Lydall (LDL) 10-K 21 Feb 18 2017 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 15, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	LDL
Entity Registrant Name	LYDALL INC /DE/
Entity Central Index Key	60,977
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		17,354,532
Entity Public Float			$ 859,559,961

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Net sales	$ 698,437	$ 566,852	$ 524,505
Cost of sales	535,375	428,310	402,008
Gross profit	163,062	138,542	122,497
Selling, product development and administrative expenses	97,635	83,750	70,020
Operating income	65,427	54,792	52,477
Gain on sale of business	0	0	(18,647)
Interest expense	2,720	1,068	755
Other expense (income), net	1,388	(1,215)	(654)
Income before income taxes	61,319	54,939	71,023
Income tax expense	11,974	17,821	24,764
Loss (income) from equity method investment	28	(69)	0
Net income	$ 49,317	$ 37,187	$ 46,259
Earnings per common share:
Basic (USD per share)	$ 2.89	$ 2.20	$ 2.76
Diluted (USD per share)	$ 2.85	$ 2.16	$ 2.71
Weighted average common shares outstanding (shares)	17,045	16,871	16,746
Weighted average common shares and equivalents outstanding (shares)	17,317	17,241	17,084

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 49,317	$ 37,187	$ 46,259
Other comprehensive income (loss):
Change in pension plans, net of income taxes of $409, $1,409, and $55, respectively	2,016	(2,400)	(90)
Foreign currency translation adjustments	25,664	(10,965)	(10,334)
Unrealized gain on hedging activities, net of tax	122	0	0
Total other comprehensive income (loss), net of tax	27,802	(13,365)	(10,424)
Comprehensive income	$ 77,119	$ 23,822	$ 35,835

CONSOLIDATED STATEMENTS OF COM4

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Income taxes related to pension plans	$ 409	$ (1,409)	$ (55)

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 59,875	$ 71,934
Accounts receivable, (net of allowance for doubtful receivables of $1,507 and $1,429, respectively)	116,712	103,316
Inventories	80,339	66,146
Taxes receivable	5,525	3,883
Prepaid expenses and other current assets	11,044	10,327
Total current assets	273,495	255,606
Property, plant and equipment, net	170,332	160,795
Goodwill	68,969	63,606
Other intangible assets, net	40,543	41,447
Deferred tax assets	1,146
Deferred tax assets		248
Other assets, net	6,386	5,327
Total assets	560,871	527,029
Current liabilities:
Current portion of long-term debt	277	634
Accounts payable	71,931	56,346
Accrued payroll and other compensation	15,978	14,016
Accrued taxes	2,230	6,460
Other accrued liabilities	11,690	12,988
Total current liabilities	102,106	90,444
Long-term debt	76,913	128,141
Deferred tax liabilities	14,714
Deferred tax liabilities		15,849
Benefit plan liabilities	9,743	14,729
Other long-term liabilities	3,999	4,410
Commitments and Contingencies (Note 14)
Stockholders’ equity:
Preferred stock (par value $0.01 per share; authorized 500 shares; none issued or outstanding) (Note 8)	0	0
Common stock (par value $0.01 per share; authorized 30,000 shares; issued 25,018 and 24,858 shares, respectively) (Note 8)	250	249
Capital in excess of par value	88,006	82,387
Retained earnings	374,783	325,466
Accumulated other comprehensive loss	(20,148)	(47,950)
Treasury stock, 7,675 and 7,626 shares of common stock, respectively, at cost	(89,495)	(86,696)
Total stockholders’ equity	353,396	273,456
Total liabilities and stockholders’ equity	$ 560,871	$ 527,029

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful receivables	$ 1,507	$ 1,429
Preferred stock, par value (USD per share)	$ 0.01	$ 0.01
Preferred stock, authorized (shares)	500,000	500,000
Preferred stock, issued (shares)	0	0
Preferred stock, outstanding (shares)	0	0
Common stock, par value (USD per share)	$ 0.01	$ 0.01
Common stock, authorized (shares)	30,000,000	30,000,000
Common stock, issued (shares)	25,018,000	24,858,000
Treasury stock, shares (shares)	7,626,000	7,626,000

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 49,317	$ 37,187	$ 46,259
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sale of business	0	0	(18,647)
Depreciation and amortization	26,130	19,559	17,275
Inventory step-up amortization	1,108	1,954	0
Long-lived asset impairment charges	772	0	1,354
Deferred income taxes	(2,933)	(1,172)	3,585
Stock-based compensation	4,269	4,359	2,827
Income (loss) from equity method investment	28	(69)	0
Changes in assets and liabilities:
Accounts receivable	(8,046)	379	(2,749)
Inventories	(11,116)	500	479
Taxes receivable	1,216	(1,169)	(276)
Prepaid expenses and other assets	(784)	(3,355)	(1,337)
Accounts payable	14,315	3,505	(4,886)
Accrued taxes	(4,708)	1,244	(198)
Accrued payroll and other compensation	1,103	1,770	(3,416)
Benefit plan liabilities	(5,245)	487	(4,778)
Other, net	(58)	2,210	66
Net cash provided by operating activities	62,936	69,727	36,110
Cash flows from investing activities:
Business acquisitions, net of cash acquired	(323)	(152,242)	0
Capital expenditures	(27,006)	(25,466)	(20,645)
Proceeds from sale of business, net	0	0	28,550
Net cash (used for) provided by investing activities	(27,329)	(177,708)	7,905
Cash flows from financing activities:
Proceeds from borrowings	0	116,600	0
Debt repayments	(51,762)	(10,328)	(20,571)
Common stock issued	1,323	1,194	1,521
Common stock repurchased	(2,770)	(1,091)	(8,701)
Excess tax benefit on stock awards	0	0	1,044
Net cash (used for) provided by financing activities	(53,209)	106,375	(26,707)
Effect of exchange rate changes on cash	5,543	(2,369)	(3,450)
(Decrease) increase in cash and cash equivalents	(12,059)	(3,975)	13,858
Cash and cash equivalents at beginning of period	71,934	75,909	62,051
Cash and cash equivalents at end of period	59,875	71,934	75,909
Cash paid during the year for:
Interest	2,747	787	632
Income taxes, net	$ 16,158	$ 15,739	$ 20,180

CONSOLIDATED STATEMENTS OF CAS8

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Non-cash capital expenditures	$ 6.5	$ 8.6	$ 5.9

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning balance (shares) at Dec. 31, 2014		24,631
Beginning balance at Dec. 31, 2014	$ 212,599	$ 2,463	$ 68,961	$ 242,099	$ (24,161)	$ (76,763)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	46,259			46,259
Other comprehensive loss, net of tax	(10,424)				(10,424)
Stock repurchased	(8,778)					(8,778)
Stock issued under employee plans (in shares)		91
Stock issued under employee plans	1,698	$ (2)	1,700
Excess tax benefit on stock awards	1,044		1,044
Stock-based compensation expense	2,477		2,477
Stock issued to directors (in shares)		10
Stock issued to directors	350		350
Change in par value	0	$ (2,214)	2,214
Ending balance (shares) at Dec. 31, 2015		24,732
Ending balance at Dec. 31, 2015	245,225	$ 247	76,746	288,358	(34,585)	(85,541)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	37,187			37,187
Other comprehensive loss, net of tax	(13,365)				(13,365)
Stock repurchased	(1,155)					(1,155)
Stock issued under employee plans (in shares)		119
Stock issued under employee plans	1,158	$ 2	1,156
Stock-based compensation expense	4,009		4,009
Stock issued to directors (in shares)		7
Stock issued to directors	$ 350		350
Ending balance (shares) at Dec. 31, 2016	24,858	24,858
Ending balance at Dec. 31, 2016	$ 273,456	$ 249	82,387	325,466	(47,950)	(86,696)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Recently adopted accounting standards	47		126	(79)
Net income	49,317			49,317
Other comprehensive loss, net of tax	27,802				27,802
Stock repurchased	(2,799)					(2,799)
Stock issued under employee plans (in shares)		152
Stock issued under employee plans	1,351	$ 1	1,350
Stock-based compensation expense	3,868		3,868
Stock issued to directors (in shares)		8
Stock issued to directors	$ 401		401
Ending balance (shares) at Dec. 31, 2017	25,018	25,018
Ending balance at Dec. 31, 2017	$ 353,396	$ 250	$ 88,006	$ 374,783	$ (20,148)	$ (89,495)

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Business — Lydall, Inc. and its subsidiaries (the “Company” or “Lydall”) design and manufacture specialty engineered nonwoven filtration media, industrial thermal insulating solutions, and thermal and acoustical barriers for filtration/separation and heat abatement and sound dampening applications. On July 7, 2016, the Company completed an acquisition of the nonwoven and coating materials businesses primarily operating under the Texel brand (“Texel”) from ADS, Inc. (“ADS”), a Canadian based corporation. The Texel operations manufacture nonwoven needle punch materials and predominantly serve the geosynthetic, liquid filtration, and other industrial markets. The acquired businesses are included in the Company's Technical Nonwovens reporting segment. On December 31, 2016, the Company completed an acquisition of the nonwoven needle punch materials businesses, operating under the Gutsche (“Gutsche”) brand, a German based corporation. The Gutsche operations manufacture nonwoven needle punch materials and predominantly serve the industrial filtration and high performance nonwoven markets. The acquired businesses are included in the Company's Technical Nonwovens reporting segment. Principles of consolidation — The Consolidated Financial Statements include the accounts of Lydall, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated. Estimates and assumptions — The preparation of the Company’s Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the financial statement dates and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. Risks and uncertainties — Worldwide economic cycles and political changes affect the markets that the Company’s businesses serve and affect demand for Lydall’s products and impact profitability. Among other factors, disruptions in the global credit and financial markets, including diminished liquidity and credit availability, swings in consumer confidence and spending, unstable economic growth and fluctuations in unemployment rates has caused economic instability and can have a negative impact on the Company’s results of operations, financial condition and liquidity. Cash and cash equivalents — Cash and cash equivalents include cash on hand and highly liquid investments with original maturities of three months or less at the date of purchase. Concentrations of credit risk — Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents and trade accounts receivable. The Company places its cash and cash equivalents in high-quality financial institutions. Concentrations of credit risk with respect to trade accounts receivable are limited by the large number of customers comprising the Company’s customer base and their dispersion across many different industries and geographies. At December 31, 2017 and 2016 , Ford Motor Company ("Ford") represented 12.0% and 14.2% of total accounts receivable, respectively. No other customers accounted for more than 10.0% of total accounts receivable at December 31, 2017 and 2016 . Foreign and export sales were 54.2% of the Company’s net sales in 2017 , 46.9% in 2016 , and 44.2% in 2015 . Export sales primarily to Canada, Mexico, Asia and Europe were $55.9 million , $53.2 million , and $52.5 million in 2017 , 2016 , and 2015 , respectively. The Company performs ongoing credit evaluations of its customers’ financial condition and generally does not require collateral. Sales to the automotive market, included in the Thermal/Acoustical Metals and Thermal/Acoustical Fibers segments, were 48.3% of the Company’s net sales in 2017 , 56.2% in 2016 , and 56.6% in 2015 . Sales to Ford were 17.3% , 19.6% , and 18.2% of Lydall’s 2017 , 2016 , and 2015 net sales, respectively. No other customers accounted for more than 10% of total net sales in 2017 , 2016 , and 2015 . Inventories — Inventories are valued at lower of cost or net realizable value, cost being determined using the first-in, first-out (FIFO) cost method. Inventories in excess of requirements for current or anticipated orders have been written down to net realizable value. Pre-production design and development costs — The Company enters into contractual agreements with certain customers to design and develop molds, dies and tools (collectively, “tooling”). All such tooling contracts relate to parts that the Company will supply to customers under long-term supply agreements. Tooling costs are accumulated in work-in process inventory and are charged to operations as the related revenue from the tooling is recognized. Revenue is recognized as tooling is delivered and accepted by the customer. The Company also may progress bill on certain tooling being constructed. These billings are recorded as progress billings (a reduction of the associated work-in-process inventory) until the appropriate revenue recognition criteria have been met. Periodically, the Company enters into contractually guaranteed reimbursement arrangements as a mechanism to collect amounts due from customers from tooling sales. Under these arrangements, amounts due from tooling sales are collected as parts are delivered over the part supply arrangement, in accordance with the specific terms of the arrangement. The amounts due from the customer in such transactions are recorded in “Prepaid expenses and other current assets” or “Other assets, net” based upon the expected term of the reimbursement arrangement. The following tooling related assets were included in the Consolidated Balance Sheets as of December 31, 2017 and 2016 : December, 31 In thousands 2017 2016 Inventories, net of progress billings and reserves $ 18,540 $ 9,388 Prepaid expenses and other current assets 281 258 Total tooling related assets $ 18,821 $ 9,646 Amounts included in “Prepaid expenses and other current assets” include the short-term portion of receivables due under contractually guaranteed reimbursement arrangements. Included in the inventory balance was an offset for progress billings of $1.7 million and $0.9 million at December 31, 2017 and 2016 , respectively. Company owned tooling is recorded in “Property, plant and equipment, net” at December 31, 2017 and December 31, 2016 . Property, plant and equipment — Property, plant, and equipment are stated at cost. Assets held under capital leases are recorded at the lower of the net present value of the minimum lease payments or the fair value of the leased asset at the inception of the lease. Property, plant and equipment, including property, plant and equipment under capital leases, are depreciated over their estimated useful lives using the straight-line method. Leasehold improvements are depreciated on a straight-line basis over the term of the lease or the life of the asset, whichever is shorter. The cost and accumulated depreciation amounts applicable to assets sold or otherwise disposed of are removed from the asset and accumulated depreciation accounts and any net gain or loss is included in the Consolidated Statements of Operations. Expenses for maintenance and repairs are charged to expense as incurred. Goodwill and other intangible assets — Goodwill represents costs in excess of fair values assigned to the underlying net assets of acquired companies. Goodwill and other intangible assets with indefinite lives are not amortized but are subject to annual impairment tests. All other intangible assets are amortized over their estimated useful lives, which range from 4 to 14 years. In performing impairment tests, the Company considers discounted cash flows and other market factors as best evidence of fair value. There are inherent uncertainties and management judgment required in these analyses. Valuation of long-lived assets — The Company evaluates the recoverability of long-lived assets, or asset groups, whenever events or changes in circumstances indicate that carrying amounts may not be recoverable. Should such evaluations indicate that the related future undiscounted cash flows are not sufficient to recover the carrying values of the assets, such carrying values would be reduced to fair value and this adjusted carrying value would become the assets’ new cost basis. For long-lived assets held for sale, assets are written down to fair value, less costs to sell. Fair value is determined primarily using future anticipated cash flows that are directly associated with, and that are expected to arise as a direct result of the use and eventual disposition of the asset, or asset group, as well as market conditions and other factors. There are inherent uncertainties and management judgment required in these analyses. Contingencies and environmental obligations — The Company makes judgments and estimates in accordance with applicable accounting rules when it establishes reserves for legal proceedings, claims, investigations, environmental obligations and other contingent matters. Provisions for such matters are charged to expense when it is probable that a liability has been incurred and reasonable estimates of the liability can be made. Estimates of environmental liabilities are based on a variety of matters, including, but not limited to, the stage of investigation, the stage of the remedial design, evaluation of existing remediation technologies, and presently enacted laws and regulations. The amount and timing of all future expenses related to legal proceedings, claims, investigations, environmental obligations and other contingent matters may vary significantly from estimates. Employer sponsored benefit plans — The Company recognizes the funded status of its domestic defined benefit pension plan. Net benefit obligations are calculated based on actuarial valuations using key assumptions related to discount rates, mortality rates and expected return on plan assets. Derivative instruments — Derivative instruments are measured at fair value and recognized as either assets or liabilities on the Consolidated Balance Sheet in either current or non-current other assets or other accrued liabilities or other long-term liabilities depending upon maturity and commitment. For derivative instruments that are designated and qualify as a fair value hedge, the gain or loss on the derivative as well as the offsetting loss or gain on the hedged item attributable to the hedged risk are recognized in the Consolidated Statement of Operations. For derivative instruments that are designated and qualify as a cash flow hedge, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income and reclassified into earnings in the same period or periods in which the hedge transaction affects earnings. The Company selectively uses financial instruments to manage market risk associated with exposure to fluctuations in interest rates and foreign currency rates. These financial exposures are monitored and managed by the Company as an integral part of its risk management program. The Company does not engage in derivative instruments for speculative or trading purposes. Lydall has historically not been a party to a significant number of derivative instruments. Revenue recognition — The Company recognizes revenue (1) once evidence of an arrangement exists; (2) product delivery has occurred; (3) pricing is fixed or determinable; and (4) collection is reasonably assured. The four criteria required to recognize revenue are considered to be met, and the passage of title to the customer occurs, at the respective FOB point and, therefore, revenue is recognized at that time. The Company’s standard sales and shipping terms are FOB shipping point, therefore, substantially all revenue is recognized upon shipment. However, the Company conducts business with certain customers on FOB destination terms and in these instances revenue is recognized upon receipt by the customer. The Company generally does not provide specific customer inspection or acceptance provisions in its sales terms, with the exception of tooling sales discussed in “Pre-production design and development costs” above. Sales returns and allowances are recorded as identified or communicated by the customer and internally approved. The Company does not provide customers with general rights of return for products sold; however, in limited circumstances, the Company will allow sales returns and allowances from customers if the products sold do not conform to specifications. Shipping and handling costs consist primarily of costs incurred to deliver products to customers and internal costs related to preparing products for shipment and are recorded in cost of sales. Amounts billed to customers as shipping and handling are classified as revenue. Research and development — Research and development costs are charged to expense as incurred and amounted to $10.8 million in 2017 , $9.0 million in 2016 , and $8.5 million in 2015 . Research and development costs were primarily comprised of development personnel salaries, prototype material costs and testing and trials of new products. Earnings per share — Basic earnings per common share are equal to net income divided by the weighted average number of common shares outstanding during the period. Diluted earnings per common share are equal to net income divided by the weighted average number of common shares outstanding during the period, including the effect of stock options and stock awards, if such effect is dilutive. Income taxes — The provision for income taxes is based upon income reported in the accompanying Consolidated Financial Statements. Deferred income taxes reflect the impact of temporary differences between the amounts of income and expense recognized for financial reporting purposes and such amounts recognized for tax purposes. In the event the Company was to determine that it would not be able to realize all or a portion of its deferred tax assets in the future, the Company would record a valuation allowance through a charge to income in the period that such determination was made. Conversely, if the Company was to determine that it would be able to realize its deferred tax assets in the future in excess of the net carrying amounts, the Company would decrease the recorded valuation allowance and record an increase to income in the period that such determination was made. See Note 13 to the consolidated financial statements for additional provision items recorded in regards to the Tax Cuts and Jobs Act (the "Tax Reform Act"). Translation of foreign currencies — Assets and liabilities of foreign subsidiaries are translated at exchange rates prevailing on the balance sheet date. Revenues and expenses are translated at average exchange rates prevailing during the period. Any resulting translation gains or losses are reported in other comprehensive income (loss). Stock options and share grants — The Company accounts for awards of equity instruments under the fair value method of accounting and recognizes such amounts in the Consolidated Statements of Operations. The Company recognizes expense on a straight-line basis over the vesting period of the entire award. Prior to January 1, 2016, stock-based compensation expense included estimated effects of forfeitures. Upon adoption of ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, in 2016, an accounting policy election was made to account for forfeitures as they occur. As a result of the adoption of this ASU, the Company recognized excess tax benefits from stock award exercises and vesting as a discrete tax benefit during the years ended December 31, 2017 and December 31, 2016. The Company applied these changes prospectively, and therefore the year ending December 31, 2015 was not adjusted. The Company estimates the fair value of option grants based on the Black Scholes option-pricing model. Expected volatility and expected term are based on historical information. The calculation assumes that future volatility and expected term are not likely to materially differ from the Company’s historical stock price volatility and historical exercise data, respectively. Compensation expense for all restricted stock awards is recorded based on the market value of the stock on the grant date and recognized as expense over the vesting period of the award. Compensation expense for performance-based restricted stock is also impacted by the probability of achieving the performance targets. Recently Adopted Accounting Standards Effective January 1, 2017, the Company adopted the Financial Accounting Standards Board ("FASB") Accounting Standards Update ("ASU") No. 2015-11, “Inventory” (Topic 330): Simplifying the Measurement of Inventory." This ASU requires an entity to measure inventory at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. Subsequent measurement is unchanged for inventory measured using last-in, first-out (“LIFO”) or the retail inventory method. The adoption of this ASU did not have any impact on the Company’s consolidated financial statements.

Acquisitions and Divestitures

Acquisitions and Divestitures	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Acquisitions and Divestitures	Acquisitions and Divestitures Acquisitions On December 31, 2016, the Company completed an acquisition of the nonwoven needle punch materials businesses, which include MGF Gutsche & Co GmbH KG, FRG and Gutsche Environmental Technology (Yixing) Co. Ltd., China, operating under Gutsche (“Gutsche”), a German based corporation. The Gutsche operations manufacture nonwoven needle punch materials and predominantly serve the industrial filtration and high performance nonwoven markets. The Company acquired one hundred percent of Gutsche for $57.6 million , net of a receivable of $3.0 million related to an estimated post-closing purchase price adjustment. In the second quarter of 2017, the Company finalized the post closing adjustment resulting in an increase in the purchase price of $0.4 million resulting in a final purchase price of $58.0 million . The purchase price was financed with a combination of cash on hand and $31.6 million of borrowings through the Company's amended $175 million credit facility. The operating results of the Gutsche business have been included in the Consolidated Statements of Operations since December 31, 2016, the date of the acquisition, and are reported within the Technical Nonwovens segment. For the year ended December 31, 2017 , Gutsche reported net sales and operating income of $51.5 million and $2.9 million , respectively. Operating income for the year ended December 31, 2017 included $0.6 million of purchase accounting inventory fair value step-up adjustments in cost of sales upon the sale of inventory and $0.2 million of restructuring expenses. There were no sales or operating income for Gutsche during the year ended December 31, 2016 as the acquisition occurred on December 31, 2016 . On July 7, 2016, the Company completed an acquisition of the nonwoven and coating materials businesses primarily operating under Texel from ADS, a Canadian based corporation. The Texel operations manufacture nonwoven needle punch materials and predominantly serve the geosynthetic, liquid filtration, and other industrial markets. The Company acquired one hundred percent of Texel for $102.7 million in cash, including a post-closing working capital adjustment. The purchase price was financed with a combination of cash on hand and $85.0 million of borrowings through the Company’s amended $175 million credit facility. As part of the acquisition, the Company acquired a fifty percent interest in a joint venture, Afitex Texel Geosynthetiques, Inc., with a fair value of $0.6 million . The joint venture is accounted for under the equity method of accounting. The operating results of the Texel business have been included in the Consolidated Statements of Operations since July 7, 2016, the date of the acquisition, and are reported within the Technical Nonwovens segment. For the year ended December 31, 2017 , Texel reported net sales and operating income of $84.8 million and $6.9 million , respectively. Operating income for the year ended December 31, 2017 included $0.5 million of purchase accounting inventory fair value step-up adjustments in cost of sales upon the sale of inventory. From the date of the acquisition through December 31, 2016 , Texel reported net sales and operating income of $40.9 million and $2.5 million , respectively. Operating income from the date of the acquisition through the year ended December 31, 2016 included $2.0 million of purchase accounting inventory fair value step-up adjustments in cost of sales upon the sale of inventory. During the year ended December 31, 2017 and 2016 the Company incurred $0.1 million and $3.7 million , respectively, of acquisition related costs related to the acquisitions of Texel and Gutsche. These transaction costs include legal fees and other professional services fees to complete the transaction. These corporate office expenses have been recognized in the Company’s Condensed Consolidated Statements of Operations as selling, product development and administrative expenses. The following table summarizes the fair values of identifiable assets acquired and liabilities assumed at the date of the Texel and Gutsche acquisitions: In thousands Texel Gutsche Cash and cash equivalents $ 1,610 $ 9,400 Accounts Receivable 13,355 7,736 Inventories 17,525 6,417 Prepaid expenses and other current assets 2,469 1,125 Non-current environmental indemnification receivable (Note 14) 925 — Property, plant and equipment, net 31,525 7,969 Investment in joint venture 616 — Goodwill (Note 5) 28,655 19,729 Other intangible assets, net (Note 5) 22,887 15,622 Other long-term assets — 1,545 Total assets acquired 119,567 69,543 Current liabilities (8,520 ) (8,376 ) Long-term environmental remediation liability (Note 14) (925 ) — Other long-term liabilities — (2,742 ) Deferred tax liabilities (7,413 ) (470 ) Total liabilities assumed (16,858 ) (11,588 ) Net assets acquired $ 102,709 $ 57,955 The final purchase price allocation related to Texel reflects post-closing adjustments pursuant to the terms of the Stock Purchase Agreement. The final purchase price allocation related to Gutsche reflects post-closing adjustments pursuant to the terms of the Gutsche Share Purchase Agreement. The following table reflects the results of the Company for the year ended December 31, 2017 and the unaudited pro forma operating results of the Company for years ended December 31, 2016 and 2015 , which give effect to the acquisitions of Texel and Gutsche as if they had occurred on January 1, 2015. The pro forma information includes the historical financial results of the Company and the acquired businesses. The pro forma results are not necessarily indicative of the operating results that would have occurred had the acquisition been effective January 1, 2015, nor are they intended to be indicative of results that may occur in the future. The pro forma information does not include the effects of any synergies related to the acquisitions. For The Years Ended (Actual) (Unaudited (Unaudited In thousands 2017 2016 2015 Net Sales $ 698,437 $ 654,877 $ 651,252 Net Income $ 49,317 $ 43,559 $ 47,956 Earnings per share: Basic $ 2.89 $ 2.58 $ 2.86 Diluted $ 2.85 $ 2.53 $ 2.81 Included in earnings during the year ended December 31, 2017 was $3.9 million of amortization expense, $1.1 million of fair value step-up adjustments to inventory and acquisition related expenses of $0.1 million related to Texel and Gutsche. Pro forma earnings during the year ended December 31, 2016 were adjusted to exclude non-recurring items such as acquisition-related costs of $4.3 million and expense related to the fair value adjustment to inventory of $2.0 million . No amount was included in the pro forma earnings during the year ended December 31, 2016 related to inventory fair value adjustments which would have been recognized in cost of sales as the corresponding inventory would have been completely sold during 2015. Pro forma earnings during the year ended December 31, 2016 were adjusted to include additional expense of $3.9 million related to the amortization of the acquired intangible assets recognized at fair value in purchase accounting, additional depreciation expense of $1.2 million resulting from increased basis of property, plant and equipment, and additional interest expense of $0.8 million associated with borrowings under the Company’s Amended Credit Facility. Customer freight billings of $0.9 million were reclassed from costs of sales to net sales for the year ended December 31, 2016. Pro forma earnings during the year ended December 31, 2015 were adjusted to include acquisition-related costs of $0.8 million , expense of $3.2 million related to the amortization of the fair value adjustments to inventory, $3.5 million of additional amortization of the acquired intangible assets recognized at fair value in purchase accounting, additional depreciation expense of $2.1 million resulting from increased basis of property, plant and equipment, as well as $1.2 million of interest expense associated with borrowings under the Company’s Amended Credit Facility. Customer freight billings of $1.6 million were reclassed from costs of sales to net sales for the year ended December 31, 2015 . Divestiture On January 30, 2015, the Company sold all of the outstanding shares of common stock of its Life Sciences Vital Fluids business, reported as Other Products and Services, for a cash purchase price of $30.1 million . The disposition was completed pursuant to a Stock Purchase and Sale Agreement, dated January 30, 2015, by and among the Company, and the buyer. The Company recognized a pre-tax gain on the sale of $18.6 million , reported as non-operating income in the first quarter of 2015. Net of income taxes, the Company reported a gain on sale of $11.8 million . In accordance with the revised accounting guidance for reporting discontinued operations, the Company did not report Life Sciences Vital Fluids as a discontinued operation as it would not be considered a strategic shift in Lydall's business. Accordingly, the operating results of Life Sciences Vital Fluids are included in the operating results of the Company through the sale date in 2015.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories as of December 31, 2017 and 2016 were as follows: December 31, In thousands 2017 2016 Raw materials $ 28,672 $ 24,518 Work in process 29,427 17,161 Finished goods 23,901 25,360 82,000 67,039 Less: Progress billings (1,661 ) (893 ) Total inventories $ 80,339 $ 66,146 Included in work in process is gross tooling inventory of $20.2 million and $10.3 million at December 31, 2017 and 2016 , respectively. Tooling inventory, net of progress billings, was $18.5 million and $9.4 million at December 31, 2017 and 2016 , respectively.

