Gibraltar Industries (ROCK) 10-K27 Feb 182017 FY Annual reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2017	Feb. 20, 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	ROCK
Entity Registrant Name	GIBRALTAR INDUSTRIES, INC.
Entity Central Index Key	912,562
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		31,748,874
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Public Float			$ 1,140

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	$ 986,918	$ 1,007,981	$ 1,040,873
Cost of sales	750,374	763,219	853,897
Gross profit	236,544	244,762	186,976
Selling, general, and administrative expense	143,448	161,099	133,381
Intangible asset impairment	247	10,175	4,863
Income from operations	92,849	73,488	48,732
Interest expense	14,032	14,577	15,003
Other expense (income)	909	8,928	(3,371)
Income before taxes	77,908	49,983	37,100
Provision for income taxes	14,943	16,264	13,624
Income from continuing operations	62,965	33,719	23,476
Discontinued operations:
Loss before taxes	(644)	(70)	(44)
Benefit of income taxes	(239)	(26)	(16)
Loss from discontinued operations	(405)	(44)	(28)
Net income	$ 62,560	$ 33,675	$ 23,448
Net earnings per share – Basic:
(Loss) income from continuing operations (in dollars per share)	$ 1.98	$ 1.07	$ 0.75
Loss from discontinued operations (in dollars per share)	(0.01)	0	0
Net (loss) income (in dollars per share)	$ 1.97	$ 1.07	$ 0.75
Weighted average shares outstanding – Basic (in shares)	31,701	31,536	31,233
Net earnings per share – Diluted:
Income (Loss) from Continuing Operations, Per Diluted Share	$ 1.95	$ 1.05	$ 0.74
Loss from discontinued operations (in dollars per share)	(0.01)	0	0
Net (loss) income (in dollars per share)	$ 1.94	$ 1.05	$ 0.74
Weighted average shares outstanding – Diluted (in shares)	32,250	32,069	31,545

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - 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, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net income	$ 25,176	$ 20,619	$ 12,769	$ 3,996	$ (7,752)	$ 13,786	$ 18,612	$ 9,029	$ 62,560	$ 33,675	$ 23,448
Other comprehensive income (loss):
Foreign currency translation adjustment									3,150	6,945	(6,228)
Reclassification of loss on cash flow hedges, net of tax									0	0	143
Adjustment to retirement benefit liability, net of tax									(9)	55	49
Adjustment to post-retirement healthcare benefit liability, net of tax									214	695	171
Other comprehensive income (loss)									3,355	7,695	(5,865)
Total comprehensive income									$ 65,915	$ 41,370	$ 17,583

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 222,280	$ 170,177
Accounts receivable, net	145,385	124,072
Inventories	86,372	89,612
Other current assets	8,727	7,336
Total current assets	462,764	391,197
Property, plant, and equipment, net	97,098	108,304
Goodwill	321,074	304,032
Acquired intangibles	105,768	110,790
Other assets	4,681	3,922
Total assets	991,385	918,245
Current liabilities:
Accounts payable	82,387	69,944
Accrued expenses	75,467	70,392
Billings in Excess of Cost	12,779	11,352
Current maturities of long-term debt	400	400
Total current liabilities	171,033	152,088
Long-term debt	209,621	209,237
Deferred income taxes	31,237	38,002
Other non-current liabilities	47,775	58,038
Shareholders’ equity:
Preferred stock, $0.01 par value; authorized 10,000 shares; none outstanding	0	0
Common stock, $0.01 par value; authorized 50,000 shares; 32,332 and 32,085 shares outstanding in 2017 and 2016	323	320
Additional paid-in capital	271,957	264,418
Retained earnings	274,562	211,748
Accumulated other comprehensive loss	(4,366)	(7,721)
Cost of 615 and 530 common shares held in treasury in 2017 and 2016	(10,757)	(7,885)
Total shareholders’ equity	531,719	460,880
Total liabilities and shareholders' equity	$ 991,385	$ 918,245

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares outstanding	32,332,000	32,085,000
Treasury stock, shares	615,000	530,000

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	$ 62,560	$ 33,675	$ 23,448
Loss from discontinued operations	(405)	(44)	(28)
Income from continuing operations	62,965	33,719	23,476
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	21,690	24,114	30,548
Intangible asset impairment	247	10,175	4,863
Loss on sale of business	0	(8,763)	0
Stock compensation expense	7,122	6,373	3,891
Net gain on sale of assets	(123)	(42)	(6,431)
Exit activity (recoveries) costs, non-cash	(1,877)	7,530	8,504
Benefit of deferred income taxes	(7,105)	(4,893)	(2,051)
Other, net	2,118	1,934	4,759
Changes in operating assets and liabilities (excluding the effects of acquisitions):
Accounts receivable	(21,806)	37,828	(17,215)
Inventories	870	11,782	22,271
Other current assets and other assets	(2,629)	2,511	759
Accounts payable	11,332	(17,060)	(5,157)
Accrued expenses and other non-current liabilities	(2,734)	1,253	19,004
Net cash provided by operating activities	70,070	123,987	87,221
Cash Flows from Investing Activities
Purchases of property, plant, and equipment	(11,399)	(10,779)	(12,373)
Acquisitions, net of cash acquired	(18,494)	(23,412)	(140,621)
Net proceeds from sale of property and equipment	13,096	953	26,500
Net proceeds from sale of business	0	8,250	0
Other, net	0	1,118	1,154
Net cash used in investing activities	(16,797)	(23,870)	(125,340)
Cash Flows from Financing Activities
Long-term debt payments	(400)	(400)	(73,642)
Proceeds from long-term debt	0	0	73,242
Payment of debt issuance costs	0	(54)	(1,166)
Purchase of treasury stock at market prices	(2,872)	(1,539)	(956)
Net proceeds from issuance of common stock	674	3,341	1,801
Net cash (used in) provided by financing activities	(2,598)	1,348	(721)
Effect of exchange rate changes on cash	1,428	(146)	(2,912)
Net increase (decrease) in cash and cash equivalents	52,103	101,319	(41,752)
Cash and cash equivalents at beginning of year	170,177	68,858	110,610
Cash and cash equivalents at end of year	$ 222,280	$ 170,177	$ 68,858

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Balance, shares at Dec. 31, 2014		31,342,000				429,000
Balance at Dec. 31, 2014	$ 387,229	$ 313	$ 247,232	$ 154,625	$ (9,551)	$ (5,390)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	23,448			23,448
Foreign currency translation adjustment	(6,228)				(6,228)
Adjustment to retirement benefit liability, net of tax	49				49
Adjustment to post-retirement healthcare benefit liability, net of taxes	171				171
Unrealized loss on cash flow hedges, net of tax	(143)				(143)
Stock compensation expense	3,891		3,891
Cumulative effect of accounting change (see Note 1)	537		537
Net settlement of restricted stock units, shares		297,000				55,000
Net settlement of restricted stock units	$ (956)	$ 3	(3)			$ (956)
Issuance of restricted stock, shares		21,000
Stock options exercised, shares	119,096	119,000
Stock options exercised	$ 1,802	$ 1	1,801
Balance, shares at Dec. 31, 2015		31,779,000				484,000
Balance at Dec. 31, 2015	410,086	$ 317	253,458	178,073	(15,416)	$ (6,346)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	33,675			33,675
Foreign currency translation adjustment	6,945				6,945
Adjustment to retirement benefit liability, net of tax	55				55
Adjustment to post-retirement healthcare benefit liability, net of taxes	695				695
Unrealized loss on cash flow hedges, net of tax	0
Stock compensation expense	6,373		6,373
Cumulative effect of accounting change (see Note 1)	1,249		1,249
Net settlement of restricted stock units, shares		131,000				46,000
Net settlement of restricted stock units	$ (1,539)	$ 1	(1)			$ (1,539)
Stock options exercised, shares	175,125	175,000
Stock options exercised	$ 3,341	$ 2	3,339
Balance, shares at Dec. 31, 2016		32,085,000				530,000
Balance at Dec. 31, 2016	460,880	$ 320	264,418	211,748	(7,721)	$ (7,885)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	62,560			62,560
Foreign currency translation adjustment	3,150				3,150
Adjustment to retirement benefit liability, net of tax	(9)				(9)
Adjustment to post-retirement healthcare benefit liability, net of taxes	214				214
Unrealized loss on cash flow hedges, net of tax	0
Stock compensation expense	7,122		7,122
Cumulative effect of accounting change (see Note 1)	0		(254)	254
Net settlement of restricted stock units, shares		203,000				85,000
Net settlement of restricted stock units	$ (2,872)	$ 3	(3)			$ (2,872)
Issuance of restricted stock, shares		2,000
Stock options exercised, shares	42,058	42,000
Stock options exercised	$ 674		674
Balance, shares at Dec. 31, 2017		32,332,000				615,000
Balance at Dec. 31, 2017	$ 531,719	$ 323	$ 271,957	$ 274,562	$ (4,366)	$ (10,757)

Consolidated Statements of Sha8

Consolidated Statements of Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Adjustment to retirement benefit liability, taxes	$ 25	$ 9	$ 30
Adjustment to post-retirement healthcare benefit liability, taxes	99	830	$ 45
Unrealized loss on cash flow hedge	$ 82	$ 82

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2017
Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Principles of consolidation The consolidated financial statements include the accounts of Gibraltar Industries, Inc. and subsidiaries (the "Company"). All intercompany accounts and transactions have been eliminated in consolidation. Use of estimates The preparation of the 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 amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Revenue recognition The majority of the Company's revenue is recognized when products are shipped or service is provided, the customer takes ownership and assumes the risk of loss, collection of the corresponding receivable is probable, persuasive evidence of an arrangement exists, and the sales price is fixed or determinable. Sales returns, allowances, and customer incentives, including rebates, are treated as reductions to sales and are provided for based on historical experience and current estimates. Revenues representing 28.0% and 25.8% of sales for the years ended December 31, 2017 and 2016 , respectively, were recognized under the percentage of completion accounting method as calculated by the cost-to-cost measurement method on contracts. The recognition of revenue under this method is utilized in the Renewable Energy and Conservation segment. Revenue from contracts using the percentage of completion method of accounting is recognized as work progresses toward completion as determined by the ratio of cumulative costs incurred to date to estimated total contract costs at completion, multiplied by the total contract revenue. Changes in estimates affecting sales, costs and profits are recognized in the period in which the change becomes known using the cumulative catch-up method of accounting, resulting in the cumulative effect of changes reflected in the period. Estimates are reviewed and updated quarterly for all contracts. A significant change in an estimate on one or more contracts could have a material effect on our results of operations. Contract costs include all direct costs related to contract performance. Selling and administrative expenses are charged to operations as incurred. Provisions for estimated losses on uncompleted contracts are recognized in the period in which such losses are determined. Because of inherent uncertainties in estimating costs, it is reasonably possible that changes in performance could result in revisions to cost and revenue, which are recognized in the period when the revisions are determined. Cash and cash equivalents All highly liquid investments with a maturity of three months or less are considered cash equivalents. Accounts receivable and allowance for doubtful accounts Accounts receivable are composed of trade and contract receivables recorded at either the invoiced amount or costs in excess of billings, are expected to be collected within one year, and do not bear interest. The allowance for doubtful accounts is the Company’s best estimate of the probable amount of uncollectible accounts in the Company’s existing accounts receivable. The Company determines the allowance based on a number of factors, including historical experience, credit worthiness of customers, and current market and economic conditions. The Company reviews the allowance for doubtful accounts on a regular basis. Account balances are charged against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. The following table summarizes activity recorded within the allowance for doubtful accounts balances for the years ended December 31 (in thousands): 2017 2016 2015 Beginning balance $ 5,272 $ 4,868 $ 4,280 Bad debt expense 1,253 2,519 1,404 Accounts written off and other adjustments (91 ) (2,115 ) (816 ) Ending balance $ 6,434 $ 5,272 $ 4,868 Concentrations of credit risk on accounts receivable are limited to those from significant customers that are believed to be financially sound. As of December 31, 2017 and 2016 , the Company's most significant customer is a home improvement retailer. The home improvement retailer purchases from the Residential Products segment. Accounts receivable as a percentage of consolidated accounts receivable from the home improvement retailer as of December 31, 2017 was 13.6% . Accounts receivable as a percentage of consolidated accounts receivable from the home improvement retailer as of December 31, 2016 , was 13.7% . Net sales as a percentage of consolidated net sales to the home improvement retailer were 12% , 11% and 11% for the years ended December 31, 2017 , 2016 and 2015 , respectively. Note 2 "Accounts Receivable" contains additional information on the Company's accounts receivable. Inventories Inventories are valued at the lower of cost, determined using the first-in, first-out method, or net realizable value. Shipping and handling costs are recognized as a component of cost of sales. Property, plant, and equipment Property, plant, and equipment are stated at cost and depreciated over their estimated useful lives using the straight-line method. Interest is capitalized in connection with construction of qualified assets. Expenditures that exceed an established dollar threshold and that extend the useful lives of assets are capitalized, while repair and maintenance costs are expensed as incurred. The estimated useful lives of land improvements, buildings, and building improvements are 15 to 40 years, while the estimated useful lives for machinery and equipment are 3 to 20 years. The table below sets forth the amount of interest capitalized and depreciation expense recognized during the years ended December 31 (in thousands): 2017 2016 2015 Capitalized interest $ 137 $ 138 $ 166 Depreciation expense $ 12,929 $ 14,477 $ 17,869 Acquisition related assets and liabilities Accounting for the acquisition of a business as a purchase transaction requires an allocation of the purchase price to the assets acquired and the liabilities assumed in the transaction at their respective estimated fair values. The most complex estimations of individual fair values are those involving long-lived assets, such as property, plant, and equipment and intangible assets. The Company uses all available information to make these fair value determinations and, for major business acquisitions, engages independent valuation specialists to assist in the fair value determination of the acquired long-lived assets. Goodwill and other intangible assets The Company tests goodwill for impairment at the reporting unit level on an annual basis at October 31, or more frequently if an event occurs, or circumstances change, that indicate that the fair value of a reporting unit could be below its carrying value. The reporting units are at the component level, or one level below the operating segment level. Goodwill is assigned to each reporting unit as of the date the reporting unit is acquired and based upon the expected synergies of the acquisition. The Company may elect to perform a qualitative assessment that considers economic, industry and company-specific factors for some or all of our selected reporting units. If, after completing the assessment, it is determined that it is more likely than not that the fair value of a reporting unit is less than its carrying value, the Company proceeds to a quantitative test. The Company may also elect to perform a quantitative test instead of a qualitative test for any or all of the Company's reporting units. The quantitative impairment test consists of comparing the fair value of a reporting unit, determined using two valuation techniques, to its carrying value. If the carrying value of the reporting unit exceeds its fair value, goodwill is considered impaired, and a loss measured by the excess of the carrying value of the reporting unit over the fair value of the reporting unit must be recorded. The Company also tests its indefinite-lived intangible assets for impairment on an annual basis as of October 31, or more frequently if an event occurs, or circumstances change, that indicate that the fair value of an indefinite-lived intangible asset could be below its carrying value. The impairment test consists of comparing the fair value of the indefinite-lived intangible asset, determined using discounted cash flows on a relief-from-royalty basis, with its carrying amount. An impairment loss would be recognized for the carrying amount in excess of its fair value. Acquired identifiable intangible assets are recorded at cost. Identifiable intangible assets with finite useful lives are amortized over their estimated useful lives. Impairment of long-lived assets Long-lived assets, including acquired identifiable intangible assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of those assets may not be recoverable. In specific situations, when the Company has selected individual assets to be sold or scrapped, the Company obtains market value data for those specific assets and measures and records the impairment loss based on such data. Otherwise, the Company uses undiscounted cash flows to determine whether impairment exists and measures any impairment loss by approximating fair value using acceptable valuation techniques, including discounted cash flow models and third-party appraisals. The Company recognized impairment charges related to intangible assets during the years ended December 31, 2017, 2016 and 2015. Several of these impairment charges related to exit activities during the three year period ended December 31, 2017 as described in Note 14 of the consolidated financial statements. Deferred charges Deferred charges associated with initial costs incurred to enter into new debt arrangements are included as a component of long-term debt and are amortized as a part of interest expense over the terms of the associated debt agreements. Advertising The Company expenses advertising costs as incurred. For the years ended December 31, 2017 , 2016 and 2015 , advertising costs were $4.9 million, $5.1 million, and $4.7 million, respectively. Research and Development The Company expenses research and development costs as incurred. For the years ended December 31, 2017 , 2016 and 2015 , research and development costs were $2.9 million, $2.2 million, and $0.9 million, respectively. Foreign currency transactions and translation The assets and liabilities of the Company’s foreign subsidiaries are translated into U.S. dollars at the rate of exchange in effect at the balance sheet date. Income and expense items are translated at the average exchange rates prevailing during the period. Income taxes The provision for income taxes is determined using the asset and liability approach. Under this approach, deferred income taxes represent the expected future tax consequences of temporary differences between the carrying amounts and tax basis of assets and liabilities. The Company records a valuation allowance to reduce deferred tax assets when uncertainty exists regarding their realization. On December 22, 2017, the President of the United States signed into law the Tax Cuts and Jobs Act (the “Tax Reform Act”). Further information on the impact of the Tax Reform Act is included in Note 15 of the consolidated financial statements. Equity-based compensation The Company measures the cost of equity-based compensation based on grant date fair value and recognizes the cost over the period in which the employee is required to provide service in exchange for the award reduced by forfeitures. Equity-based compensation consists of grants of stock options, deferred stock units, restricted stock, restricted stock units, and performance stock units. Equity-based compensation expense is included as a component of selling, general, and administrative expenses. The Company’s equity-based compensation plans are discussed in more detail in Note 12 of the consolidated financial statements. Sale-Leaseback Transactions During the first quarter of 2015, in order to capitalize on favorable real estate market conditions, the Company entered into a transaction to sell one of its real estate properties to an independent third party for $26.4 million. The Company leased back the entire property under a five year operating lease agreement. In accordance with the U.S. generally accepted accounting principles, the Company accounted for the transaction as a sale-leaseback. The net present value of the Company's future minimum lease payments of $5.8 million were less than the gain on sale of $13.1 million. As such, the portion of the gain equal to the fair value of the future minimum lease payments was deferred and is being amortized on a straight-line basis over the five year term of the lease. The gain exceeding the fair value of the minimum lease payments amounted to $7.4 million and was recognized during the quarter ended March 31, 2015 as a component of selling, general, and administrative expenses. The minimum lease payment for each of the five years is $1.4 million. These amounts have been included in the future minimum lease payments table in Note 17 of the consolidated financial statements. Recent accounting pronouncements Recent Accounting Pronouncements Adopted Standard Description Financial Statement Effect or Other Significant Matters ASU No. 2016-09 Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting The standard simplifies the accounting for share-based payment award transactions including: income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The provisions of this standard are effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted. The Company has adopted all amendments included in this standard under each required transition method. The Company concluded there were no material changes to prior periods, except for the following: the Company (a) reclassified its prior periods excess tax benefit for stock compensation of $1,249,000 in 2016 and $537,000 in 2015 on its consolidated statement of cash flows from a financing activity to an operating activity; and (b) recognized a cumulative-effect adjustment of $254,000 as an increase to retained earnings and decrease to additional paid-in capital on the Company's consolidated statement of shareholders' equity as of January 1, 2017 to reflect the change in value for a restricted stock unit liability award as of December 31, 2016, as if the award had been classified as an equity award since its respective grant date. Date of adoption: Q1 2017 ASU No. 2017-04 Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment The standard eliminates the "Step 2" analysis to determine the amount of impairment realized when a reporting unit's carrying amount exceeds its fair value in its "Step 1" analysis of accounting for impairment of goodwill. The impairment charge would be the amount determined in "Step 1." The provisions of this standard are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for annual and interim goodwill impairment testing dates after January 1, 2017. The Company has adopted this standard and it did not have any impact on the Company's consolidated financial statements. Date of adoption: Q1 2017 ASU No. 2017-07 Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost The standard requires an employer to recognize the service cost component of net periodic pension costs and net periodic postretirement benefit costs in the same line item(s) as other compensation costs from services rendered by pertinent employees during the period. Other components of net benefit cost are required to be presented separately from the service cost component and outside a subtotal of income from operations. The provisions of this standard are effective for annual reporting periods beginning after December 15, 2017, including interim periods within those annual periods. Early adoption is permitted as of the beginning of an annual period for which financial statements (interim or annual) have not been issued or made available for issuance. The Company has adopted this standard and has applied it retrospectively for the presentation of the service cost component, as well as, other components of net periodic pension cost and net periodic postretirement benefit cost in our statement of operations. The adoption decreased selling, general, and administrative expense by $524,000 and $647,000 for the twelve months ended December 31, 2016 and 2015, respectively, and comparably increased other expense by the same amounts, respectively. This guidance did not have any impact on our balance sheet or our statement of cash flows. Date of adoption: Q1 2017 Recent Accounting Pronouncements Not Yet Adopted Standard Description Financial Statement Effect or Other Significant Matters ASU No. 2014-09 Revenue from Contracts with Customers (Topic 606) And All Related ASUs The standard requires an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The standard also requires additional disclosures about the nature, amount, timing, and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and assets recognized from costs incurred to obtain or fulfill a contract. The provisions of the standard, as well as all subsequently issued clarifications to the standard, are effective for fiscal years beginning after December 15, 2017 and interim periods within those fiscal years. The standard can be adopted using either a full retrospective or modified retrospective approach. The Company currently believes the most significant impact of this standard upon adoption relates to the revenue recognition for certain custom fabricated products for which there is no alternative use and where the Company has written enforceable rights to payment for performance to date should the customer terminate the contract. These products are within the Company's Industrial and Infrastructure Products segment. Under this standard, the Company expects to recognize revenue on an over time basis on these custom fabricated products in the Industrial and Infrastructure Products segment which is a change from our current revenue recognition policy of point-in-time basis. The Company expects revenue recognition related to the remaining Industrial and Infrastructure Products segment, Residential Products segment and Renewable Energy and Conservation segment to remain substantially unchanged upon adoption of this standard. The Company has identified and implemented appropriate changes to the Company's business processes, systems and internal controls to support recognition and disclosure under this standard. The Company will use the modified retrospective transition method approach and apply it to open contracts as of January 1, 2018. Under this method, incremental disclosures will be provided to present each financial statement line item for 2018 under the prior standard. The Company estimates the cumulative effect of adoption to be approximately $750,000 increase to opening retained earnings, as of January 1, 2018. Planned date of adoption: Q1 2018 ASU No. 2016-02 Leases (Topic 842) The standard requires lessees to recognize most leases as assets and liabilities on the balance sheet, but record expenses on the statement of operations in a manner similar to current accounting. For lessors, the guidance modifies the classification criteria and accounting for sales-type and direct financing leases. The standard also requires additional disclosures about leasing arrangements and requires a modified retrospective transition approach for existing leases, whereby the standard will be applied to the earliest year presented. The provisions of the standard are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the impact of this standard on the Company's consolidated financial statements and related disclosures, including the impact on the Company's current lease portfolio from both a lessor and lessee perspective. The adoption of this standard will primarily result in an increase in the assets and liabilities on the Company's consolidated balance sheet and related disclosures. Planned date of adoption: Q1 2019 Standard Description Financial Statement Effect or Other Significant Matters ASU No. 2016-15 Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments The standard provides guidance on eight specific cash flow issues to reduce diversity in reporting. The provisions of this standard are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. The Company is evaluating the requirements of this standard and anticipates its impact on the Company's consolidated financial statements to be immaterial. Planned date of adoption: Q1 2018 ASU No. 2016-16 Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory The standard allows an entity to recognize income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The provisions of this standard are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within those annual reporting periods. Early adoption is permitted as of the beginning of an annual reporting period for which financial statements (interim or annual) have not been issued or made available for issuance. The Company is evaluating the requirements of this standard and anticipates its impact on the Company's consolidated financial statements to be immaterial. Planned date of adoption: Q1 2018 ASU No. 2018-02 Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income The standard allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. The provisions of this standard are effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption of the standard is permitted, including adoption in any interim period. The Company is evaluating the requirements of this standard and anticipates its impact on the Company's consolidation financial statements to be immaterial. The Company plans to apply the amendments in the period of adoption with an adjustment in the consolidated statement of shareholders' equity as of the beginning of the reporting period and any subsequent period, if changes to provisional amounts result in additional amounts stranded in accumulated other comprehensive income. Planned date of adoption: Q1 2018 We consider the applicability and impact of all ASUs. ASUs not listed above were assessed and determined to be either not applicable, or had or are expected to have minimal impact on our financial statements and related disclosures.

