less: Net loss attributable to noncontrolling interest	(35)	(23)	(77)	(48)	(83)	(82)	(86)	(106)	(183)	(357)	(357)
Net income attributable to Belden	43,526	85,881	28,869	2,618	30,519	1,027	35,977	25,687	160,894	93,210	128,003
Less: Preferred stock dividends	8,733	8,732	8,733	8,733	8,733	8,732	8,733	8,733	34,931	34,931	15,428
Net income (loss) attributable to Belden common stockholders	$ 34,793	$ 77,149	$ 20,136	$ (6,115)	$ 21,786	$ (7,705)	$ 27,244	$ 16,954	$ 125,963	$ 58,279	$ 112,575
Basic income (loss) per share attributable to Belden common stockholders:	$ 0.87	$ 1.90	$ 0.49	$ (0.15)	$ 0.52	$ (0.18)	$ 0.64	$ 0.40	$ 3.10	$ 1.38	$ 2.67
Diluted income (loss) per share attributable to Belden stockholders:	$ 0.87	$ 1.80	$ 0.49	$ (0.15)	$ 0.51	$ (0.18)	$ 0.64	$ 0.40	$ 3.08	$ 1.37	$ 2.65

Quarterly Operating Results (_4

Quarterly Operating Results (Unaudited) - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Severance, restructuring, and acquisition integration costs	$ 11,600	$ 11,700	$ 24,900	$ 20,400	$ 9,900	$ 16,700	$ 9,600	$ 6,600	$ 68,613	$ 42,790	$ 31,140
Overstatement Of Revenues
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Qualifying misstatement					27,800	11,800	10,400	6,100
Overstatement Of Net Income
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) $ in Millions	Jan. 30, 2019USD ($)
Subsequent Event | SAM earnout | Settled Litigation
Subsequent Events [Line Items]
Interest and fees incurred for settlement	$ 0.9

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounts Receivable - Allowance for Doubtful Accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	$ 7,766	$ 8,104	$ 8,281
Charged to Costs and Expenses	1,273	950	2,517
Divestitures/ Acquisitions	1,168	38	(1)
Charge Offs	(1,389)	(905)	(1,336)
Recoveries	(293)	(995)	(1,046)
Currency Movement	(294)	574	(311)
Ending Balance	8,231	7,766	8,104
Inventories - Excess and Obsolete Allowances
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	25,269	24,561	22,531
Charged to Costs and Expenses	3,659	2,348	3,921
Divestitures/ Acquisitions	6,204	2,628	(706)
Charge Offs	(3,328)	(3,219)	0
Recoveries	(2,709)	(2,205)	(1,142)
Currency Movement	(199)	1,156	(43)
Ending Balance	28,896	25,269	24,561
Deferred Income Tax Asset - Valuation Allowance
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	151,841	104,771	117,071
Charged to Costs and Expenses	20,274	39,307	10,782
Divestitures/ Acquisitions	33,870	0	616
Charge Offs	(93,432)	(3,322)	(8,074)
Recoveries	(17,930)	(1,712)	(10,526)
Currency Movement	(3,751)	12,797	(5,098)
Ending Balance	$ 90,872	$ 151,841	$ 104,771