Property, Plant and Equipment,

Property, Plant and Equipment, Net	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Net	Property, Plant and Equipment, Net Property, plant and equipment as of December 31, 2017 and 2016 were as follows: Estimated Useful Lives December 31, In thousands 2017 2016 Land – $ 4,289 $ 3,981 Buildings and improvements 10-35 years 84,337 74,397 Machinery and equipment 5-25 years 254,881 226,675 Office equipment 2-8 years 33,880 31,504 Vehicles 3-6 years 1,706 1,553 Assets under capital leases: Land – 241 226 Buildings and improvements 10-35 years 221 4,806 Machinery and equipment 5-25 years 1,051 — Office equipment 2-8 years 34 — 380,640 343,142 Accumulated depreciation (226,581 ) (196,251 ) Accumulated depreciation of capital leases (239 ) (2,915 ) 153,820 143,976 Construction in progress 16,512 16,819 Total property, plant and equipment, net $ 170,332 $ 160,795 Depreciation expense was $21.4 million in 2017 , $17.8 million in 2016 , and $16.4 million in 2015 .

Goodwill and Long-Lived Assets

Goodwill and Long-Lived Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Long-Lived Assets	Goodwill and Long-Lived Assets Gross and net carrying amounts of goodwill at December 31, 2017 and 2016 were as follows: In thousands Performance Materials Technical Nonwovens Thermal/ Acoustical Metals Totals Goodwill $ 12,777 $ 50,829 $ 12,160 $ 75,766 Accumulated amortization/impairment — — (12,160 ) (12,160 ) Balance at December 31, 2016 12,777 50,829 — 63,606 Goodwill 13,307 55,662 12,160 81,129 Accumulated amortization/impairment — — (12,160 ) (12,160 ) Balance at December 31, 2017 $ 13,307 $ 55,662 $ — $ 68,969 The changes in the carrying amounts of goodwill in 2017 and 2016 were as follows: In thousands Performance Materials Technical Nonwovens Totals Balance at January 1, 2016 $ 12,898 $ 3,943 $ 16,841 Goodwill addition — 47,987 47,987 Currency translation adjustment (121 ) (1,101 ) (1,222 ) Balance at December 31, 2016 12,777 50,829 63,606 Goodwill adjustment — 323 323 Currency translation adjustment 530 4,510 5,040 Balance at December 31, 2017 $ 13,307 $ 55,662 $ 68,969 Goodwill Associated with Acquisitions and Divestitures The goodwill adjustment of $0.3 million in 2017 within the Technical Nonwovens segment is the result of the final post-closing adjustments related to the acquisition of Gutsche on December 31, 2016. The goodwill addition of $48.0 million in 2016 within the Technical Nonwovens segment results from the acquisitions of Texel on July 7, 2016 and Gutsche on December 31, 2016. The amount allocated to goodwill is reflective of the benefits the Company expects to realize from its entrance into the geosynthetic market, expansion in the liquid filtration and other industrial markets and Texel's and Gutsche's assembled workforce. None of the goodwill associated with the Texel acquisition is expected to be deductible for income tax purposes. Of the $22.3 million of goodwill associated with the Gutsche acquisition at December 31, 2017, $19.0 million is expected to be deductible for income tax purposes. Goodwill Impairment Testing During the fourth quarter of 2017 , the Company performed its annual impairment analysis of the $13.3 million of goodwill in the Performance Materials reporting unit (PM reporting unit) and $55.7 million in the Technical Nonwovens reporting unit. The Company used the qualitative method to analyze the goodwill for the Performance Materials and Technical Nonwovens reporting units. When considering capital markets environment, economic conditions, industry trends, results of operations, and other factors, the Company concluded that it is not more likely than not that the fair value of each reporting unit was less than its carrying amount. For the Performance Materials reporting unit the Company also considered changes in assumptions used in the Company's most recent quantitative annual testing, including results of operations, the magnitude of excess of fair value over carrying value and other factors. As a result, the Company concluded that the Performance Materials and Technical Nonwovens reporting units' goodwill was not impaired. Other Intangible Assets The table below presents the gross carrying amount and, as applicable, the accumulated amortization of the Company’s acquired intangible assets other than goodwill included in “Other intangible assets, net” in the Consolidated Balance Sheets as of December 31, 2017 and 2016 : December 31, 2017 December 31, 2016 In thousands Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortized intangible assets Customer relationships $ 39,474 $ (4,460 ) $ 36,131 $ (1,284 ) Patents 4,504 (3,821 ) 4,028 (3,300 ) Technology 2,500 (644 ) 2,500 (477 ) Trade names 4,288 (1,461 ) 3,912 (394 ) License agreements 640 (640 ) 583 (583 ) Other 586 (423 ) 536 (205 ) Total amortized intangible assets $ 51,992 $ (11,449 ) $ 47,690 $ (6,243 ) In connection with the acquisition of Texel on July 7, 2016, the Company recorded intangible assets of $22.9 million , which included $20.8 million of customer relationships and $2.1 million of trade names. As of December 31, 2017, the weighted average useful lives of the Texel intangible assets was 12 years. In connection with the acquisition of Gutsche on December 31, 2016, the Company recorded intangible assets of $15.6 million , which included $13.8 million of customer relationships, $1.7 million of trade names and $0.1 million of backlog. As of December 31, 2017, the weighted average useful lives of the Gutsche intangible assets was 11 years. Amortization of all intangible assets for the years ended December 31, 2017 , 2016 , and 2015 was $4.5 million , $1.5 million , and $0.8 million , respectively. The increase in amortization expense during 2017, compared to 2016, was primarily due to the acquisitions of Texel and Gutsche. Estimated amortization expense for intangible assets is expected to be $6.0 million , $5.7 million , $5.3 million , $4.5 million and $3.8 million for each of the years ending December 31, 2018 through 2022 , respectively. As of December 31, 2017 , the weighted average useful life of intangible assets was approximately 11 years. Impairment of Long-Lived Assets During the first quarter of 2017, the Company tested for impairment a discrete long-lived asset group in the Performance Materials segment with a carrying value of $1.3 million , as a result of indicators of possible impairment. To determine the recoverability of this asset group, the Company completed an undiscounted cash flow analysis and compared it to the asset group carrying value. This analysis was primarily dependent on the expectations for net sales over the estimated remaining useful life of the underlying asset group. The impairment test concluded that the asset group was not recoverable as the resulting undiscounted cash flows were less than their carrying amount. Accordingly, the Company determined the fair value of the asset group to assess if there was an impairment. Determining fair value is judgmental in nature and requires the use of significant estimates and assumptions considered to be Level 3 inputs. To determine the estimated fair value of the asset group the Company used the market approach. Under the market approach, the determination of fair value considered market conditions including an independent appraisal of the components of the asset group. The estimated fair value of the asset group was $0.5 million , below its carrying value of $1.3 million , which resulted in a long-lived asset impairment charge of $0.8 million included in selling, product development and administrative expenses during the quarter ended March 31, 2017. This long-lived asset group, with a net book value of $0.5 million , is classified as held for sale as of December 31, 2017.

Long-term Debt and Financing Ar

Long-term Debt and Financing Arrangements	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Long-term Debt and Financing Arrangements	Long-term Debt and Financing Arrangements On July 7, 2016, the Company amended its $100.0 million senior secured revolving credit facility (“Amended Credit Facility”) which increased the available borrowing from $100 million to $175 million , added a fourth lender and extended the maturity date to July 7, 2021. The Amended Credit Facility is secured by substantially all of the assets of the Company. Under the terms of the Amended Credit Facility, the lenders are providing a $175 million revolving credit facility to the Company, under which the lenders may make revolving loans and issue letters of credit to or for the benefit of the Company and its subsidiaries. The Company may request the Amended Credit Facility be increased by an aggregate amount not to exceed $50 million through an accordion feature, subject to specified conditions set forth in the Amended Credit Facility. The Amended Credit Facility contains a number of affirmative and negative covenants, including financial and operational covenants. The Company is required to meet a minimum interest coverage ratio. The interest coverage ratio requires that, at the end of each fiscal quarter, the ratio of consolidated EBIT to Consolidated Interest Charges, both as defined in the Amended Credit Facility, may not be less than 2.0 to 1.0 for the immediately preceding 12 month period. In addition, the Company must maintain a Consolidated Leverage Ratio, as defined in the Amended Credit Facility, as of the end of each fiscal quarter of no greater than 3.0 to 1.0 . The Company must also meet minimum consolidated EBITDA as of the end of each fiscal quarter for the preceding 12 month period of $30.0 million . The Company was in compliance with all covenants during 2017 and at December 31, 2017. Interest is charged on borrowings at the Company’s option of either: (i) Base Rate plus the Applicable Rate, or (ii) the Eurodollar Rate plus the Applicable Rate. The Base Rate is a fluctuating rate equal to the highest of (a) the federal funds rate plus 0.50% , (b) the prime rate as set by Bank of America, and (c) the Eurocurrency Rate plus 1.00% . The Eurocurrency Rate means (i) if denominated in LIBOR quoted currency, a fluctuating LIBOR per annum rate equal to the London Interbank Offered Rate; (ii) if denominated in Canadian Dollars, the rate per annum equal to the Canadian Dealer Offered Rate; or (iii) the rate per annum as designated with respect to such alternative currency at the time such alternative currency is approved by the Lenders. The Applicable Rate is determined based on the Company’s Consolidated Leverage Ratio (as defined in the Amended Credit Agreement). The Applicable Rate added to the Base Rate Committed Loans ranges from 15 basis points to 100 basis points, and the Applicable Rate added to Eurocurrency Rate Committed Loans and Letters of Credit ranges from 75 basis points to 175 basis points. The Company pays a quarterly fee ranging from 17.5 basis points to 30 basis points on the unused portion of the $175 million available under the Amended Credit Facility. In April 2017, the Company entered into a three -year interest rate swap agreement with a bank which converts the interest on the first notional $60.0 million of the Company's one-month LIBOR-based borrowings under its Amended Credit Facility from a variable rate, plus the borrowing spread, to a fixed rate of 1.58% plus the borrowing spread. The notional amount reduces quarterly by $5.0 million through March 31, 2020. The Company is accounting for the interest rate swap agreement as a cash flow hedge. Effectiveness of this derivative agreement is assessed quarterly by ensuring that the critical terms of the swap continue to match the critical terms of the hedged debt. At December 31, 2017 , the Company had borrowing availability of $94.5 million under the Amended Credit Facility net of $76.6 million of borrowings outstanding and standby letters of credit outstanding of $3.9 million . In addition to the amounts outstanding under the Amended Credit Facility, the Company has various acquired foreign credit facilities totaling approximately $9.8 million . At December 31, 2017 , the Company's foreign subsidiaries had $0.1 million in borrowings outstanding as well as $2.8 million in standby letters of credit outstanding. The Company also has capital lease agreements for machinery and equipment at multiple operations requiring monthly principal and interest payments through 2020. Total outstanding debt consists of: December 31, In thousands Effective Rate Maturity 2017 2016 Revolver Loan, due July 7, 2021 2.57% 2021 $ 76,600 $ 126,600 Other Foreign Bank Borrowings 0.80% - 3.40% 2017 — 1,430 Capital Leases 1.65% - 2.09% 2019 - 2020 590 745 77,190 128,775 Less portion due within one year (277 ) (634 ) Total long-term debt $ 76,913 $ 128,141 As of December 31, 2017 , total debt maturing in 2018, 2019, and 2021 is $0.3 million , $0.3 million , and $76.6 million , respectively. The weighted average interest rate on long-term debt was 2.2% for the year ended December 31, 2017 , compared with 1.4% and 1.3% for the years ended December 31, 2016 and 2015 , respectively. The fair values of the Company’s long-term debt are determined using discounted cash flows based upon the Company’s estimated current interest cost for similar type borrowings or current market value, which falls under Level 2 of the fair value hierarchy. The carrying values of the long-term debt approximate fair market value.

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives The Company selectively uses financial instruments to manage market risk associated with exposure to fluctuations in interest rates and foreign currency rates. These financial exposures are monitored and managed by the Company as an integral part of its risk management program. The Company’s interest rate exposure is most sensitive to fluctuations in interest rates in the United States and Europe, which impact interest paid on its debt. The Company has debt with variable rates of interest based generally on LIBOR. From time to time, the Company may enter into interest rate swap agreements to manage interest rate risk. These instruments are designated as cash flow hedges and are recorded at fair value using Level 2 observable market inputs. Derivative instruments are recognized as either assets or liabilities on the balance sheet in either current or non-current other assets or other accrued liabilities or other long-term liabilities depending upon maturity and commitment. For derivative instruments that are designated and qualify as a cash flow hedge, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income and reclassified into earnings in the same period or periods in which the hedge transaction affects earnings. Any ineffective portion, or amounts related to contracts that are not designated as hedges, are recorded directly to earnings. The Company's policy for classifying cash flows from derivatives is to report the cash flows consistent with the underlying hedged item. The Company does not use derivatives for speculative or trading purposes. In April 2017, the Company entered into a three -year interest rate swap agreement with a bank which converts the interest on the first notional $60.0 million of the Company's one-month LIBOR-based borrowings under its Amended Credit Facility from a variable rate, plus the borrowing spread, to a fixed rate of 1.58% plus the borrowing spread. The notional amount reduces quarterly by $5.0 million through March 31, 2020. The interest rate swap agreement was accounted for as cash flow hedge. Effectiveness of this derivative agreement is assessed quarterly by ensuring that the critical terms of the swap continue to match the critical terms of the hedged debt. The following table sets forth the fair value amounts of derivative instruments held by the Company: December 31, 2017 December 31, 2016 In thousands Asset Derivatives Liability Derivatives Asset Derivatives Liability Derivatives Derivatives designated as hedging instruments: Interest rate contract $ 157 $ — $ — $ — Total derivatives $ 157 $ — $ — $ — The following table sets forth the income, recorded in accumulated other comprehensive income, net of tax, for the quarters and twelve months ended December 31, 2017 and 2016 for derivatives held by the Company and designated as hedging instruments: Quarter Ended December 31, Twelve Months Ended December 31, 2017 2016 2017 2016 Cash flow hedges: Interest rate contract $ 129 $ — $ 122 $ — $ 129 — $ 122 $ —

Capital Stock

Capital Stock	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Capital Stock	Capital Stock Preferred Stock — The Company has authorized Preferred Stock with a par value of $0.01 . None of the 500,000 authorized shares have been issued. Common Stock — As of December 31, 2017 , 10,214 Lydall stockholders of record held 17,343,839 shares of Common Stock. Dividend policy — The Company does not pay a cash dividend on its common stock. The Company’s Amended Credit Facility does not place any restrictions on cash dividend payments, so long as the payments do not place the Company in default.

Employer Sponsored Benefit Plan

Employer Sponsored Benefit Plan	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Employer Sponsored Benefit Plan	Employer Sponsored Benefit Plan The Company maintains a domestic defined benefit pension plan, which covers certain domestic Lydall employees, is noncontributory and benefits are based on either years of service or eligible compensation paid while a participant is in a plan. The plan has been closed to new employees for several years and benefits under the pension plan are no longer accruing. The Company’s funding policy for its domestic defined benefit pension plan is to fund not less than the ERISA minimum funding standard and not more than the maximum amount that can be deducted for federal income tax purposes. Plan assets and benefit obligations of the domestic defined benefit pension plan are as follows: December 31, In thousands 2017 2016 Change in benefit obligation: Net benefit obligation at beginning of year $ 50,086 $ 48,081 Interest cost 2,058 2,139 Actuarial loss 2,126 2,062 Gross benefits paid (2,388 ) (2,196 ) Net benefit obligation at end of year $ 51,882 $ 50,086 Change in plan assets: Fair value of plan assets at beginning of year $ 37,038 $ 35,413 Actual return on plan assets 5,924 221 Contributions 3,600 3,600 Gross benefits paid (2,388 ) (2,196 ) Fair value of plan assets at end of year $ 44,174 $ 37,038 Net benefit obligation in excess of plan assets $ (7,708 ) $ (13,048 ) Balance sheet amounts: Noncurrent liabilities $ (7,708 ) $ (13,048 ) Total liabilities $ (7,708 ) $ (13,048 ) Amounts recognized in accumulated other comprehensive income, net of tax consist of: Net actuarial loss $ 17,632 $ 19,689 Net amount recognized $ 17,632 $ 19,689 At December 31, 2017 , in addition to the accrued benefit liability of $7.7 million recognized for the Company’s domestic defined benefit pension plan, the Company also had foreign regulatory labor agreements with an accrued benefit liability of $1.9 million and accumulated other comprehensive loss, net of tax, of $0.4 million . At December 31, 2016 , in addition to the accrued benefit liability of $13.0 million recognized for the Company’s domestic defined benefit pension plan, the Company also had foreign regulatory labor agreements with an accrued benefit liability of $1.5 million and accumulated other comprehensive loss, net of tax, of $0.4 million . The domestic defined benefit pension plan liability, net of tax, included in other comprehensive income decreased by $2.1 million for the year ended December 31, 2017 . The domestic defined benefit pension plan liability, net of tax, included in other comprehensive income increased by $2.4 million for the year ended December 31, 2016 . These changes are mainly due to changes in pension assumptions, primarily the discount rates. Aggregated information for the domestic defined benefit pension plan with an accumulated benefit obligation in excess of plan assets is provided in the tables below: December 31, In thousands 2017 2016 Projected benefit obligation $ 51,882 $ 50,086 Accumulated benefit obligation $ 51,882 $ 50,086 Fair value of plan assets $ 44,174 $ 37,038 Components of net periodic benefit cost for the domestic pension plan: December 31, In thousands 2017 2016 2015 Interest cost $ 2,058 $ 2,139 $ 2,066 Expected return on plan assets (2,376 ) (2,419 ) (2,360 ) Amortization of actuarial net loss 1,092 933 897 Total net periodic benefit cost $ 774 $ 653 $ 603 It is estimated that $1.0 million of actuarial net loss will be amortized from accumulated other comprehensive loss into net periodic benefit costs for the domestic pension plan in 2018 . The major assumptions used in determining the year-end benefit obligation and annual net cost for the domestic pension plan are presented in the following table: Benefit Obligation Net Cost For the years ended December 31, 2017 2016 2017 2016 2015 Discount rate 3.71 % 4.21 % 4.21 % 4.56 % 4.16 % Expected return on plan assets 5.80 % 6.30 % 6.30 % 7.00 % 7.25 % Plan Assets The domestic defined benefit pension plan is administered by the Lydall Retirement Committee (the "Committee"), which is appointed by the Board of Directors. The Committee’s responsibilities are to establish a funding policy for the Lydall Pooled Pension Investment Trust (“the Trust”) and to appoint and oversee the investment advisor responsible for the Trust’s investments. The Committee is a named fiduciary under the plan, and the Committee has granted discretion to the investment advisor with respect to management of the Trust’s investments. The assets of the domestic defined benefit pension plan are invested in the Trust for the purpose of investment diversification. In determining the expected return on plan assets, the Committee considers the relative weighting of plan assets, the historical performance of marketable debt and equity securities and economic and other indicators of future performance. Investment management objectives include maintaining an adequate level of diversification to balance market risk and to provide sufficient liquidity for near-term payments of benefits accrued under the domestic pension plan and to pay the expenses of administration. The long-term investment objective of the Trust is to achieve a total return equal to or greater than the Trust’s actuarially assumed rate of return, currently 5.80% . Though it is the intent of the Committee to achieve income and growth, that intent does not include taking extraordinary risks or engaging in investment activities not commonly considered prudent under the standards imposed by ERISA. The Committee defines risk as the probability of not meeting the Trust’s objectives and the probability of not meeting the Trust’s liability requirements. The allowable investments include: securities, mutual funds, sub-advisers, independent investment managers and/or programs, and cash or cash equivalents. Prohibited investments include: single strategy hedge funds, investment in individual securities, direct investment in venture capital, CMO derivatives and commodities. The Committee’s target asset allocation seeks to control risk through portfolio diversification and takes into account, among other factors, objectives discussed above, current funding levels, cash flow conditions and economic and industry trends. In developing strategic asset allocation guidelines for the portfolio, an emphasis was placed on the long-term characteristics of individual asset classes, and the benefits of diversification among multiple asset classes. Investment decisions are based on the returns and risk relative to the Plan's liabilities, an approach commonly referred to as liability-driven investing. This approach does not preclude taking risk; instead, it reframes risk from a total-return framework to one mindful of liability-driven investing as the funded status of the domestic defined benefit pension plan improves. The following table presents the target allocation of pension plan assets for 2018 and the actual allocation of plan assets as of December 31, 2017 and 2016 by major asset category: Target Allocation Actual Allocation of Plan Assets Asset Category 2018 2017 2016 Domestic equities 21% - 31% 26 % 30 % International equities 21% - 31% 26 % 30 % Fixed income 35% - 45% 40 % 28 % Hedge fund of funds 3% - 13% 7 % 10 % Cash and cash equivalents 0% - 5% 1 % 2 % Domestic and international equities consist primarily of mutual funds valued at the closing price reported in the active market in which individual securities are traded. Equity securities include investments in domestic and international mutual funds with a blend of small, mid and large cap investments. Emerging market equities are to comprise no more than 25% of the international equities allocation. Equity securities held by the Trust are publicly traded in active markets and are classified within Level 1 of the fair value hierarchy. Fixed income consists of long duration f ixed income held in proprietary funds pooled with other investor accounts which use the net asset value (NAV) per share practical expedient to measure fair value. The total nets assets of the fund are calculated at the close of trading by the fund’s custodian. The net asset value per share is calculated by dividing the total net assets of the fund by the number of units outstanding on the valuation date. Such investments are not classified in the fair value hierarchy. Fixed income investments provide a moderate return and are aligned with the interest rate risk of the Plan's obligations. Hedge funds are pooled funds that employ a range of investment strategies including equity and fixed income, credit driven, macro and multi oriented strategies. The hedge funds are measured at fair value using the NAV practical expedient and are not classified in the fair value hierar chy. Generally, underlying investments held by the Funds which are publicly traded are valued at their current observable market values. Other investments are valued using procedures established by the portfolio manager. Hedge funds are incorporated to diversify the portfolio and to diminish equity volatility. Cash and cash equivalents include investments readily converted to cash valued in the active market in which the funds were traded and are classified within Level 1 of the fair value hierarchy. The investments of the Trust are stated at fair value. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The asset’s fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Valuation techniques used need to maximize the use of observable inputs and minimize the use of unobservable inputs. The framework for measuring fair value provides a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). Effective December 31, 2016, the Company adopted ASU No. 2015-07, “Fair Value Measurement (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share”, which removed from the fair value hierarchy, investments for which the practical expedient is used to measure fair value at NAV. The fixed income long duration fund and the hedge fund of funds were measured at fair value using the NAV practical expedient and are included as a reconciling item to the fair value table. The following tables set forth the fair value of the Trust’s assets by major asset category as of December 31, 2017 and December 31, 2016 : December 31, 2017 In thousands Level 1 Level 2 Level 3 Measured at NAV Total Domestic equity $ 11,577 $ — $ — — $ 11,577 International equity 11,626 — — — 11,626 Fixed income — — — 17,360 17,360 Hedge fund of funds — — — 3,054 3,054 Cash and cash equivalents 557 — — — 557 Total Assets at Fair Value $ 23,760 $ — $ — 20,414 $ 44,174 December 31, 2016 In thousands Level 1 Level 2 Level 3 Measured at NAV Total Domestic equity $ 10,964 $ — $ — — $ 10,964 International equity 10,944 — — — 10,944 Fixed income — — — 10,499 10,499 Hedge fund of funds — — — 3,863 3,863 Cash and cash equivalents 768 — — — 768 Total Assets at Fair Value $ 22,676 $ — $ — 14,362 $ 37,038 Estimated Future Contributions and Benefit Payments The Company expects to contribute approximately $3.0 million to $4.0 million in cash to its domestic defined benefit pension plan in 2018 , but is evaluating this strategy as a result of the recent changes to U.S. tax law enacted on December 22, 2017. Estimated future benefit payments for the next 10 years are as follows: In thousands 2018 2019 2020 2021 2022 2023-2027 Benefit payments $ 2,499 $ 2,615 $ 2,741 $ 2,824 $ 2,854 $ 14,801 Employee Savings Plan The Company also sponsors a 401(k) Plan. Employer contributions to this plan amounted to $2.6 million in 2017 , $2.5 million in 2016 , and $2.3 million in 2015 . Matching contributions by the Company are made on employee pretax contributions up to five percent of compensation, with the first three percent matched at 100% and the next two percent matched at 50% .