Accounts Receivable

Accounts Receivable	12 Months Ended
Accounts Receivable	Dec. 31, 2017
Receivables [Abstract]
Accounts Receivable	ACCOUNTS RECEIVABLE Accounts receivable at December 31 consisted of the following (in thousands): 2017 2016 Trade accounts receivable $ 78,858 $ 81,193 Contract receivables: Amounts billed 61,351 41,569 Costs in excess of billings 11,610 6,582 Total contract receivables 72,961 48,151 Total accounts receivables 151,819 129,344 Less allowance for doubtful accounts (6,434 ) (5,272 ) Accounts receivable $ 145,385 $ 124,072 Contract receivables are primarily associated with developers, contractors and customers in connection with the Renewable Energy and Conservation segment. Costs in excess of billings principally represent revenues recognized on contracts that were not billable as of the balance sheet date. These amounts will be billed in accordance with contract terms, generally as certain milestones are reached or upon shipment. All of the costs in excess of billings are expected to be collected within one year. In situations where billings exceed revenues recognized, the excess is included in billings in excess of cost in the consolidated balance sheet.

Inventories

Inventories	12 Months Ended
Inventories	Dec. 31, 2017
Inventory Disclosure [Abstract]
Inventories	INVENTORIES Inventories at December 31 consisted of the following (in thousands): 2017 2016 Raw material $ 42,661 $ 41,758 Work-in-process 10,598 12,268 Finished goods 33,113 35,586 Total inventories $ 86,372 $ 89,612 The following table summarizes activity recorded within the reserve for excess, obsolete and slow moving inventory for the years ended December 31 (in thousands): 2017 2016 2015 Beginning balance $ 3,801 $ 7,428 $ 5,575 Excess, obsolete and slow moving inventory expense 1,276 (239 ) 1,539 Scrapped inventory and other adjustments (1,382 ) (3,388 ) 314 Ending balance $ 3,695 $ 3,801 $ 7,428

Property, Plant, and Equipment

Property, Plant, and Equipment	12 Months Ended
Property, Plant, and Equipment	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	PROPERTY, PLANT, AND EQUIPMENT Components of property, plant, and equipment at December 31 consisted of the following (in thousands): 2017 2016 Land and land improvements $ 6,301 $ 7,102 Building and improvements 46,562 50,283 Machinery and equipment 195,301 212,774 Construction in progress 8,522 2,202 Property, plant, and equipment, gross 256,686 272,361 Less: accumulated depreciation (159,588 ) (164,057 ) Property, plant, and equipment, net $ 97,098 $ 108,304

Acquisitions

Acquisitions	12 Months Ended
Acquisitions	Dec. 31, 2017
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS 2017 Acquisition On February 22, 2017, the Company acquired all of the outstanding stock of Package Concierge. Package Concierge is a leading provider of multifamily electronic package delivery locker systems in the United States. The acquisition of Package Concierge is expected to enable the Company to expand its position in the fast-growing package delivery solutions market. The results of Package Concierge have been included in the Company's consolidated financial results since the date of acquisition (within the Company's Residential Products segment). The final aggregate purchase consideration for the acquisition of Package Concierge was $18.9 million, which includes a working capital adjustment and certain other adjustments provided for in the stock purchase agreement. The purchase price for the acquisition was allocated to the assets acquired and liabilities assumed based upon their respective fair values. The excess consideration was recorded as goodwill and approximated $16.8 million, which is not deductible for tax purposes. Goodwill represents future economic benefits arising from other assets acquired that could not be individually identified including workforce additions, growth opportunities, and increased presence in the building products markets. The allocation of the purchase consideration to the fair value of the assets acquired and liabilities assumed is as follows as of the date of the acquisition (in thousands): Cash $ 590 Working capital (1,998 ) Property, plant, and equipment 55 Acquired intangible assets 3,600 Other assets 8 Deferred income taxes (128 ) Goodwill 16,790 Fair value of purchase consideration $ 18,917 The intangible assets acquired in this acquisition consisted of the following (in thousands): Fair Value Estimated Trademarks $ 600 Indefinite Technology 1,300 10 years Customer relationships 1,700 7 years Total $ 3,600 2016 Acquisition On October 11, 2016, the Company acquired all of the outstanding stock of Nexus Corporation ("Nexus"). Nexus is a leading provider of commercial-scale greenhouses to customers in the United States. The acquisition of Nexus is expected to enable the Company to strengthen its position in the commercial greenhouse market in the United States. The results of Nexus have been included in the Company's consolidated financial results since the date of acquisition (within the Company's Renewable Energy and Conservation segment). The final aggregate purchase consideration for the acquisition of Nexus was $23.8 million, which includes a working capital adjustment and certain other adjustments provided for in the stock purchase agreement. At December 31, 2016, $1.0 million of the estimated purchase price was accrued. Upon settlement of the final purchase adjustments, $0.2 million was paid in cash by the Company during the first quarter of 2017, with the difference of $0.8 million recorded as a reduction to goodwill in 2017 upon finalization of the purchase price allocation. The purchase price for the acquisition was allocated to the assets acquired and liabilities assumed based upon their respective fair values. The excess consideration was recorded as goodwill and approximated $11.5 million, of which all is deductible for tax purposes. The allocation of the purchase consideration to the fair value of the assets acquired and liabilities assumed is as follows as of the date of the acquisition (in thousands): Cash $ 2,495 Working capital (1,109 ) Property, plant, and equipment 4,702 Acquired intangible assets 6,200 Other assets 23 Goodwill 11,451 Fair value of purchase consideration $ 23,762 The intangible assets acquired in this acquisition consisted of the following (in thousands): Fair Value Estimated Trademarks $ 3,200 Indefinite Technology 1,300 15 years Customer relationships 800 11 years Backlog 900 0.25 years Total $ 6,200 2015 Acquisition On June 9, 2015, the Company acquired all of the outstanding stock of Rough Brothers Manufacturing, Inc., RBI Solar, Inc., and affiliates, collectively known as "RBI." RBI has established itself during the past decade among North America’s fastest-growing providers of racking and mounting systems for solar energy installations and is among the largest commercial greenhouse manufacturers in North America. RBI is a full service provider that engineers, manufactures and installs racking systems for solar power developers, contractors and companies. In addition, RBI designs and manufactures greenhouses for commercial, institutional and retail customers. The acquisition of RBI enables the Company to leverage its expertise in structural metals manufacturing, materials sourcing and logistics to help meet the fast-growing demand for solar racking solutions. The results of RBI have been included in the Company’s consolidated financial results since the date of acquisition (within the Company's Renewable Energy and Conservation segment). The final aggregate purchase consideration for the acquisition of RBI was $147.6 million, which includes payments for working capital and certain other adjustments provided for in the stock purchase agreement. The purchase price for the acquisition was allocated to the assets acquired and liabilities assumed based upon their respective fair values. The excess consideration of $57.2 million, was recorded as goodwill of which $38.0 million is deductible for tax purposes. The allocation of the purchase consideration to the fair value of the assets acquired and liabilities assumed is as follows as of the date of the acquisition (in thousands): Cash $ 4,651 Working capital 21,436 Property, plant, and equipment 12,797 Acquired intangible assets 56,392 Other assets 3,049 Deferred income taxes (4,892 ) Other liabilities (3,028 ) Goodwill 57,180 Fair value of purchase consideration $ 147,585 The Company recorded an indemnification asset and liability of $3.0 million on the opening balance sheet related to the seller’s obligation to fully indemnify the Company for the outcome of potential contingent liabilities related to the uncertainty of income tax positions in foreign jurisdictions. The liability and related indemnification asset may or may not be realized, and any unrealized liability is scheduled to expire in 2018. The intangible assets acquired in this acquisition consisted of the following (in thousands): Fair Value Estimated Trademarks $ 13,550 Indefinite Technology 3,550 7-15 years Customer relationships 32,892 11-17 years Non-compete agreements 1,300 5 years Backlog 5,100 0.5 years Total $ 56,392 The following unaudited pro forma financial information presents the combined results of continuing operations as if the acquisition of RBI had occurred as of January 1, 2014. The pro forma information includes certain adjustments, including depreciation and amortization expense, interest expense and certain other adjustments, together with related income tax effects. The pro forma amounts may not be indicative of the results that actually would have been achieved had the acquisitions occurred as of January 1, 2014 and are not necessarily indicative of future results of the combined companies (in thousands, except per share data): Twelve Months Ended December 31, 2015 2014 Net sales $ 1,128,915 $ 1,026,014 Net income (loss) $ 33,587 $ (46,714 ) Net income (loss) per share - Basic $ 1.08 $ (1.50 ) Net income (loss) per share - Diluted $ 1.06 $ (1.50 ) The acquisitions of Package Concierge and Nexus were funded from available cash on hand. The 2015 acquisition of RBI was financed through a combination of cash on hand and borrowings under the Company's revolving credit facility. The Company incurred certain acquisition-related costs composed of legal and consulting fees, and these costs were recognized as a component of selling, general, and administrative expenses in the consolidated statement of operations. The Company also recognized costs related to the sale of inventory at fair value as a result of allocating the purchase price of recent acquisitions. All acquisition related costs consisted of the following for the years ended December 31 (in thousands): 2017 2016 2015 Selling, general and administrative costs $ 146 $ 228 $ 732 Cost of sales — 81 230 Total acquisition related costs $ 146 $ 309 $ 962