Equity Compensation Plans

Equity Compensation Plans	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Compensation Plans	Equity Compensation Plans As of December 31, 2017 , the Company’s equity compensation plans consisted of the 2003 Stock Incentive Compensation Plan (the “2003 Plan”) and the 2012 Stock Incentive Plan (the “2012 Plan” and together with the 2003 Plan, the “Plans”) under which incentive and non-qualified stock options and time and performance based restricted shares have been granted to employees and directors from authorized but unissued shares of common stock or treasury shares. The 2003 Plan is not active, but continues to govern all outstanding awards granted under the plan until the awards themselves are exercised or terminate in accordance with their terms. The 2012 Plan, approved by stockholders on April 27, 2012, authorized 1,750,000 shares of common stock for awards. The 2012 Plan also authorizes an additional 1,200,000 shares of common stock to the extent awards granted under prior stock plans that were outstanding as of April 27, 2012 are forfeited. The 2012 Plan provides for the following type of awards: options, restricted stock, restricted stock units and other stock-based awards. The Company accounts for the expense of all share-based compensation by measuring the awards at fair value on the date of grant. The Company recognizes expense on a straight-line basis over the vesting period of the entire award. Options issued by the Company under its stock option plans have a term of ten years and generally vest ratably over a period of three to four years. Time-based restricted stock grants are expensed over the vesting period of the award, which is typically two to four years. The number of performance based restricted shares that vest or forfeit depend upon achievement of certain targets during the performance period. Prior to January 1, 2016, stock-based compensation expense included estimated effects of forfeitures. Upon adoption of ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, in 2016, an accounting policy election was made to account for forfeitures as they occur. Compensation expense for performance based awards is recorded based upon the service period and management’s assessment of the probability of achieving the performance goals and will be adjusted based upon actual achievement. Stock options issued under the current plan must have an exercise price that may not be less than the fair market value of the Company’s Common Stock on the date of grant. The Plans provide for automatic acceleration of vesting in the event of a change in control of the Company. Upon the exercise of a stock option under the Plans, shares are issued from authorized shares or treasury shares held by the Company. The Company incurred compensation expense of $4.3 million , $4.4 million , and $2.8 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively, for all stock-based compensation plans, including restricted stock awards. No compensation costs were capitalized as part of inventory. The associated tax benefit realized was $4.0 million , $1.9 million , and $1.5 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. Stock Options The fair value of each option granted was estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions for the years ended December 31: 2017 2016 2015 Risk-free interest rate 2.2 % 1.8 % 1.8 % Expected life 5.5 years 5.5 years 5.5 years Expected volatility 33 % 42 % 43 % Expected dividend yield — % — % — % The following is a summary of the option activity as of December 31, 2017 and changes during the year then ended: In thousands except per share amounts and years Shares Weighted-Average Exercise Price Weighted- Average Remaining Contractual Term (years) Aggregate Intrinsic Value Outstanding at December 31, 2016 427 $ 25.32 Granted 100 $ 51.85 Exercised (91) $ 14.87 Forfeited/Cancelled (3) $ 64.20 Outstanding at December 31, 2017 433 $ 33.37 7.1 $ 8,116 Options exercisable at December 31, 2017 230 $ 22.11 5.5 $ 6,703 Unvested at December 31, 2017 203 $ 46.05 8.1 $ 1,413 The Company granted 99,840 , 56,580 , and 91,900 stock options during 2017 , 2016 , and 2015 , respectively. The weighted-average grant-date fair value of options granted during the years 2017 , 2016 , and 2015 was $17.91 , $21.11 , and $15.28 , respectively. There were 90,897 options exercised in 2017 , 76,333 options exercised in 2016 , and 166,175 options exercised in 2015 . The intrinsic value for options exercised during 2017 was $3.6 million and the associated tax benefit realized from stock options exercised was $1.1 million . The total intrinsic value for options exercised during 2016 was $2.4 million and the associated tax benefit realized from stock options exercised was $0.7 million . The total intrinsic value for options exercised during 2015 was $3.5 million and the associated tax benefit realized from stock options exercised was $1.1 million . The amount of cash received from the exercise of stock options was $1.3 million in 2017 , $1.2 million in 2016 , and $1.5 million in 2015 . At December 31, 2017 , the total unrecognized compensation cost related to non-vested stock option awards was approximately $3.4 million , with a weighted average expected amortization period of 3.1 years . Restricted Stock The following is a summary of the Company’s unvested restricted shares for the year ended and as of December 31, 2017 : In thousands except per share amounts Outstanding Restricted Shares Shares Weighted-Average Grant-Date Fair Value Nonvested at December 31, 2016 296 $ 34.01 Granted 76 $ 45.18 Vested (139) $ 22.63 Forfeited/Cancelled (14) $ 38.95 Nonvested December 31, 2017 219 $ 44.77 Restricted stock includes both performance-based and time-based awards. Compensation for restricted stock is recorded based on the market value of the stock on the grant date and amortized to expense over the vesting period of the award. The Company granted 52,595 , 44,423 , and 38,170 shares of performance-based restricted stock during 2017 , 2016 , and 2015 , respectively. The Company granted 22,700 shares of time-based restricted stock in 2017 , 31,455 shares in 2016 , and 33,755 in 2015 . The Company granted 485 and 8,570 of time-based restricted stock units in 2017 and 2016, respectively. The weighted average fair value per share of restricted stock granted was $45.18 , $49.70 , and $34.09 during 2017 , 2016 , and 2015 , respectively. During 2017 , 2016 , and 2015 , respectively, there were 14,045 , 33,800 and 147,187 shares of restricted stock forfeited. The fair value of awards for which restrictions lapsed during the years ended December 31, 2017 , 2016 , and 2015 was $8.0 million , $3.4 million , and $1.4 million , respectively. At December 31, 2017 , the total unrecognized compensation cost related to non-vested restricted stock awards was approximately $5.9 million , with a weighted average expected amortization period of 2.3 years . Stock Repurchases During the year ended December 31, 2017 , the Company acquired 42,288 shares of common stock valued at $2.8 million , through withholding, pursuant to provisions in agreements with recipients of restricted stock granted under the Company's equity compensation plans, which allow the Company to withhold the number of shares having fair value equal to each recipient's tax withholding due.

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring In April 2017, the Company commenced a restructuring plan in the Technical Nonwovens segment which will include plant consolidations and transfer of equipment to other facilities within the segment's Europe and China operations. The consolidation of certain plants, which is expected to conclude in the second quarter of 2019, is expected to reduce operating costs, increase efficiency and enhance the Company’s flexibility by better aligning its manufacturing footprint with the segment's customer base. Accordingly, the Company expects to record pre-tax expenses of approximately $5.0 million , in connection with this restructuring plan, of which approximately $4.8 million is expected to result in cash expenditures over the period of consolidation. The Company also expects to incur cash expenditures of approximately $3.5 million for capital expenditures associated with this plan. During the year ended December 31, 2017, the Company recorded pre-tax restructuring expenses of $0.7 million as part of this restructuring plan. Restructuring expenses of $0.4 million were recorded in cost of sales and $0.3 million were recorded in selling, product development and administrative expenses. The Company expects to record approximately $3.5 million to $4.0 million of restructuring expenses in 2018 with the remainder to be recorded in 2019. Actual pre-tax expenses incurred and total estimated pre-tax expenses for the restructuring program by type are as follows: In thousands Severance and Related Expenses Contract Termination Expenses Facility Exit, Move and Set-up Expenses Total Total estimated expenses $ 1,200 $ 300 $ 3,500 $ 5,000 Expenses incurred through December 31, 2017 181 154 327 662 Estimated remaining expense at December 31, 2017 $ 1,019 $ 146 $ 3,173 $ 4,338 There were cash outflows of $0.2 million for the restructuring program for the year ended December 31, 2017. Accrued restructuring costs were as follows at December 31, 2017: In thousands Total Pre-tax restructuring expenses, excluding depreciation $ 510 Cash paid (177 ) Balance as of December 31, 2017 $ 333

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Information	Segment Information The Company’s reportable segments as of December 31, 2017 were Performance Materials, Technical Nonwovens, Thermal/Acoustical Metals, and Thermal/Acoustical Fibers. Other Products and Services (“OPS”) included Life Sciences Vital Fluids, which was sold on January 30, 2015. On December 31, 2016, the Company completed an acquisition of the nonwoven needle punch materials businesses, which include MGF Gutsche & Co GmbH KG, FRG and Gutsche Environmental Technology (Yixing) Co. Ltd., China, operating under Gutsche (“Gutsche”), a German based corporation. The Gutsche operations manufacture nonwoven needle punch materials and predominantly serve the industrial filtration and high performance nonwoven markets. The acquired businesses are included in the Company's Technical Nonwovens reporting segment. On July 7, 2016, the Company completed an acquisition of the nonwoven and coating materials businesses primarily operating under the Texel brand (“Texel”) from ADS, Inc. (“ADS”), a Canadian based corporation. The Texel operations manufacture nonwoven needle punch materials and predominantly serve the geosynthetic, liquid filtration, and other industrial markets. The acquired businesses are included in the Company's Technical Nonwovens reporting segment. During the third quarter of 2017, the Company announced its plan to combine the Thermal/Acoustical Metals and Thermal/Acoustical Fibers operating segments into a single operating segment named Thermal Acoustical Solutions ("TAS"). Combining these automotive segments into one segment is expected to allow for better customer alignment, leverage operating disciplines and realize efficiencies across the global automotive operations. Through December 31, 2017 these two segments continued to be managed separately as the Company defined the future global structure and strategies of the combined businesses and effective January 1, 2018 has commenced the reporting of the two businesses as a single consolidated operating segment. Performance Materials Segment The Performance Materials segment includes filtration media solutions primarily for air, fluid power, and industrial applications (“Filtration”), thermal insulation solutions for building products, appliances, and energy and industrial markets (“Thermal Insulation”) and air and liquid life science applications (“Life Sciences Filtration”). Filtration products include LydAir® MG (Micro-Glass) Air Filtration Media, LydAir® MB (Melt Blown) Air Filtration Media, LydAir® SC (Synthetic Composite) Air Filtration Media, and Arioso™ Membrane Composite Media. These products constitute the critical media component of clean-air systems for applications in clean-space, commercial, industrial and residential HVAC, power generation, and industrial processes. Lydall has leveraged its extensive technical expertise and applications knowledge into a suite of media products covering the vast liquid filtration landscape across the engine and industrial fields. The LyPore® Liquid Filtration Media series address a variety of application needs in fluid power including hydraulic filters, air-water and air-oil coalescing, industrial fluid processes and diesel fuel filtration. Thermal Insulation products are high performance nonwoven veils, papers, mats and specialty composites for the building products, appliance, and energy and industrial markets. The Manniglas® Thermal Insulation brand is diverse in its product application ranging from high temperature seals and gaskets in ovens and ranges to specialty veils for HVAC and cavity wall insulation. The appLY® Mat Needled Glass Mats have been developed to expand Lydall’s high temperature technology portfolio for broad application into the appliance market and supplements the Lytherm® Insulation Media product brand, traditionally utilized in the industrial market for kilns and furnaces used in metal processing. Lydall’s Cryotherm® Super-Insulating Media, CRS-Wrap® Super-Insulating Media and Cryo-Lite™ Cryogenic Insulation products are industry standards for state-of-the-art cryogenic insulation designs used by manufacturers of cryogenic equipment for liquid gas storage, piping, and transportation. Life Sciences is comprised of products which have been designed to meet the stringent requirements of critical applications including biopharmaceutical pre-filtration and clarification, lateral flow diagnostic and analytical testing, respiratory protection, potable water filtration and high purity process filtration such as that found in food and beverage and medical applications. Lydall also offers ultra-high molecular weight polyethylene membranes under the Solupor® trade name. These specialty microporous membranes are utilized in various markets and applications including air and liquid filtration and transdermal drug delivery. Solupor® membranes incorporate a unique combination of high mechanical strength, chemical inertness, gamma stability and very high porosity making them ideal for many applications. Technical Nonwovens Segment The Technical Nonwovens segment primarily produces needle punch nonwoven solutions for myriad industries and applications. Products are manufactured and sold globally under the leading brands of Lydall Industrial Filtration, Southern Felt, Gutsche, and Texel. Industrial Filtration products include nonwoven rolled-good felt media and filter bags used primarily in industrial air and liquid filtration applications. Nonwoven filter media is an effective solution to satisfy increasing emission control regulations in a wide range of industries, including power, cement, steel, asphalt, incineration, mining, food, and pharmaceutical. Advanced Materials products include nonwoven rolled-good media used in commercial applications and predominantly serves the geosynthetics, automotive, industrial, medical, and safety apparel markets. Automotive media is provided to Tier I/II suppliers and as well as the Company's Thermal/Acoustical Fibers segment. Technical Nonwovens segment products include air and liquid filtration media sold under the brand names Fiberlox® high performance filtration felts, Checkstatic™ conductive filtration felts, Microfelt® high efficiency filtration felts, Pleatlox® pleatable filtration felts, Ultratech™ PTFE filtration felts, Powertech® and Powerlox® power generation filtration felts, Microcap® high efficiency liquid filtration felts, Duotech membrane composite filtration felts, along with our porotex® family of high temperature filtration felts including microvel® and optivel® products. Technical Nonwovens Advanced Materials products are sold under the brand names Thermofit® thermo-formable products, Ecoduo® recycled content materials, Duotex® floor protection products, and Versaflex® composite molding materials. Technical Nonwovens also offers extensive finishing and coating capabilities which provide custom engineered properties tailored to meet the most demanding applications. The business leverages a wide range of fiber types and extensive technical capabilities to provide products that meet our customers’ needs across a variety of applications providing both high performance and durability. Thermal/Acoustical Metals Segment The Thermal/Acoustical Metals segment offers a full range of innovative engineered products tailored for the transportation sector to thermally shield sensitive components from high heat, improve exhaust gas treatment and lower harmful emissions as well as assist in the reduction of powertrain and road noise. Lydall products are found in the underbody (tunnel, fuel tank, rear muffler, spare tire) and underhood (outer dash, powertrain, catalytic converter, turbo charger, manifolds) of cars, trucks, SUVs, heavy duty trucks and recreational vehicles. Thermal/Acoustical Metals segment products are formed on production lines capable of efficiently combining multiple layers of metal and thermal - acoustical insulation media to provide an engineered thermal and acoustical shielding solution for an array of application areas in the global automotive and truck markets. The flux® product family in Thermal/Acoustical Metals includes several patented or IP-rich products that address applications which include: Direct Exhaust Mount heat shields, which are assembled to high temperature components like catalytic converters, turbochargers or exhaust manifolds using aluminized and stainless steel and high performance and high temperature heat insulating materials; Powertrain heat shields that absorb noise at the source and do not contribute to the engine's noise budget; and durable, thermally robust solutions for temperature sensitive plastic components such as fuel tanks that are in proximity to high temperature heat sources. Thermal/Acoustical Fibers Segment The Thermal/Acoustical Fibers segment offers innovative engineered products to assist primarily in noise vibration and harshness (NVH) abatement within the transportation sector. Lydall products are found in the interior (dash insulators, cabin flooring), underbody (wheel well, aerodynamic belly pan, fuel tank, exhaust) and under hood (engine compartment) of cars, trucks, SUVs, heavy duty trucks and recreational vehicles. Thermal/Acoustical Fibers segment products offer thermal and acoustical insulating solutions comprised of organic and inorganic fiber composites for the automotive and truck markets primarily in North America. Lydall’s dBCore® is a lightweight acoustical composite that emphasizes absorption principles over heavy-mass type systems. Lydall’s dBLyte® is a high-performance acoustical barrier with sound absorption and blocking properties and can be used throughout a vehicle’s interior to minimize intrusive noise from an engine compartment and road. Lydall’s ZeroClearance® is an innovative thermal solution that utilizes an adhesive backing for attachment and is used to protect vehicle components from excessive heat. Lydall’s specially engineered products provide a solution that provides weight reduction, superior noise suppression, and increased durability over conventional designs. Thermal/Acoustical Metals segment and Thermal/Acoustical Fibers segment operating results include allocations of certain costs shared between the segments. Other Products and Services The Life Sciences Vital Fluids business offered specialty products for blood filtration devices, blood transfusion single-use containers and the design and manufacture of single-use solutions for cell growth, frozen storage and fluid handling, as well as equipment for bioprocessing applications. On January 30, 2015, the Company sold all of the outstanding shares of common stock of its Life Sciences Vital Fluids business for a cash purchase price of $30.1 million . The disposition was completed pursuant to a Stock Purchase and Sale Agreement, dated January 30, 2015, by and among the Company, and the buyer. The Company recognized an after-tax gain on the sale of this business of approximately $11.8 million in the first quarter of 2015. Net sales by segment and for OPS, as well as reconciling items, to equal consolidated net sales for the years ended December 31, 2017 , 2016 , and 2015 were as follows: Consolidated Net Sales For the Years Ended December 31, In thousands 2017 2016 2015 Performance Materials Segment: Filtration $ 77,254 $ 70,430 $ 62,716 Thermal Insulation 29,496 27,783 28,311 Life Sciences Filtration 9,919 12,915 10,451 Performance Materials Segment net sales 116,669 111,128 101,478 Technical Nonwovens Segment (1),(4) : Industrial Filtration 147,087 90,415 113,044 Advanced Materials (2) 121,990 65,090 26,089 Technical Nonwovens net sales 269,077 155,505 139,133 Thermal/Acoustical Metals Segment: Metal parts 168,995 156,187 141,117 Tooling 19,551 18,787 19,815 Thermal/Acoustical Metals Segment net sales 188,546 174,974 160,932 Thermal/Acoustical Fibers Segment: Fiber parts 153,424 144,345 135,595 Tooling 4,337 5,067 3,152 Thermal/Acoustical Fibers Segment net sales 157,761 149,412 138,747 Other Products and Services: Life Sciences Vital Fluids (3) — — 1,671 Other Products and Services net sales — — 1,671 Eliminations and Other (2) (33,616 ) (24,167 ) (17,456 ) Consolidated Net Sales $ 698,437 $ 566,852 $ 524,505 Operating income by segment and for OPS and Corporate Office Expenses for the years ended December 31, 2017 , 2016 , and 2015 were as follows: Operating Income For the Years Ended December 31, In thousands 2017 2016 2015 Performance Materials Segment $ 12,043 $ 12,339 $ 6,790 Technical Nonwovens Segment (1),(4) 26,047 15,584 13,431 Thermal/Acoustical Metals Segment 10,072 11,562 15,517 Thermal/Acoustical Fibers Segment 42,870 41,452 37,086 Other Products and Services (3) — — 118 Corporate Office Expenses (25,605 ) (26,145 ) (20,465 ) Consolidated Operating Income $ 65,427 $ 54,792 $ 52,477 Operating results in 2017 were negatively impacted by $1.7 million of expenses associated with the planned combination of the T/A Metals and T/A Fibers segments, primarily in the T/A Metals segment, a $1.1 million purchase accounting adjustment related to inventory step-up in the Technical Nonwovens segment, $0.7 million and $0.3 million related to severance expenses for a reduction in force in the T/A Metals and Technical Nonwovens segments, respectively, $0.8 million of corporate strategic initiatives expenses within Corporate Office Expenses, a $0.8 million non-cash long-lived asset impairment in the Performance Materials segments and $0.7 million of restructuring expenses in the Technical Nonwovens segment. Operating results in 2016 were negatively impacted by $3.7 million of acquisition related expenses within Corporate Office Expenses, $3.5 million related to a settlement with the German Cartel Office in the T/A Metals segment and a $2.0 million purchase accounting adjustment related to inventory step-up in the Technical Nonwovens segment. Operating results in 2015 were negatively impacted by a $1.4 million long-lived asset impairment charge within the Performance Materials segment and unfavorable foreign currency translation of $2.0 million impacting the Performance Materials, T/A Metals and Industrial Filtration segments. Total assets by segment and for OPS and the Corporate Office were as follows at December 31, 2017 , 2016 , and 2015 : Total Assets December 31, In thousands 2017 2016 2015 Performance Materials Segment $ 72,837 $ 66,965 $ 66,706 Technical Nonwovens Segment (1),(4) 271,713 268,104 89,566 Thermal/Acoustical Metals Segment 139,655 119,494 111,195 Thermal/Acoustical Fibers Segment 49,646 47,097 38,881 Other Products and Services (3) — — — Corporate Office 27,020 25,369 51,912 Total Assets $ 560,871 $ 527,029 $ 358,260 Total capital expenditures and depreciation and amortization by segment and for OPS and the Corporate Office for the years ended December 31, 2017 , 2016 , and 2015 were as follows: Capital Expenditures Depreciation and Amortization In thousands 2017 2016 2015 2017 2016 2015 Performance Materials Segment $ 3,610 $ 4,098 $ 3,519 $ 3,999 $ 4,023 $ 4,499 Technical Nonwovens Segment (1),(4) 2,903 1,248 968 12,633 6,778 4,996 Thermal/Acoustical Metals Segment 12,316 15,425 11,494 5,489 5,094 4,233 Thermal/Acoustical Fibers Segment 5,146 6,899 4,807 3,135 2,570 2,400 Other Products and Services (3) — — 22 — — 45 Corporate Office 940 489 745 874 1,094 1,102 Total $ 24,915 $ 28,159 $ 21,555 $ 26,130 $ 19,559 $ 17,275 Net sales by geographic area for the years ended December 31, 2017 , 2016 and 2015 and long-lived asset information by geographic area as of December 31, 2017 , 2016 , and 2015 were as follows: Net Sales Long-Lived Assets In thousands 2017 2016 2015 2017 2016 2015 United States (3) $ 376,086 $ 354,371 $ 344,950 $ 93,583 $ 88,918 $ 76,502 France 56,214 52,042 47,495 14,268 12,692 12,899 Germany (4) 105,828 63,301 68,861 20,872 15,649 10,149 United Kingdom 24,921 23,871 26,598 4,916 4,903 6,399 Canada (1) 84,701 40,871 — 30,739 30,911 — China (4) 47,856 30,361 33,885 11,896 11,996 9,953 Other 2,831 2,035 2,716 1,590 1,301 815 Total $ 698,437 $ 566,852 $ 524,505 $ 177,864 $ 166,370 $ 116,717 (1) Technical Nonwovens segment includes results of Texel for the period following the date of acquisition of July 7, 2016. (2) Included in the Technical Nonwovens segment and Eliminations and Other is $26.5 million , $18.2 million and $13.8 million of intercompany sales to the T/A Fibers segment for the years ended December 31, 2017 , 2016 and 2015 , respectively. (3) Other Products and Services reports results for the period preceding the date of disposition of the Vital Fluids Life Sciences business on January 30, 2015. (4) Technical Nonwovens segment includes results of Gutsche as of the acquisition date of December 31, 2016. Foreign sales are based on the country in which the sales originated (i.e., where the Company’s legal entity is domiciled). Sales to Ford Motor Company in 2017 , 2016 , and 2015 were $120.7 million , $110.9 million , and $95.4 million , respectively, and accounted for 17.3% , 19.6% , and 18.2% of Lydall’s net sales in the years ended December 31, 2017 , 2016 , and 2015 , respectively. These sales were reported in the Thermal/Acoustical Metal and Thermal/Acoustical Fiber segments. No other customers accounted for more than 10.0% of total net sales in 2017 , 2016 , and 2015 .

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On December 22, 2017, the United States enacted significant changes to U.S. tax law following the passage and signing of the Tax Cuts and Jobs Act (the "Tax Reform Act"). The legislation significantly changes U.S. tax law by, among other things, lowering corporate income tax rates, implementing a territorial tax system and imposing a one-time repatriation tax on undistributed foreign earnings. The Tax Reform Act permanently reduces the U.S. corporate income tax rate from a maximum of 35% to a flat 21% rate, effective January 1, 2018. Income tax effects resulting from changes in tax laws are accounted for by the Company in accordance with authoritative guidance, which requires that these tax effects be recognized in the period in which the law is enacted. On December 22, 2017, the SEC staff issued Staff Accounting Bulletin No. 118 ("SAB 118") to address the application of U.S. GAAP in situations where a registrant does not have the necessary information available, prepared, or analyzed in reasonable detail to complete the accounting for certain income tax effects of the Tax Reform Act. SAB 118 provides a measurement period, not to exceed one year from the enactment of the Tax Reform Act. In accordance with SAB 118, the Company is required to reflect the income tax effects of those aspects of the Tax Reform Act for which the accounting is complete. To the extent there are areas that are incomplete, but are capable of reasonable estimates, a provisional amount is required to be recorded by the Company. If a reasonable estimate is unable to be calculated, the Company is required to disclose why. The Company has recognized provisional tax impacts related to the one-time mandatory repatriation of foreign earnings and the revaluation of deferred tax assets and liabilities and included these amounts in its consolidated financial statements for the year ended December 31, 2017. The ultimate impact may differ from these provisional amounts, possibly materially, due to, among other things, additional analysis, changes in interpretations and assumptions, additional regulatory guidance from Treasury, the Internal Revenue Service and State Governments, and actions the Company may take as a result of the Tax Reform Act. The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to reverse. As a result of the reduction in the U.S. corporate income tax rate from 35% to 21% under the Tax Reform Act, the Company revalued its ending net deferred tax liabilities at December 31, 2017 and recognized a provisional $4.5 million tax benefit in the Company's consolidated statement of operations for the year ended December 31, 2017. The Tax Reform Act also provided for a one-time deemed mandatory repatriation of post-1986 undistributed foreign subsidiary earnings and profits ("E&P") through the year ended December 31, 2017. The Company had an estimated $12.0 million of undistributed foreign E&P subject to the one-time mandatory repatriation and recognized a provisional $0.5 million of income tax expense in the Company's consolidated statement of operations for the year ended December 31, 2017. The Company's undistributed earnings for which it had previously made an indefinite reinvestment assertion under ASC 740-30 are approximately $6.2 million . The Company has not yet made a determination to remain permanently reinvested outside of the United States in response to the Tax Reform Act. As a result, the Company has not included a provisional tax cost related to this balance at this time as a reasonable estimate has not been determined. The Tax Reform Act also made certain changes to section 162(m) of the Internal Revenue Code which impacts the deductibility of performance based stock compensation paid to executives after January 1, 2018. As a result, the Company has recorded a provisional reserve of $0.3 million against a portion of its deferred tax assets related to stock based compensation, as future realization of the assets is not reasonably assured. While the Tax Reform Act provides for a territorial tax system, beginning in 2018, it includes two new U.S. tax base erosion provisions, the global intangible low-taxed income ("GILTI") provisions and the base-erosion and anti-abuse tax ("BEAT") provisions. The GILTI provisions require the Company to include in its U.S. income tax return foreign subsidiary earnings in excess of an allowable return on the foreign subsidiary's tangible assets. The Company has elected to account for GILTI tax in the period in which it is incurred, and therefore has not provided any deferred tax impacts of GILTI in its consolidated financial statements for the year ended December 31, 2017. The BEAT provisions in the Tax Reform Act eliminates the deduction of certain base-erosion payments made to related foreign corporations, and impose a minimum tax if greater than regular tax. The Company does not expect it will be subject to this tax and therefore has not included any tax impacts of BEAT in its consolidated financial statements for the year ended December 31, 2017. Starting January 1, 2018, the Company will account for BEAT in the period in which it is incurred to the extent this expectation changes. The provision for income taxes consists of the following: For the years ended December 31, In thousands 2017 2016 2015 Current: Federal $ 11,526 $ 15,376 $ 18,291 State 956 1,513 1,204 Foreign 2,425 2,104 1,684 Total Current $ 14,907 $ 18,993 $ 21,179 Deferred: Federal $ (2,472 ) $ (594 ) $ 1,583 State 256 601 1,696 Foreign (717 ) (1,179 ) 306 Total Deferred (2,933 ) (1,172 ) 3,585 Provision for income taxes $ 11,974 $ 17,821 $ 24,764 The following is a reconciliation of the difference between the actual provision for income taxes and the provision computed by applying the federal statutory tax rate on earnings: For the years ended December 31, 2017 2016 2015 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % State income taxes 1.6 2.1 2.9 Valuation allowances for deferred tax assets, including state 0.1 1.3 1.3 Research and development credits (1.0 ) (1.2 ) (1.5 ) Capitalized transaction costs — 0.7 — Domestic production activities deduction (1.8 ) (2.7 ) (1.6 ) Stock based compensation (4.4 ) (2.1 ) (0.2 ) German Cartel settlement — 2.2 — Foreign operations and intercompany financing (2.8 ) (3.5 ) (1.3 ) Reserves for uncertain tax positions (1.7 ) (0.1 ) (0.4 ) Repatriation of foreign undistributed earnings 1.3 — — Revaluation of deferred tax liabilities due to federal rate change (7.3 ) — — Other 0.5 0.7 0.7 Effective income tax rate 19.5 % 32.4 % 34.9 % In 2017, in addition to the Tax Reform Act, which favorably impacted the effective tax rate by a net $3.7 million , the effective tax rate of 19.5% was impacted by a favorable mix of taxable income generated from foreign operations and intercompany financing, resulting in a tax benefit of $1.7 million , net of $0.7 million of expense to correct a foreign tax error in prior years. The Company also recorded a tax benefit of $1.1 million attributable to the Domestic Production Activities Deduction, a tax benefit of $2.7 million related to stock based compensation and a tax benefit of $1.5 million attributable to the release of certain reserves for uncertain tax positions from the settlement of the IRS tax audit that closed in the third quarter of 2017. These favorable adjustments were partially offset by tax expense of $0.3 million against certain deferred tax assets in China, as future realization of the assets is not reasonably assured. In 2016, the effective tax rate of 32.4% was positively impacted by a favorable mix of taxable income generated from countries with lower tax rates compared to that of the United States, resulting in a tax benefit of $1.3 million . The Company also recorded a tax benefit of $1.5 million attributable to the Domestic Production Activities Deduction and a tax benefit of $1.1 million related to stock based compensation. These favorable adjustments were partially offset by tax expense of $1.2 million related to a nondeductible German Cartel settlement and a net increase in valuation allowance against certain deferred tax assets of $0.7 million , primarily related to tax valuation allowances of $0.5 million recorded against certain net deferred tax assets in the Netherlands and China, as future realization of the assets is not reasonably assured. In 2015, the effective tax rate of 34.9% was positively impacted by a favorable mix of taxable income generated from countries with lower tax rates compared to that of the United States, resulting in a tax benefit of $1.0 million . The Company also recorded a tax benefit of $1.2 million attributable to the Domestic Production Activities Deduction and a tax benefit of $1.1 million related to research and development credits. These favorable adjustments were partially offset by tax expense of $0.9 million related to a net increase in valuation allowance against certain deferred tax assets and by a $0.6 million reduction to state deferred tax assets as a result of state tax law changes that led the Company to deem the asset unrealizable in future periods. The net increase in valuation allowance against certain deferred tax assets of $0.9 million in 2015 was primarily related to tax valuation allowances of $0.8 million recorded against certain net deferred tax assets in the Netherlands and China, as future realization of the assets is not reasonably assured. The Company maintains valuation allowances against certain deferred tax assets where realization is not reasonably assured. The Company evaluates the likelihood of the realization of deferred tax assets and reduces the carrying amount to the extent it believes a portion will not be realized. The Company’s effective tax rates in future periods could be affected by earnings being lower or higher than anticipated in countries where tax rates differ from the United States federal rate, the relative impact of permanent tax adjustments on higher or lower earnings from domestic operations, changes in net deferred tax asset valuation allowances, completion of acquisitions or divestitures, changes in tax rates or tax laws and the outcome of tax audits. The following schedule presents net current and net long-term deferred tax assets and liabilities by tax jurisdiction as of December 31, 2017 and 2016: 2017 2016 Deferred Tax Assets Deferred Tax Assets In thousands Current Long-term Current Long-term Federal $ — $ — $ — $ — State — — — — Foreign — 1,146 — 248 Totals $ — $ 1,146 $ — $ 248 2017 2016 Deferred Tax Liabilities Deferred Tax Liabilities In thousands Current Long-term Current Long-term Federal $ — $ 7,288 $ — $ 7,705 State — 424 — 531 Foreign — 7,002 — 7,613 Totals $ — $ 14,714 $ — $ 15,849 Net deferred tax assets (liabilities) consist of the following as of December 31, 2017 and 2016 : December 31, In thousands 2017 2016 Deferred tax assets: Accounts receivable $ 132 $ 225 Inventories 164 743 Net operating loss carryforwards 5,339 3,851 Other accrued liabilities 1,053 4,592 Pension 1,482 3,545 Tax Credits 1,735 1,687 Total deferred tax assets 9,905 14,643 Deferred tax liabilities: Intangible assets 2,073 4,224 Property, plant and equipment 15,691 21,117 Total deferred tax liabilities 17,764 25,341 Valuation allowance 5,709 4,903 Net deferred tax liabilities $ (13,568 ) $ (15,601 ) For the years ended December 31, 2017 , 2016 and 2015 , income before income taxes was derived from the following sources: For the years ended December 31, In thousands 2017 2016 2015 United States $ 54,212 $ 53,356 $ 64,923 Foreign 7,107 1,583 6,100 Total income before income taxes $ 61,319 $ 54,939 $ 71,023 At December 31, 2017, the Company had approximately $4.0 million of state net operating loss carryforward which expires in 2035 and 2036. The Company has not recorded a deferred tax asset for this carryforward as the Company anticipates paying a non-income based franchise tax for the foreseeable future in the applicable jurisdiction. In addition, at December 31, 2017, the Company had $2.2 million of state tax credit carry forwards that expire between 2018 and 2033. As of December 31, 2017, the Company has provided a valuation reserve against $2.2 million of its state tax credit carryforwards. The Company also has $6.0 million of foreign net operating loss carryovers in China, $5.2 million of net operating loss carryovers in Germany and $10.0 million of net operating loss carryovers in the Netherlands. The Netherlands’ net operating losses expire between the years 2018 and 2025 and the China net operating losses expire between the years 2018 and 2022. The Company has recorded a full valuation allowance against all of its net operating losses in the Netherlands and China, as future realization is not reasonably assured. The Company evaluates and weighs the positive and negative evidence present at each period. The Company will continue to monitor the realization criteria based on future operating results. The Company and its subsidiaries file a consolidated federal income tax return, as well as returns required by various state and foreign jurisdictions. In the normal course of business, the Company is subject to examination by taxing authorities, including such major jurisdictions as the United States, China, France, Germany, Hong Kong, the Netherlands, Canada and the United Kingdom. Within the next fiscal year, the Company expects to conclude certain income tax matters through the year ended December 31, 2014 and it is reasonably expected that net unrecognized benefits of $0.2 million may be recognized. The total amount of unrecognized tax benefits that would affect the effective tax rate if recognized is $2.5 million as of December 31, 2017. However, $1.5 million of the unrecognized tax benefits, if recognized, would be offset in pre-tax income by the reversal of indemnification assets due to the Company. The Company is no longer subject to U.S. federal examinations for years before 2015, state and local examinations for years before 2013, and non-U.S. income tax examinations for years before 2003. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: In thousands 2017 2016 Unrecognized tax benefits at beginning of year $ 3,219 $ 1,657 Decreases relating to positions taken in prior periods — (63 ) Increases relating to positions taken in prior periods 221 — Increases relating to current period 475 1,678 Decreases due to settlements with tax authorities (1,372 ) — Decreases due to lapse of statute of limitations (17 ) (53 ) Unrecognized tax benefits at end of year $ 2,526 $ 3,219 The Company recognizes the interest accrued and the penalties related to unrecognized tax benefits as a component of tax expense.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases The Company has operating leases that resulted in expense of $5.8 million in 2017 , $5.4 million in 2016 , and $5.1 million in 2015 . These contracts include building, office equipment, vehicle and machinery leases that require payment of property taxes, insurance, repairs and other operating costs. Approximate future minimum lease payments under noncancelable leases are: Payments due by period In thousands Operating Lease Payments Capital Lease Payments Total 2018 $ 4,829 $ 283 $ 5,112 2019 3,842 292 4,134 2020 2,934 36 2,970 2021 1,981 — 1,981 2022 1,877 — 1,877 Thereafter 10,341 — 10,341 Total 25,804 611 26,415 Interest on capital leases — (9 ) (9 ) Total $ 25,804 $ 602 $ 26,406 Commitments and Contingencies The Company is subject to legal proceedings, claims, investigations and inquiries that arise in the ordinary course of business such as, but not limited to, actions with respect to commercial, intellectual property, employment, personal injury and environmental matters. While the outcome of any matter is inherently uncertain and the Company cannot be sure that it will prevail in any of the cases, subject to the matter referenced below, the Company is not aware of any matters pending that are expected to be material with respect to the Company’s business, financial position, results of operations or cash flows. Environmental Obligations The Company has elected to remediate environmental contamination discovered prior to the closing of the Texel acquisition at a certain property in the province of Quebec, Canada (“the Property”) that was acquired by Lydall. The Company records accruals for environmental costs when such losses are probable and reasonably estimable. In 2016, the Company, through the engagement of a third-party environmental service firm, determined the final scope and timing of the remediation project and estimated the cost of the remediation project to range between $0.9 million and $1.5 million . Based upon this range of estimated remediation costs, the Company recorded an environmental liability of $0.9 million within other long-term liabilities on the Company's balance sheet at December 31, 2016. In July, 2017, the third-party environmental service firm completed its initial investigatory work and, based on information provided from the results of such work, the Company increased its environmental liability by $0.6 million to $1.5 million at June 30, 2017. During the year ended December 31, 2017, the environmental liability was reduced by $0.7 million , reflecting payments made to vendors, resulting in a balance of $0.8 million at December 31, 2017. The remaining balance for the environmental liability of $0.8 million (which remains fully offset as described below) is included within other long-term liabilities on the Company's balance sheet at December 31, 2017. Pursuant to the Share Purchase Agreement, ADS has agreed to indemnify the Company from all costs and liabilities associated with the contamination and remediation work, including the costs of preparation and approval of the remediation plan and other reports in relation therewith. This indemnity was secured by an environmental escrow account, which was established in the amount of $3.0 million Canadian Dollars (approximately $2.4 million U.S. Dollars as of December 31, 2017). Should the costs and liabilities exceed the environmental escrow amount, the Company also has access to the general indemnity escrow account, which was originally established in the amount of $14.0 million Canadian Dollars (approximately $11.1 million U.S. Dollars as of December 31, 2017), and based on the Share Purchase Agreement was reduced to approximately $7.0 million Canadian Dollars (approximately $5.6 million U.S. Dollars as of December 31, 2017). Based on the foregoing, an indemnification asset of $0.9 million was also recorded in other assets at December 31, 2016 as the Company believed, and still believes, collection from ADS is probable. This indemnification asset was increased by $0.6 million to reflect the most current estimate of $1.5 million at June 30, 2017. The indemnification asset was decreased by $0.7 million reflecting reimbursement for indemnification from ADS for payments made by the Company to its vendors during the year ended December 31, 2017. The resulting indemnification asset balance is $0.8 million at December 31, 2017. The accrual for remediation costs will be adjusted as further information develops, estimates change and payments to vendors are made for remediation, with an off-setting adjustment to the indemnification asset from ADS if collection is deemed probable. In the fourth quarter of 2016, as part of a groundwater discharging permitting process, water samples collected from wells and process water basins at the Company’s Rochester New Hampshire manufacturing facility, within the Performance Materials segment, showed concentrations of Perfluorinated Compounds (“PFCs”) in excess of state ambient groundwater quality standards. In January 2017, the Company received a notification from the State of New Hampshire Department of Environmental Services (“NHDES”) naming Lydall Performance Materials, Inc. a responsible party with respect to the discharge of regulated contaminants and, as such, is required to take action to investigate and remediate the impacts in accordance with standards established by the NHDES. The Company conducted a site investigation, the scope of which was reviewed by the NHDES, in order to assess the extent of potential soil and groundwater contamination and develop a remedial action. Based on input received from NHDES in March 2017 with regard to the scope of the site investigation, the Company recorded $0.2 million of expense in the first quarter of 2017 associated with the expected costs of conducting this site investigation. Based on additional information obtained through the results of its site investigation and correspondence with NHDES in September 2017, no additional expense was recorded in the third quarter of 2017. In the fourth quarter of 2017, the Company completed its state-approved site investigation report and submitted it to the NHDES. The Company does not know the scope or extent of its future obligations, if any, that may arise from the NHDES review of the site investigation report and therefore is unable to estimate the cost of any required future corrective actions. The Company expects a response from the NHDES to the site investigation report in the first quarter of 2018. During the year ended December 31, 2017, the environmental liability of $0.2 million has been reduced by $0.2 million reflecting payments made to vendors, resulting in no balance at December 31, 2017. While the site investigation is complete, the Company cannot be sure that costs will not exceed the current estimates until a response is received from the NHDES nor that any future corrective action at this location would not have a material effect on the Company’s financial condition, results of operations or liquidity. Provisions for such matters are charged to expense when it is probable that a liability has been incurred and reasonable estimates of the liability can be made. Estimates of environmental liabilities are based on a variety of matters, including, but not limited to, the stage of investigation, the stage of the remedial design, evaluation of existing remediation technologies, and presently enacted laws and regulations. In future periods, a number of factors could significantly impact any estimates of environmental remediation costs.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table provides a reconciliation of weighted-average shares used to determine basic and diluted earnings per share. For the years ended In thousands 2017 2016 2015 Basic average common shares outstanding 17,045 16,871 16,746 Effect of dilutive options and restricted stock awards 272 370 338 Diluted average common shares outstanding 17,317 17,241 17,084 For the years ended December 31, 2017 , 2016 and 2015 , stock options for 44,837 , 94,796 , and 121,057 shares of Common Stock, respectively, were not considered in computing diluted earnings per common share as the stock options were considered anti-dilutive.

Quarterly Financial Information

Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information (Unaudited)	Quarterly Financial Information (Unaudited) The following table summarizes quarterly financial results for 2017 and 2016 . In management’s opinion, all material adjustments necessary for a fair statement of the information for such quarters have been reflected. 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter In thousands except per share data 2017 2016 2017 2016 2017 2016 2017 2016 Net sales $ 165,487 $ 129,700 $ 174,879 $ 137,235 $ 180,041 $ 155,725 $ 178,030 $ 144,192 Gross profit $ 40,424 $ 32,377 $ 43,253 $ 35,990 $ 39,980 $ 38,193 $ 39,405 $ 31,982 Net income $ 11,669 $ 9,169 $ 13,125 $ 10,813 $ 10,675 $ 12,785 $ 13,848 $ 4,420 Earnings per common share: Basic $ 0.69 $ 0.54 $ 0.77 $ 0.64 $ 0.63 $ 0.76 $ 0.81 $ 0.26 Diluted $ 0.68 $ 0.54 $ 0.76 $ 0.63 $ 0.62 $ 0.75 $ 0.80 $ 0.26 The table above includes the quarterly results of Texel since the acquisition date of July 7, 2016. The Gutsche acquisition was on December 31, 2016, therefore, there are no operating results included in the table above from Gutsche for 2016. The following components are included gross profit and net income for 2017 and 2016 and impact the comparability of each year: 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter In thousands except per share data 2017 2016 2017 2016 2017 2016 2017 2016 Gross profit impact: Inventory step-up purchase accounting adjustments $ 481 $ — $ 543 $ — $ 83 $ 1,607 $ — $ 347 Restructuring, severance and segment consolidation expenses 441 — 92 — 287 — 155 — Net income impact: Inventory step-up purchase accounting adjustments 350 — 394 — 59 1,176 — 254 Restructuring, severance and segment consolidation expenses 702 — 216 — 910 — 488 — Long-lived asset impairment charge 490 — — — — — — — Strategic initiatives expenses 125 365 — 1,080 219 820 205 786 German Cartel settlement — — — — — — — 3,479 During the quarter ended December 31, 2017, the Company recorded an out of period adjustment reducing net income by $0.8 million to correct a foreign tax error in prior periods. This error resulted in the overstatement of net income by less than $0.1 million in each of the first, second, and third quarters of 2017. This error also impacted each quarter in 2016, 2015 and 2014 by less than $0.1 million . The Company evaluated the impact of these errors and determined them to be immaterial to all quarters and years. During the quarter ended December 31, 2016, the Company recorded out of period adjustments reducing gross profit by $0.9 million and net income by $0.6 million to correct inventory and cost of sales errors within the T/A Metals and Technical Nonwovens segments. These errors resulted in the overstatement of gross profit by $0.5 million and net income by $0.3 million in the second quarter of 2016 and overstatement of gross profit by $0.4 million and net income by $0.3 million in the third quarter of 2016. The Company evaluated the impact of these errors and determined them to be immaterial to all quarters in 2016.

Recently Issued Accounting Stan

Recently Issued Accounting Standards	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Recently Issued Accounting Standards	Recently Issued Accounting Standards In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)." The objective of this standard update is to remove inconsistent practices with regard to revenue recognition between US GAAP and IFRS. The standard intends to improve comparability of revenue recognition practices across entities, industries, jurisdictions and capital markets. ASU 2014-09 is effective for the Company’s interim and annual reporting periods beginning January 1, 2018, and is to be adopted using either a full retrospective or modified retrospective transition method with early adoption permitted for annual periods beginning after December 15, 2016. The new standard requires new comprehensive qualitative and quantitative disclosures relating to the nature, amount, timing and uncertainty of revenue arising from contracts with customers, including significant judgments and estimates used when applying the guidance. Subsequent to the issuance of ASU No. 2014-09, the FASB has issued the following update; ASU No. 2016-20, “Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers”. The amendments in this update affects the guidance contained within ASU 2014-09 and were assessed as part of the Company's revenue recognition project plan. In the first quarter of 2018, the Company will complete its conversion activities, including the integration of the standard update into financial reporting processes and systems, and the final cumulative effect adjustment to be recorded upon implementation of ASU 2014-09. The Company continues to assess the impacts to all of its segments under the new standard and has identified an impact to the timing of revenue recognition across all segments. The Company currently recognizes revenue at a point in time typically when products are shipped and risk of loss has transferred to the customer, whereas the implementation of the new standard will result in revenue associated with certain customer contracts moving to an over-time revenue recognition model. Under the new standard, the customized nature of some products combined with contractual provisions that provide the Company with an enforceable right to payment will require the Company to recognize revenue related to these customer contracts prior to the product being shipped to the customer. As such, revenue associated with these contracts will be recognized as costs are incurred. This change generally results in an acceleration of revenue compared with the Company's previous revenue recognition method for these contracts. The Company will adopt ASU 2014-09 effective January 1, 2018, under the modified retrospective transition method. At the adoption date, the cumulative impact of revenue that would have been recognized over time, is expected to be approximately $17.0 million to $23.0 million . The impact is primarily driven by tooling net sales of approximately $15.0 million to $19.0 million from customer contracts within the TAS segment. The Company expects the related adoption impact to retained earnings to be approximately $1.0 million to $2.5 million , primarily due to lower margin tooling net sales and will recognize the cumulative effect of these adjustments net of tax. Additionally, the Company will recognize the cumulative effect of adoption on its Consolidated Balance sheet primarily as an increase in unbilled accounts receivable and a reduction in inventoriable costs as of January 1, 2018. The Company is also evaluating the disclosure requirements under the new standard that are effective in the first quarter of 2018, including disclosure of contract assets as well as disaggregated presentation of revenue. The new standard also requires expanded disclosure regarding the nature, timing, and uncertainty of revenue, cash flow and customer contract balances, including how and when the Company satisfies its performance obligations and the relationship between revenue recognized and changes in contract balances during a reporting period. The Company will continue to evaluate these disclosure requirements and incorporated the collection of relevant data into its reporting process in the first quarter of 2018. During the first quarter of 2018, the Company will continue to analyze the adoption impact and disclose the final impact in the March 31, 2018 Form 10-Q. In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, "Leases (Topic 842)". This ASU requires entities that lease assets with lease terms of more than 12 months to recognize right-of-use assets and lease liabilities created by those leases on their balance sheets. The ASU will also require new qualitative and quantitative disclosures to help investors and other financial statement users better understand the amount, timing, and uncertainty of cash flows arising from leases. This ASU is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the method and impact the adoption of ASU 2016-02 will have on the Company’s consolidated financial statements and disclosures. In January 2017, the FASB issued ASU 2017-01, "Business Combinations (Topic 805): Clarifying the Definition of a Business", which adds guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill, and consolidation. The a mendments of this ASU provide a screen to determine when an integrated set of assets and activities is not a business. The ASU is effective for fiscal years beginning after December 15, 2017. The Company is currently evaluating the impact the adoption of ASU 2017-01 will have on the Company’s consolidated financial statements and disclosures. In January 2017, the FASB issued ASU 2017-04, "Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment", which eliminates Step 2 from the goodwill impairment test. Instead, an entity should perform its annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount and recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit's fair value, not to exceed the total amount of goodwill allocated to the reporting unit. The ASU is effective for fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company is currently evaluating the impact the adoption of ASU 2017-04 will have on the Company’s consolidated financial statements and disclosures. In May 2017, the FASB issued ASU No. 2017-09, "Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting". This ASU requires an entity to apply modification accounting in Topic 718 when there are changes to the terms or conditions of a share-based payment award, unless the fair value, vesting conditions, and classification of the modified award are the same as the original award immediately before the original award is modified. This ASU is effective for fiscal years beginning after December 15, 2017, with early adoption permitted. The Company is currently evaluating the method and impact the adoption of ASU 2017-09 will have on the Company’s consolidated financial statements and disclosures. In August 2017, the FASB issued ASU No. 2017-12, "Derivatives and Hedging (Topic 815): Targeted Improvements to Account for Hedging Activities". This ASU provides various improvements revolving around the financial reporting of hedging relationships that will require an entity to amend the presentation and disclosure of hedging activities to better portray the economic results of an entity's risk management activities in its financial statements. This ASU will also require an entity with cash flow and net investment hedges existing at the date of the adoption to apply a cumulative-effect adjustment related to eliminating the separate measurement of ineffectiveness to accumulated other comprehensive income with a corresponding adjustment to the opening balance of retained earnings as of the beginning of the fiscal year that the entity adopts this ASU. This ASU is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the method and impact the adoption of ASU 2017-12 will have on the Company’s consolidated financial statements and disclosures. In February 2018, the FASB issued ASU No. 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income". This ASU allows for reclassification of stranded tax effects resulting from the Tax Cuts and Jobs Act from accumulated other comprehensive income to retained earnings. This ASU is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the method and impact the adoption of ASU 2018-02 will have on the Company’s consolidated financial statements and disclosures.