Goodwill and Related Intangible

Goodwill and Related Intangible Assets	12 Months Ended
Goodwill and Related Intangible Assets	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Related Intangible Assets	GOODWILL AND RELATED INTANGIBLE ASSETS Goodwill The changes in the carrying amount of goodwill for the years ended December 31 were as follows (in thousands): Residential Products Industrial and Infrastructure Products Renewable Energy and Conservation Total Balance at December 31, 2015 $ 181,285 $ 53,704 $ 57,401 $ 292,390 Acquired goodwill — — 12,283 12,283 Impairment — — (929 ) (929 ) Foreign currency translation — 180 108 288 Balance at December 31, 2016 $ 181,285 $ 53,884 $ 68,863 $ 304,032 Acquired goodwill 16,790 — — 16,790 Adjustments to prior year acquisitions — — (832 ) (832 ) Foreign currency translation — 396 688 1,084 Balance at December 31, 2017 $ 198,075 $ 54,280 $ 68,719 $ 321,074 Goodwill is recognized net of accumulated impairment losses of $235.4 million as of December 31, 2017 and 2016 , respectively. No goodwill impairment charges were recognized by the Company during 2017. Annual Impairment Testing The Company performed its annual goodwill impairment test as of October 31, 2017 , 2016 , and 2015 . The Company did not recognize any impairment charges during 2017, 2016, and 2015 as a result of the annual goodwill impairment test. However, subsequent to the annual goodwill impairment test as of October 31, 2016, the Company discontinued its European residential solar racking business which resulted in an impairment charge against goodwill of $0.9 million which was recorded for the year ended December 31, 2016. During the October 31, 2017 impairment test, the Company conducted a quantitative analysis for all eleven of the Company’s reporting units. The quantitative impairment test consists of comparing the fair value of a reporting unit with its carrying value including goodwill. The fair value of each reporting unit evaluated under the quantitative test was determined using two valuation techniques: an income approach and a market approach. Each valuation approach relies on significant assumptions including a weighted average cost of capital ("WACC") based upon the capital structure of market participants in the Company’s peer groups, projected revenue growth, forecasted cash flows, and earnings multiples based on the market value of the Company and market participants within its peer groups. As a result of our annual testing for 2017 and 2016, none of the reporting units with goodwill as of our testing date had carrying values in excess of their fair values. Interim Impairment Testing We test goodwill and indefinite-lived intangible assets for impairment on an annual basis as of October 31 and at interim dates when indicators of impairment are present. In 2017, 2016 and 2015, no indicators of impairment were identified as of interim dates; therefore, no interim tests were performed. Acquired Intangible Assets Acquired intangible assets consist of the following (in thousands): December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Estimated Useful Life Indefinite-lived intangible assets: Trademarks $ 45,107 $ — $ 44,720 $ — Indefinite Finite-lived intangible assets: Trademarks 5,876 3,062 5,808 2,427 5 to 15 Years Unpatented technology 28,107 12,033 26,720 10,041 5 to 20 Years Customer relationships 80,707 39,652 78,569 33,585 5 to 17 Years Non-compete agreements 1,649 931 1,649 623 4 to 10 Years Backlog — — 900 900 .5 to 2 Years 116,339 55,678 113,646 47,576 Total acquired intangible assets $ 161,446 $ 55,678 $ 158,366 $ 47,576 The Company recognized impairment charges related to indefinite-lived trademark intangible assets for the years ended December 31, 2017 , 2016 and 2015. The Company also recognized impairment charges related to finite-lived intangible assets for the year ended December 31, 2016. The following table summarizes the impairment charges for the years ended December 31 (in thousands): 2017 2016 2015 Indefinite-lived intangibles (1) Definite-lived intangibles Indefinite-lived intangibles (2) Definite-lived intangibles (3) Indefinite-lived intangibles (4) Definite-lived intangibles Residential Products $ — $ — $ — $ — $ 440 $ — Industrial and Infrastructure Products — — 7,980 — 4,423 — Renewable Energy and Conservation 247 — 1,068 198 — — Impairment charges $ 247 $ — $ 9,048 $ 198 $ 4,863 $ — (1) Renewable Energy and Conservation impairment charges due to the discontinuation of its domestic greenhouse business in China. (2) Industrial and Infrastructure Products impairment charges due to discontinuation of U.S. bar grating product line and annual testing. Renewable Energy and Conservation impairment due to discontinuation of European residential solar racking business and annual testing. (3) Renewable Energy and Conservation impairment due to discontinuation of European residential solar racking business. (4) 2015 impairment charges recognized as a result of the Company’s annual impairment test of indefinite-lived intangibles. The Company recognized amortization expense related to the definite-lived intangible assets. The following table summarizes amortization expense for the years ended December 31 (in thousands): 2017 2016 2015 Amortization expense $ 8,761 $ 9,637 $ 12,679 Amortization expense related to acquired intangible assets for the next five years ended December 31 is estimated as follows (in thousands): 2018 2019 2020 2021 2022 Amortization expense $ 8,289 $ 7,618 $ 7,106 $ 6,504 $ 6,093

Accrued Expenses

Accrued Expenses	12 Months Ended
Accrued Expenses	Dec. 31, 2017
Accrued Liabilities, Current [Abstract]
Accrued Expenses	ACCRUED EXPENSES Accrued expenses at December 31 consist of the following (in thousands): 2017 2016 Compensation $ 34,752 $ 27,669 Interest and taxes 8,002 13,102 Customer rebates 10,517 10,303 Insurance 7,261 7,584 Other 14,935 11,734 Total accrued expenses $ 75,467 $ 70,392 Accrued expenses for insurance are primarily for general liability, workers’ compensation and employee healthcare policies for which the Company is self-insured up to certain per-occurrence and aggregate limits. The amounts accrued represent the Company's best estimates of the probable amount of claims to be paid. Differences between the amounts accrued and the amount that may be reasonably possible of payment are not material.

Debt

Debt	12 Months Ended
Debt	Dec. 31, 2017
Long-term Debt, Unclassified [Abstract]
Debt	DEBT Long-term debt at December 31 consists of the following (in thousands): 2017 2016 Senior Subordinated 6.25% Notes $ 210,000 $ 210,000 Other debt 2,400 2,800 Less unamortized debt issuance costs (2,379 ) (3,163 ) Total debt 210,021 209,637 Less current maturities 400 400 Total long-term debt $ 209,621 $ 209,237 The Company's Fifth Amended and Restated Credit Agreement dated December 9, 2015 (the "Senior Credit Agreement") was amended to convert our revolving credit facility into a secured cash flow revolver, and terminates on December 9, 2020. The Senior Credit Agreement provides for a revolving credit facility and letters of credit in an aggregate amount of $300 million . The Company has the option to request additional financing from the banks to either increase the revolving credit facility to $500 million or in the form of a term loan of up to $200 million . The Senior Credit Agreement contains three financial covenants. As of December 31, 2017 , the Company is in compliance with all three covenants. Borrowings under the Senior Credit Agreement are secured by the trade receivables, inventory, personal property, equipment, and certain real property of the Company’s significant domestic subsidiaries. Interest rates on the revolving credit facility are based on the LIBOR plus an additional margin that ranges from 1.25% to 2.25% for LIBOR loans based on the Total Leverage Ratio. In addition, the revolving credit facility is subject to an undrawn commitment fee ranging between 0.20% and 0.30% based on the Total Leverage Ratio and the daily average undrawn balance. Standby letters of credit of $11.2 million have been issued under the Senior Credit Agreement to third parties on behalf of the Company as of December 31, 2017. These letters of credit reduce the amount otherwise available under the revolving credit facility. The Company had $288.8 million and $287.2 million of availability under the revolving credit facility at December 31, 2017 and 2016, respectively. On January 31, 2013, the Company issued $210 million of 6.25% Senior Subordinated Notes (" 6.25% Notes") due February 1, 2021 . The provisions of the 6.25% Notes include, without limitation, restrictions on indebtedness, liens, and distributions from restricted subsidiaries, asset sales, affiliate transactions, dividends, and other restricted payments. Dividend payments are subject to annual limits and interest is paid semiannually on February 1 and August 1 of each year. The aggregate maturities of long-term debt for the next five years and thereafter are as follows (in thousands): 2018 2019 2020 2021 2022 Thereafter Long-term debt payments $ 400 $ 400 $ 400 $ 210,400 $ 400 $ 400 Total cash paid for interest in the years ended December 31 was (in thousands): 2017 2016 2015 Cash paid for interest $ 13,385 $ 13,906 $ 15,374

Employee Retirement Plans

Employee Retirement Plans	12 Months Ended
Employee Retirement Plans	Dec. 31, 2017
Defined Benefit Plan [Abstract]
Employee Retirement Plans	EMPLOYEE RETIREMENT PLANS Pension The Company has an unfunded supplemental pension plan which provides defined pension benefits to certain former salaried employees upon retirement. Benefits under the plan are based on the salaries of individual plan participants in the year they were admitted into the plan. The plan has been frozen, no additional participants will be added to the plan in the future and there are no active employees in the plan. The following table presents the changes in the plan’s projected benefit obligation, fair value of plan assets, and funded status for the years ended December 31 (in thousands): 2017 2016 Projected benefit obligation at January 1 $ 1,377 $ 1,685 Interest cost 46 59 Actuarial losses (gains) 7 5 Benefits paid (360 ) (372 ) Projected benefit obligation at December 31 1,070 1,377 Fair value of plan assets — — Under funded status (1,070 ) (1,377 ) Unamortized prior service cost 2 4 Unrecognized actuarial gain (173 ) (200 ) Net amount recognized $ (1,241 ) $ (1,573 ) Amounts recognized in the consolidated financial statements consisted of (in thousands): 2017 2016 Accrued pension liability: Current portion $ 327 $ 360 Long term portion 743 1,016 Pre-tax accumulated other comprehensive income – retirement benefit liability adjustment 171 197 Net amount recognized $ 1,241 $ 1,573 The plan’s accumulated benefit obligation equaled the projected benefit obligation as of December 31, 2017 and 2016 . The measurement date used to determine pension benefit measures was December 31. Components of net periodic pension cost for the years ended December 31 were as follows (in thousands): 2017 2016 2015 Interest cost $ 46 $ 59 $ 66 Amortization of unrecognized prior service cost 2 6 14 Gain amortization (19 ) (13 ) — Net periodic pension cost $ 29 $ 52 $ 80 Assumptions used to calculate the benefit obligation: Discount rate 3.55 % 3.81 % 3.94 % Expected benefit payments from the plan for the years ended December 31 are as follows (in thousands): 2018 2019 2020 2021 2022 2023 - 2027 Expected benefit payments $ 327 $ 228 $ 137 $ 100 $ 100 $ 292 401(k) Employees of all U.S. subsidiaries are eligible to participate in the Company’s 401(k) Plan. Multiemployer Pension Plans In addition, the Company contributes to a number of multiemployer defined benefit pension plans under the terms of collective-bargaining agreements that cover union-represented employees. The risks of participating in these multiemployer plans are different from single-employer plans in the following aspects: a) Assets contributed to the multiemployer plan by one employer may be used to provide benefits to employees of other participating employers. b) If a participating employer stops contributing to the plan, the unfunded obligations of the plan may be borne by the remaining participating employers. c) If the Company chooses to stop participating in some of the multiemployer plans, the Company may be required to pay those plans an amount based on the underfunded status of the plan, referred to as a withdrawal liability. At December 31, 2017 , the Company employed 2,022 people, of which approximately 11% were represented by unions through various collective bargaining agreements (CBAs). Three of the Company's six CBAs expired and were successfully renegotiated in 2016. None of our CBA's expire until April 30, 2018 . The Company’s participation in these plans for the year ended December 31, 2017 is outlined in the table below. The “EIN/ Pension Plan Number” column provides the Employee Identification Number (EIN) and three-digit plan number, if applicable. Unless otherwise noted, the most recent Pension Protection Act (PPA) zone status available in 2017 and 2016 is for the plan’s year ended December 31, 2016 and 2015 , respectively. The zone status is based on information that the Company received from the plans and is certified by the plans’ actuaries. Among other factors, plans in the red zone are generally less than 65% funded, plans in the yellow zone are less than 80% funded, and plans in the green zone are at least 80% funded. EIN/ Pension PPA Zone Status Surcharge Pension Fund Plan Number 2016 2015 Imposed National Integrated Group Pension Plan 22-6190618-001 Red Red Yes Sheet Metal Workers’ National Pension Plan 52-6112463-001 Yellow Yellow Yes Sheet Metal Workers’ Pension Plan of Northern California 51-6115939-001 Red Red Yes All of the funds have rehabilitation plans in place. Each plan with a rehabilitation plan requires minimum contributions from the Company. Given the status of these plans, it is reasonably possible that future contributions to the plans will increase although the Company cannot reasonably estimate a possible range of increased contributions as of December 31, 2017 . The Company did not contribute more than 5% of any fund’s total contributions in any of the three years in the period ended December 31, 2017 . The table below sets forth the contributions made by the Company to each multiemployer plan for the years ended December 31 (in thousands): Pension Fund 2017 2016 2015 National Integrated Group Pension Plan $ 220 $ 218 $ 246 Sheet Metal Workers’ National Pension Plan 42 50 56 Sheet Metal Workers’ Pension Plan of Northern California 30 28 31 $ 292 $ 296 $ 333 At the date the financial statements were issued, Forms 5500 were not available for the plan year ended December 31, 2017 . Total Retirement Plan Expense Total expense for all retirement plans for the years ended December 31 was (in thousands): 2017 2016 2015 $ 3,044 $ 2,887 $ 2,934

Accumulated Other Comprehensive

Accumulated Other Comprehensive (Loss) Income	12 Months Ended
Accumulated Other Comprehensive (Loss) Income	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive (Loss) Income	ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME The cumulative balance of each component of accumulated other comprehensive (loss) income is as follows (in thousands): Foreign Currency Translation Adjustment Minimum Pension Liability Adjustment Unamortized Post-Retirement Health Care Costs Total Pre-Tax Amount Tax (Benefit) Expense Accumulated Other Comprehensive (Loss) Income Balance at December 31, 2015 $ (12,793 ) $ 118 $ (4,251 ) $ (16,926 ) $ (1,510 ) $ (15,416 ) Minimum pension and post retirement health care plan adjustments — 79 1,101 1,180 430 750 Foreign currency translation adjustment 6,945 — — 6,945 — 6,945 Balance at December 31, 2016 $ (5,848 ) $ 197 $ (3,150 ) $ (8,801 ) $ (1,080 ) $ (7,721 ) Minimum pension and post retirement health care plan adjustments — (26 ) 341 315 110 205 Foreign currency translation adjustment 3,150 — — 3,150 — 3,150 Balance at December 31, 2017 $ (2,698 ) $ 171 $ (2,809 ) $ (5,336 ) $ (970 ) $ (4,366 ) The realized adjustments relating to the Company’s minimum pension liability and post retirement health care costs were reclassified from accumulated other comprehensive loss and included in other expense in the consolidated statements of operations. The realized adjustments relating to the Company’s foreign currency translation adjustment were reclassified from accumulated other comprehensive loss and included in other expense in the consolidated statements of operations. The 2016 reclassification above includes $6.9 million of foreign currency loss on the divestiture of European industrial manufacturing business in April 2016.