Changes in Accumulated Other Co

Changes in Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Changes in Accumulated Other Comprehensive Income (Loss)	Changes in Accumulated Other Comprehensive Income (Loss) The following table discloses the changes by classification within accumulated other comprehensive income (loss) for the period ended December 31, 2017 , 2016 and 2015 : In thousands Foreign Currency Translation Adjustment Defined Benefit Pension Adjustment Gains and Losses on Cash Flow Hedges Total Accumulated Other Comprehensive (Loss) Income Balance at December 31, 2014 $ (6,586 ) $ (17,575 ) $ — $ (24,161 ) Other Comprehensive loss (10,334 ) (637 ) (a) — (10,971 ) Amounts reclassified from accumulated other comprehensive loss — 547 (b) — 547 Balance at December 31, 2015 $ (16,920 ) $ (17,665 ) $ — $ (34,585 ) Other Comprehensive loss (10,965 ) (2,969 ) (a) — (13,934 ) Amounts reclassified from accumulated other comprehensive loss 569 (b) — 569 Balance at December 31, 2016 $ (27,885 ) $ (20,065 ) $ — $ (47,950 ) Other Comprehensive income 25,664 1,299 (a) 122 (c) 27,085 Amounts reclassified from accumulated other comprehensive loss — 717 (b) — 717 Balance at December 31, 2017 $ (2,221 ) $ (18,049 ) $ 122 $ (20,148 ) (a) Amount represents actuarial (losses) gains arising from the Company’s postretirement benefit obligation. This amount was $1.3 million , net of $0.1 million tax expense, for 2017 , $(3.0) million , net of a $1.6 million tax benefit, for 2016 and $(0.6) million , net of $0.4 million tax benefit in 2015 . (See Note 9) (b) Amount represents the amortization of actuarial losses to pension expense arising from the Company’s postretirement benefit obligation. This amount was $0.7 million , net of $0.4 million tax benefit in 2017 , $0.6 million , net of $0.4 million tax benefit in 2016 , and $0.5 million , net of $0.3 million tax benefit in 2015 . (See Note 9) (c) Amount represents unrealized losses on the fair value of hedging activities, net of taxes, for the year ended December 31, 2017 .

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2017
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	Schedule II LYDALL, INC. VALUATION AND QUALIFYING ACCOUNTS FOR THE YEARS ENDED December 31, 2017 , 2016 AND 2015 In thousands Balance at January 1, Charges to Costs and Expenses Charges (Deductions) to Other Accounts Deductions Balance at December 31, 2017 Allowance for doubtful receivables $ 1,429 $ 541 $ 103 2 $ (566 ) 1 $ 1,507 Tax valuation allowances 4,903 886 394 2 (474 ) 3 5,709 2016 Allowance for doubtful receivables $ 1,251 $ 941 $ (123 ) 2 $ (640 ) 1 $ 1,429 Tax valuation allowances 4,307 762 (140 ) 2 (26 ) 3 4,903 2015 Allowance for doubtful receivables $ 709 $ 855 $ (53 ) 2 $ (260 ) 1 $ 1,251 Tax valuation allowances 3,727 1,615 (272 ) 2,4 (763 ) 3 4,307 1. Uncollected receivables written off and recoveries. 2. Foreign currency translation and other adjustments. 3. Reduction to income tax expense. 4. Adjustments relating to the acquisition of Industrial Filtration.

Significant Accounting Polici29

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Principles of consolidation	Principles of consolidation — The Consolidated Financial Statements include the accounts of Lydall, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated.
Estimates and assumptions	Estimates and assumptions — The preparation of the Company’s Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the financial statement dates and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.
Risks and uncertainties	Risks and uncertainties — Worldwide economic cycles and political changes affect the markets that the Company’s businesses serve and affect demand for Lydall’s products and impact profitability. Among other factors, disruptions in the global credit and financial markets, including diminished liquidity and credit availability, swings in consumer confidence and spending, unstable economic growth and fluctuations in unemployment rates has caused economic instability and can have a negative impact on the Company’s results of operations, financial condition and liquidity.
Cash and cash equivalents	Cash and cash equivalents — Cash and cash equivalents include cash on hand and highly liquid investments with original maturities of three months or less at the date of purchase.
Concentration of credit risk	Concentrations of credit risk — Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents and trade accounts receivable. The Company places its cash and cash equivalents in high-quality financial institutions. Concentrations of credit risk with respect to trade accounts receivable are limited by the large number of customers comprising the Company’s customer base and their dispersion across many different industries and geographies.
Inventories	Inventories — Inventories are valued at lower of cost or net realizable value, cost being determined using the first-in, first-out (FIFO) cost method. Inventories in excess of requirements for current or anticipated orders have been written down to net realizable value.
Pre-production design and development costs	Pre-production design and development costs — The Company enters into contractual agreements with certain customers to design and develop molds, dies and tools (collectively, “tooling”). All such tooling contracts relate to parts that the Company will supply to customers under long-term supply agreements. Tooling costs are accumulated in work-in process inventory and are charged to operations as the related revenue from the tooling is recognized. Revenue is recognized as tooling is delivered and accepted by the customer. The Company also may progress bill on certain tooling being constructed. These billings are recorded as progress billings (a reduction of the associated work-in-process inventory) until the appropriate revenue recognition criteria have been met. Periodically, the Company enters into contractually guaranteed reimbursement arrangements as a mechanism to collect amounts due from customers from tooling sales. Under these arrangements, amounts due from tooling sales are collected as parts are delivered over the part supply arrangement, in accordance with the specific terms of the arrangement. The amounts due from the customer in such transactions are recorded in “Prepaid expenses and other current assets” or “Other assets, net” based upon the expected term of the reimbursement arrangement.
Property, plant and equipment	Property, plant and equipment — Property, plant, and equipment are stated at cost. Assets held under capital leases are recorded at the lower of the net present value of the minimum lease payments or the fair value of the leased asset at the inception of the lease. Property, plant and equipment, including property, plant and equipment under capital leases, are depreciated over their estimated useful lives using the straight-line method. Leasehold improvements are depreciated on a straight-line basis over the term of the lease or the life of the asset, whichever is shorter. The cost and accumulated depreciation amounts applicable to assets sold or otherwise disposed of are removed from the asset and accumulated depreciation accounts and any net gain or loss is included in the Consolidated Statements of Operations. Expenses for maintenance and repairs are charged to expense as incurred.
Goodwill and other intangible assets	Goodwill and other intangible assets — Goodwill represents costs in excess of fair values assigned to the underlying net assets of acquired companies. Goodwill and other intangible assets with indefinite lives are not amortized but are subject to annual impairment tests. All other intangible assets are amortized over their estimated useful lives, which range from 4 to 14 years. In performing impairment tests, the Company considers discounted cash flows and other market factors as best evidence of fair value. There are inherent uncertainties and management judgment required in these analyses.
Valuation of long-lived assets	Valuation of long-lived assets — The Company evaluates the recoverability of long-lived assets, or asset groups, whenever events or changes in circumstances indicate that carrying amounts may not be recoverable. Should such evaluations indicate that the related future undiscounted cash flows are not sufficient to recover the carrying values of the assets, such carrying values would be reduced to fair value and this adjusted carrying value would become the assets’ new cost basis. For long-lived assets held for sale, assets are written down to fair value, less costs to sell. Fair value is determined primarily using future anticipated cash flows that are directly associated with, and that are expected to arise as a direct result of the use and eventual disposition of the asset, or asset group, as well as market conditions and other factors. There are inherent uncertainties and management judgment required in these analyses.
Contingencies and environmental obligations	Contingencies and environmental obligations — The Company makes judgments and estimates in accordance with applicable accounting rules when it establishes reserves for legal proceedings, claims, investigations, environmental obligations and other contingent matters. Provisions for such matters are charged to expense when it is probable that a liability has been incurred and reasonable estimates of the liability can be made. Estimates of environmental liabilities are based on a variety of matters, including, but not limited to, the stage of investigation, the stage of the remedial design, evaluation of existing remediation technologies, and presently enacted laws and regulations. The amount and timing of all future expenses related to legal proceedings, claims, investigations, environmental obligations and other contingent matters may vary significantly from estimates.
Employer sponsored benefit plans	Employer sponsored benefit plans — The Company recognizes the funded status of its domestic defined benefit pension plan. Net benefit obligations are calculated based on actuarial valuations using key assumptions related to discount rates, mortality rates and expected return on plan assets.
Derivative instruments	Derivative instruments — Derivative instruments are measured at fair value and recognized as either assets or liabilities on the Consolidated Balance Sheet in either current or non-current other assets or other accrued liabilities or other long-term liabilities depending upon maturity and commitment. For derivative instruments that are designated and qualify as a fair value hedge, the gain or loss on the derivative as well as the offsetting loss or gain on the hedged item attributable to the hedged risk are recognized in the Consolidated Statement of Operations. For derivative instruments that are designated and qualify as a cash flow hedge, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income and reclassified into earnings in the same period or periods in which the hedge transaction affects earnings. The Company selectively uses financial instruments to manage market risk associated with exposure to fluctuations in interest rates and foreign currency rates. These financial exposures are monitored and managed by the Company as an integral part of its risk management program. The Company does not engage in derivative instruments for speculative or trading purposes. Lydall has historically not been a party to a significant number of derivative instruments. Derivatives The Company selectively uses financial instruments to manage market risk associated with exposure to fluctuations in interest rates and foreign currency rates. These financial exposures are monitored and managed by the Company as an integral part of its risk management program. The Company’s interest rate exposure is most sensitive to fluctuations in interest rates in the United States and Europe, which impact interest paid on its debt. The Company has debt with variable rates of interest based generally on LIBOR. From time to time, the Company may enter into interest rate swap agreements to manage interest rate risk. These instruments are designated as cash flow hedges and are recorded at fair value using Level 2 observable market inputs. Derivative instruments are recognized as either assets or liabilities on the balance sheet in either current or non-current other assets or other accrued liabilities or other long-term liabilities depending upon maturity and commitment. For derivative instruments that are designated and qualify as a cash flow hedge, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income and reclassified into earnings in the same period or periods in which the hedge transaction affects earnings. Any ineffective portion, or amounts related to contracts that are not designated as hedges, are recorded directly to earnings. The Company's policy for classifying cash flows from derivatives is to report the cash flows consistent with the underlying hedged item. The Company does not use derivatives for speculative or trading purposes.
Revenue recognition	Revenue recognition — The Company recognizes revenue (1) once evidence of an arrangement exists; (2) product delivery has occurred; (3) pricing is fixed or determinable; and (4) collection is reasonably assured. The four criteria required to recognize revenue are considered to be met, and the passage of title to the customer occurs, at the respective FOB point and, therefore, revenue is recognized at that time. The Company’s standard sales and shipping terms are FOB shipping point, therefore, substantially all revenue is recognized upon shipment. However, the Company conducts business with certain customers on FOB destination terms and in these instances revenue is recognized upon receipt by the customer. The Company generally does not provide specific customer inspection or acceptance provisions in its sales terms, with the exception of tooling sales discussed in “Pre-production design and development costs” above. Sales returns and allowances are recorded as identified or communicated by the customer and internally approved. The Company does not provide customers with general rights of return for products sold; however, in limited circumstances, the Company will allow sales returns and allowances from customers if the products sold do not conform to specifications. Shipping and handling costs consist primarily of costs incurred to deliver products to customers and internal costs related to preparing products for shipment and are recorded in cost of sales. Amounts billed to customers as shipping and handling are classified as revenue.
Research and development	Research and development — Research and development costs are charged to expense as incurred and amounted to $10.8 million in 2017 , $9.0 million in 2016 , and $8.5 million in 2015 . Research and development costs were primarily comprised of development personnel salaries, prototype material costs and testing and trials of new products.
Earnings per share	Earnings per share — Basic earnings per common share are equal to net income divided by the weighted average number of common shares outstanding during the period. Diluted earnings per common share are equal to net income divided by the weighted average number of common shares outstanding during the period, including the effect of stock options and stock awards, if such effect is dilutive.
Income taxes	Income taxes — The provision for income taxes is based upon income reported in the accompanying Consolidated Financial Statements. Deferred income taxes reflect the impact of temporary differences between the amounts of income and expense recognized for financial reporting purposes and such amounts recognized for tax purposes. In the event the Company was to determine that it would not be able to realize all or a portion of its deferred tax assets in the future, the Company would record a valuation allowance through a charge to income in the period that such determination was made. Conversely, if the Company was to determine that it would be able to realize its deferred tax assets in the future in excess of the net carrying amounts, the Company would decrease the recorded valuation allowance and record an increase to income in the period that such determination was made.
Translation of foreign currencies	Translation of foreign currencies — Assets and liabilities of foreign subsidiaries are translated at exchange rates prevailing on the balance sheet date. Revenues and expenses are translated at average exchange rates prevailing during the period. Any resulting translation gains or losses are reported in other comprehensive income (loss).
Stock options and share grants	Stock options and share grants — The Company accounts for awards of equity instruments under the fair value method of accounting and recognizes such amounts in the Consolidated Statements of Operations. The Company recognizes expense on a straight-line basis over the vesting period of the entire award. Prior to January 1, 2016, stock-based compensation expense included estimated effects of forfeitures. Upon adoption of ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, in 2016, an accounting policy election was made to account for forfeitures as they occur. As a result of the adoption of this ASU, the Company recognized excess tax benefits from stock award exercises and vesting as a discrete tax benefit during the years ended December 31, 2017 and December 31, 2016. The Company applied these changes prospectively, and therefore the year ending December 31, 2015 was not adjusted. The Company estimates the fair value of option grants based on the Black Scholes option-pricing model. Expected volatility and expected term are based on historical information. The calculation assumes that future volatility and expected term are not likely to materially differ from the Company’s historical stock price volatility and historical exercise data, respectively. Compensation expense for all restricted stock awards is recorded based on the market value of the stock on the grant date and recognized as expense over the vesting period of the award. Compensation expense for performance-based restricted stock is also impacted by the probability of achieving the performance targets.
Recently adopted accounting standards and recently issued accounting standards	Recently Adopted Accounting Standards Effective January 1, 2017, the Company adopted the Financial Accounting Standards Board ("FASB") Accounting Standards Update ("ASU") No. 2015-11, “Inventory” (Topic 330): Simplifying the Measurement of Inventory." This ASU requires an entity to measure inventory at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. Subsequent measurement is unchanged for inventory measured using last-in, first-out (“LIFO”) or the retail inventory method. The adoption of this ASU did not have any impact on the Company’s consolidated financial statements. Recently Issued Accounting Standards In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)." The objective of this standard update is to remove inconsistent practices with regard to revenue recognition between US GAAP and IFRS. The standard intends to improve comparability of revenue recognition practices across entities, industries, jurisdictions and capital markets. ASU 2014-09 is effective for the Company’s interim and annual reporting periods beginning January 1, 2018, and is to be adopted using either a full retrospective or modified retrospective transition method with early adoption permitted for annual periods beginning after December 15, 2016. The new standard requires new comprehensive qualitative and quantitative disclosures relating to the nature, amount, timing and uncertainty of revenue arising from contracts with customers, including significant judgments and estimates used when applying the guidance. Subsequent to the issuance of ASU No. 2014-09, the FASB has issued the following update; ASU No. 2016-20, “Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers”. The amendments in this update affects the guidance contained within ASU 2014-09 and were assessed as part of the Company's revenue recognition project plan. In the first quarter of 2018, the Company will complete its conversion activities, including the integration of the standard update into financial reporting processes and systems, and the final cumulative effect adjustment to be recorded upon implementation of ASU 2014-09. The Company continues to assess the impacts to all of its segments under the new standard and has identified an impact to the timing of revenue recognition across all segments. The Company currently recognizes revenue at a point in time typically when products are shipped and risk of loss has transferred to the customer, whereas the implementation of the new standard will result in revenue associated with certain customer contracts moving to an over-time revenue recognition model. Under the new standard, the customized nature of some products combined with contractual provisions that provide the Company with an enforceable right to payment will require the Company to recognize revenue related to these customer contracts prior to the product being shipped to the customer. As such, revenue associated with these contracts will be recognized as costs are incurred. This change generally results in an acceleration of revenue compared with the Company's previous revenue recognition method for these contracts. The Company will adopt ASU 2014-09 effective January 1, 2018, under the modified retrospective transition method. At the adoption date, the cumulative impact of revenue that would have been recognized over time, is expected to be approximately $17.0 million to $23.0 million . The impact is primarily driven by tooling net sales of approximately $15.0 million to $19.0 million from customer contracts within the TAS segment. The Company expects the related adoption impact to retained earnings to be approximately $1.0 million to $2.5 million , primarily due to lower margin tooling net sales and will recognize the cumulative effect of these adjustments net of tax. Additionally, the Company will recognize the cumulative effect of adoption on its Consolidated Balance sheet primarily as an increase in unbilled accounts receivable and a reduction in inventoriable costs as of January 1, 2018. The Company is also evaluating the disclosure requirements under the new standard that are effective in the first quarter of 2018, including disclosure of contract assets as well as disaggregated presentation of revenue. The new standard also requires expanded disclosure regarding the nature, timing, and uncertainty of revenue, cash flow and customer contract balances, including how and when the Company satisfies its performance obligations and the relationship between revenue recognized and changes in contract balances during a reporting period. The Company will continue to evaluate these disclosure requirements and incorporated the collection of relevant data into its reporting process in the first quarter of 2018. During the first quarter of 2018, the Company will continue to analyze the adoption impact and disclose the final impact in the March 31, 2018 Form 10-Q. In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, "Leases (Topic 842)". This ASU requires entities that lease assets with lease terms of more than 12 months to recognize right-of-use assets and lease liabilities created by those leases on their balance sheets. The ASU will also require new qualitative and quantitative disclosures to help investors and other financial statement users better understand the amount, timing, and uncertainty of cash flows arising from leases. This ASU is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the method and impact the adoption of ASU 2016-02 will have on the Company’s consolidated financial statements and disclosures. In January 2017, the FASB issued ASU 2017-01, "Business Combinations (Topic 805): Clarifying the Definition of a Business", which adds guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill, and consolidation. The a mendments of this ASU provide a screen to determine when an integrated set of assets and activities is not a business. The ASU is effective for fiscal years beginning after December 15, 2017. The Company is currently evaluating the impact the adoption of ASU 2017-01 will have on the Company’s consolidated financial statements and disclosures. In January 2017, the FASB issued ASU 2017-04, "Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment", which eliminates Step 2 from the goodwill impairment test. Instead, an entity should perform its annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount and recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit's fair value, not to exceed the total amount of goodwill allocated to the reporting unit. The ASU is effective for fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company is currently evaluating the impact the adoption of ASU 2017-04 will have on the Company’s consolidated financial statements and disclosures. In May 2017, the FASB issued ASU No. 2017-09, "Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting". This ASU requires an entity to apply modification accounting in Topic 718 when there are changes to the terms or conditions of a share-based payment award, unless the fair value, vesting conditions, and classification of the modified award are the same as the original award immediately before the original award is modified. This ASU is effective for fiscal years beginning after December 15, 2017, with early adoption permitted. The Company is currently evaluating the method and impact the adoption of ASU 2017-09 will have on the Company’s consolidated financial statements and disclosures. In August 2017, the FASB issued ASU No. 2017-12, "Derivatives and Hedging (Topic 815): Targeted Improvements to Account for Hedging Activities". This ASU provides various improvements revolving around the financial reporting of hedging relationships that will require an entity to amend the presentation and disclosure of hedging activities to better portray the economic results of an entity's risk management activities in its financial statements. This ASU will also require an entity with cash flow and net investment hedges existing at the date of the adoption to apply a cumulative-effect adjustment related to eliminating the separate measurement of ineffectiveness to accumulated other comprehensive income with a corresponding adjustment to the opening balance of retained earnings as of the beginning of the fiscal year that the entity adopts this ASU. This ASU is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the method and impact the adoption of ASU 2017-12 will have on the Company’s consolidated financial statements and disclosures. In February 2018, the FASB issued ASU No. 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income". This ASU allows for reclassification of stranded tax effects resulting from the Tax Cuts and Jobs Act from accumulated other comprehensive income to retained earnings. This ASU is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the method and impact the adoption of ASU 2018-02 will have on the Company’s consolidated financial statements and disclosures.

Significant Accounting Polici30

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of Assets included in the Consolidated Balance Sheet	The following tooling related assets were included in the Consolidated Balance Sheets as of December 31, 2017 and 2016 : December, 31 In thousands 2017 2016 Inventories, net of progress billings and reserves $ 18,540 $ 9,388 Prepaid expenses and other current assets 281 258 Total tooling related assets $ 18,821 $ 9,646

Acquisitions and Divestitures (

Acquisitions and Divestitures (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of Fair Values of Identifiable Assets Acquired and Liabilities Assumed at Date of Acquisition	The following table summarizes the fair values of identifiable assets acquired and liabilities assumed at the date of the Texel and Gutsche acquisitions: In thousands Texel Gutsche Cash and cash equivalents $ 1,610 $ 9,400 Accounts Receivable 13,355 7,736 Inventories 17,525 6,417 Prepaid expenses and other current assets 2,469 1,125 Non-current environmental indemnification receivable (Note 14) 925 — Property, plant and equipment, net 31,525 7,969 Investment in joint venture 616 — Goodwill (Note 5) 28,655 19,729 Other intangible assets, net (Note 5) 22,887 15,622 Other long-term assets — 1,545 Total assets acquired 119,567 69,543 Current liabilities (8,520 ) (8,376 ) Long-term environmental remediation liability (Note 14) (925 ) — Other long-term liabilities — (2,742 ) Deferred tax liabilities (7,413 ) (470 ) Total liabilities assumed (16,858 ) (11,588 ) Net assets acquired $ 102,709 $ 57,955
Schedule of Unaudited Pro Forma Operating Results	The following table reflects the results of the Company for the year ended December 31, 2017 and the unaudited pro forma operating results of the Company for years ended December 31, 2016 and 2015 , which give effect to the acquisitions of Texel and Gutsche as if they had occurred on January 1, 2015. The pro forma information includes the historical financial results of the Company and the acquired businesses. The pro forma results are not necessarily indicative of the operating results that would have occurred had the acquisition been effective January 1, 2015, nor are they intended to be indicative of results that may occur in the future. The pro forma information does not include the effects of any synergies related to the acquisitions. For The Years Ended (Actual) (Unaudited (Unaudited In thousands 2017 2016 2015 Net Sales $ 698,437 $ 654,877 $ 651,252 Net Income $ 49,317 $ 43,559 $ 47,956 Earnings per share: Basic $ 2.89 $ 2.58 $ 2.86 Diluted $ 2.85 $ 2.53 $ 2.81

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories as of December 31, 2017 and 2016 were as follows: December 31, In thousands 2017 2016 Raw materials $ 28,672 $ 24,518 Work in process 29,427 17,161 Finished goods 23,901 25,360 82,000 67,039 Less: Progress billings (1,661 ) (893 ) Total inventories $ 80,339 $ 66,146

Property, Plant and Equipment33

Property, Plant and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	Property, plant and equipment as of December 31, 2017 and 2016 were as follows: Estimated Useful Lives December 31, In thousands 2017 2016 Land – $ 4,289 $ 3,981 Buildings and improvements 10-35 years 84,337 74,397 Machinery and equipment 5-25 years 254,881 226,675 Office equipment 2-8 years 33,880 31,504 Vehicles 3-6 years 1,706 1,553 Assets under capital leases: Land – 241 226 Buildings and improvements 10-35 years 221 4,806 Machinery and equipment 5-25 years 1,051 — Office equipment 2-8 years 34 — 380,640 343,142 Accumulated depreciation (226,581 ) (196,251 ) Accumulated depreciation of capital leases (239 ) (2,915 ) 153,820 143,976 Construction in progress 16,512 16,819 Total property, plant and equipment, net $ 170,332 $ 160,795

Goodwill and Long-Lived Assets

Goodwill and Long-Lived Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Gross and Net Carrying Amounts of Goodwill	Gross and net carrying amounts of goodwill at December 31, 2017 and 2016 were as follows: In thousands Performance Materials Technical Nonwovens Thermal/ Acoustical Metals Totals Goodwill $ 12,777 $ 50,829 $ 12,160 $ 75,766 Accumulated amortization/impairment — — (12,160 ) (12,160 ) Balance at December 31, 2016 12,777 50,829 — 63,606 Goodwill 13,307 55,662 12,160 81,129 Accumulated amortization/impairment — — (12,160 ) (12,160 ) Balance at December 31, 2017 $ 13,307 $ 55,662 $ — $ 68,969
Schedule of Changes in the Carrying Amounts of Goodwill	The changes in the carrying amounts of goodwill in 2017 and 2016 were as follows: In thousands Performance Materials Technical Nonwovens Totals Balance at January 1, 2016 $ 12,898 $ 3,943 $ 16,841 Goodwill addition — 47,987 47,987 Currency translation adjustment (121 ) (1,101 ) (1,222 ) Balance at December 31, 2016 12,777 50,829 63,606 Goodwill adjustment — 323 323 Currency translation adjustment 530 4,510 5,040 Balance at December 31, 2017 $ 13,307 $ 55,662 $ 68,969
Schedule of Amortization of the Company's Acquired Intangible Assets other than Goodwill	The table below presents the gross carrying amount and, as applicable, the accumulated amortization of the Company’s acquired intangible assets other than goodwill included in “Other intangible assets, net” in the Consolidated Balance Sheets as of December 31, 2017 and 2016 : December 31, 2017 December 31, 2016 In thousands Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortized intangible assets Customer relationships $ 39,474 $ (4,460 ) $ 36,131 $ (1,284 ) Patents 4,504 (3,821 ) 4,028 (3,300 ) Technology 2,500 (644 ) 2,500 (477 ) Trade names 4,288 (1,461 ) 3,912 (394 ) License agreements 640 (640 ) 583 (583 ) Other 586 (423 ) 536 (205 ) Total amortized intangible assets $ 51,992 $ (11,449 ) $ 47,690 $ (6,243 )

Long-term Debt and Financing 35

Long-term Debt and Financing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Maturities of Long-term Debt	Total outstanding debt consists of: December 31, In thousands Effective Rate Maturity 2017 2016 Revolver Loan, due July 7, 2021 2.57% 2021 $ 76,600 $ 126,600 Other Foreign Bank Borrowings 0.80% - 3.40% 2017 — 1,430 Capital Leases 1.65% - 2.09% 2019 - 2020 590 745 77,190 128,775 Less portion due within one year (277 ) (634 ) Total long-term debt $ 76,913 $ 128,141

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Assets at Fair Value	The following table sets forth the fair value amounts of derivative instruments held by the Company: December 31, 2017 December 31, 2016 In thousands Asset Derivatives Liability Derivatives Asset Derivatives Liability Derivatives Derivatives designated as hedging instruments: Interest rate contract $ 157 $ — $ — $ — Total derivatives $ 157 $ — $ — $ —
Schedule of Derivative Liabilities at Fair Value	The following table sets forth the fair value amounts of derivative instruments held by the Company: December 31, 2017 December 31, 2016 In thousands Asset Derivatives Liability Derivatives Asset Derivatives Liability Derivatives Derivatives designated as hedging instruments: Interest rate contract $ 157 $ — $ — $ — Total derivatives $ 157 $ — $ — $ —
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss)	The following table sets forth the income, recorded in accumulated other comprehensive income, net of tax, for the quarters and twelve months ended December 31, 2017 and 2016 for derivatives held by the Company and designated as hedging instruments: Quarter Ended December 31, Twelve Months Ended December 31, 2017 2016 2017 2016 Cash flow hedges: Interest rate contract $ 129 $ — $ 122 $ — $ 129 — $ 122 $ —

Employer Sponsored Benefit Pl37

Employer Sponsored Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Schedule of Net Funded Status	Plan assets and benefit obligations of the domestic defined benefit pension plan are as follows: December 31, In thousands 2017 2016 Change in benefit obligation: Net benefit obligation at beginning of year $ 50,086 $ 48,081 Interest cost 2,058 2,139 Actuarial loss 2,126 2,062 Gross benefits paid (2,388 ) (2,196 ) Net benefit obligation at end of year $ 51,882 $ 50,086 Change in plan assets: Fair value of plan assets at beginning of year $ 37,038 $ 35,413 Actual return on plan assets 5,924 221 Contributions 3,600 3,600 Gross benefits paid (2,388 ) (2,196 ) Fair value of plan assets at end of year $ 44,174 $ 37,038 Net benefit obligation in excess of plan assets $ (7,708 ) $ (13,048 ) Balance sheet amounts: Noncurrent liabilities $ (7,708 ) $ (13,048 ) Total liabilities $ (7,708 ) $ (13,048 ) Amounts recognized in accumulated other comprehensive income, net of tax consist of: Net actuarial loss $ 17,632 $ 19,689 Net amount recognized $ 17,632 $ 19,689
Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets	Aggregated information for the domestic defined benefit pension plan with an accumulated benefit obligation in excess of plan assets is provided in the tables below: December 31, In thousands 2017 2016 Projected benefit obligation $ 51,882 $ 50,086 Accumulated benefit obligation $ 51,882 $ 50,086 Fair value of plan assets $ 44,174 $ 37,038
Schedule of Components of Net Periodic Benefit Cost for Domestic Pension Plan	Components of net periodic benefit cost for the domestic pension plan: December 31, In thousands 2017 2016 2015 Interest cost $ 2,058 $ 2,139 $ 2,066 Expected return on plan assets (2,376 ) (2,419 ) (2,360 ) Amortization of actuarial net loss 1,092 933 897 Total net periodic benefit cost $ 774 $ 653 $ 603
Schedule of Net Periodic Benefit Cost Not yet Recognized	The major assumptions used in determining the year-end benefit obligation and annual net cost for the domestic pension plan are presented in the following table: Benefit Obligation Net Cost For the years ended December 31, 2017 2016 2017 2016 2015 Discount rate 3.71 % 4.21 % 4.21 % 4.56 % 4.16 % Expected return on plan assets 5.80 % 6.30 % 6.30 % 7.00 % 7.25 %
Schedule of Allocation of Plan Assets	The following table presents the target allocation of pension plan assets for 2018 and the actual allocation of plan assets as of December 31, 2017 and 2016 by major asset category: Target Allocation Actual Allocation of Plan Assets Asset Category 2018 2017 2016 Domestic equities 21% - 31% 26 % 30 % International equities 21% - 31% 26 % 30 % Fixed income 35% - 45% 40 % 28 % Hedge fund of funds 3% - 13% 7 % 10 % Cash and cash equivalents 0% - 5% 1 % 2 %
Schedule of Changes in Fair Value of Plan Assets	The following tables set forth the fair value of the Trust’s assets by major asset category as of December 31, 2017 and December 31, 2016 : December 31, 2017 In thousands Level 1 Level 2 Level 3 Measured at NAV Total Domestic equity $ 11,577 $ — $ — — $ 11,577 International equity 11,626 — — — 11,626 Fixed income — — — 17,360 17,360 Hedge fund of funds — — — 3,054 3,054 Cash and cash equivalents 557 — — — 557 Total Assets at Fair Value $ 23,760 $ — $ — 20,414 $ 44,174 December 31, 2016 In thousands Level 1 Level 2 Level 3 Measured at NAV Total Domestic equity $ 10,964 $ — $ — — $ 10,964 International equity 10,944 — — — 10,944 Fixed income — — — 10,499 10,499 Hedge fund of funds — — — 3,863 3,863 Cash and cash equivalents 768 — — — 768 Total Assets at Fair Value $ 22,676 $ — $ — 14,362 $ 37,038
Schedule of Expected Benefit Payments	The Company expects to contribute approximately $3.0 million to $4.0 million in cash to its domestic defined benefit pension plan in 2018 , but is evaluating this strategy as a result of the recent changes to U.S. tax law enacted on December 22, 2017. Estimated future benefit payments for the next 10 years are as follows: In thousands 2018 2019 2020 2021 2022 2023-2027 Benefit payments $ 2,499 $ 2,615 $ 2,741 $ 2,824 $ 2,854 $ 14,801

Equity Compensation Plans (Tabl

Equity Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The fair value of each option granted was estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions for the years ended December 31: 2017 2016 2015 Risk-free interest rate 2.2 % 1.8 % 1.8 % Expected life 5.5 years 5.5 years 5.5 years Expected volatility 33 % 42 % 43 % Expected dividend yield — % — % — %
Schedule of Nonvested Share Activity	The following is a summary of the option activity as of December 31, 2017 and changes during the year then ended: In thousands except per share amounts and years Shares Weighted-Average Exercise Price Weighted- Average Remaining Contractual Term (years) Aggregate Intrinsic Value Outstanding at December 31, 2016 427 $ 25.32 Granted 100 $ 51.85 Exercised (91) $ 14.87 Forfeited/Cancelled (3) $ 64.20 Outstanding at December 31, 2017 433 $ 33.37 7.1 $ 8,116 Options exercisable at December 31, 2017 230 $ 22.11 5.5 $ 6,703 Unvested at December 31, 2017 203 $ 46.05 8.1 $ 1,413
Schedule of Nonvested Restricted Stock Units Activity	The following is a summary of the Company’s unvested restricted shares for the year ended and as of December 31, 2017 : In thousands except per share amounts Outstanding Restricted Shares Shares Weighted-Average Grant-Date Fair Value Nonvested at December 31, 2016 296 $ 34.01 Granted 76 $ 45.18 Vested (139) $ 22.63 Forfeited/Cancelled (14) $ 38.95 Nonvested December 31, 2017 219 $ 44.77

Restructuring (Tables)

Restructuring (Tables)	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Schedule of Restructuring and Related Costs	Actual pre-tax expenses incurred and total estimated pre-tax expenses for the restructuring program by type are as follows: In thousands Severance and Related Expenses Contract Termination Expenses Facility Exit, Move and Set-up Expenses Total Total estimated expenses $ 1,200 $ 300 $ 3,500 $ 5,000 Expenses incurred through December 31, 2017 181 154 327 662 Estimated remaining expense at December 31, 2017 $ 1,019 $ 146 $ 3,173 $ 4,338
Schedule of Restructuring Reserve by Type of Cost	Accrued restructuring costs were as follows at December 31, 2017: In thousands Total Pre-tax restructuring expenses, excluding depreciation $ 510 Cash paid (177 ) Balance as of December 31, 2017 $ 333

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of Net Sales by Segment and for OPS, Reconciling Items to Equal to Consolidated Net Sales	Net sales by segment and for OPS, as well as reconciling items, to equal consolidated net sales for the years ended December 31, 2017 , 2016 , and 2015 were as follows: Consolidated Net Sales For the Years Ended December 31, In thousands 2017 2016 2015 Performance Materials Segment: Filtration $ 77,254 $ 70,430 $ 62,716 Thermal Insulation 29,496 27,783 28,311 Life Sciences Filtration 9,919 12,915 10,451 Performance Materials Segment net sales 116,669 111,128 101,478 Technical Nonwovens Segment (1),(4) : Industrial Filtration 147,087 90,415 113,044 Advanced Materials (2) 121,990 65,090 26,089 Technical Nonwovens net sales 269,077 155,505 139,133 Thermal/Acoustical Metals Segment: Metal parts 168,995 156,187 141,117 Tooling 19,551 18,787 19,815 Thermal/Acoustical Metals Segment net sales 188,546 174,974 160,932 Thermal/Acoustical Fibers Segment: Fiber parts 153,424 144,345 135,595 Tooling 4,337 5,067 3,152 Thermal/Acoustical Fibers Segment net sales 157,761 149,412 138,747 Other Products and Services: Life Sciences Vital Fluids (3) — — 1,671 Other Products and Services net sales — — 1,671 Eliminations and Other (2) (33,616 ) (24,167 ) (17,456 ) Consolidated Net Sales $ 698,437 $ 566,852 $ 524,505 Operating income by segment and for OPS and Corporate Office Expenses for the years ended December 31, 2017 , 2016 , and 2015 were as follows: Operating Income For the Years Ended December 31, In thousands 2017 2016 2015 Performance Materials Segment $ 12,043 $ 12,339 $ 6,790 Technical Nonwovens Segment (1),(4) 26,047 15,584 13,431 Thermal/Acoustical Metals Segment 10,072 11,562 15,517 Thermal/Acoustical Fibers Segment 42,870 41,452 37,086 Other Products and Services (3) — — 118 Corporate Office Expenses (25,605 ) (26,145 ) (20,465 ) Consolidated Operating Income $ 65,427 $ 54,792 $ 52,477
Schedule of Total Assets by Segment	Total assets by segment and for OPS and the Corporate Office were as follows at December 31, 2017 , 2016 , and 2015 : Total Assets December 31, In thousands 2017 2016 2015 Performance Materials Segment $ 72,837 $ 66,965 $ 66,706 Technical Nonwovens Segment (1),(4) 271,713 268,104 89,566 Thermal/Acoustical Metals Segment 139,655 119,494 111,195 Thermal/Acoustical Fibers Segment 49,646 47,097 38,881 Other Products and Services (3) — — — Corporate Office 27,020 25,369 51,912 Total Assets $ 560,871 $ 527,029 $ 358,260 Total capital expenditures and depreciation and amortization by segment and for OPS and the Corporate Office for the years ended December 31, 2017 , 2016 , and 2015 were as follows: Capital Expenditures Depreciation and Amortization In thousands 2017 2016 2015 2017 2016 2015 Performance Materials Segment $ 3,610 $ 4,098 $ 3,519 $ 3,999 $ 4,023 $ 4,499 Technical Nonwovens Segment (1),(4) 2,903 1,248 968 12,633 6,778 4,996 Thermal/Acoustical Metals Segment 12,316 15,425 11,494 5,489 5,094 4,233 Thermal/Acoustical Fibers Segment 5,146 6,899 4,807 3,135 2,570 2,400 Other Products and Services (3) — — 22 — — 45 Corporate Office 940 489 745 874 1,094 1,102 Total $ 24,915 $ 28,159 $ 21,555 $ 26,130 $ 19,559 $ 17,275
Schedule of Net Sales by Geographic Area	Net sales by geographic area for the years ended December 31, 2017 , 2016 and 2015 and long-lived asset information by geographic area as of December 31, 2017 , 2016 , and 2015 were as follows: Net Sales Long-Lived Assets In thousands 2017 2016 2015 2017 2016 2015 United States (3) $ 376,086 $ 354,371 $ 344,950 $ 93,583 $ 88,918 $ 76,502 France 56,214 52,042 47,495 14,268 12,692 12,899 Germany (4) 105,828 63,301 68,861 20,872 15,649 10,149 United Kingdom 24,921 23,871 26,598 4,916 4,903 6,399 Canada (1) 84,701 40,871 — 30,739 30,911 — China (4) 47,856 30,361 33,885 11,896 11,996 9,953 Other 2,831 2,035 2,716 1,590 1,301 815 Total $ 698,437 $ 566,852 $ 524,505 $ 177,864 $ 166,370 $ 116,717 (1) Technical Nonwovens segment includes results of Texel for the period following the date of acquisition of July 7, 2016. (2) Included in the Technical Nonwovens segment and Eliminations and Other is $26.5 million , $18.2 million and $13.8 million of intercompany sales to the T/A Fibers segment for the years ended December 31, 2017 , 2016 and 2015 , respectively. (3) Other Products and Services reports results for the period preceding the date of disposition of the Vital Fluids Life Sciences business on January 30, 2015. (4) Technical Nonwovens segment includes results of Gutsche as of the acquisition date of December 31, 2016.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Components of Provision for Income Taxes	The provision for income taxes consists of the following: For the years ended December 31, In thousands 2017 2016 2015 Current: Federal $ 11,526 $ 15,376 $ 18,291 State 956 1,513 1,204 Foreign 2,425 2,104 1,684 Total Current $ 14,907 $ 18,993 $ 21,179 Deferred: Federal $ (2,472 ) $ (594 ) $ 1,583 State 256 601 1,696 Foreign (717 ) (1,179 ) 306 Total Deferred (2,933 ) (1,172 ) 3,585 Provision for income taxes $ 11,974 $ 17,821 $ 24,764
Schedule of Reconciliation of the Difference between the Actual Provisions for Income Taxes	The following is a reconciliation of the difference between the actual provision for income taxes and the provision computed by applying the federal statutory tax rate on earnings: For the years ended December 31, 2017 2016 2015 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % State income taxes 1.6 2.1 2.9 Valuation allowances for deferred tax assets, including state 0.1 1.3 1.3 Research and development credits (1.0 ) (1.2 ) (1.5 ) Capitalized transaction costs — 0.7 — Domestic production activities deduction (1.8 ) (2.7 ) (1.6 ) Stock based compensation (4.4 ) (2.1 ) (0.2 ) German Cartel settlement — 2.2 — Foreign operations and intercompany financing (2.8 ) (3.5 ) (1.3 ) Reserves for uncertain tax positions (1.7 ) (0.1 ) (0.4 ) Repatriation of foreign undistributed earnings 1.3 — — Revaluation of deferred tax liabilities due to federal rate change (7.3 ) — — Other 0.5 0.7 0.7 Effective income tax rate 19.5 % 32.4 % 34.9 %
Schedule of Net Current and Net Long-Term Deferred Tax Assets and Liabilities by Tax Jurisdiction	The following schedule presents net current and net long-term deferred tax assets and liabilities by tax jurisdiction as of December 31, 2017 and 2016: 2017 2016 Deferred Tax Assets Deferred Tax Assets In thousands Current Long-term Current Long-term Federal $ — $ — $ — $ — State — — — — Foreign — 1,146 — 248 Totals $ — $ 1,146 $ — $ 248 2017 2016 Deferred Tax Liabilities Deferred Tax Liabilities In thousands Current Long-term Current Long-term Federal $ — $ 7,288 $ — $ 7,705 State — 424 — 531 Foreign — 7,002 — 7,613 Totals $ — $ 14,714 $ — $ 15,849
Schedule of Components of Deferred Tax Asset and Liability	Net deferred tax assets (liabilities) consist of the following as of December 31, 2017 and 2016 : December 31, In thousands 2017 2016 Deferred tax assets: Accounts receivable $ 132 $ 225 Inventories 164 743 Net operating loss carryforwards 5,339 3,851 Other accrued liabilities 1,053 4,592 Pension 1,482 3,545 Tax Credits 1,735 1,687 Total deferred tax assets 9,905 14,643 Deferred tax liabilities: Intangible assets 2,073 4,224 Property, plant and equipment 15,691 21,117 Total deferred tax liabilities 17,764 25,341 Valuation allowance 5,709 4,903 Net deferred tax liabilities $ (13,568 ) $ (15,601 )
Schedule of Income from Continuing Operations before Income Taxes	For the years ended December 31, 2017 , 2016 and 2015 , income before income taxes was derived from the following sources: For the years ended December 31, In thousands 2017 2016 2015 United States $ 54,212 $ 53,356 $ 64,923 Foreign 7,107 1,583 6,100 Total income before income taxes $ 61,319 $ 54,939 $ 71,023
Schedule of Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: In thousands 2017 2016 Unrecognized tax benefits at beginning of year $ 3,219 $ 1,657 Decreases relating to positions taken in prior periods — (63 ) Increases relating to positions taken in prior periods 221 — Increases relating to current period 475 1,678 Decreases due to settlements with tax authorities (1,372 ) — Decreases due to lapse of statute of limitations (17 ) (53 ) Unrecognized tax benefits at end of year $ 2,526 $ 3,219

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments	Approximate future minimum lease payments under noncancelable leases are: Payments due by period In thousands Operating Lease Payments Capital Lease Payments Total 2018 $ 4,829 $ 283 $ 5,112 2019 3,842 292 4,134 2020 2,934 36 2,970 2021 1,981 — 1,981 2022 1,877 — 1,877 Thereafter 10,341 — 10,341 Total 25,804 611 26,415 Interest on capital leases — (9 ) (9 ) Total $ 25,804 $ 602 $ 26,406

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Reconciliation of Weighted Average Shares Used to Determine Basic and Diluted Earnings Per Share	The following table provides a reconciliation of weighted-average shares used to determine basic and diluted earnings per share. For the years ended In thousands 2017 2016 2015 Basic average common shares outstanding 17,045 16,871 16,746 Effect of dilutive options and restricted stock awards 272 370 338 Diluted average common shares outstanding 17,317 17,241 17,084

Quarterly Financial Informati44

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Results	The following table summarizes quarterly financial results for 2017 and 2016 . In management’s opinion, all material adjustments necessary for a fair statement of the information for such quarters have been reflected. 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter In thousands except per share data 2017 2016 2017 2016 2017 2016 2017 2016 Net sales $ 165,487 $ 129,700 $ 174,879 $ 137,235 $ 180,041 $ 155,725 $ 178,030 $ 144,192 Gross profit $ 40,424 $ 32,377 $ 43,253 $ 35,990 $ 39,980 $ 38,193 $ 39,405 $ 31,982 Net income $ 11,669 $ 9,169 $ 13,125 $ 10,813 $ 10,675 $ 12,785 $ 13,848 $ 4,420 Earnings per common share: Basic $ 0.69 $ 0.54 $ 0.77 $ 0.64 $ 0.63 $ 0.76 $ 0.81 $ 0.26 Diluted $ 0.68 $ 0.54 $ 0.76 $ 0.63 $ 0.62 $ 0.75 $ 0.80 $ 0.26
Schedule of Components of Gross Profit and Net Income (Loss)	The following components are included gross profit and net income for 2017 and 2016 and impact the comparability of each year: 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter In thousands except per share data 2017 2016 2017 2016 2017 2016 2017 2016 Gross profit impact: Inventory step-up purchase accounting adjustments $ 481 $ — $ 543 $ — $ 83 $ 1,607 $ — $ 347 Restructuring, severance and segment consolidation expenses 441 — 92 — 287 — 155 — Net income impact: Inventory step-up purchase accounting adjustments 350 — 394 — 59 1,176 — 254 Restructuring, severance and segment consolidation expenses 702 — 216 — 910 — 488 — Long-lived asset impairment charge 490 — — — — — — — Strategic initiatives expenses 125 365 — 1,080 219 820 205 786 German Cartel settlement — — — — — — — 3,479

Changes in Accumulated Other 45

Changes in Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Changes by Classification within Accumulated Other Comprehensive Income (Loss)	The following table discloses the changes by classification within accumulated other comprehensive income (loss) for the period ended December 31, 2017 , 2016 and 2015 : In thousands Foreign Currency Translation Adjustment Defined Benefit Pension Adjustment Gains and Losses on Cash Flow Hedges Total Accumulated Other Comprehensive (Loss) Income Balance at December 31, 2014 $ (6,586 ) $ (17,575 ) $ — $ (24,161 ) Other Comprehensive loss (10,334 ) (637 ) (a) — (10,971 ) Amounts reclassified from accumulated other comprehensive loss — 547 (b) — 547 Balance at December 31, 2015 $ (16,920 ) $ (17,665 ) $ — $ (34,585 ) Other Comprehensive loss (10,965 ) (2,969 ) (a) — (13,934 ) Amounts reclassified from accumulated other comprehensive loss 569 (b) — 569 Balance at December 31, 2016 $ (27,885 ) $ (20,065 ) $ — $ (47,950 ) Other Comprehensive income 25,664 1,299 (a) 122 (c) 27,085 Amounts reclassified from accumulated other comprehensive loss — 717 (b) — 717 Balance at December 31, 2017 $ (2,221 ) $ (18,049 ) $ 122 $ (20,148 ) (a) Amount represents actuarial (losses) gains arising from the Company’s postretirement benefit obligation. This amount was $1.3 million , net of $0.1 million tax expense, for 2017 , $(3.0) million , net of a $1.6 million tax benefit, for 2016 and $(0.6) million , net of $0.4 million tax benefit in 2015 . (See Note 9) (b) Amount represents the amortization of actuarial losses to pension expense arising from the Company’s postretirement benefit obligation. This amount was $0.7 million , net of $0.4 million tax benefit in 2017 , $0.6 million , net of $0.4 million tax benefit in 2016 , and $0.5 million , net of $0.3 million tax benefit in 2015 . (See Note 9) (c) Amount represents unrealized losses on the fair value of hedging activities, net of taxes, for the year ended December 31, 2017 .