Equity-Based Compensation

Equity-Based Compensation	12 Months Ended
Equity-Based Compensation	Dec. 31, 2017
Share-based Compensation [Abstract]
Equity-Based Compensation	EQUITY-BASED COMPENSATION The Company awards equity-based compensation to employees and directors, which is recognized in the statements of operations based on the grant-date fair value of the award. The Company uses the straight-line method for recording compensation expense over a vesting period generally up to four years with either graded or cliff vesting. Stock compensation expense recognized during the period is based on the value of the portion of equity-based awards that is ultimately expected to vest during the period reduced by the unvested expense on awards forfeited during the period. The shareholders of the Company authorized the Gibraltar Industries, Inc. 2015 Equity Incentive Plan (the "Plan") that allows the Company to grant equity-based incentive compensation awards to eligible participants, and the Gibraltar Industries, Inc. 2016 Stock Plan for Non-Employee Directors ("Non-Employee Directors Plan") that allows the Company to grant awards of shares of the Company's common stock to non-employee Directors of the Company. The Company's the 2005 Equity Incentive Plan (the "Prior Plan") was amended in 2015 to terminate issuance of further awards from the Prior Plan. At December 31, 2017 , 354,000 shares were available for issuance under the Plan as incentive stock options or other stock awards and 73,000 shares were available for issuance under the Non-Employee Directors Plan as awards of shares of the Company's common stock. The Company recognized the following compensation expense in connection with awards that vested under the Plan, the Prior Plan, and the Non-Employee Directors Plan along with the related tax benefits recognized during the years ended December 31 (in thousands): 2017 2016 2015 Expense recognized under the Prior Plan $ 1,059 $ 1,937 $ 1,953 Expense recognized under the Plan 5,643 3,993 1,938 Expense recognized under the Non-Employee Directors Plan 420 443 — Total stock compensation expense $ 7,122 $ 6,373 $ 3,891 Tax benefits recognized related to stock compensation expense $ 2,133 $ 2,485 $ 1,518 Equity Based Awards - Settled in Stock The following table provides the number of stock unit awards granted and restricted shares issued during the years ended December 31, along with the weighted-average grant-date fair value of each award: 2017 2016 2015 Awards Number of Awards Weighted Average Grant Date Fair Value Number of Awards Weighted Average Grant Date Fair Value Number of Awards Weighted Average Grant Date Fair Value Options 25,000 $ 12.85 — $ — 37,500 $ 7.67 Deferred stock units 10,170 $ 34.42 11,945 $ 29.30 — $ — Restricted shares 2,034 $ 34.42 3,185 $ 29.30 21,318 $ 17.48 Restricted stock units 133,548 $ 36.56 141,982 $ 25.44 212,419 $ 17.78 Performance stock units 108,748 $ 42.72 — $ — 396,714 $ 19.78 Stock Options The fair value of stock options granted during the years ended December 31, 2017 and December 31, 2015 were estimated on the date of grant using the Black-Scholes option pricing model. No options were granted in 2016. Expected stock volatility was based on volatility of the Company’s stock price using a historical period commensurate with the expected life of the options. The following table provides the weighted average assumptions used to value stock options issued during the year ended December 31: Year of Grant Fair Value Expected Life (in years) Expected Stock Volatility Risk-free Interest Rate Expected Dividend Yield 2017 $ 12.85 4.00 35.7 % 1.7 % — % 2015 $ 7.67 4.00 35.7 % 1.5 % — % The following table summarizes the ranges of outstanding and exercisable options at December 31, 2017 : Range of Exercise Prices Options Outstanding Weighted Average Remaining Contractual Life (in years) Weighted Average Exercise Price Options Exercisable Weighted Average Exercise Price $8.90 – $9.32 28,750 2.70 $ 8.90 28,750 $ 8.90 $9.33 – $11.73 92,441 3.70 $ 9.74 92,441 $ 9.74 $11.74 – $17.94 39,475 1.70 $ 13.72 39,475 $ 13.72 $17.95 – $23.80 37,000 0.69 $ 22.16 37,000 $ 22.16 $23.81 – $43.05 50,000 8.57 $ 33.90 — $ — 247,666 197,666 The following table summarizes information about stock option transactions: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (in years) Aggregate Intrinsic Value Balance at January 1, 2015 569,319 $ 15.88 Granted 37,500 25.44 Exercised (119,096 ) 15.13 Expired / Forfeited (29,374 ) 20.28 Balance at December 31, 2015 458,349 $ 16.57 Exercised (175,125 ) 19.08 Forfeited (6,000 ) 18.22 Balance at December 31, 2016 277,224 $ 14.95 Granted 25,000 42.35 Exercised (42,058 ) 16.02 Forfeited (12,500 ) 25.44 Balance at December 31, 2017 247,666 $ 17.01 5.27 $ 4,194,000 The aggregate intrinsic value in the preceding table represents the total pre-tax intrinsic value, based on the $33.00 per share market price of the Company’s common stock as of December 31, 2017 , which would have been received by the option holders had all option holders with an exercise price below the per share market price on December 31, 2017 , exercised their options as of that date. Stock units and Restricted Shares The following table summarizes information about non-vested restricted stock units, performance stock units (that will convert to shares upon vesting) and restricted shares: Restricted Weighted Restricted Weighted Performance Stock Units (2) (3) Weighted Average Grant Date Fair Value Deferred Stock Units (1) Weighted Average Grant Date Fair Value Balance at December 31, 2016 536,164 $ 17.79 7,361 $ 17.07 396,714 $ 19.78 11,945 $ 29.30 Granted 133,548 36.56 2,034 34.42 108,748 42.72 10,170 34.42 Vested (202,788 ) 15.71 (5,137 ) 23.75 — — — — Forfeited (25,108 ) 25.88 — — (25,000 ) 25.44 — — Balance at December 31, 2017 441,816 $ 23.96 4,258 $ 17.30 480,462 $ 24.68 22,115 $ 31.65 (1) Vested and issued upon retirement. (2) Amount granted in 2017 represents 78,482 units awarded in February 2017 and 5,266 units awarded in April 2017 that will convert to shares based upon the Company's actual return on invested capital ("ROIC") compared to targeted ROIC thresholds. The remaining 25,000 units were awarded in February 2017 and April 2017. The number of these shares to be issued to the recipients will be determined based upon the ranking of the Company's total shareholder return ("TSR") over a three (3) year performance period ended December 31, 2020 compared to the TSR of companies in the S&P Small Cap Industrial Sector over the same three year period. (3) The December 31, 2016 balance includes 321,714 units awarded in June 2015 that convert to shares based on RBI's gross profit performance relative to their targeted gross profit for 2016 and 2017. RBI achieved its targeted gross profit performance, and the Company will issue 321,714 shares to the recipients in 2018. The remaining 75,000 units were awarded in December 2015; of which 25,000 were forfeited in 2017 and 50,000 remain outstanding as of December 31, 2017. The number of these shares to be issued to the recipient will be determined based upon the ranking of the Company's total shareholder return over a three (3) year performance period ended December 31, 2018 compared to the total shareholder return of companies in the S&P Small Cap Industrial Sector over such period. The fair value of the restricted shares, restricted stock units, and deferred stock units, as well as, the performance stock units ("PSUs") payable based on the Company's ROIC or targeted gross profit performance issued during the three years ended December 31, 2017 was based on the Company stock price at grant date of the award. The fair values of the PSU's payable based on TSR ranking issued during the three years ended December 31, 2017 were determined using a Monte Carlo simulation. The following table sets forth the aggregate intrinsic value of options exercised and aggregate fair value of restricted stock units and restricted shares that vested during the years ended December 31 (in thousands): 2017 2016 2015 Aggregate intrinsic value of options exercised $ 628 $ 2,439 $ 1,089 Aggregate fair value of vested restricted stock units $ 6,756 $ 4,368 $ 6,578 Aggregate fair value of vested restricted shares $ 70 $ 247 $ 111 Aggregate fair value of vested deferred stock units $ 350 $ 443 $ — As of December 31, 2017 , there was $9.2 million of total unrecognized compensation cost related to non-vested options, restricted shares, and restricted stock units. That cost is expected to be recognized over a weighted average period of 2.0 years . Equity Based Awards - Settled in Cash As of December 31, 2017, the Company's total share-based liabilities recorded on the consolidated balance sheet was $48.0 million , of which $29.3 million was included in non-current liabilities. Total share-based liabilities at December 31, 2016 was $45.5 million , of which $40.2 million was included in non-current liabilities. The Company's equity based awards that are settled in cash include performance stock units settled in cash and a management stock purchase plan. Performance Stock Units - Settled in Cash The Company has also PSUs that will convert to cash after three years based upon a one year performance period. The cost of these awards is recognized over the requisite vesting period. The PSUs earned over the performance period are determined based on the Company's actual ROIC relative to the ROIC targeted for the performance period. The following table provides the number of PSUs which will convert to cash for the years ending December 31: 2016 2015 Awards Number of Units (2) Grant Date Fair Value (in $000s) Number of Units (3) Performance stock units (1) 128,000 $ 3,100 219,000 $ 4,039 (1) There were no performance stock units that convert to cash granted to participants in 2017. (2) The participants earned 200% of target aggregating 256,000 PSUs earned. This award will convert to cash and be payable in January 2019. (3) The participants earned 200% of target aggregating 438,000 PSUs earned. This award will be converted to cash and will be paid to participants in the first quarter of 2018 at the trailing 90 -day closing price of the Company's common stock as of December 31, 2017. The following table summarizes the compensation expense recognized from the change in fair value and vesting of performance stock units awarded for the years ended December 31 (in thousands): 2017 2016 2015 Performance stock unit compensation expense $ 3,591 $ 10,377 $ 6,965 Management Stock Purchase Plan The Management Stock Purchase Plan ("MSPP") provides participants the ability to defer a portion of their compensation or Directors’ fees, which deferral is converted to restricted stock units, and credited to an account. Participants eligible to defer a portion of their compensation also receive a company-matching award in restricted stock units equal to a percentage of their compensation. The account represents a share-based liability that is converted to and settled in cash payable to participants upon retirement or a termination of their service to the Company. The following table provides the number of restricted stock units credited to active participant accounts, balance of vested and unvested restricted stock units within active participant accounts, payments made with respect to restricted stock units issued under the MSPP, and MSPP expense during years ended December 31: 2017 2016 2015 Restricted stock units credited 84,299 198,155 94,047 Restricted stock units balance, vested and unvested 389,189 646,669 519,668 Share-based liabilities paid, in thousands $ 6,058 $ 3,137 $ 1,901 MSPP expense, in thousands $ 2,432 $ 8,565 $ 2,767

Fair Value Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS Fair value is defined as 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. Depending on the nature of the asset or liability, various techniques and assumptions can be used to estimate fair value. A financial asset or liability’s classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement as follows: • Level 1 - Quoted prices in active markets for identical assets or liabilities. • Level 2 - Observable inputs other than quoted prices in active markets for similar assets and liabilities. • Level 3 - Inputs that are unobservable inputs for the asset or liability. The Company had no financial assets or liabilities measured at fair value on a recurring basis at December 31, 2017 and 2016. The Company's only financial instrument for which carrying value differs from its fair value is long-term debt. At December 31, 2017 and 2016, the fair value of outstanding debt net of unamortized debt issuance costs was $213.8 million and $219.9 million, respectively, compared to its carrying value of $ 210.0 million and $ 209.6 million , respectively. The fair value of the Company's Senior Subordinated 6.25% Notes is classified as Level 2 within the fair value hierarchy and was estimated based on quoted market prices adjusted for unamortized debt issuance costs. The Company’s other financial instruments primarily consist of cash and cash equivalents, accounts receivable, notes receivable, and accounts payable. The carrying values for our financial instruments approximate fair value. The Company did not have any other material assets or liabilities carried at fair value and measured on a recurring basis as of December 31, 2017 and 2016 . Other non-recurring fair value measurements The Company recognized the impairment of certain intangible assets and property, plant, and equipment during the years ended December 31, 2017 , 2016 and 2015 . The Company uses unobservable inputs, classified as Level 3 inputs, in determining the fair value of these assets. See Note 6 and Note 14 of the consolidated financial statements for more disclosure regarding the impairment of certain intangible assets and property, plant, and equipment, respectively. The Company also applied fair value principles for the goodwill impairment tests performed during 2017 , 2016 , and 2015 . The Company used two valuation models to estimate the fair values of its reporting units, both of which primarily use Level 3 inputs. See Note 6 of the consolidated financial statements for the results of the Company’s goodwill impairment tests. Additionally, the Company's recent acquisition activity, as described in Note 5 of the consolidated financial statements, used Level 3 inputs to estimate fair values allocated to the assets acquired and liabilities assumed.

Exit Activity Costs and Asset I

Exit Activity Costs and Asset Impairments	12 Months Ended
Exit Activity Costs and Asset Impairments	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Exit Activity Costs and Asset Impairments	EXIT ACTIVITY COSTS AND ASSET IMPAIRMENTS The Company completed the third year of its five year planned transformation strategy formulated to transform its operations and improve its financial results over this five year period. This strategy includes an 80/20 simplification initiative which, in part, focuses the Company’s internal resources on further increasing the value provided to our customers. A result of this initiative was the identification of low-volume, low margin, internally-produced products which have been or will be outsourced or discontinued. Portfolio management, another key part of the strategy and a natural adjunct to the 80/20 initiative, is another initiative in which management conducts strategic reviews of our current portfolio for future profitable growth and greater shareholder returns. This initiative has resulted in the sale and exiting of less profitable businesses or products lines in order to enable the Company to re-allocate leadership, time, capital and resources to the highest potential platforms and businesses. Exit activity costs and asset impairment charges were incurred as a result of these initiatives. In 2017, the 80/20 simplification initiative was initiated at additional business units as well as continued at those business units which commenced activity in 2016 and 2015. Correspondingly, the Company executed the portfolio management strategy in 2016, which had carryover effect in 2017. The portfolio management resulted in the execution of three transactions directly related to this strategy: the sale of its European industrial manufacturing business to a third party in April 2016, the exiting of its small European residential solar racking business and the exiting of its U.S. bar grating product line. Both the exit of the Company's small European residential solar racking business and the exit of the Company's U.S. bar grating product line commenced in the fourth quarter of 2016 and were essentially completed in 2017. During 2017, asset impairment charges incurred by the Company were more than offset by a gain on sale of assets previously impaired in 2016 as a result of businesses and product lines discontinued. Specifically, asset sales related to the exit of both the Company's small European residential solar racking business and U.S. bar grating product line during 2017 resulted in a net gain. Asset impairments relate to the write-down of inventory and impairment of machinery, equipment and facilities associated with either businesses sold or exited, discontinued product lines or the reduction of manufactured goods offered within a product line. These assets were written down to their sale or scrap value, and were subsequently sold or disposed of. The Company also incurred exit activity costs in 2017 which related to contract termination costs, severance costs, and other moving and closing costs. The above initiatives led to the closing and consolidation of three facilities in 2017. The Company closed and consolidated seven facilities during 2016 and four facilities in 2015, which resulted in asset impairment charges and exit activity costs in both years. In addition, the Company sold and leased back a facility in 2015. The following table sets forth the inventory write-downs, asset impairment charges, exit activity costs and gain on facilities sold in conjunction with these efforts, incurred by segment during the years ended December 31 related to the restructuring activities described above (in thousands): 2017 2016 2015 Inventory write-downs &/or asset impairment charges Exit activity costs Total Inventory write-downs &/or asset impairment charges Exit activity costs Total Inventory write-downs &/or asset impairment charges Exit activity costs Gain on sale leaseback Total Residential Products $ 345 $ 1,058 $ 1,403 $ 1,459 $ 1,074 $ 2,533 $ 6,495 $ 1,256 $ (6,799 ) $ 952 Industrial & Infrastructure Products (2,484 ) 2,820 336 4,221 4,546 8,767 2,009 162 — 2,171 Renewable Energy & Conservation 509 2,986 3,495 1,850 539 2,389 — — — — Corporate — 261 261 — 58 58 — — — — Total exit activity costs & asset impairments $ (1,630 ) $ 7,125 $ 5,495 $ 7,530 $ 6,217 $ 13,747 $ 8,504 $ 1,418 $ (6,799 ) $ 3,123 The following table provides a summary of where the above exit activity costs and asset impairments are recorded in the consolidated statements of operations for the years ended December 31 (in thousands): 2017 2016 2015 Cost of sales $ 911 $ 9,922 $ 9,381 Selling, general, and administrative expense 4,584 3,825 (6,258 ) Total exit activity costs and asset impairments $ 5,495 $ 13,747 $ 3,123 The following table reconciles the beginning and ending liability for exit activity costs relating to the Company’s facility consolidation efforts (in thousands): 2017 2016 Balance as of January 1 $ 3,744 $ 603 Exit activity costs recognized 7,125 6,217 Cash payments (9,908 ) (3,076 ) Balance as of December 31 $ 961 $ 3,744 As noted above, the Company sold its European industrial manufacturing business to a third party on April 15, 2016, from its Industrial and Infrastructure Products segment. The pretax loss on the disposal was $8.8 million . The sale resulted in a net loss of $2.0 million on net proceeds of $8.3 million . This divestiture did not meet the criteria to be reported as a discontinued operation as it does not represent a strategic shift that has or will have a major effect on the Company’s operations. Therefore, prior period results of continuing operations have not been restated to exclude the impact of the divested business’s financial results. The pretax loss on disposal is presented within other expense (income) in the consolidated statement of operations. Neither the exit of the Company’s small European residential solar racking business nor its U.S. bar grating product line met the criteria to be reported as a discontinued operation. The costs related to exiting this business and product line are reflected in the above tables.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES On December 22, 2017, the President of the United States signed into law the Tax Cuts and Jobs Act (“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 transition tax on deemed repatriated earnings of foreign subsidiaries. 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. 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 U.S. net deferred tax liabilities at December 31, 2017 and recognized a provisional $16.2 million tax benefit in the Company’s consolidated statement of operations for the year ended December 31, 2017. The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the 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. The Tax Reform Act provided for a one-time transition tax on post-1986 undistributed foreign subsidiary earnings and profits (“E&P”). The Company recognized a provisional $3.7 million of income tax expense as a result of the transition tax and related repatriation in the Company’s consolidated statement of operations for the year ended December 31, 2017. 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 expects that it will be subject to incremental U.S. tax on GILTI income beginning in 2018, due to expense allocations required by the U.S. foreign tax credit rules. 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. 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 when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Reform Act. The Company has recognized the provisional tax impacts related to the one-time transition tax, withholding tax 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. As there is some uncertainty around the grandfathering provisions related to performance-based executive compensation, we have not included a provisional amount for deferred tax assets related to performance-based executive compensation as we believe that all of our plans are grandfathered. Our preliminary estimate of the one-time transition tax and the re-measurement of our deferred tax assets and liabilities is subject to the finalization of management’s analysis related to certain matters, such as developing interpretations of the provisions of the 2017 Tax Reform Act, changes to certain estimates and amounts related to the earnings and profits of certain subsidiaries and the filing of our tax returns, U.S. Treasury regulations, administrative interpretations or court decisions interpreting the 2017 Tax Reform Act may require further adjustments and changes in our estimates. The final determination of the one-time transition tax and the re-measurement of our deferred assets and liabilities will be completed as additional information becomes available, but no later than one year from the enactment of the 2017 Tax Reform Act. The components of income (loss) before taxes from continuing operations consisted of the following for the years ended December 31 (in thousands): 2017 2016 2015 Domestic $ 78,468 $ 37,316 $ 40,176 Foreign (560 ) 12,667 (3,076 ) Income before taxes from continuing operations $ 77,908 $ 49,983 $ 37,100 The provision for (benefit of) income taxes from continuing operations for the years ended December 31 consisted of the following (in thousands): 2017 2016 2015 Current: U.S. Federal $ 16,882 $ 14,703 $ 12,294 State 2,479 2,987 2,010 Foreign 2,687 3,467 1,371 Total current 22,048 21,157 15,675 Deferred: U.S. Federal (7,466 ) (5,404 ) (178 ) State 1,246 1,595 273 Foreign (885 ) (1,084 ) (2,146 ) Total deferred (7,105 ) (4,893 ) (2,051 ) Provision for income taxes $ 14,943 $ 16,264 $ 13,624 The benefit of income taxes from discontinued operations for the years ended December 31 consisted of the following (in thousands): 2017 2016 2015 Current: U.S. Federal $ 219 $ 24 $ 15 State 20 2 1 Foreign — — — Benefit of income taxes $ 239 $ 26 $ 16 The provision for income taxes from continuing operations differs from the federal statutory rate of 35% for the years ended December 31 due to the following (in thousands): 2017 2016 2015 Statutory rate $ 27,268 35.0 % $ 17,494 35.0 % $ 12,985 35.0 % State taxes, less federal effect 2,442 3.1 % 3,033 6.1 % 1,845 5.0 % Tax effect of Tax Reform Act (12,535 ) (16.1 )% — — % — — % Domestic manufacturer's deduction (1,578 ) (2.0 )% (1,363 ) (2.7 )% (795 ) (2.1 )% Excess tax benefit on stock based compensation (1,415 ) (1.8 )% — — % — — % Federal tax credits (373 ) (0.5 )% (439 ) (0.9 )% (242 ) (0.7 )% Uncertain tax positions (148 ) (0.2 )% (154 ) (0.3 )% (344 ) (0.9 )% Change in valuation allowance 660 0.8 % 685 1.4 % 284 0.7 % Non-deductible expenses 499 0.7 % 556 1.1 % 2 — % Foreign rate differential 2 — % (677 ) (1.4 )% (6 ) — % Intangible asset impairment — — % 341 0.7 % — — % Worthless stock deduction — — % (868 ) (1.7 )% — — % Intercompany debt discharge — — % (2,389 ) (4.8 )% — — % Other 121 0.2 % 45 — % (105 ) (0.3 )% $ 14,943 19.2 % $ 16,264 32.5 % $ 13,624 36.7 % Deferred tax liabilities (assets) at December 31 consist of the following (in thousands): 2017 2016 Depreciation $ 9,563 $ 17,367 Goodwill 32,662 43,562 Intangible assets 10,928 14,731 Foreign withholding tax 1,014 — Other 652 892 Gross deferred tax liabilities 54,819 76,552 Equity compensation (12,577 ) (21,439 ) Other (13,247 ) (18,473 ) Gross deferred tax assets (25,824 ) (39,912 ) Valuation allowances 2,242 1,362 Deferred tax assets, net of valuation allowances (23,582 ) (38,550 ) Net deferred tax liabilities $ 31,237 $ 38,002 At December 31, 2017 , the Company had net operating loss carry forwards for federal, state, and foreign income tax purposes totaling $22.5 million . The federal and state net operating loss carry forwards will expire between 2018 and 2037 . The foreign net operating loss carry forwards have an indefinite carry forward period, except for Japan that expires between 2023 and 2026. The Company recognized $3.5 million of deferred tax assets, net of the federal tax benefit, related to these net operating losses prior to any valuation allowances. Deferred taxes include net deferred tax assets relating to certain state and foreign tax jurisdictions. A reduction of the carrying amount of deferred tax assets by a valuation allowance is required if it is more likely than not that such assets will not be realized. The following sets forth a reconciliation of the beginning and ending amount of the Company’s valuation allowance (in thousands): 2017 2016 2015 Balance as of January 1 $ 1,362 $ 766 $ 400 Cost charged to the tax provision 1,505 983 286 Reductions (820 ) (338 ) (78 ) Currency translation 195 (49 ) — Balance as of December 31 $ 2,242 $ 1,362 $ 766 The Company made net payments for income taxes for the following amounts for the years ended December 31 (in thousands): 2017 2016 2015 Payments made for income taxes, net $ 26,186 $ 17,700 $ 11,879 At December 31, 2017, the Company had $27.2 million of undistributed earnings of foreign subsidiaries. The Company expects to execute a one-time repatriation of $24.4 million in cash to the U.S., net of withholding tax. The funds will be used for general corporate purposes. The Company continues to maintain its assertion that all remaining foreign earnings will be indefinitely reinvested. Any excess earnings could be used to grow the Company's foreign operations through launches of new capital projects or additional acquisitions. Determination of the amount of unrecognized deferred U.S. income tax liability related to our remaining unremitted foreign earnings is not practicable due to the complexities associated with its hypothetical calculation. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): 2017 2016 2015 Balance as of January 1 $ 3,466 $ 3,876 $ 1,414 Additions for tax positions of the current year 99 33 148 Additions for tax positions of prior years — — 2,955 Reductions for tax positions of prior years for: Settlements and changes in judgment (422 ) (256 ) (331 ) Lapses of applicable statute of limitations — — (310 ) Divestitures and foreign currency translation 393 (187 ) — Balance as of December 31 $ 3,536 $ 3,466 $ 3,876 In 2017 and 2016, the unrecognized tax benefits of $0.3 million and $0.6 million, respectively, would affect the effective tax rate, if recognized as of December 31, 2017 and 2016 . $3.2 million and $2.8 million of unrecognized tax benefits related to the acquisition of RBI on June 9, 2015, if recognized would be offset by an equal indemnification asset at December 31, 2017 and 2016 . The Company classifies accrued interest and penalties related to unrecognized tax benefits in income tax expense. The Company and its U.S. subsidiaries file a U.S. federal consolidated income tax return. Foreign and U.S. state jurisdictions have statute of limitations generally ranging from four to ten years. Currently, the Company is under examination in Germany for 2009 through 2012 . The Company's U.S. federal consolidated income tax return remains subject to examination for 2015, 2016 and 2017. Interest (net of federal tax benefit) and penalties recognized during the years ended December 31 were (in thousands): 2017 2016 2015 Interest and penalties recognized as income $ 130 $ 122 $ 87