Significant Accounting Polici46

Significant Accounting Policies - Narrative (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Line Items]
Percentage of foreign and export sales	54.20%	46.90%	44.20%
Export sales	$ 55,900	$ 53,200	$ 52,500
Percentage of sales to automotive market	48.30%	56.20%	56.60%
Progress billings adjustment	$ 1,661	$ 893
Finite-lived intangible asset useful life	11 years
Research and development expense	$ 10,800	$ 9,000	$ 8,500
Minimum
Accounting Policies [Line Items]
Finite-lived intangible asset useful life	4 years
Maximum
Accounting Policies [Line Items]
Finite-lived intangible asset useful life	14 years
Ford Motor Company
Accounting Policies [Line Items]
Percentage of accounts receivable from significant customer	12.00%	14.20%

Significant Accounting Polici47

Significant Accounting Policies - Tooling Related Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Line Items]
Total tooling related assets	$ 18,821	$ 9,646
Inventories, net of progress billings and reserves
Accounting Policies [Line Items]
Total tooling related assets	18,540	9,388
Prepaid expenses and other current assets
Accounting Policies [Line Items]
Total tooling related assets	$ 281	$ 258

Acquisitions and Divestitures -

Acquisitions and Divestitures - Acquisitions Narrative (Details) - USD ($)	Jul. 07, 2016	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jul. 06, 2016
Business Acquisition [Line Items]
Net income/(loss)		$ 13,848,000	$ 10,675,000	$ 13,125,000	$ 11,669,000	$ 4,420,000	$ 12,785,000	$ 10,813,000	$ 9,169,000		$ 49,317,000	$ 37,187,000	$ 46,259,000
Amended Credit Facility | Revolving Credit Facility
Business Acquisition [Line Items]
Maximum borrowing capacity	$ 175,000,000													$ 100,000,000
Gutsche
Business Acquisition [Line Items]
Percentage of voting interest acquired						100.00%				100.00%		100.00%
Payment to acquire business												$ 57,600,000
Estimated post-closing working capital adjustment												3,000,000
Post-closing adjustment			400,000
Consideration transferred including post-closing adjustment			$ 58,000,000
Purchase price borrowings						$ 31,600,000				$ 31,600,000		31,600,000
Net sales of acquiree since acquisition date											51,500,000
Operating income of acquiree since acquisition date											2,900,000
Purchase accounting inventory fair value step-up adjustment											600,000
Restructuring expenses											200,000
Investment in joint venture						$ 0				0		0
Texel
Business Acquisition [Line Items]
Percentage of voting interest acquired	100.00%
Payment to acquire business	$ 102,700,000
Purchase price borrowings	85,000,000
Net sales of acquiree since acquisition date										40,900,000	84,800,000
Operating income of acquiree since acquisition date										2,500,000	6,900,000
Purchase accounting inventory fair value step-up adjustment										$ 2,000,000	500,000
Investment in joint venture	$ 616,000
Texel | Afitex Texel Geosynthetiques, Inc.
Business Acquisition [Line Items]
Interest in joint venture as part of acquisition	50.00%
Investment in joint venture	$ 600,000
Acquisition-related Costs | Texel
Business Acquisition [Line Items]
Net income/(loss)												4,300,000
Acquisition-related Costs | Texel Brand and Gutsche
Business Acquisition [Line Items]
Net income/(loss)											$ (100,000)	$ (3,700,000)

Acquisitions and Divestitures49

Acquisitions and Divestitures - Divestitures Narrative (Details) - USD ($) $ in Thousands	Jan. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain on sale		$ 0	$ 0	$ 18,647
Life Sciences Vital Fluids | Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Business sold cash received	$ 30,100
Pre-tax gain on sale	18,600
Gain on disposal of business	$ 11,800

Acquisitions and Divestitures50

Acquisitions and Divestitures - Fair Values of Identifiable Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Jul. 07, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill (Note 5)	$ 68,969	$ 63,606		$ 16,841
Texel
Business Acquisition [Line Items]
Cash and cash equivalents			$ 1,610
Accounts Receivable			13,355
Inventories			17,525
Prepaid expenses and other current assets			2,469
Non-current environmental indemnification receivable (Note 14)			925
Property, plant and equipment, net			31,525
Investment in joint venture			616
Goodwill (Note 5)			28,655
Other intangible assets, net (Note 5)			22,887
Other long-term assets			0
Total assets acquired			119,567
Current liabilities			(8,520)
Long-term environmental remediation liability (Note 14)			(925)
Other long-term liabilities			0
Deferred tax liabilities			(7,413)
Total liabilities assumed			(16,858)
Net assets acquired			$ 102,709
Gutsche
Business Acquisition [Line Items]
Cash and cash equivalents		9,400
Accounts Receivable		7,736
Inventories		6,417
Prepaid expenses and other current assets		1,125
Non-current environmental indemnification receivable (Note 14)		0
Property, plant and equipment, net		7,969
Investment in joint venture		0
Goodwill (Note 5)		19,729
Other intangible assets, net (Note 5)		15,622
Other long-term assets		1,545
Total assets acquired		69,543
Current liabilities		(8,376)
Long-term environmental remediation liability (Note 14)		0
Other long-term liabilities		(2,742)
Deferred tax liabilities		(470)
Total liabilities assumed		(11,588)
Net assets acquired		$ 57,955

Acquisitions and Divestitures51

Acquisitions and Divestitures - Unaudited Pro Forma Operating Results (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Combinations [Abstract]
Net Sales	$ 698,437	$ 654,877	$ 651,252
Net Income	$ 49,317	$ 43,559	$ 47,956
Earnings Per Share [Abstract]
Basic (in dollars per share)	$ 2.89	$ 2.58	$ 2.86
Diluted (in dollars per share)	$ 2.85	$ 2.53	$ 2.81

Acquisitions and Divestitures52

Acquisitions and Divestitures - Pro-Forma Additional Information (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income/(loss)	$ 13,848,000	$ 10,675,000	$ 13,125,000	$ 11,669,000	$ 4,420,000	$ 12,785,000	$ 10,813,000	$ 9,169,000	$ 49,317,000	$ 37,187,000	$ 46,259,000
Texel
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Amortization expense									3,900,000	3,900,000	3,500,000
Acquisition related costs									100,000		800,000
Depreciation expense										1,200,000	2,100,000
Interest expense										800,000	1,200,000
Reclassification from cost of sales										900,000	1,600,000
Reclassification to net sales										900,000	1,600,000
Texel | Acquisition-related Costs
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income/(loss)										4,300,000
Texel | Fair Value Adjustment to Inventory
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income/(loss)									$ 1,100,000	2,000,000
Inventory adjustment expense										$ 0	$ 3,200,000

Inventories - Summary (Detail)

Inventories - Summary (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 28,672	$ 24,518
Work in process	29,427	17,161
Finished goods	23,901	25,360
Inventory, gross	82,000	67,039
Less: Progress billings	(1,661)	(893)
Total inventories	$ 80,339	$ 66,146

Inventories - Narrative (Detail

Inventories - Narrative (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Gross tooling inventory	$ 20.2	$ 10.3
Tooling inventory, net of progress billings	$ 18.5	$ 9.4

Property, Plant and Equipment55

Property, Plant and Equipment, Net - Summary (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment, Gross [Abstract]
Property, plant and equipment, at cost	$ 380,640	$ 343,142
Accumulated depreciation	(226,581)	(196,251)
Accumulated depreciation of capital leases	(239)	(2,915)
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]
Property and equipment, net excluding work in progress	153,820	143,976
Construction in progress	16,512	16,819
Total property, plant and equipment, net	170,332	160,795
Land
Property, Plant and Equipment, Gross [Abstract]
Property, plant and equipment, at cost	4,289	3,981
Land | Assets Held Under Capital Leases
Property, Plant and Equipment, Gross [Abstract]
Property, plant and equipment, at cost	241	226
Buildings and improvements
Property, Plant and Equipment, Gross [Abstract]
Property, plant and equipment, at cost	$ 84,337	74,397
Buildings and improvements | Minimum
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]
Property, plant and equipment useful life	10 years
Buildings and improvements | Maximum
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]
Property, plant and equipment useful life	35 years
Buildings and improvements | Assets Held Under Capital Leases
Property, Plant and Equipment, Gross [Abstract]
Property, plant and equipment, at cost	$ 221	4,806
Buildings and improvements | Assets Held Under Capital Leases | Minimum
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]
Property, plant and equipment useful life	10 years
Buildings and improvements | Assets Held Under Capital Leases | Maximum
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]
Property, plant and equipment useful life	35 years
Machinery and equipment
Property, Plant and Equipment, Gross [Abstract]
Property, plant and equipment, at cost	$ 254,881	226,675
Machinery and equipment | Minimum
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]
Property, plant and equipment useful life	5 years
Machinery and equipment | Maximum
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]
Property, plant and equipment useful life	25 years
Machinery and equipment | Assets Held Under Capital Leases
Property, Plant and Equipment, Gross [Abstract]
Property, plant and equipment, at cost	$ 1,051	0
Office equipment
Property, Plant and Equipment, Gross [Abstract]
Property, plant and equipment, at cost	$ 33,880	31,504
Office equipment | Minimum
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]
Property, plant and equipment useful life	2 years
Office equipment | Maximum
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]
Property, plant and equipment useful life	8 years
Office equipment | Assets Held Under Capital Leases
Property, Plant and Equipment, Gross [Abstract]
Property, plant and equipment, at cost	$ 34	0
Vehicles
Property, Plant and Equipment, Gross [Abstract]
Property, plant and equipment, at cost	$ 1,706	$ 1,553
Vehicles | Minimum
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]
Property, plant and equipment useful life	3 years
Vehicles | Maximum
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]
Property, plant and equipment useful life	6 years

Property, Plant and Equipment56

Property, Plant and Equipment, Net - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 21.4	$ 17.8	$ 16.4

Goodwill and Long-Lived Asset57

Goodwill and Long-Lived Assets - Gross and Net Carrying Amounts of Goodwill (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Goodwill	$ 81,129	$ 75,766
Accumulated amortization/impairment	(12,160)	(12,160)
Goodwill	68,969	63,606	$ 16,841
Performance Materials
Goodwill [Line Items]
Goodwill	13,307	12,777
Accumulated amortization/impairment	0	0
Goodwill	13,307	12,777	12,898
Technical Nonwovens
Goodwill [Line Items]
Goodwill	55,662	50,829
Accumulated amortization/impairment	0	0
Goodwill	55,662	50,829	$ 3,943
Thermal/ Acoustical Metals
Goodwill [Line Items]
Goodwill	12,160	12,160
Accumulated amortization/impairment	(12,160)	(12,160)
Goodwill	$ 0	$ 0

Goodwill and Long-Lived Asset58

Goodwill and Long-Lived Assets - Changes in Carrying Amount of Goodwill by Reporting Unit (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Beginning Balance		$ 63,606	$ 16,841
Goodwill addition / adjustment		323	47,987
Currency translation adjustment		5,040	(1,222)
Ending Balance	$ 63,606	68,969	63,606
Performance Materials
Goodwill [Roll Forward]
Beginning Balance		12,777	12,898
Goodwill addition / adjustment		0	0
Currency translation adjustment		530	(121)
Ending Balance	12,777	13,307	12,777
Technical Nonwovens
Goodwill [Roll Forward]
Beginning Balance		50,829	3,943
Goodwill addition / adjustment	300	323	47,987
Currency translation adjustment		4,510	(1,101)
Ending Balance	$ 50,829	$ 55,662	$ 50,829

Goodwill and Long-Lived Asset59

Goodwill and Long-Lived Assets - Other Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amortized intangible assets
Gross Carrying Amount	$ 51,992	$ 47,690
Accumulated Amortization	(11,449)	(6,243)
Customer relationships
Amortized intangible assets
Gross Carrying Amount	39,474	36,131
Accumulated Amortization	(4,460)	(1,284)
Patents
Amortized intangible assets
Gross Carrying Amount	4,504	4,028
Accumulated Amortization	(3,821)	(3,300)
Technology
Amortized intangible assets
Gross Carrying Amount	2,500	2,500
Accumulated Amortization	(644)	(477)
Trade names
Amortized intangible assets
Gross Carrying Amount	4,288	3,912
Accumulated Amortization	(1,461)	(394)
License agreements
Amortized intangible assets
Gross Carrying Amount	640	583
Accumulated Amortization	(640)	(583)
Other
Amortized intangible assets
Gross Carrying Amount	586	536
Accumulated Amortization	$ (423)	$ (205)

Goodwill and Long-Lived Asset60

Goodwill and Long-Lived Assets - Narrative (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Jul. 07, 2016	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Goodwill adjustment					$ 323	$ 47,987
Gross goodwill	$ 75,766			$ 75,766	81,129	75,766
Goodwill	63,606			63,606	68,969	63,606	$ 16,841
Amortization of intangible assets					4,500	1,500	800
Estimated amortization expense for intangible assets in 2018					6,000
Estimated amortization expense for intangible assets in 2019					5,700
Estimated amortization expense for intangible assets in 2020					5,300
Estimated amortization expense for intangible assets in 2021					4,500
Estimated amortization expense for intangible assets in 2022					$ 3,800
Weighted average useful life					11 years
Carrying value of asset group	527,029			527,029	$ 560,871	527,029	358,260
Gutsche
Goodwill [Line Items]
Gross goodwill	22,300			22,300		22,300
Goodwill expected to be deductible for income tax purposes	19,000			19,000		19,000
Goodwill	19,729			19,729		19,729
Intangible assets						15,600
Gutsche | Customer relationships
Goodwill [Line Items]
Intangible assets						$ 13,800
Weighted average useful lives of acquired assets						11 years
Gutsche | Trade names
Goodwill [Line Items]
Intangible assets						$ 1,700
Gutsche | Backlog
Goodwill [Line Items]
Intangible assets						$ 100
Texel
Goodwill [Line Items]
Goodwill		$ 28,655
Intangible assets		22,900
Texel | Customer relationships
Goodwill [Line Items]
Intangible assets		20,800
Weighted average useful lives of acquired assets						12 years
Texel | Trade names
Goodwill [Line Items]
Intangible assets		$ 2,100
Technical Nonwovens
Goodwill [Line Items]
Goodwill adjustment	300				323	$ 47,987
Gross goodwill	50,829			50,829	55,662	50,829
Goodwill	$ 50,829			50,829	55,662	$ 50,829	$ 3,943
Technical Nonwovens | Texel Brand and Gutsche
Goodwill [Line Items]
Goodwill acquired during period.				$ 48,000
Performance Materials Segment
Goodwill [Line Items]
Goodwill					13,300
Carrying value of asset group			$ 1,300
Asset impairment charges			800
Fair value of assets			$ 500
Held-for-sale of continuing operations | Performance Materials Segment
Goodwill [Line Items]
Carrying value of asset group					$ 500

Long-term Debt and Financing 61

Long-term Debt and Financing Arrangements - Narrative (Detail)	Jul. 07, 2016USD ($)	Apr. 30, 2017USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016	Jul. 06, 2016USD ($)	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term debt maturing in 2018					$ 300,000
Long-term debt maturing in 2019					300,000
Long-term debt maturing in 2021					$ 76,600,000
Weight-average interest rate (as a percent)					2.20%	1.40%		1.30%
Minimum
Debt Instrument [Line Items]
Unused borrowing capacity, commitment fee percentage					0.175%
Maximum
Debt Instrument [Line Items]
Unused borrowing capacity, commitment fee percentage					0.30%
Base Rate | Minimum
Debt Instrument [Line Items]
Basis spread (as a percent)					0.15%
Base Rate | Maximum
Debt Instrument [Line Items]
Basis spread (as a percent)					1.00%
Eurocurrency Rate | Minimum
Debt Instrument [Line Items]
Basis spread (as a percent)					0.75%
Eurocurrency Rate | Maximum
Debt Instrument [Line Items]
Basis spread (as a percent)					1.75%
Amended Credit Facility
Debt Instrument [Line Items]
Letters of credit outstanding					$ 3,900,000
Amended Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 175,000,000						$ 100,000,000
Maximum borrowing capacity possible value of increase (not to exceed)	$ 50,000,000
Credit facility fixed charge coverage ratio (not less than)				2
Required consolidated leverage ratio as of end of each fiscal quarter			3	3
Required consolidated EBITDA				$ 30,000,000
Remaining borrowing availability					94,500,000
Borrowings outstanding					76,600,000
Amended Credit Facility | Revolving Credit Facility | Federal Funds Effective Swap Rate
Debt Instrument [Line Items]
Basis spread (as a percent)				0.50%
Amended Credit Facility | Revolving Credit Facility | Eurocurrency Rate
Debt Instrument [Line Items]
Basis spread (as a percent)				1.00%
Amended Credit Facility | Foreign Credit Facilities
Debt Instrument [Line Items]
Remaining borrowing availability					9,800,000
Borrowings outstanding					100,000
Letters of credit outstanding					$ 2,800,000
Interest rate contract
Debt Instrument [Line Items]
Term of derivative contract		3 years
Notional amount of derivative		$ 60,000,000
Derivative fixed interest rate (as a percent)		1.58%
Derivative quarterly reduction amount			$ 5,000,000
Other Foreign Bank Borrowings
Debt Instrument [Line Items]
Maturity					2,017
Other Foreign Bank Borrowings | Minimum
Debt Instrument [Line Items]
Effective rate (as a percent)					0.80%
Other Foreign Bank Borrowings | Maximum
Debt Instrument [Line Items]
Effective rate (as a percent)					3.40%
Capital Leases | Minimum
Debt Instrument [Line Items]
Effective rate (as a percent)					1.65%
Maturity					2,019
Capital Leases | Maximum
Debt Instrument [Line Items]
Effective rate (as a percent)					2.09%
Maturity					2,020

Long-term Debt and Financing 62

Long-term Debt and Financing Arrangements - Total Outstanding Debt (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term debt	$ 77,190	$ 128,775
Less portion due within one year	(277)	(634)
Total long-term debt	$ 76,913	128,141
Revolver Loan, due July 7, 2021
Debt Instrument [Line Items]
Effective Rate (as a percent)	2.57%
Maturity	2,021
Long-term debt	$ 76,600	126,600
Other Foreign Bank Borrowings
Debt Instrument [Line Items]
Maturity	2,017
Long-term debt	$ 0	1,430
Capital Leases
Debt Instrument [Line Items]
Long-term debt	$ 590	$ 745

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) - Interest rate contract - USD ($)	1 Months Ended	3 Months Ended
	Apr. 30, 2017	Sep. 30, 2017
Derivative [Line Items]
Term of derivative contract	3 years
Notional amount of derivative	$ 60,000,000
Derivative fixed interest rate (as a percent)	1.58%
Derivative quarterly reduction amount		$ 5,000,000

Derivatives - Fair Value Amount

Derivatives - Fair Value Amounts of Derivative Instruments (Details) - Derivatives designated as hedging instrument - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 157	$ 0
Liability Derivatives	0	0
Interest rate contract
Derivatives, Fair Value [Line Items]
Asset Derivatives	157	0
Liability Derivatives	$ 0	$ 0

Derivatives - Loss Recorded in

Derivatives - Loss Recorded in Accumulated Other Comprehensive Income (Loss) (Details) - Derivatives designated as hedging instrument - Cash flow hedges - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in other comprehensive income	$ 129	$ 0	$ 122	$ 0
Interest rate contract
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in other comprehensive income	$ 129	$ 0	$ 122	$ 0

Capital Stock - Narrative (Deta

Capital Stock - Narrative (Detail)	12 Months Ended
	Dec. 31, 2017stockholder$ / sharesshares	Dec. 31, 2016$ / sharesshares	Mar. 31, 2015$ / shares
Equity [Abstract]
Preferred stock, par value (USD per share) | $ / shares	$ 0.01	$ 0.01	$ 0.01
Preferred stock, issued (shares)	0	0
Preferred stock, authorized (shares)	500,000	500,000
Number of Stockholders | stockholder	10,214
Common stock, shares, outstanding (in shares)	17,343,839

Employer Sponsored Benefit Pl67

Employer Sponsored Benefit Plan - Plan Assets and Benefit Obligations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in benefit obligation:
Interest cost	$ 2,058	$ 2,139	$ 2,066
Change in plan assets:
Fair value of plan assets at beginning of year	37,038
Fair value of plan assets at end of year	44,174	37,038
Balance sheet amounts:
Noncurrent liabilities	(9,743)	(14,729)
Domestic Plan
Change in benefit obligation:
Net benefit obligation at beginning of year	50,086	48,081
Interest cost	2,058	2,139
Actuarial loss	2,126	2,062
Gross benefits paid	(2,388)	(2,196)
Net benefit obligation at end of year	51,882	50,086	48,081
Change in plan assets:
Fair value of plan assets at beginning of year	37,038	35,413
Actual return on plan assets	5,924	221
Contributions	3,600	3,600
Gross benefits paid	(2,388)	(2,196)
Fair value of plan assets at end of year	44,174	37,038	$ 35,413
Net benefit obligation in excess of plan assets	(7,708)	(13,048)
Balance sheet amounts:
Noncurrent liabilities	(7,708)	(13,048)
Total liabilities	(7,708)	(13,048)
Amounts recognized in accumulated other comprehensive income, net of tax consist of:
Net actuarial loss	17,632	19,689
Net amount recognized	$ 17,632	$ 19,689

Employer Sponsored Benefit Pl68

Employer Sponsored Benefit Plan - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Future amortization of gain (loss)	$ (1)
Discount rate, benefit obligation	3.71%	4.21%
Expected return on plan assets, benefit obligation	5.80%	6.30%
Defined Contribution Plan:
Employer Contributions to 401(k) Plan	$ 2.6	$ 2.5	$ 2.3
Matching contribution, percent of employees' gross pay	5.00%
Matching contribution, percent of employees' gross pay, first 3%	100.00%
Matching contribution, percent of employees' gross pay, remaining 2%	50.00%
Minimum
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in next fiscal year	$ 3
Maximum
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in next fiscal year	4
United States
Defined Benefit Plan Disclosure [Line Items]
Pension plan liability	7.7	13
Increase in OCI pension adjustment	2.1	2.4
Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Pension plan liability	1.9	1.5
Accumulated other comprehensive loss, net of tax	$ 0.4	$ 0.4

Employer Sponsored Benefit Pl69

Employer Sponsored Benefit Plan - Defined Benefit Pension Plan with an Accumulated Benefit Obligation In Excess of Plan Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Projected benefit obligation	$ 51,882	$ 50,086
Accumulated benefit obligation	51,882	50,086
Fair value of plan assets	$ 44,174	$ 37,038

Employer Sponsored Benefit Pl70

Employer Sponsored Benefit Plan - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Retirement Benefits [Abstract]
Interest cost	$ 2,058	$ 2,139	$ 2,066
Expected return on plan assets	(2,376)	(2,419)	(2,360)
Amortization of actuarial net loss	1,092	933	897
Total net periodic benefit cost	$ 774	$ 653	$ 603

Employer Sponsored Benefit Pl71

Employer Sponsored Benefit Plan - Assumptions Used in Determining the Year-End Benefit Obligation and Annual Net Cost (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Benefit Obligation
Discount rate	3.71%	4.21%
Expected return on plan assets	5.80%	6.30%
Net Cost
Discount rate	4.21%	4.56%	4.16%
Expected return on plan assets	6.30%	7.00%	7.25%

Employer Sponsored Benefit Pl72

Employer Sponsored Benefit Plan - Target Allocation and the Actual Allocation of Plan Assets (Detail)	Dec. 31, 2017	Dec. 31, 2016
Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Actual Allocation of Plan Assets	26.00%	30.00%
International equities
Defined Benefit Plan Disclosure [Line Items]
Actual Allocation of Plan Assets	26.00%	30.00%
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Actual Allocation of Plan Assets	40.00%	28.00%
Hedge fund of funds
Defined Benefit Plan Disclosure [Line Items]
Actual Allocation of Plan Assets	7.00%	10.00%
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Actual Allocation of Plan Assets	1.00%	2.00%
Minimum | Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	21.00%
Minimum | International equities
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	21.00%
Minimum | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	35.00%
Minimum | Hedge fund of funds
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	3.00%
Minimum | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	0.00%
Maximum | Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	31.00%
Maximum | International equities
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	31.00%
Maximum | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	45.00%
Maximum | Hedge fund of funds
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	13.00%
Maximum | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	5.00%

Employer Sponsored Benefit Pl73

Employer Sponsored Benefit Plan - Trust Assets at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	$ 44,174	$ 37,038
Measured at NAV	20,414	14,362
Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	11,577	10,964
Measured at NAV	0	0
International equities
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	11,626	10,944
Measured at NAV	0	0
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	17,360	10,499
Measured at NAV	17,360	10,499
Hedge fund of funds
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	3,054	3,863
Measured at NAV	3,054	3,863
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	557	768
Measured at NAV	0	0
Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	23,760	22,676
Level 1 | Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	11,577	10,964
Level 1 | International equities
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	11,626	10,944
Level 1 | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 1 | Hedge fund of funds
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 1 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	557	768
Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 2 | Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 2 | International equities
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 2 | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 2 | Hedge fund of funds
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 2 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 3 | Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 3 | International equities
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 3 | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 3 | Hedge fund of funds
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	0	0
Level 3 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Total Assets at Fair Value	$ 0	$ 0

Employer Sponsored Benefit Pl74

Employer Sponsored Benefit Plan - Estimated Future Benefit Payments (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Retirement Benefits [Abstract]
2,018	$ 2,499
2,019	2,615
2,020	2,741
2,021	2,824
2,022	2,854
2023-2027	$ 14,801

Equity Compensation Plans - Nar

Equity Compensation Plans - Narrative (Detail) - USD ($)	Apr. 27, 2012	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense		$ 4,300,000	$ 4,400,000	$ 2,800,000
Compensation costs capitalized as part of inventory		0	0	0
Tax benefit from compensation expense		$ 4,000,000	$ 1,900,000	$ 1,500,000
Options granted (in shares)		99,840	56,580	91,900
Weighted-average grant-date fair value of options (in dollars per share)		$ 17.91	$ 21.11	$ 15.28
Options exercised (in shares)		90,897	76,333	166,175
Total intrinsic value for options exercised		$ 3,600,000	$ 2,400,000	$ 3,500,000
Cash received from exercise of stock option		1,300,000	1,200,000	1,500,000
Fair value of restrictions lapsed		$ 8,000,000	3,400,000	1,400,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award, term		10 years
Realized income tax benefit		$ 1,100,000	$ 700,000	$ 1,100,000
Total unrecognized compensation cost		$ 3,400,000
Weighted average expected amortization period		3 years 1 month
Stock Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award, vesting period		3 years
Stock Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award, vesting period		4 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value of options (in dollars per share)		$ 45.18	$ 49.70	$ 34.09
Total unrecognized compensation cost		$ 5,900,000
Weighted average expected amortization period		2 years 3 months 24 days
Granted (in shares)		76,000
Restricted stock forfeited (in shares)		14,045	33,800	147,187
Shares paid for tax withholding for share based compensation (in shares)		42,288
Shares paid for tax withholding for share based compensation, value of shares withheld		$ 2,800,000
Time Based Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		22,700	31,455	33,755
Time Based Restricted Stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award, vesting period		2 years
Time Based Restricted Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award, vesting period		4 years
Performance Based Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		52,595	44,423	38,170
Time-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		485	8,570
2012 Stock Repurchase Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share options and restricted shares authorized (in shares)	1,750,000
Number of additional shares authorized (in shares)	1,200,000

Equity Compensation Plans - Wei

Equity Compensation Plans - Weighted-Average Assumptions (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free interest rate	2.20%	1.80%	1.80%
Expected life	5 years 5 months 19 days	5 years 5 months 19 days	5 years 5 months 19 days
Expected volatility	33.00%	42.00%	43.00%
Expected dividend yield	0.00%	0.00%	0.00%

Equity Compensation Plans - Sum

Equity Compensation Plans - Summary of Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares:
Outstanding at beginning of period (in shares)	427,000
Granted (in shares)	99,840	56,580	91,900
Exercised (in shares)	(90,897)	(76,333)	(166,175)
Forfeited/Cancelled (in shares)	(3,000)
Outstanding at end of period (in shares)	433,000	427,000
Options exercisable at end of period (in shares)	230,000
Unvested at end of period (in shares)	203,000
Weighted-Average Exercise Price:
Outstanding at beginning of period (in dollars per share)	$ 25.32
Granted (in dollars per share)	51.85
Exercised (in dollars per share)	14.87
Forfeited/Cancelled (in dollars per share)	64.20
Outstanding at end of period (in dollars per share)	33.37	$ 25.32
Options exercisable at end of period (in dollars per share)	22.11
Unvested at end of period (in dollars per share)	$ 46.05
Weighted- Average Remaining Contractual Term (years)
Outstanding at end of period	7 years 1 month
Options exercisable at end of period	5 years 5 months 19 days
Unvested at end of period	8 years 1 month
Aggregate Intrinsic Value
Outstanding at end of period	$ 8,116
Options exercisable at end of period	6,703
Unvested at end of period	$ 1,413