Earnings per Share

Earnings per Share	12 Months Ended
Earnings per Share	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings per Share	EARNINGS PER SHARE Basic earnings per share is based on the weighted average number of common shares outstanding. Diluted earnings per share is based on the weighted average number of common shares outstanding, as well as dilutive common shares which include shares issuable under the equity compensation plans described in Note 12 of the consolidated financial statements. The weighted average number of diluted shares does not include potential anti-dilutive common shares aggregating 468,000 , 653,000 and 643,000 at December 31, 2017, 2016 and 2015, respectively. The treasury stock method is used to calculate dilutive shares, which reduces the gross number of dilutive shares by the number of shares purchasable from the proceeds of the options assumed to be exercised and the unrecognized expense related to the restricted stock and restricted stock awards assumed to have vested. Basic earnings and diluted weighted-average shares outstanding are as follows for the years ended December 31 (in thousands): 2017 2016 2015 Numerator: Income from continuing operations $ 62,965 $ 33,719 $ 23,476 Loss from discontinued operations (405 ) (44 ) (28 ) Net income available to common shareholders $ 62,560 $ 33,675 $ 23,448 Denominator for basic earnings per share: Weighted average shares outstanding 31,701 31,536 31,233 Denominator for diluted earnings per share: Common stock options and restricted stock 549 533 312 Weighted average shares and conversions 32,250 32,069 31,545

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES The Company leases certain facilities and equipment under operating leases. As leases expire, it can be expected that, in the normal course of business, certain leases will be renewed or replaced. Certain lease agreements include escalating rent payments over the lease terms. The Company expenses rent on a straight-line basis over the lease term which commences on the date the Company has the right to control the property. Rent expense under operating leases for the years ended December 31 aggregated (in thousands): 2017 2016 2015 Rent expense $ 11,964 $ 13,652 $ 13,959 Future minimum lease payments under these noncancelable operating leases as of December 31, 2017 are as follows (in thousands): 2018 2019 2020 2021 2022 Thereafter Future minimum lease payments 11,072 9,274 6,521 4,773 3,817 5,211 The Company is a party to certain claims and legal actions generally incidental to its business. For certain divestiture transactions completed in prior years, the Company has agreed to indemnify the buyer for various liabilities that may arise after the disposal date, subject to limits of time and amount. The Company is a party to certain claims made under these indemnification provisions. As of December 31, 2017, the Company has a contingent liability recorded for such provisions related to discontinued operations. Management does not believe that the outcome of this claim, or other claims which are not clearly determinable at the present time, would significantly affect the Company's financial condition or results of operation.

Related Party Transactions

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS A former officer of one of the Company's operating segments is the owner of certain real estate properties leased for manufacturing and distribution purposes by that operating segment. The leases are in effect until June 2018 and June 2020. For the years ended December 31, 2017 and 2016 , the Company incurred $1.1 million and $1.0 million of lease expense for these properties. All amounts incurred during 2017 and 2016 were expensed as a component of cost of sales.

Segment Information

Segment Information	12 Months Ended
Segment Information	Dec. 31, 2017
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Segment Information	SEGMENT INFORMATION The Company is organized into three reportable segments on the basis of the production process and products and services provided by each segment, identified as follows: (i) Residential Products, which primarily includes roof and foundation ventilation products, centralized mail systems and electronic package solutions, rain dispersion products and roofing accessories; (ii) Industrial and Infrastructure Products, which primarily includes expanded and perforated metal, expansion joints and structural bearings; and (iii) Renewable Energy and Conservation, which primarily includes designing, engineering, manufacturing and installation of solar racking systems and greenhouse structures. When determining the reportable segments, the Company aggregated operating segments based on their similar economic and operating characteristics. The following table illustrates certain measurements used by management to assess the performance of the segments described above as of and for the years ended December 31 (in thousands): 2017 2016 2015 Net sales: Residential Products $ 466,603 $ 430,938 $ 475,653 Industrial and Infrastructure Products 215,211 296,513 378,224 Less: Intersegment sales (1,247 ) (1,495 ) (1,536 ) 213,964 295,018 376,688 Renewable Energy and Conservation 306,351 282,025 188,532 Total consolidated net sales $ 986,918 $ 1,007,981 $ 1,040,873 Income (loss) from operations: Residential Products $ 76,893 $ 65,241 $ 46,804 Industrial and Infrastructure Products 8,159 1,306 15,581 Renewable Energy and Conservation 30,218 43,214 12,659 Unallocated corporate expenses (22,421 ) (36,273 ) (26,312 ) $ 92,849 $ 73,488 $ 48,732 Depreciation and Amortization Residential Products $ 9,183 $ 9,297 $ 9,967 Industrial and Infrastructure Products 6,529 8,237 12,108 Renewable Energy and Conservation 5,657 6,203 7,811 Unallocated corporate expenses 321 377 662 $ 21,690 $ 24,114 $ 30,548 Total assets Residential Products $ 358,838 $ 331,975 $ 363,339 Industrial and Infrastructure Products 203,455 225,691 273,987 Renewable Energy and Conservation 219,806 207,241 215,211 Unallocated corporate assets 209,286 153,338 37,235 $ 991,385 $ 918,245 $ 889,772 Capital expenditures Residential Products $ 5,236 $ 5,182 $ 3,328 Industrial and Infrastructure Products 2,094 2,060 4,846 Renewable Energy and Conservation 3,648 3,160 3,871 Unallocated corporate expenditures 421 377 328 $ 11,399 $ 10,779 $ 12,373 Net sales by region or origin and long-lived assets by region of domicile for the years ended and as of December 31 are as follows (in thousands): 2017 2016 2015 Net sales North America $ 977,942 $ 963,797 $ 968,414 Europe 1,131 19,447 48,216 Asia 7,845 24,737 24,243 Total $ 986,918 $ 1,007,981 $ 1,040,873 Long-lived assets North America $ 97,956 $ 108,334 $ 110,571 Europe 3,222 2,900 11,084 Asia 601 992 1,292 Total $ 101,779 $ 112,226 $ 122,947

Supplemental Financial Informat

Supplemental Financial Information	12 Months Ended
Supplemental Financial Information	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Supplemental Financial Information	SUPPLEMENTAL FINANCIAL INFORMATION The following information sets forth the consolidating summary financial statements of the issuer (Gibraltar Industries, Inc.) and guarantors, which guarantee the Senior Subordinated 6.25% Notes due February 1, 2021, and the non-guarantors. The guarantors are 100% owned domestic subsidiaries of the issuer and the guarantees are full, unconditional, joint and several. Investments in subsidiaries are accounted for by the parent using the equity method of accounting. The guarantor subsidiaries and non-guarantor subsidiaries are presented on a combined basis. The principal elimination entries eliminate investments in subsidiaries and intercompany balances and transactions. GIBRALTAR INDUSTRIES, INC. CONSOLIDATING STATEMENT OF OPERATIONS YEAR ENDED DECEMBER 31, 2017 (in thousands) Gibraltar Industries, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Total Net sales $ — $ 947,604 $ 52,738 $ (13,424 ) $ 986,918 Cost of sales — 719,587 43,187 (12,400 ) 750,374 Gross profit — 228,017 9,551 (1,024 ) 236,544 Selling, general, and administrative expense 147 133,409 9,892 — 143,448 Intangible asset impairment — 200 47 — 247 (Loss) income from operations (147 ) 94,408 (388 ) (1,024 ) 92,849 Interest expense (income) 13,609 512 (89 ) — 14,032 Other expense — 500 409 — 909 (Loss) income before taxes (13,756 ) 93,396 (708 ) (1,024 ) 77,908 (Benefit of) provision for income taxes (5,079 ) 19,787 235 — 14,943 (Loss) income from continuing operations (8,677 ) 73,609 (943 ) (1,024 ) 62,965 Discontinued operations: Loss before taxes — (644 ) — — (644 ) Benefit of income taxes — (239 ) — — (239 ) Loss from discontinued operations — (405 ) — — (405 ) Equity in earnings from subsidiaries 72,261 (943 ) — (71,318 ) — Net income (loss) $ 63,584 $ 72,261 $ (943 ) $ (72,342 ) $ 62,560 GIBRALTAR INDUSTRIES, INC. CONSOLIDATING STATEMENT OF OPERATIONS YEAR ENDED DECEMBER 31, 2016 (in thousands) Gibraltar Guarantor Non-Guarantor Eliminations Total Net sales $ — $ 950,945 $ 78,184 $ (21,148 ) $ 1,007,981 Cost of sales — 722,315 62,729 (21,825 ) 763,219 Gross profit — 228,630 15,455 677 244,762 Selling, general, and administrative expense 14,302 137,343 9,454 — 161,099 Intangible asset impairment — 7,980 2,195 — 10,175 (Loss) income from operations (14,302 ) 83,307 3,806 677 73,488 Interest expense (income) 13,609 1,042 (74 ) — 14,577 Other expense (income) 8,716 512 (300 ) — 8,928 (Loss) income before taxes (36,627 ) 81,753 4,180 677 49,983 (Benefit of) provision for income taxes (11,768 ) 27,551 481 — 16,264 (Loss) income from continuing operations (24,859 ) 54,202 3,699 677 33,719 Discontinued operations: Loss before taxes — (70 ) — — (70 ) Benefit of income taxes — (26 ) — — (26 ) Loss from discontinued operations — (44 ) — — (44 ) Equity in earnings from subsidiaries 57,857 3,699 — (61,556 ) — Net income $ 32,998 $ 57,857 $ 3,699 $ (60,879 ) $ 33,675 GIBRALTAR INDUSTRIES, INC. CONSOLIDATING STATEMENT OF OPERATIONS YEAR ENDED DECEMBER 31, 2015 (in thousands) Gibraltar Guarantor Non-Guarantor Eliminations Total Net sales $ — $ 960,614 $ 109,984 $ (29,725 ) $ 1,040,873 Cost of sales — 785,085 94,949 (26,137 ) 853,897 Gross profit — 175,529 15,035 (3,588 ) 186,976 Selling, general, and administrative expense 133 115,882 17,366 — 133,381 Intangible asset impairment — 4,863 — — 4,863 (Loss) income from operations (133 ) 54,784 (2,331 ) (3,588 ) 48,732 Interest expense (income) 13,609 1,469 (75 ) — 15,003 Other expense (income) 50 (3,154 ) (267 ) — (3,371 ) (Loss) income before taxes (13,792 ) 56,469 (1,989 ) (3,588 ) 37,100 (Benefit of) provision for income taxes (4,427 ) 18,827 (776 ) — 13,624 (Loss) income from continuing operations (9,365 ) 37,642 (1,213 ) (3,588 ) 23,476 Discontinued operations: Loss before taxes — (44 ) — — (44 ) Benefit of income taxes — (16 ) — — (16 ) Loss from discontinued operations — (28 ) — — (28 ) Equity in earnings from subsidiaries 36,401 (1,213 ) — (35,188 ) — Net income (loss) $ 27,036 $ 36,401 $ (1,213 ) $ (38,776 ) $ 23,448 GIBRALTAR INDUSTRIES, INC. CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (in thousands) Gibraltar Industries, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Total Year ended December 31, 2017 Net income (loss) $ 63,584 $ 72,261 $ (943 ) $ (72,342 ) $ 62,560 Other comprehensive income: Foreign currency translation adjustment — — 3,150 — 3,150 Adjustment to retirement benefit liability, net of tax — (9 ) — — (9 ) Adjustment to post-retirement healthcare benefit liability, net of tax — 214 — — 214 Other comprehensive income — 205 3,150 — 3,355 Total comprehensive income $ 63,584 $ 72,466 $ 2,207 $ (72,342 ) $ 65,915 Gibraltar Industries, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Total Year ended December 31, 2016 Net income $ 32,998 $ 57,857 $ 3,699 $ (60,879 ) $ 33,675 Other comprehensive income: Foreign currency translation adjustment — — 6,945 — 6,945 Adjustment to retirement benefit liability, net of tax — 55 — — 55 Adjustment to post-retirement healthcare benefit liability, net of tax — 695 — — 695 Other comprehensive income — 750 6,945 — 7,695 Total comprehensive income $ 32,998 $ 58,607 $ 10,644 $ (60,879 ) $ 41,370 Gibraltar Industries, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Total Year ended December 31, 2015 Net income (loss) $ 27,036 $ 36,401 $ (1,213 ) $ (38,776 ) $ 23,448 Other comprehensive income (loss): Foreign currency translation adjustment — — (6,228 ) — (6,228 ) Adjustment to retirement benefit liability, net of tax — 34 15 — 49 Adjustment to post-retirement healthcare benefit liability, net of tax — 171 — — 171 Unrealized loss on cash flow hedges, net of tax — 143 — — 143 Other comprehensive income (loss) — 348 (6,213 ) — (5,865 ) Total comprehensive income (loss) $ 27,036 $ 36,749 $ (7,426 ) $ (38,776 ) $ 17,583 GIBRALTAR INDUSTRIES, INC. CONSOLIDATING BALANCE SHEET DECEMBER 31, 2017 (in thousands) Gibraltar Industries, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Total Assets Current assets: Cash and cash equivalents $ — $ 192,604 $ 29,676 $ — $ 222,280 Accounts receivable, net — 138,903 6,482 — 145,385 Intercompany balances 324 4,166 (4,490 ) — — Inventories — 82,457 3,915 — 86,372 Other current assets 5,415 (368 ) 3,680 — 8,727 Total current assets 5,739 417,762 39,263 — 462,764 Property, plant, and equipment, net — 93,906 3,192 — 97,098 Goodwill — 298,258 22,816 — 321,074 Acquired intangibles — 97,171 8,597 — 105,768 Other assets — 4,681 — — 4,681 Investment in subsidiaries 739,970 61,746 — (801,716 ) — $ 745,709 $ 973,524 $ 73,868 $ (801,716 ) $ 991,385 Liabilities and Shareholders’ Equity Current liabilities: Accounts payable $ — $ 77,786 $ 4,601 $ — $ 82,387 Accrued expenses 5,469 67,746 2,252 — 75,467 Billings in excess of cost — 9,840 2,939 — 12,779 Current maturities of long-term debt — 400 — — 400 Total current liabilities 5,469 155,772 9,792 — 171,033 Long-term debt 208,521 1,100 — — 209,621 Deferred income taxes — 28,907 2,330 — 31,237 Other non-current liabilities — 47,775 — — 47,775 Shareholders’ equity 531,719 739,970 61,746 (801,716 ) 531,719 $ 745,709 $ 973,524 $ 73,868 $ (801,716 ) $ 991,385 GIBRALTAR INDUSTRIES, INC. CONSOLIDATING BALANCE SHEET DECEMBER 31, 2016 (in thousands) Gibraltar Guarantor Non-Guarantor Eliminations Total Assets Current assets: Cash and cash equivalents $ — $ 143,826 $ 26,351 $ — $ 170,177 Accounts receivable, net — 117,526 6,546 — 124,072 Intercompany balances (615 ) 6,152 (5,537 ) — — Inventories — 85,483 4,129 — 89,612 Other current assets 13,783 (10,070 ) 3,623 — 7,336 Total current assets 13,168 342,917 35,112 — 391,197 Property, plant, and equipment, net — 104,642 3,662 — 108,304 Goodwill — 282,300 21,732 — 304,032 Acquired intangibles — 101,520 9,270 — 110,790 Other assets — 3,922 — — 3,922 Investment in subsidiaries 663,118 58,477 — (721,595 ) — $ 676,286 $ 893,778 $ 69,776 $ (721,595 ) $ 918,245 Liabilities and Shareholders’ Equity Current liabilities: Accounts payable $ — $ 66,363 $ 3,581 $ — $ 69,944 Accrued expenses 7,369 60,004 3,019 — 70,392 Billings in excess of cost — 9,301 2,051 — 11,352 Current maturities of long-term debt — 400 — — 400 Total current liabilities 7,369 136,068 8,651 — 152,088 Long-term debt 208,037 1,200 — — 209,237 Deferred income taxes — 35,354 2,648 — 38,002 Other non-current liabilities — 58,038 — — 58,038 Shareholders’ equity 460,880 663,118 58,477 (721,595 ) 460,880 $ 676,286 $ 893,778 $ 69,776 $ (721,595 ) $ 918,245 GIBRALTAR INDUSTRIES, INC. CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS DECEMBER 31, 2017 (in thousands) Gibraltar Industries, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Total Cash Flows from Operating Activities Net cash (used in) provided by operating activities $ (15,172 ) $ 83,114 $ 2,128 $ — $ 70,070 Cash Flows from Investing Activities Purchases of property, plant, and equipment — (11,026 ) (373 ) — (11,399 ) Acquisitions, net of cash acquired — (18,494 ) — — (18,494 ) Net proceeds from sale of property and equipment — 12,905 191 — 13,096 Net cash used in investing activities — (16,615 ) (182 ) — (16,797 ) Cash Flows from Financing Activities Long-term debt payments — (400 ) — — (400 ) Purchase of treasury stock at market prices (2,872 ) — — — (2,872 ) Intercompany financing 17,370 (17,321 ) (49 ) — — Net proceeds from issuance of common stock 674 — — — 674 Net cash provided by (used in) financing activities 15,172 (17,721 ) (49 ) — (2,598 ) Effect of exchange rate changes on cash — — 1,428 — 1,428 Net increase in cash and cash equivalents — 48,778 3,325 — 52,103 Cash and cash equivalents at beginning of year — 143,826 26,351 — 170,177 Cash and cash equivalents at end of year $ — $ 192,604 $ 29,676 $ — $ 222,280 GIBRALTAR INDUSTRIES, INC. CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS DECEMBER 31, 2016 (in thousands) Gibraltar Guarantor Non-Guarantor Eliminations Total Cash Flows from Operating Activities Net cash (used in) provided by operating activities $ (34,243 ) $ 140,890 $ 17,340 $ — $ 123,987 Cash Flows from Investing Activities Purchases of property, plant, and equipment — (10,321 ) (458 ) — (10,779 ) Acquisitions, net of cash acquired — (23,412 ) — — (23,412 ) Net proceeds from sale of property and equipment — 230 723 — 953 Net proceeds from sale of business — — 8,250 — 8,250 Other, net — 1,118 — — 1,118 Net cash (used in) provided by investing activities — (32,385 ) 8,515 — (23,870 ) Cash Flows from Financing Activities Long-term debt payments — (400 ) — — (400 ) Payment of debt issuance costs — (54 ) — — (54 ) Purchase of treasury stock at market prices (1,539 ) — — — (1,539 ) Intercompany financing 32,441 (3,822 ) (28,619 ) — — Net proceeds from issuance of common stock 3,341 — — — 3,341 Net cash provided by (used in) financing activities 34,243 (4,276 ) (28,619 ) — 1,348 Effect of exchange rate changes on cash — — (146 ) — (146 ) Net increase (decrease) in cash and cash equivalents — 104,229 (2,910 ) — 101,319 Cash and cash equivalents at beginning of year — 39,597 29,261 — 68,858 Cash and cash equivalents at end of year $ — $ 143,826 $ 26,351 $ — $ 170,177 GIBRALTAR INDUSTRIES, INC. CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS DECEMBER 31, 2015 (in thousands) Gibraltar Guarantor Non-Guarantor Eliminations Total Cash Flows from Operating Activities Net cash (used in) provided by operating activities $ (13,309 ) $ 94,977 $ 5,553 $ — $ 87,221 Cash Flows from Investing Activities Purchases of property, plant, and equipment — (11,754 ) (619 ) — (12,373 ) Acquisitions, net of cash acquired — (114,145 ) (26,476 ) — (140,621 ) Net proceeds from sale of property and equipment — 26,500 — — 26,500 Other, net — 1,154 1,154 Net cash used in investing activities — (98,245 ) (27,095 ) — (125,340 ) Cash Flows from Financing Activities Long-term debt payments — (73,642 ) — — (73,642 ) Proceeds from long-term debt — 73,242 73,242 Payment of debt issuance costs — (1,166 ) — — (1,166 ) Purchase of treasury stock at market prices (956 ) — — — (956 ) Intercompany financing 12,464 (47,035 ) 34,571 — — Net proceeds from issuance of common stock 1,801 — — — 1,801 Net cash provided by (used in) financing activities 13,309 (48,601 ) 34,571 — (721 ) Effect of exchange rate changes on cash — — (2,912 ) — (2,912 ) Net (decrease) increase in cash and cash equivalents — (51,869 ) 10,117 — (41,752 ) Cash and cash equivalents at beginning of year — 91,466 19,144 — 110,610 Cash and cash equivalents at end of year $ — $ 39,597 $ 29,261 $ — $ 68,858

Quarterly Unaudited Financial D

Quarterly Unaudited Financial Data	12 Months Ended
Quarterly Unaudited Financial Data	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
QUARTERLY UNAUDITED FINANCIAL DATA	QUARTERLY UNAUDITED FINANCIAL DATA GIBRALTAR INDUSTRIES, INC. QUARTERLY UNAUDITED FINANCIAL DATA (in thousands, except per share data) 2017 Quarters Ended March 31 June 30 September 30 December 31 Total Net sales $ 206,605 $ 247,627 $ 274,574 $ 258,112 $ 986,918 Gross profit $ 49,255 $ 61,825 $ 68,735 $ 56,729 $ 236,544 Income from operations $ 9,679 $ 24,930 $ 35,693 $ 22,547 $ 92,849 Interest expense $ 3,576 $ 3,550 $ 3,486 $ 3,420 $ 14,032 Net income from continuing operations $ 3,996 $ 13,174 $ 20,619 $ 25,176 $ 62,965 Net loss from discontinued operations $ — $ (405 ) $ — $ — $ (405 ) Total net income $ 3,996 $ 12,769 $ 20,619 $ 25,176 $ 62,560 Income per share from continuing operations: Basic $ 0.13 $ 0.41 $ 0.65 $ 0.79 $ 1.98 Diluted $ 0.12 $ 0.41 $ 0.64 $ 0.78 $ 1.95 Loss per share from discontinued operations: Basic $ — $ (0.01 ) $ — $ — $ (0.01 ) Diluted $ — $ (0.01 ) $ — $ — $ (0.01 ) 2016 Quarters Ended March 31 June 30 September 30 December 31 Total Net sales $ 237,671 $ 265,738 $ 272,734 $ 231,838 $ 1,007,981 Gross profit $ 54,150 $ 68,843 $ 67,887 $ 53,882 $ 244,762 Income from operations $ 17,761 $ 28,576 $ 26,522 $ 629 $ 73,488 Interest expense $ 3,691 $ 3,666 $ 3,625 $ 3,595 $ 14,577 Net income (loss) from continuing operations $ 9,029 $ 18,612 $ 13,786 $ (7,708 ) $ 33,719 Net loss from discontinued operations $ — $ — $ — $ (44 ) $ (44 ) Total net income (loss) $ 9,029 $ 18,612 $ 13,786 $ (7,752 ) $ 33,675 Income (loss) per share from continuing operations: Basic $ 0.29 $ 0.59 $ 0.44 $ (0.24 ) $ 1.07 Diluted $ 0.28 $ 0.58 $ 0.43 $ (0.24 ) $ 1.05 Loss per share from discontinued operations: Basic $ — $ — $ — $ — $ — Diluted $ — $ — $ — $ — $ —

Summary of Significant Accoun30

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2017
Accounting Policies [Abstract]
Principles of consolidation	Principles of consolidation The consolidated financial statements include the accounts of Gibraltar Industries, Inc. and subsidiaries (the "Company"). All intercompany accounts and transactions have been eliminated in consolidation.
Use of estimates	Use of estimates The preparation of the 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 amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates.
Revenue recognition	Revenue recognition The majority of the Company's revenue is recognized when products are shipped or service is provided, the customer takes ownership and assumes the risk of loss, collection of the corresponding receivable is probable, persuasive evidence of an arrangement exists, and the sales price is fixed or determinable. Sales returns, allowances, and customer incentives, including rebates, are treated as reductions to sales and are provided for based on historical experience and current estimates. Revenues representing 28.0% and 25.8% of sales for the years ended December 31, 2017 and 2016 , respectively, were recognized under the percentage of completion accounting method as calculated by the cost-to-cost measurement method on contracts. The recognition of revenue under this method is utilized in the Renewable Energy and Conservation segment. Revenue from contracts using the percentage of completion method of accounting is recognized as work progresses toward completion as determined by the ratio of cumulative costs incurred to date to estimated total contract costs at completion, multiplied by the total contract revenue. Changes in estimates affecting sales, costs and profits are recognized in the period in which the change becomes known using the cumulative catch-up method of accounting, resulting in the cumulative effect of changes reflected in the period. Estimates are reviewed and updated quarterly for all contracts. A significant change in an estimate on one or more contracts could have a material effect on our results of operations. Contract costs include all direct costs related to contract performance. Selling and administrative expenses are charged to operations as incurred. Provisions for estimated losses on uncompleted contracts are recognized in the period in which such losses are determined. Because of inherent uncertainties in estimating costs, it is reasonably possible that changes in performance could result in revisions to cost and revenue, which are recognized in the period when the revisions are determined.
Cash and cash equivalents	Cash and cash equivalents All highly liquid investments with a maturity of three months or less are considered cash equivalents.
Accounts receivable	Accounts receivable and allowance for doubtful accounts Accounts receivable are composed of trade and contract receivables recorded at either the invoiced amount or costs in excess of billings, are expected to be collected within one year, and do not bear interest. The allowance for doubtful accounts is the Company’s best estimate of the probable amount of uncollectible accounts in the Company’s existing accounts receivable. The Company determines the allowance based on a number of factors, including historical experience, credit worthiness of customers, and current market and economic conditions. The Company reviews the allowance for doubtful accounts on a regular basis. Account balances are charged against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. The following table summarizes activity recorded within the allowance for doubtful accounts balances for the years ended December 31 (in thousands): 2017 2016 2015 Beginning balance $ 5,272 $ 4,868 $ 4,280 Bad debt expense 1,253 2,519 1,404 Accounts written off and other adjustments (91 ) (2,115 ) (816 ) Ending balance $ 6,434 $ 5,272 $ 4,868 Concentrations of credit risk on accounts receivable are limited to those from significant customers that are believed to be financially sound. As of December 31, 2017 and 2016 , the Company's most significant customer is a home improvement retailer. The home improvement retailer purchases from the Residential Products segmen
Inventories	Inventories Inventories are valued at the lower of cost, determined using the first-in, first-out method, or net realizable value. Shipping and handling costs are recognized as a component of cost of sales.
Property, plant, and equipment	Property, plant, and equipment Property, plant, and equipment are stated at cost and depreciated over their estimated useful lives using the straight-line method. Interest is capitalized in connection with construction of qualified assets. Expenditures that exceed an established dollar threshold and that extend the useful lives of assets are capitalized, while repair and maintenance costs are expensed as incurred. The estimated useful lives of land improvements, buildings, and building improvements are 15 to 40 years, while the estimated useful lives for machinery and equipment are 3 to 20 years.
Acquisition related assets and liabilities	Acquisition related assets and liabilities Accounting for the acquisition of a business as a purchase transaction requires an allocation of the purchase price to the assets acquired and the liabilities assumed in the transaction at their respective estimated fair values. The most complex estimations of individual fair values are those involving long-lived assets, such as property, plant, and equipment and intangible assets. The Company uses all available information to make these fair value determinations and, for major business acquisitions, engages independent valuation specialists to assist in the fair value determination of the acquired long-lived assets.
Goodwill and other intangible assets	Goodwill and other intangible assets The Company tests goodwill for impairment at the reporting unit level on an annual basis at October 31, or more frequently if an event occurs, or circumstances change, that indicate that the fair value of a reporting unit could be below its carrying value. The reporting units are at the component level, or one level below the operating segment level. Goodwill is assigned to each reporting unit as of the date the reporting unit is acquired and based upon the expected synergies of the acquisition. The Company may elect to perform a qualitative assessment that considers economic, industry and company-specific factors for some or all of our selected reporting units. If, after completing the assessment, it is determined that it is more likely than not that the fair value of a reporting unit is less than its carrying value, the Company proceeds to a quantitative test. The Company may also elect to perform a quantitative test instead of a qualitative test for any or all of the Company's reporting units. The quantitative impairment test consists of comparing the fair value of a reporting unit, determined using two valuation techniques, to its carrying value. If the carrying value of the reporting unit exceeds its fair value, goodwill is considered impaired, and a loss measured by the excess of the carrying value of the reporting unit over the fair value of the reporting unit must be recorded. The Company also tests its indefinite-lived intangible assets for impairment on an annual basis as of October 31, or more frequently if an event occurs, or circumstances change, that indicate that the fair value of an indefinite-lived intangible asset could be below its carrying value. The impairment test consists of comparing the fair value of the indefinite-lived intangible asset, determined using discounted cash flows on a relief-from-royalty basis, with its carrying amount. An impairment loss would be recognized for the carrying amount in excess of its fair value. Acquired identifiable intangible assets are recorded at cost. Identifiable intangible assets with finite useful lives are amortized over their estimated useful lives.
Impairment of long-lived assets	Impairment of long-lived assets Long-lived assets, including acquired identifiable intangible assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of those assets may not be recoverable. In specific situations, when the Company has selected individual assets to be sold or scrapped, the Company obtains market value data for those specific assets and measures and records the impairment loss based on such data. Otherwise, the Company uses undiscounted cash flows to determine whether impairment exists and measures any impairment loss by approximating fair value using acceptable valuation techniques, including discounted cash flow models and third-party appraisals. The Company recognized impairment charges related to intangible assets during the years ended December 31, 2017, 2016 and 2015. Several of these impairment charges related to exit activities during the three year period ended December 31, 2017 as described in Note 14 of the consolidated financial statements.
Deferred charges	Deferred charges Deferred charges associated with initial costs incurred to enter into new debt arrangements are included as a component of long-term debt and are amortized as a part of interest expense over the terms of the associated debt agreements.
Advertising	Advertising The Company expenses advertising costs as incurred.
Foreign currency transactions and translation	Foreign currency transactions and translation The assets and liabilities of the Company’s foreign subsidiaries are translated into U.S. dollars at the rate of exchange in effect at the balance sheet date. Income and expense items are translated at the average exchange rates prevailing during the period.
Income taxes	Income taxes The provision for income taxes is determined using the asset and liability approach. Under this approach, deferred income taxes represent the expected future tax consequences of temporary differences between the carrying amounts and tax basis of assets and liabilities. The Company records a valuation allowance to reduce deferred tax assets when uncertainty exists regarding their realization.
Equity-based compensation	Equity-based compensation The Company measures the cost of equity-based compensation based on grant date fair value and recognizes the cost over the period in which the employee is required to provide service in exchange for the award reduced by forfeitures. Equity-based compensation consists of grants of stock options, deferred stock units, restricted stock, restricted stock units, and performance stock units. Equity-based compensation expense is included as a component of selling, general, and administrative expenses. The Company’s equity-based compensation plans are discussed in more detail in Note 12 of the consolidated financial statements.
Recent accounting pronouncements	Recent accounting pronouncements Recent Accounting Pronouncements Adopted Standard Description Financial Statement Effect or Other Significant Matters ASU No. 2016-09 Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting The standard simplifies the accounting for share-based payment award transactions including: income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The provisions of this standard are effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted. The Company has adopted all amendments included in this standard under each required transition method. The Company concluded there were no material changes to prior periods, except for the following: the Company (a) reclassified its prior periods excess tax benefit for stock compensation of $1,249,000 in 2016 and $537,000 in 2015 on its consolidated statement of cash flows from a financing activity to an operating activity; and (b) recognized a cumulative-effect adjustment of $254,000 as an increase to retained earnings and decrease to additional paid-in capital on the Company's consolidated statement of shareholders' equity as of January 1, 2017 to reflect the change in value for a restricted stock unit liability award as of December 31, 2016, as if the award had been classified as an equity award since its respective grant date. Date of adoption: Q1 2017 ASU No. 2017-04 Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment The standard eliminates the "Step 2" analysis to determine the amount of impairment realized when a reporting unit's carrying amount exceeds its fair value in its "Step 1" analysis of accounting for impairment of goodwill. The impairment charge would be the amount determined in "Step 1." The provisions of this standard are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for annual and interim goodwill impairment testing dates after January 1, 2017. The Company has adopted this standard and it did not have any impact on the Company's consolidated financial statements. Date of adoption: Q1 2017 ASU No. 2017-07 Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost The standard requires an employer to recognize the service cost component of net periodic pension costs and net periodic postretirement benefit costs in the same line item(s) as other compensation costs from services rendered by pertinent employees during the period. Other components of net benefit cost are required to be presented separately from the service cost component and outside a subtotal of income from operations. The provisions of this standard are effective for annual reporting periods beginning after December 15, 2017, including interim periods within those annual periods. Early adoption is permitted as of the beginning of an annual period for which financial statements (interim or annual) have not been issued or made available for issuance. The Company has adopted this standard and has applied it retrospectively for the presentation of the service cost component, as well as, other components of net periodic pension cost and net periodic postretirement benefit cost in our statement of operations. The adoption decreased selling, general, and administrative expense by $524,000 and $647,000 for the twelve months ended December 31, 2016 and 2015, respectively, and comparably increased other expense by the same amounts, respectively. This guidance did not have any impact on our balance sheet or our statement of cash flows. Date of adoption: Q1 2017 Recent Accounting Pronouncements Not Yet Adopted Standard Description Financial Statement Effect or Other Significant Matters ASU No. 2014-09 Revenue from Contracts with Customers (Topic 606) And All Related ASUs The standard requires an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The standard also requires additional disclosures about the nature, amount, timing, and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and assets recognized from costs incurred to obtain or fulfill a contract. The provisions of the standard, as well as all subsequently issued clarifications to the standard, are effective for fiscal years beginning after December 15, 2017 and interim periods within those fiscal years. The standard can be adopted using either a full retrospective or modified retrospective approach. The Company currently believes the most significant impact of this standard upon adoption relates to the revenue recognition for certain custom fabricated products for which there is no alternative use and where the Company has written enforceable rights to payment for performance to date should the customer terminate the contract. These products are within the Company's Industrial and Infrastructure Products segment. Under this standard, the Company expects to recognize revenue on an over time basis on these custom fabricated products in the Industrial and Infrastructure Products segment which is a change from our current revenue recognition policy of point-in-time basis. The Company expects revenue recognition related to the remaining Industrial and Infrastructure Products segment, Residential Products segment and Renewable Energy and Conservation segment to remain substantially unchanged upon adoption of this standard. The Company has identified and implemented appropriate changes to the Company's business processes, systems and internal controls to support recognition and disclosure under this standard. The Company will use the modified retrospective transition method approach and apply it to open contracts as of January 1, 2018. Under this method, incremental disclosures will be provided to present each financial statement line item for 2018 under the prior standard. The Company estimates the cumulative effect of adoption to be approximately $750,000 increase to opening retained earnings, as of January 1, 2018. Planned date of adoption: Q1 2018 ASU No. 2016-02 Leases (Topic 842) The standard requires lessees to recognize most leases as assets and liabilities on the balance sheet, but record expenses on the statement of operations in a manner similar to current accounting. For lessors, the guidance modifies the classification criteria and accounting for sales-type and direct financing leases. The standard also requires additional disclosures about leasing arrangements and requires a modified retrospective transition approach for existing leases, whereby the standard will be applied to the earliest year presented. The provisions of the standard are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the impact of this standard on the Company's consolidated financial statements and related disclosures, including the impact on the Company's current lease portfolio from both a lessor and lessee perspective. The adoption of this standard will primarily result in an increase in the assets and liabilities on the Company's consolidated balance sheet and related disclosures. Planned date of adoption: Q1 2019 Standard Description Financial Statement Effect or Other Significant Matters ASU No. 2016-15 Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments The standard provides guidance on eight specific cash flow issues to reduce diversity in reporting. The provisions of this standard are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. The Company is evaluating the requirements of this standard and anticipates its impact on the Company's consolidated financial statements to be immaterial. Planned date of adoption: Q1 2018 ASU No. 2016-16 Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory The standard allows an entity to recognize income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The provisions of this standard are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within those annual reporting periods. Early adoption is permitted as of the beginning of an annual reporting period for which financial statements (interim or annual) have not been issued or made available for issuance. The Company is evaluating the requirements of this standard and anticipates its impact on the Company's consolidated financial statements to be immaterial. Planned date of adoption: Q1 2018 ASU No. 2018-02 Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income The standard allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. The provisions of this standard are effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption of the standard is permitted, including adoption in any interim period. The Company is evaluating the requirements of this standard and anticipates its impact on the Company's consolidation financial statements to be immaterial. The Company plans to apply the amendments in the period of adoption with an adjustment in the consolidated statement of shareholders' equity as of the beginning of the reporting period and any subsequent period, if changes to provisional amounts result in additional amounts stranded in accumulated other comprehensive income. Planned date of adoption: Q1 2018