Equity Compensation Plans - S78

Equity Compensation Plans - Summary of Unvested Restricted Shares (Detail) - Restricted Stock shares in Thousands	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Shares:
Nonvested at beginning of period (in shares) | shares	296
Granted (in shares) | shares	76
Vested (in shares) | shares	(139)
Forfeited/Cancelled (in shares) | shares	(14)
Nonvested at end of period (in shares) | shares	219
Weighted-Average Grant-Date Fair Value:
Nonvested at beginning of period (in dollars per share) | $ / shares	$ 34.01
Granted (in dollars per share) | $ / shares	45.18
Vested (in dollars per share) | $ / shares	22.63
Forfeited/Cancelled (in dollars per share) | $ / shares	38.95
Nonvested at end of period (in dollars per share) | $ / shares	$ 44.77

Restructuring - Narrative (Deta

Restructuring - Narrative (Details) - Technical Nonwovens - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Apr. 30, 2017
Restructuring Cost and Reserve [Line Items]
Estimated pre-tax restructuring expense		$ 5,000
Restructuring, expected costs resulting in future cash expenditures			$ 4,800
Cash paid		177
Pre-tax restructuring expenses, excluding depreciation		700
Cost of Sales
Restructuring Cost and Reserve [Line Items]
Pre-tax restructuring expenses, excluding depreciation		400
Selling, Product Development and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Pre-tax restructuring expenses, excluding depreciation		$ 300
Forecast
Restructuring Cost and Reserve [Line Items]
Cash paid	$ 3,500
Minimum | Forecast
Restructuring Cost and Reserve [Line Items]
Pre-tax restructuring expenses, excluding depreciation	3,500
Maximum | Forecast
Restructuring Cost and Reserve [Line Items]
Pre-tax restructuring expenses, excluding depreciation	$ 4,000

Restructuring - Actual and Esti

Restructuring - Actual and Estimated Pre-tax Expenses (Details) - Technical Nonwovens $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Restructuring Cost and Reserve [Line Items]
Total estimated expenses	$ 5,000
Expenses incurred through December 31, 2017	662
Estimated remaining expense at December 31, 2017	4,338
Severance and Related Expenses
Restructuring Cost and Reserve [Line Items]
Total estimated expenses	1,200
Expenses incurred through December 31, 2017	181
Estimated remaining expense at December 31, 2017	1,019
Contract Termination Expenses
Restructuring Cost and Reserve [Line Items]
Total estimated expenses	300
Expenses incurred through December 31, 2017	154
Estimated remaining expense at December 31, 2017	146
Facility Exit, Move and Set-up Expenses
Restructuring Cost and Reserve [Line Items]
Total estimated expenses	3,500
Expenses incurred through December 31, 2017	327
Estimated remaining expense at December 31, 2017	$ 3,173

Restructuring - Accrued Restruc

Restructuring - Accrued Restructuring Costs (Details) - Technical Nonwovens $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Restructuring Cost and Reserve [Line Items]
Pre-tax restructuring expenses, excluding depreciation	$ 510
Cash paid	(177)
Restructuring reserve	$ 333

Segment Information - Narrative

Segment Information - Narrative (Detail) - USD ($) $ in Thousands	Jan. 30, 2015	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Long-lived asset impairment charges			$ 772	$ 0	$ 1,354
Foreign currency translation loss					2,000
Net sales			$ 698,437	$ 566,852	$ 524,505
Percentage of foreign and export sales			54.20%	46.90%	44.20%
Sales Revenue | Customer Concentration Risk | Ford Motor Company
Segment Reporting Information [Line Items]
Net sales			$ 120,700	$ 110,900	$ 95,400
Percentage of foreign and export sales			17.30%	19.60%	18.20%
Corporate
Segment Reporting Information [Line Items]
Strategic initiative expenses			$ 800
Transaction related costs				$ 3,700
Thermal/Acoustical Metals Segment and Technical Nonwovens Segment
Segment Reporting Information [Line Items]
Integration related costs			700
Severance expenses			300
Technical Nonwovens Segment
Segment Reporting Information [Line Items]
Purchase accounting adjustments related to inventory step-up			1,100	2,000
Restructuring expenses			700
Intercompany sales			26,500	18,200	$ 13,800
Performance Materials
Segment Reporting Information [Line Items]
Long-lived asset impairment charges			800		$ 1,400
Thermal/Acoustical Metals Segment and Thermal/Acoustical Fibers Segment
Segment Reporting Information [Line Items]
Integration related costs			$ 1,700
Thermal/Acoustical Metals Segment
Segment Reporting Information [Line Items]
Settlement expense				$ 3,500
Held-for-sale or Disposed of by Sale, Not Discontinued Operations | Vital Fluids
Segment Reporting Information [Line Items]
Cash purchase sale price of Life Sciences Vital Fluids	$ 30,100
Gain on disposal of business		$ 11,800

Segment Information - Net Sales

Segment Information - Net Sales By Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net sales	$ 698,437	$ 566,852	$ 524,505
Operating Segments | Performance Materials Segment
Segment Reporting Information [Line Items]
Net sales	116,669	111,128	101,478
Operating Segments | Performance Materials Segment | Filtration
Segment Reporting Information [Line Items]
Net sales	77,254	70,430	62,716
Operating Segments | Performance Materials Segment | Thermal Insulation
Segment Reporting Information [Line Items]
Net sales	29,496	27,783	28,311
Operating Segments | Performance Materials Segment | Life Sciences Filtration
Segment Reporting Information [Line Items]
Net sales	9,919	12,915	10,451
Operating Segments | Technical Nonwovens Segment
Segment Reporting Information [Line Items]
Net sales	269,077	155,505	139,133
Operating Segments | Technical Nonwovens Segment | Industrial Filtration
Segment Reporting Information [Line Items]
Net sales	147,087	90,415	113,044
Operating Segments | Technical Nonwovens Segment | Advanced Materials
Segment Reporting Information [Line Items]
Net sales	121,990	65,090	26,089
Operating Segments | Thermal/Acoustical Metals Segment
Segment Reporting Information [Line Items]
Net sales	188,546	174,974	160,932
Operating Segments | Thermal/Acoustical Metals Segment | Metal parts
Segment Reporting Information [Line Items]
Net sales	168,995	156,187	141,117
Operating Segments | Thermal/Acoustical Metals Segment | Tooling
Segment Reporting Information [Line Items]
Net sales	19,551	18,787	19,815
Operating Segments | Thermal/Acoustical Fibers Segment
Segment Reporting Information [Line Items]
Net sales	157,761	149,412	138,747
Operating Segments | Thermal/Acoustical Fibers Segment | Tooling
Segment Reporting Information [Line Items]
Net sales	4,337	5,067	3,152
Operating Segments | Thermal/Acoustical Fibers Segment | Fiber parts
Segment Reporting Information [Line Items]
Net sales	153,424	144,345	135,595
Operating Segments | Other Products and Services
Segment Reporting Information [Line Items]
Net sales	0	0	1,671
Operating Segments | Other Products and Services | Life Sciences Vital Fluids
Segment Reporting Information [Line Items]
Net sales	0	0	1,671
Eliminations and Other
Segment Reporting Information [Line Items]
Net sales	$ (33,616)	$ (24,167)	$ (17,456)

Segment Information - Classific

Segment Information - Classification of Segments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Mar. 31, 2017
Segment Reporting Information [Line Items]
Operating Income	$ 65,427	$ 54,792	$ 52,477
Total Assets	560,871	527,029	358,260
Capital Expenditures	24,915	28,159	21,555
Depreciation and Amortization	26,130	19,559	17,275
Performance Materials Segment
Segment Reporting Information [Line Items]
Total Assets				$ 1,300
Operating Segments | Performance Materials Segment
Segment Reporting Information [Line Items]
Operating Income	12,043	12,339	6,790
Total Assets	72,837	66,965	66,706
Capital Expenditures	3,610	4,098	3,519
Depreciation and Amortization	3,999	4,023	4,499
Operating Segments | Technical Nonwovens Segment
Segment Reporting Information [Line Items]
Operating Income	26,047	15,584	13,431
Total Assets	271,713	268,104	89,566
Capital Expenditures	2,903	1,248	968
Depreciation and Amortization	12,633	6,778	4,996
Operating Segments | Thermal/Acoustical Metals Segment
Segment Reporting Information [Line Items]
Operating Income	10,072	11,562	15,517
Total Assets	139,655	119,494	111,195
Capital Expenditures	12,316	15,425	11,494
Depreciation and Amortization	5,489	5,094	4,233
Operating Segments | Thermal/Acoustical Fibers Segment
Segment Reporting Information [Line Items]
Operating Income	42,870	41,452	37,086
Total Assets	49,646	47,097	38,881
Capital Expenditures	5,146	6,899	4,807
Depreciation and Amortization	3,135	2,570	2,400
Operating Segments | Other Products and Services
Segment Reporting Information [Line Items]
Operating Income	0	0	118
Total Assets	0	0	0
Capital Expenditures	0	0	22
Depreciation and Amortization	0	0	45
Corporate
Segment Reporting Information [Line Items]
Operating Income	(25,605)	(26,145)	(20,465)
Total Assets	27,020	25,369	51,912
Capital Expenditures	940	489	745
Depreciation and Amortization	$ 874	$ 1,094	$ 1,102

Segment Information - Net Sal85

Segment Information - Net Sales by Geographic Area (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net sales	$ 698,437	$ 566,852	$ 524,505
Long-Lived Assets	177,864	166,370	116,717
United States
Segment Reporting Information [Line Items]
Net sales	376,086	354,371	344,950
Long-Lived Assets	93,583	88,918	76,502
France
Segment Reporting Information [Line Items]
Net sales	56,214	52,042	47,495
Long-Lived Assets	14,268	12,692	12,899
Germany
Segment Reporting Information [Line Items]
Net sales	105,828	63,301	68,861
Long-Lived Assets	20,872	15,649	10,149
United Kingdom
Segment Reporting Information [Line Items]
Net sales	24,921	23,871	26,598
Long-Lived Assets	4,916	4,903	6,399
Canada
Segment Reporting Information [Line Items]
Net sales	84,701	40,871	0
Long-Lived Assets	30,739	30,911	0
China
Segment Reporting Information [Line Items]
Net sales	47,856	30,361	33,885
Long-Lived Assets	11,896	11,996	9,953
Other
Segment Reporting Information [Line Items]
Net sales	2,831	2,035	2,716
Long-Lived Assets	1,590	1,301	815
Technical Nonwovens Segment
Segment Reporting Information [Line Items]
Intercompany sales	$ 26,500	$ 18,200	$ 13,800

Income Taxes - Components of Pr

Income Taxes - Components of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ 11,526	$ 15,376	$ 18,291
State	956	1,513	1,204
Foreign	2,425	2,104	1,684
Total Current	14,907	18,993	21,179
Deferred:
Federal	(2,472)	(594)	1,583
State	256	601	1,696
Foreign	(717)	(1,179)	306
Total Deferred	(2,933)	(1,172)	3,585
Provision for income taxes	$ 11,974	$ 17,821	$ 24,764

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the Difference between the Actual Provisions for Income Taxes (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Statutory federal income tax rate	35.00%	35.00%	35.00%
State income taxes	1.60%	2.10%	2.90%
Valuation allowances for deferred tax assets, including state	0.10%	1.30%	1.30%
Research and development credits	(1.00%)	(1.20%)	(1.50%)
Capitalized transaction costs	0.00%	0.70%	0.00%
Domestic production activities deduction	(1.80%)	(2.70%)	(1.60%)
Stock based compensation	(4.40%)	(2.10%)	(0.20%)
German Cartel settlement	0.00%	2.20%	0.00%
Foreign operations and intercompany financing	(2.80%)	(3.50%)	(1.30%)
Reserves for uncertain tax positions	(1.70%)	(0.10%)	(0.40%)
Repatriation of foreign undistributed earnings	1.30%	0.00%	0.00%
Revaluation of deferred tax liabilities due to federal rate change	(7.30%)	0.00%	0.00%
Other	0.50%	0.70%	0.70%
Effective income tax rate	19.50%	32.40%	34.90%

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Detail) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Income tax expense (benefit) related to revaluation of deferred tax liability																	$ 4,500
Undistributed accumulated earnings of foreign subsidiary	$ 12,000																12,000
Income tax expense (benefit) from repatriation tax																	500
Undistributed accumulated earnings of foreign subsidiary previously marked for reinvestment	6,200																6,200
Income tax expense (benefit) related to revaluation of deferred tax asset																	300
Income tax expense (benefit) related to Tax Reform Act																	$ 3,700
Effective tax rate for income from continuing operations (as percent)																	19.50%	32.40%	34.90%
Income tax expense (benefit) for change in tax rate																	$ 1,700
Income tax expense																	11,974	$ 17,821	$ 24,764
Income tax expense (benefit) from domestic production activities deduction																	1,100
Income tax expense (benefit) from stock-based compensation																	2,700
Income tax expense (benefit) from release of reserves																	1,500
Net income/(loss)	13,848	$ 10,675	$ 13,125	$ 11,669	$ 4,420	$ 12,785	$ 10,813	$ 9,169									49,317	37,187	46,259
Effective income tax rate reconciliation, tax expense (benefit) foreign income tax rate differential																		1,300	1,000
Effective income tax rate reconciliation, tax benefit attributable to the Domestic Production Activities Deduction																		1,500	1,200
Effective income tax rate reconciliation, tax credit related to research and development credits																		1,100	1,100
Increase in valuation allowance against certain deferred tax assets																		(1,200)	(900)
Reasonably expected net unrecognized benefits may be recognized	200																200
Total amount of net unrecognized tax benefits that would affect the effective tax rate if recognized	2,500																2,500
Amount of unrecognized tax benefit, if recognized, would be offset	1,500																1,500
Netherlands and China
Income Taxes [Line Items]
Increase in valuation allowance against certain deferred tax assets																		500	800
China
Income Taxes [Line Items]
Change in valuation allowance																	300
State
Income Taxes [Line Items]
Effective income tax rate reconciliation, state and local income taxes																		$ 700	$ 600
Operating loss carryforward	4,000																4,000
State tax credit carry forwards that expire between 2017 and 2032	2,200																2,200
Valuation reserve	2,200																2,200
Foreign | China
Income Taxes [Line Items]
Operating loss carryforward	6,000																6,000
Foreign | Germany
Income Taxes [Line Items]
Operating loss carryforward	5,200																5,200
Foreign | Netherlands
Income Taxes [Line Items]
Operating loss carryforward	10,000																10,000
Restatement Adjustment
Income Taxes [Line Items]
Net income/(loss)	$ (800)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)
Foreign Tax Error | Restatement Adjustment
Income Taxes [Line Items]
Income tax expense																	$ 700

Income Taxes - Schedule Present

Income Taxes - Schedule Presents Net Current and Net Long-Term Deferred Tax Assets and Liabilities by Tax Jurisdiction (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets and Liabilities [Line Items]
Deferred Tax Assets, Long-term	$ 1,146
Deferred Tax Assets, Current		$ 0
Deferred Tax Assets, Long-term		248
Deferred Tax Liabilities, Long-term	14,714
Deferred Tax Liabilities, Current		0
Deferred Tax Liabilities, Long-term		15,849
Federal
Deferred Tax Assets and Liabilities [Line Items]
Deferred Tax Assets, Long-term	0
Deferred Tax Assets, Current		0
Deferred Tax Assets, Long-term		0
Deferred Tax Liabilities, Long-term	7,288
Deferred Tax Liabilities, Current		0
Deferred Tax Liabilities, Long-term		7,705
State
Deferred Tax Assets and Liabilities [Line Items]
Deferred Tax Assets, Long-term	0
Deferred Tax Assets, Current		0
Deferred Tax Assets, Long-term		0
Deferred Tax Liabilities, Long-term	424
Deferred Tax Liabilities, Current		0
Deferred Tax Liabilities, Long-term		531
Foreign
Deferred Tax Assets and Liabilities [Line Items]
Deferred Tax Assets, Long-term	1,146
Deferred Tax Assets, Current		0
Deferred Tax Assets, Long-term		248
Deferred Tax Liabilities, Long-term	$ 7,002
Deferred Tax Liabilities, Current		0
Deferred Tax Liabilities, Long-term		$ 7,613

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Asset and Liability (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Accounts receivable	$ 132	$ 225
Inventories	164	743
Net operating loss carryforwards	5,339	3,851
Other accrued liabilities	1,053	4,592
Pension	1,482	3,545
Tax Credits	1,735	1,687
Total deferred tax assets	9,905	14,643
Deferred tax liabilities:
Intangible assets	2,073	4,224
Property, plant and equipment	15,691	21,117
Total deferred tax liabilities	17,764	25,341
Valuation allowance	5,709	4,903
Net deferred tax liabilities	$ (13,568)	$ (15,601)

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income from Continuing Operations before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
United States	$ 54,212	$ 53,356	$ 64,923
Foreign	7,107	1,583	6,100
Total income before income taxes	$ 61,319	$ 54,939	$ 71,023

Income Taxes - Reconciliation92

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits at beginning of year	$ 3,219	$ 1,657
Decreases relating to positions taken in prior periods	0	(63)
Increases relating to positions taken in prior periods	221	0
Increases relating to current period	475	1,678
Decreases due to settlements with tax authorities	(1,372)	0
Decreases due to lapse of statute of limitations	(17)	(53)
Unrecognized tax benefits at end of year	$ 2,526	$ 3,219

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Lease Payments (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating Lease Payments, 2018	$ 4,829
Operating Lease Payments, 2019	3,842
Operating Lease Payments, 2020	2,934
Operating Lease Payments, 2021	1,981
Operating Lease Payments, 2022	1,877
Operating Lease Payments, Thereafter	10,341
Operating Lease Payments, Total	25,804
Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Capital Lease Payments, 2018	283
Capital Lease Payments, 2019	292
Capital Lease Payments, 2020	36
Capital Lease Payments, 2021	0
Capital Lease Payments, 2022	0
Capital Lease Payments, Thereafter	0
Capital Lease Payments, Total	611
Interest on capital leases	(9)
Capital Lease Payments, Total	602
2,018	5,112
2,019	4,134
2,020	2,970
2,021	1,981
2,022	1,877
Thereafter	10,341
Total Operating and Capital Lease Payments	26,415
Interest on capital leases	(9)
Total	$ 26,406

Commitments and Contingencies94

Commitments and Contingencies - Narrative (Detail) CAD in Millions, $ in Millions	3 Months Ended	6 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2017USD ($)	Jun. 30, 2017USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2017CAD	Jul. 07, 2016USD ($)
Loss Contingencies [Line Items]
Operating leases rent expense				$ 5.8	$ 5.4	$ 5.1
Rochester, New Hampshire
Loss Contingencies [Line Items]
Environmental remediation expense	$ 0.2
Texel | Quebec, Canada
Loss Contingencies [Line Items]
Indemnification assets, mimimum estimated outcome								$ 0.9
Indemnification assets, maximum estimated outcome								$ 1.5
Environment remediation indemnity secured by environmental escrow account			$ 2.4				CAD 3
Environmental remediation indemnity secured by general escrow account			11.1				14
Environmental remediation indemnity secured by general escrow account, reduced amount after share purchase agreement			5.6				CAD 7
Environmental Contamination | Rochester, New Hampshire
Loss Contingencies [Line Items]
Environmental liability			0
Reduction to accrual for environmental liability, payments			0.2
Accrual for environmental liability, including revision (fully offset)			0.2
Environmental Contamination | Texel | Quebec, Canada
Loss Contingencies [Line Items]
Environmental liability			0.8		$ 0.9
Accrual for environmental liability, revision of estimate		$ 0.6
Reduction to accrual for environmental liability, payments			0.7
Accrual for environmental liability, including revision (fully offset)		$ 1.5	$ 0.8

Earnings Per Share - Reconcilia

Earnings Per Share - Reconciliation of Weighted Average Shares Used to Determine Basic and Diluted Earnings Per Share (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Basic average common shares outstanding (shares)	17,045	16,871	16,746
Effect of dilutive options and restricted stock awards (in shares)	272	370	338
Diluted average common shares outstanding (shares)	17,317	17,241	17,084

Earnings Per Share - Narrative

Earnings Per Share - Narrative (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Shares excluded from computation of diluted earnings per share (less than in 0.1 million in 2014) (in shares)	44,837	94,796	121,057

Quarterly Financial Informati97

Quarterly Financial Information (Unaudited) - Narrative (Detail) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Gross profit	$ 39,405	$ 39,980	$ 43,253	$ 40,424	$ 31,982	$ 38,193	$ 35,990	$ 32,377									$ 163,062	$ 138,542	$ 122,497
Net income/(loss)	13,848	10,675	13,125	11,669	4,420	12,785	10,813	9,169									$ 49,317	$ 37,187	$ 46,259
Restatement Adjustment
Business Acquisition [Line Items]
Net income/(loss)	$ (800)	$ (100)	$ (100)	$ (100)	(100)	(100)	(100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)	$ (100)
Thermal/Acoustical Metals Segment | Restatement Adjustment
Business Acquisition [Line Items]
Gross profit					(900)	(400)	(500)
Net income/(loss)					$ (600)	$ (300)	$ (300)

Quarterly Financial Informati98

Quarterly Financial Information (Unaudited) - Summary of Quarterly Financial Results (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 178,030	$ 180,041	$ 174,879	$ 165,487	$ 144,192	$ 155,725	$ 137,235	$ 129,700	$ 698,437	$ 566,852	$ 524,505
Gross profit	39,405	39,980	43,253	40,424	31,982	38,193	35,990	32,377	163,062	138,542	122,497
Net income	$ 13,848	$ 10,675	$ 13,125	$ 11,669	$ 4,420	$ 12,785	$ 10,813	$ 9,169	$ 49,317	$ 37,187	$ 46,259
Earnings per common share:
Basic (USD per share)	$ 0.81	$ 0.63	$ 0.77	$ 0.69	$ 0.26	$ 0.76	$ 0.64	$ 0.54	$ 2.89	$ 2.20	$ 2.76
Diluted (USD per share)	$ 0.80	$ 0.62	$ 0.76	$ 0.68	$ 0.26	$ 0.75	$ 0.63	$ 0.54	$ 2.85	$ 2.16	$ 2.71

Quarterly Financial Informati99

Quarterly Financial Information (Unaudited) Quarterly Financial Information (Unaudited) - Components of Gross Profit and Net Income (Details) - USD ($)	3 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Gross profit impact of inventory step-up purchase accounting adjustments	$ 0	$ 83,000	$ 543,000	$ 481,000	$ 347,000	$ 1,607,000	$ 0	$ 0
Gross profit impact of restructuring, severance, and segment consolidation expenses	155,000	287,000	92,000	441,000	0	0	0	0
Net income impact of inventory step-up purchase accounting adjustments	0	59	394	350	254	1,176	0	0
Net income impact of restructuring, severance, and segment consolidation expenses	488	910	216	702	0	0	0	0
Net income impact of long-lived asset impairment charges	0	0	0	490	0	0	0	0
Net income impact of strategic initiatives expenses	205	219	0	125	786	820	1,080	365
Net income impact of German Cartel settlement	$ 0	$ 0	$ 0	$ 0	$ 3,479	$ 0	$ 0	$ 0

Recently Issued Accounting S100

Recently Issued Accounting Standards Recently Issued Accounting Standards - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effect of net sales		$ 698,437	$ 566,852	$ 524,505
Cumulative effect recognized on initial application of the new guidance	$ 374,783	374,783	$ 325,466
Difference between Revenue Guidance in Effect before and after Topic 606 | Minimum | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effect on revenue	17,000
Effect of net sales	15,000
Cumulative effect recognized on initial application of the new guidance	1,000	1,000
Difference between Revenue Guidance in Effect before and after Topic 606 | Maximum | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effect on revenue	23,000
Effect of net sales	19,000
Cumulative effect recognized on initial application of the new guidance	$ 2,500	$ 2,500

Changes In Accumulated Other101

Changes In Accumulated Other Comprehensive Income (Loss) - Changes within Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 273,456	$ 245,225	$ 212,599
Other comprehensive income (loss)	27,085	(13,934)	(10,971)
Amounts reclassified from accumulated other comprehensive loss	717	569	547
Ending balance	353,396	273,456	245,225
Total Accumulated Other Comprehensive (Loss) Income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(47,950)	(34,585)	(24,161)
Ending balance	(20,148)	(47,950)	(34,585)
Foreign Currency Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(27,885)	(16,920)	(6,586)
Other comprehensive income (loss)	25,664	(10,965)	(10,334)
Amounts reclassified from accumulated other comprehensive loss	0		0
Ending balance	(2,221)	(27,885)	(16,920)
Defined Benefit Pension Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(20,065)	(17,665)	(17,575)
Other comprehensive income (loss)	1,299	(2,969)	(637)
Amounts reclassified from accumulated other comprehensive loss	717	569	547
Ending balance	(18,049)	(20,065)	(17,665)
Gains and Losses on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	0	0	0
Other comprehensive income (loss)	122	0	0
Amounts reclassified from accumulated other comprehensive loss		0	0
Ending balance	$ 122	$ 0	$ 0

Changes in Accumulated Other102

Changes in Accumulated Other Comprehensive Income (Loss) - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Actuarial gains (losses), net of tax	$ 1.3	$ (3)	$ (0.6)
Actuarial (losses) gains, tax expense (benefit)	0.1	(1.6)	(0.4)
Income tax expense (benefit) related to revaluation of deferred tax liability	4.5
Amortization of actuarial losses, net of tax	0.7	0.6	0.5
Amortization of actuarial losses, tax expense (benefit)	$ (0.4)	$ (0.4)	$ (0.3)

Schedule II - Valuation and 103

Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for doubtful receivables
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period	$ 1,429	$ 1,251	$ 709
Charges to Costs and Expenses	541	941	855
Charges (Deductions) to Other Accounts	103	(123)	(53)
Deductions	(566)	(640)	(260)
End of Period	1,507	1,429	1,251
Tax valuation allowances
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period	4,903	4,307	3,727
Charges to Costs and Expenses	886	762	1,615
Charges (Deductions) to Other Accounts	394	(140)	(272)
Deductions	(474)	(26)	(763)
End of Period	$ 5,709	$ 4,903	$ 4,307