Summary of Significant Accoun31

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2017
Accounting Policies [Abstract]
Summary Of Activity Recorded Within The Allowance For Doubtful Accounts	The following table summarizes activity recorded within the allowance for doubtful accounts balances for the years ended December 31 (in thousands): 2017 2016 2015 Beginning balance $ 5,272 $ 4,868 $ 4,280 Bad debt expense 1,253 2,519 1,404 Accounts written off and other adjustments (91 ) (2,115 ) (816 ) Ending balance $ 6,434 $ 5,272 $ 4,868
Summary Of Interest Capitalized And Depreciation Expense	The table below sets forth the amount of interest capitalized and depreciation expense recognized during the years ended December 31 (in thousands): 2017 2016 2015 Capitalized interest $ 137 $ 138 $ 166 Depreciation expense $ 12,929 $ 14,477 $ 17,869

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
Accounts Receivable (Tables)	Dec. 31, 2017
Receivables [Abstract]
Schedule of Accounts Receivable	Accounts receivable at December 31 consisted of the following (in thousands): 2017 2016 Trade accounts receivable $ 78,858 $ 81,193 Contract receivables: Amounts billed 61,351 41,569 Costs in excess of billings 11,610 6,582 Total contract receivables 72,961 48,151 Total accounts receivables 151,819 129,344 Less allowance for doubtful accounts (6,434 ) (5,272 ) Accounts receivable $ 145,385 $ 124,072

Inventories (Tables)

Inventories (Tables)	12 Months Ended
Inventories (Tables)	Dec. 31, 2017
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories at December 31 consisted of the following (in thousands): 2017 2016 Raw material $ 42,661 $ 41,758 Work-in-process 10,598 12,268 Finished goods 33,113 35,586 Total inventories $ 86,372 $ 89,612
Summary of Activity within the Reserve for Excess, Obsolete, and Slow Moving Inventory	The following table summarizes activity recorded within the reserve for excess, obsolete and slow moving inventory for the years ended December 31 (in thousands): 2017 2016 2015 Beginning balance $ 3,801 $ 7,428 $ 5,575 Excess, obsolete and slow moving inventory expense 1,276 (239 ) 1,539 Scrapped inventory and other adjustments (1,382 ) (3,388 ) 314 Ending balance $ 3,695 $ 3,801 $ 7,428

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	12 Months Ended
Property, Plant, and Equipment (Tables)	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Components of Property, Plant, and Equipment	Components of property, plant, and equipment at December 31 consisted of the following (in thousands): 2017 2016 Land and land improvements $ 6,301 $ 7,102 Building and improvements 46,562 50,283 Machinery and equipment 195,301 212,774 Construction in progress 8,522 2,202 Property, plant, and equipment, gross 256,686 272,361 Less: accumulated depreciation (159,588 ) (164,057 ) Property, plant, and equipment, net $ 97,098 $ 108,304

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
Acquisitions (Tables)	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of Allocation of the Purchase Price Consideration of the Fair Value of Assets Acquired and Liabilities Assumed	The allocation of the purchase consideration to the fair value of the assets acquired and liabilities assumed is as follows as of the date of the acquisition (in thousands): Cash $ 2,495 Working capital (1,109 ) Property, plant, and equipment 4,702 Acquired intangible assets 6,200 Other assets 23 Goodwill 11,451 Fair value of purchase consideration $ 23,762 The allocation of the purchase consideration to the fair value of the assets acquired and liabilities assumed is as follows as of the date of the acquisition (in thousands): Cash $ 4,651 Working capital 21,436 Property, plant, and equipment 12,797 Acquired intangible assets 56,392 Other assets 3,049 Deferred income taxes (4,892 ) Other liabilities (3,028 ) Goodwill 57,180 Fair value of purchase consideration $ 147,585 The allocation of the purchase consideration to the fair value of the assets acquired and liabilities assumed is as follows as of the date of the acquisition (in thousands): Cash $ 590 Working capital (1,998 ) Property, plant, and equipment 55 Acquired intangible assets 3,600 Other assets 8 Deferred income taxes (128 ) Goodwill 16,790 Fair value of purchase consideration $ 18,917
Schedule of Acquired Intangible Assets	The intangible assets acquired in this acquisition consisted of the following (in thousands): Fair Value Estimated Trademarks $ 3,200 Indefinite Technology 1,300 15 years Customer relationships 800 11 years Backlog 900 0.25 years Total $ 6,200 The intangible assets acquired in this acquisition consisted of the following (in thousands): Fair Value Estimated Trademarks $ 13,550 Indefinite Technology 3,550 7-15 years Customer relationships 32,892 11-17 years Non-compete agreements 1,300 5 years Backlog 5,100 0.5 years Total $ 56,392 The intangible assets acquired in this acquisition consisted of the following (in thousands): Fair Value Estimated Trademarks $ 600 Indefinite Technology 1,300 10 years Customer relationships 1,700 7 years Total $ 3,600
Pro Forma Information	The pro forma amounts may not be indicative of the results that actually would have been achieved had the acquisitions occurred as of January 1, 2014 and are not necessarily indicative of future results of the combined companies (in thousands, except per share data): Twelve Months Ended December 31, 2015 2014 Net sales $ 1,128,915 $ 1,026,014 Net income (loss) $ 33,587 $ (46,714 ) Net income (loss) per share - Basic $ 1.08 $ (1.50 ) Net income (loss) per share - Diluted $ 1.06 $ (1.50 )
Schedule of Business Combination Costs	All acquisition related costs consisted of the following for the years ended December 31 (in thousands): 2017 2016 2015 Selling, general and administrative costs $ 146 $ 228 $ 732 Cost of sales — 81 230 Total acquisition related costs $ 146 $ 309 $ 962

Goodwill and Related Intangib36

Goodwill and Related Intangible Assets (Tables)	12 Months Ended
Goodwill and Related Intangible Assets (Tables)	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill for the years ended December 31 were as follows (in thousands): Residential Products Industrial and Infrastructure Products Renewable Energy and Conservation Total Balance at December 31, 2015 $ 181,285 $ 53,704 $ 57,401 $ 292,390 Acquired goodwill — — 12,283 12,283 Impairment — — (929 ) (929 ) Foreign currency translation — 180 108 288 Balance at December 31, 2016 $ 181,285 $ 53,884 $ 68,863 $ 304,032 Acquired goodwill 16,790 — — 16,790 Adjustments to prior year acquisitions — — (832 ) (832 ) Foreign currency translation — 396 688 1,084 Balance at December 31, 2017 $ 198,075 $ 54,280 $ 68,719 $ 321,074
Schedule of Acquired Intangible Assets	Acquired intangible assets consist of the following (in thousands): December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Estimated Useful Life Indefinite-lived intangible assets: Trademarks $ 45,107 $ — $ 44,720 $ — Indefinite Finite-lived intangible assets: Trademarks 5,876 3,062 5,808 2,427 5 to 15 Years Unpatented technology 28,107 12,033 26,720 10,041 5 to 20 Years Customer relationships 80,707 39,652 78,569 33,585 5 to 17 Years Non-compete agreements 1,649 931 1,649 623 4 to 10 Years Backlog — — 900 900 .5 to 2 Years 116,339 55,678 113,646 47,576 Total acquired intangible assets $ 161,446 $ 55,678 $ 158,366 $ 47,576
Schedule of Acquired Intangible Asset Amortization Expense	The following table summarizes the impairment charges for the years ended December 31 (in thousands): 2017 2016 2015 Indefinite-lived intangibles (1) Definite-lived intangibles Indefinite-lived intangibles (2) Definite-lived intangibles (3) Indefinite-lived intangibles (4) Definite-lived intangibles Residential Products $ — $ — $ — $ — $ 440 $ — Industrial and Infrastructure Products — — 7,980 — 4,423 — Renewable Energy and Conservation 247 — 1,068 198 — — Impairment charges $ 247 $ — $ 9,048 $ 198 $ 4,863 $ — (1) Renewable Energy and Conservation impairment charges due to the discontinuation of its domestic greenhouse business in China. (2) Industrial and Infrastructure Products impairment charges due to discontinuation of U.S. bar grating product line and annual testing. Renewable Energy and Conservation impairment due to discontinuation of European residential solar racking business and annual testing. (3) Renewable Energy and Conservation impairment due to discontinuation of European residential solar racking business. (4) 2015 impairment charges recognized as a result of the Company’s annual impairment test of indefinite-lived intangibles.
Schedule of Intangible Assets Amortization Expense	The following table summarizes amortization expense for the years ended December 31 (in thousands): 2017 2016 2015 Amortization expense $ 8,761 $ 9,637 $ 12,679
Schedule of Amortization Expense	Amortization expense related to acquired intangible assets for the next five years ended December 31 is estimated as follows (in thousands): 2018 2019 2020 2021 2022 Amortization expense $ 8,289 $ 7,618 $ 7,106 $ 6,504 $ 6,093

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
Accrued Expenses (Tables)	Dec. 31, 2017
Accrued Liabilities, Current [Abstract]
Accrued Expenses	Accrued expenses at December 31 consist of the following (in thousands): 2017 2016 Compensation $ 34,752 $ 27,669 Interest and taxes 8,002 13,102 Customer rebates 10,517 10,303 Insurance 7,261 7,584 Other 14,935 11,734 Total accrued expenses $ 75,467 $ 70,392

Debt (Tables)

Debt (Tables)	12 Months Ended
Debt (Tables)	Dec. 31, 2017
Long-term Debt, Unclassified [Abstract]
Schedule of Long-Term Debt	Long-term debt at December 31 consists of the following (in thousands): 2017 2016 Senior Subordinated 6.25% Notes $ 210,000 $ 210,000 Other debt 2,400 2,800 Less unamortized debt issuance costs (2,379 ) (3,163 ) Total debt 210,021 209,637 Less current maturities 400 400 Total long-term debt $ 209,621 $ 209,237
Schedule of Aggregate Maturities of Long-Term Debt	The aggregate maturities of long-term debt for the next five years and thereafter are as follows (in thousands): 2018 2019 2020 2021 2022 Thereafter Long-term debt payments $ 400 $ 400 $ 400 $ 210,400 $ 400 $ 400
Schedule of Cash Paid for Interest	Total cash paid for interest in the years ended December 31 was (in thousands): 2017 2016 2015 Cash paid for interest $ 13,385 $ 13,906 $ 15,374

Employee Retirement Plans (Tabl

Employee Retirement Plans (Tables)	12 Months Ended
Employee Retirement Plans (Tables)	Dec. 31, 2017
Defined Benefit Plan [Abstract]
Schedule of Funded Status	The following table presents the changes in the plan’s projected benefit obligation, fair value of plan assets, and funded status for the years ended December 31 (in thousands): 2017 2016 Projected benefit obligation at January 1 $ 1,377 $ 1,685 Interest cost 46 59 Actuarial losses (gains) 7 5 Benefits paid (360 ) (372 ) Projected benefit obligation at December 31 1,070 1,377 Fair value of plan assets — — Under funded status (1,070 ) (1,377 ) Unamortized prior service cost 2 4 Unrecognized actuarial gain (173 ) (200 ) Net amount recognized $ (1,241 ) $ (1,573 )
Schedule of Defined Benefit Plan, Amounts Recognized in Consolidated Financial Statements	Amounts recognized in the consolidated financial statements consisted of (in thousands): 2017 2016 Accrued pension liability: Current portion $ 327 $ 360 Long term portion 743 1,016 Pre-tax accumulated other comprehensive income – retirement benefit liability adjustment 171 197 Net amount recognized $ 1,241 $ 1,573
Components of Net Periodic Pension and Other Post-Retirement Benefit Costs Charged to Expense	Components of net periodic pension cost for the years ended December 31 were as follows (in thousands): 2017 2016 2015 Interest cost $ 46 $ 59 $ 66 Amortization of unrecognized prior service cost 2 6 14 Gain amortization (19 ) (13 ) — Net periodic pension cost $ 29 $ 52 $ 80 Assumptions used to calculate the benefit obligation: Discount rate 3.55 % 3.81 % 3.94 %
Schedule of Expected Benefit Payments	Expected benefit payments from the plan for the years ended December 31 are as follows (in thousands): 2018 2019 2020 2021 2022 2023 - 2027 Expected benefit payments $ 327 $ 228 $ 137 $ 100 $ 100 $ 292
Schedule of Multiemployer Plans	The Company’s participation in these plans for the year ended December 31, 2017 is outlined in the table below. The “EIN/ Pension Plan Number” column provides the Employee Identification Number (EIN) and three-digit plan number, if applicable. Unless otherwise noted, the most recent Pension Protection Act (PPA) zone status available in 2017 and 2016 is for the plan’s year ended December 31, 2016 and 2015 , respectively. The zone status is based on information that the Company received from the plans and is certified by the plans’ actuaries. Among other factors, plans in the red zone are generally less than 65% funded, plans in the yellow zone are less than 80% funded, and plans in the green zone are at least 80% funded. EIN/ Pension PPA Zone Status Surcharge Pension Fund Plan Number 2016 2015 Imposed National Integrated Group Pension Plan 22-6190618-001 Red Red Yes Sheet Metal Workers’ National Pension Plan 52-6112463-001 Yellow Yellow Yes Sheet Metal Workers’ Pension Plan of Northern California 51-6115939-001 Red Red Yes
Schedule of Contributions Made by the Company to Each Multiemployer Plan	The table below sets forth the contributions made by the Company to each multiemployer plan for the years ended December 31 (in thousands): Pension Fund 2017 2016 2015 National Integrated Group Pension Plan $ 220 $ 218 $ 246 Sheet Metal Workers’ National Pension Plan 42 50 56 Sheet Metal Workers’ Pension Plan of Northern California 30 28 31 $ 292 $ 296 $ 333
Schedule of Total Expense for All Retirement Plans	Total expense for all retirement plans for the years ended December 31 was (in thousands): 2017 2016 2015 $ 3,044 $ 2,887 $ 2,934

Accumulated Other Comprehensi41

Accumulated Other Comprehensive (Loss) Income (Tables)	12 Months Ended
Accumulated Other Comprehensive (Loss) Income (Tables)	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Components of Accumulated Other Comprehensive (Loss) Income	The cumulative balance of each component of accumulated other comprehensive (loss) income is as follows (in thousands): Foreign Currency Translation Adjustment Minimum Pension Liability Adjustment Unamortized Post-Retirement Health Care Costs Total Pre-Tax Amount Tax (Benefit) Expense Accumulated Other Comprehensive (Loss) Income Balance at December 31, 2015 $ (12,793 ) $ 118 $ (4,251 ) $ (16,926 ) $ (1,510 ) $ (15,416 ) Minimum pension and post retirement health care plan adjustments — 79 1,101 1,180 430 750 Foreign currency translation adjustment 6,945 — — 6,945 — 6,945 Balance at December 31, 2016 $ (5,848 ) $ 197 $ (3,150 ) $ (8,801 ) $ (1,080 ) $ (7,721 ) Minimum pension and post retirement health care plan adjustments — (26 ) 341 315 110 205 Foreign currency translation adjustment 3,150 — — 3,150 — 3,150 Balance at December 31, 2017 $ (2,698 ) $ 171 $ (2,809 ) $ (5,336 ) $ (970 ) $ (4,366 )

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	12 Months Ended
Equity-Based Compensation (Tables)	Dec. 31, 2017
Share-based Compensation [Abstract]
Summary of Compensation Expense Connection with Awards	The Company recognized the following compensation expense in connection with awards that vested under the Plan, the Prior Plan, and the Non-Employee Directors Plan along with the related tax benefits recognized during the years ended December 31 (in thousands): 2017 2016 2015 Expense recognized under the Prior Plan $ 1,059 $ 1,937 $ 1,953 Expense recognized under the Plan 5,643 3,993 1,938 Expense recognized under the Non-Employee Directors Plan 420 443 — Total stock compensation expense $ 7,122 $ 6,373 $ 3,891 Tax benefits recognized related to stock compensation expense $ 2,133 $ 2,485 $ 1,518
Schedule of Number of Awards and Weighted Average Grant Date Fair Value	The following table provides the number of stock unit awards granted and restricted shares issued during the years ended December 31, along with the weighted-average grant-date fair value of each award: 2017 2016 2015 Awards Number of Awards Weighted Average Grant Date Fair Value Number of Awards Weighted Average Grant Date Fair Value Number of Awards Weighted Average Grant Date Fair Value Options 25,000 $ 12.85 — $ — 37,500 $ 7.67 Deferred stock units 10,170 $ 34.42 11,945 $ 29.30 — $ — Restricted shares 2,034 $ 34.42 3,185 $ 29.30 21,318 $ 17.48 Restricted stock units 133,548 $ 36.56 141,982 $ 25.44 212,419 $ 17.78 Performance stock units 108,748 $ 42.72 — $ — 396,714 $ 19.78
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The following table provides the weighted average assumptions used to value stock options issued during the year ended December 31: Year of Grant Fair Value Expected Life (in years) Expected Stock Volatility Risk-free Interest Rate Expected Dividend Yield 2017 $ 12.85 4.00 35.7 % 1.7 % — % 2015 $ 7.67 4.00 35.7 % 1.5 % — %
Summary of Ranges of Outstanding and Exercisable Options	The following table summarizes the ranges of outstanding and exercisable options at December 31, 2017 : Range of Exercise Prices Options Outstanding Weighted Average Remaining Contractual Life (in years) Weighted Average Exercise Price Options Exercisable Weighted Average Exercise Price $8.90 – $9.32 28,750 2.70 $ 8.90 28,750 $ 8.90 $9.33 – $11.73 92,441 3.70 $ 9.74 92,441 $ 9.74 $11.74 – $17.94 39,475 1.70 $ 13.72 39,475 $ 13.72 $17.95 – $23.80 37,000 0.69 $ 22.16 37,000 $ 22.16 $23.81 – $43.05 50,000 8.57 $ 33.90 — $ — 247,666 197,666
Summary of Stock Options Transactions	The following table summarizes information about stock option transactions: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (in years) Aggregate Intrinsic Value Balance at January 1, 2015 569,319 $ 15.88 Granted 37,500 25.44 Exercised (119,096 ) 15.13 Expired / Forfeited (29,374 ) 20.28 Balance at December 31, 2015 458,349 $ 16.57 Exercised (175,125 ) 19.08 Forfeited (6,000 ) 18.22 Balance at December 31, 2016 277,224 $ 14.95 Granted 25,000 42.35 Exercised (42,058 ) 16.02 Forfeited (12,500 ) 25.44 Balance at December 31, 2017 247,666 $ 17.01 5.27 $ 4,194,000
Summary of Information About Restricted Stock Units and Weighted Average Grant Date Fair Value	The following table summarizes information about non-vested restricted stock units, performance stock units (that will convert to shares upon vesting) and restricted shares: Restricted Weighted Restricted Weighted Performance Stock Units (2) (3) Weighted Average Grant Date Fair Value Deferred Stock Units (1) Weighted Average Grant Date Fair Value Balance at December 31, 2016 536,164 $ 17.79 7,361 $ 17.07 396,714 $ 19.78 11,945 $ 29.30 Granted 133,548 36.56 2,034 34.42 108,748 42.72 10,170 34.42 Vested (202,788 ) 15.71 (5,137 ) 23.75 — — — — Forfeited (25,108 ) 25.88 — — (25,000 ) 25.44 — — Balance at December 31, 2017 441,816 $ 23.96 4,258 $ 17.30 480,462 $ 24.68 22,115 $ 31.65 (1) Vested and issued upon retirement.
Aggregate Intrinsic Value of Options Exercised and Aggregate Fair Value of Restricted Stock Units and Restricted Shares that Vested	The following table sets forth the aggregate intrinsic value of options exercised and aggregate fair value of restricted stock units and restricted shares that vested during the years ended December 31 (in thousands): 2017 2016 2015 Aggregate intrinsic value of options exercised $ 628 $ 2,439 $ 1,089 Aggregate fair value of vested restricted stock units $ 6,756 $ 4,368 $ 6,578 Aggregate fair value of vested restricted shares $ 70 $ 247 $ 111 Aggregate fair value of vested deferred stock units $ 350 $ 443 $ —
PSUs Eligible for Conversion to Cash	The following table provides the number of PSUs which will convert to cash for the years ending December 31: 2016 2015 Awards Number of Units (2) Grant Date Fair Value (in $000s) Number of Units (3) Performance stock units (1) 128,000 $ 3,100 219,000 $ 4,039 (1) There were no performance stock units that convert to cash granted to participants in 2017. (2) The participants earned 200% of target aggregating 256,000 PSUs earned. This award will convert to cash and be payable in January 2019. (3) The participants earned 200% of target aggregating 438,000 PSUs earned. This award will be converted to cash and will be paid to participants in the first quarter of 2018 at the trailing 90 -day closing price of the Company's common stock as of December 31, 2017.
Schedule of Compensation Expense Recognized from Change in Fair Value and Vesting of Performance Stock Units	The following table summarizes the compensation expense recognized from the change in fair value and vesting of performance stock units awarded for the years ended December 31 (in thousands): 2017 2016 2015 Performance stock unit compensation expense $ 3,591 $ 10,377 $ 6,965
Cash Paid to Settle Liability Awards	The following table provides the number of restricted stock units credited to active participant accounts, balance of vested and unvested restricted stock units within active participant accounts, payments made with respect to restricted stock units issued under the MSPP, and MSPP expense during years ended December 31: 2017 2016 2015 Restricted stock units credited 84,299 198,155 94,047 Restricted stock units balance, vested and unvested 389,189 646,669 519,668 Share-based liabilities paid, in thousands $ 6,058 $ 3,137 $ 1,901 MSPP expense, in thousands $ 2,432 $ 8,565 $ 2,767

Exit Activity Costs and Asset43

Exit Activity Costs and Asset Impairments (Tables)	12 Months Ended
Exit Activity Costs and Asset Impairments (Tables)	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Summary of Exit Activity Costs and Asset Impairments Recorded in the Consolidated Statements of Operations	The following table provides a summary of where the above exit activity costs and asset impairments are recorded in the consolidated statements of operations for the years ended December 31 (in thousands): 2017 2016 2015 Cost of sales $ 911 $ 9,922 $ 9,381 Selling, general, and administrative expense 4,584 3,825 (6,258 ) Total exit activity costs and asset impairments $ 5,495 $ 13,747 $ 3,123
Reconciliation of Liability for Exit Activity Costs Relating to Facility Consolidation Efforts	The following table sets forth the inventory write-downs, asset impairment charges, exit activity costs and gain on facilities sold in conjunction with these efforts, incurred by segment during the years ended December 31 related to the restructuring activities described above (in thousands): 2017 2016 2015 Inventory write-downs &/or asset impairment charges Exit activity costs Total Inventory write-downs &/or asset impairment charges Exit activity costs Total Inventory write-downs &/or asset impairment charges Exit activity costs Gain on sale leaseback Total Residential Products $ 345 $ 1,058 $ 1,403 $ 1,459 $ 1,074 $ 2,533 $ 6,495 $ 1,256 $ (6,799 ) $ 952 Industrial & Infrastructure Products (2,484 ) 2,820 336 4,221 4,546 8,767 2,009 162 — 2,171 Renewable Energy & Conservation 509 2,986 3,495 1,850 539 2,389 — — — — Corporate — 261 261 — 58 58 — — — — Total exit activity costs & asset impairments $ (1,630 ) $ 7,125 $ 5,495 $ 7,530 $ 6,217 $ 13,747 $ 8,504 $ 1,418 $ (6,799 ) $ 3,123 The following table reconciles the beginning and ending liability for exit activity costs relating to the Company’s facility consolidation efforts (in thousands): 2017 2016 Balance as of January 1 $ 3,744 $ 603 Exit activity costs recognized 7,125 6,217 Cash payments (9,908 ) (3,076 ) Balance as of December 31 $ 961 $ 3,744

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Components of Income (Loss) Before Taxes from Continuing Operations	The components of income (loss) before taxes from continuing operations consisted of the following for the years ended December 31 (in thousands): 2017 2016 2015 Domestic $ 78,468 $ 37,316 $ 40,176 Foreign (560 ) 12,667 (3,076 ) Income before taxes from continuing operations $ 77,908 $ 49,983 $ 37,100
Summary of Provision for Income Taxes for Continuing Operations	The provision for (benefit of) income taxes from continuing operations for the years ended December 31 consisted of the following (in thousands): 2017 2016 2015 Current: U.S. Federal $ 16,882 $ 14,703 $ 12,294 State 2,479 2,987 2,010 Foreign 2,687 3,467 1,371 Total current 22,048 21,157 15,675 Deferred: U.S. Federal (7,466 ) (5,404 ) (178 ) State 1,246 1,595 273 Foreign (885 ) (1,084 ) (2,146 ) Total deferred (7,105 ) (4,893 ) (2,051 ) Provision for income taxes $ 14,943 $ 16,264 $ 13,624
(Benefit of) Provision for Income Taxes from Discontinued Operations	The benefit of income taxes from discontinued operations for the years ended December 31 consisted of the following (in thousands): 2017 2016 2015 Current: U.S. Federal $ 219 $ 24 $ 15 State 20 2 1 Foreign — — — Benefit of income taxes $ 239 $ 26 $ 16
Provision for Income Taxes from Continuing Operations Differs from the Federal Statutory Rate	The provision for income taxes from continuing operations differs from the federal statutory rate of 35% for the years ended December 31 due to the following (in thousands): 2017 2016 2015 Statutory rate $ 27,268 35.0 % $ 17,494 35.0 % $ 12,985 35.0 % State taxes, less federal effect 2,442 3.1 % 3,033 6.1 % 1,845 5.0 % Tax effect of Tax Reform Act (12,535 ) (16.1 )% — — % — — % Domestic manufacturer's deduction (1,578 ) (2.0 )% (1,363 ) (2.7 )% (795 ) (2.1 )% Excess tax benefit on stock based compensation (1,415 ) (1.8 )% — — % — — % Federal tax credits (373 ) (0.5 )% (439 ) (0.9 )% (242 ) (0.7 )% Uncertain tax positions (148 ) (0.2 )% (154 ) (0.3 )% (344 ) (0.9 )% Change in valuation allowance 660 0.8 % 685 1.4 % 284 0.7 % Non-deductible expenses 499 0.7 % 556 1.1 % 2 — % Foreign rate differential 2 — % (677 ) (1.4 )% (6 ) — % Intangible asset impairment — — % 341 0.7 % — — % Worthless stock deduction — — % (868 ) (1.7 )% — — % Intercompany debt discharge — — % (2,389 ) (4.8 )% — — % Other 121 0.2 % 45 — % (105 ) (0.3 )% $ 14,943 19.2 % $ 16,264 32.5 % $ 13,624 36.7 %
Deferred Tax Liabilities (Assets)	Deferred tax liabilities (assets) at December 31 consist of the following (in thousands): 2017 2016 Depreciation $ 9,563 $ 17,367 Goodwill 32,662 43,562 Intangible assets 10,928 14,731 Foreign withholding tax 1,014 — Other 652 892 Gross deferred tax liabilities 54,819 76,552 Equity compensation (12,577 ) (21,439 ) Other (13,247 ) (18,473 ) Gross deferred tax assets (25,824 ) (39,912 ) Valuation allowances 2,242 1,362 Deferred tax assets, net of valuation allowances (23,582 ) (38,550 ) Net deferred tax liabilities $ 31,237 $ 38,002
Summary of Valuation Allowance	The following sets forth a reconciliation of the beginning and ending amount of the Company’s valuation allowance (in thousands): 2017 2016 2015 Balance as of January 1 $ 1,362 $ 766 $ 400 Cost charged to the tax provision 1,505 983 286 Reductions (820 ) (338 ) (78 ) Currency translation 195 (49 ) — Balance as of December 31 $ 2,242 $ 1,362 $ 766
Income Taxes Paid, Net of Tax Refunds	The Company made net payments for income taxes for the following amounts for the years ended December 31 (in thousands): 2017 2016 2015 Payments made for income taxes, net $ 26,186 $ 17,700 $ 11,879
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): 2017 2016 2015 Balance as of January 1 $ 3,466 $ 3,876 $ 1,414 Additions for tax positions of the current year 99 33 148 Additions for tax positions of prior years — — 2,955 Reductions for tax positions of prior years for: Settlements and changes in judgment (422 ) (256 ) (331 ) Lapses of applicable statute of limitations — — (310 ) Divestitures and foreign currency translation 393 (187 ) — Balance as of December 31 $ 3,536 $ 3,466 $ 3,876
Interest (Net of Federal Tax Benefit) and Penalties Recognized	Interest (net of federal tax benefit) and penalties recognized during the years ended December 31 were (in thousands): 2017 2016 2015 Interest and penalties recognized as income $ 130 $ 122 $ 87

Earnings per Share (Tables)

Earnings per Share (Tables)	12 Months Ended
Earnings per Share (Tables)	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Earnings per Share	ears ended December 31 (in thousands): 2017 2016 2015 Numerator: Income from continuing operations $ 62,965 $ 33,719 $ 23,476 Loss from discontinued operations (405 ) (44 ) (28 ) Net income available to common shareholders $ 62,560 $ 33,675 $ 23,448 Denominator for basic earnings per share: Weighted average shares outstanding 31,701 31,536 31,233 Denominator for diluted earnings per share: Common stock options and restricted stock 549 533 312 Weighted average shares and conversions 32,250 32,069 31,545

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Rent Expense under Operating Leases	Rent expense under operating leases for the years ended December 31 aggregated (in thousands): 2017 2016 2015 Rent expense $ 11,964 $ 13,652 $ 13,959
Schedule of Future Minimum Lease Payments under Non-Cancelable Operating Leases	Future minimum lease payments under these noncancelable operating leases as of December 31, 2017 are as follows (in thousands): 2018 2019 2020 2021 2022 Thereafter Future minimum lease payments 11,072 9,274 6,521 4,773 3,817 5,211

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
Segment Information (Tables)	Dec. 31, 2017
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Measurements Used by Management to Assess Performance of Segments	The following table illustrates certain measurements used by management to assess the performance of the segments described above as of and for the years ended December 31 (in thousands): 2017 2016 2015 Net sales: Residential Products $ 466,603 $ 430,938 $ 475,653 Industrial and Infrastructure Products 215,211 296,513 378,224 Less: Intersegment sales (1,247 ) (1,495 ) (1,536 ) 213,964 295,018 376,688 Renewable Energy and Conservation 306,351 282,025 188,532 Total consolidated net sales $ 986,918 $ 1,007,981 $ 1,040,873 Income (loss) from operations: Residential Products $ 76,893 $ 65,241 $ 46,804 Industrial and Infrastructure Products 8,159 1,306 15,581 Renewable Energy and Conservation 30,218 43,214 12,659 Unallocated corporate expenses (22,421 ) (36,273 ) (26,312 ) $ 92,849 $ 73,488 $ 48,732 Depreciation and Amortization Residential Products $ 9,183 $ 9,297 $ 9,967 Industrial and Infrastructure Products 6,529 8,237 12,108 Renewable Energy and Conservation 5,657 6,203 7,811 Unallocated corporate expenses 321 377 662 $ 21,690 $ 24,114 $ 30,548 Total assets Residential Products $ 358,838 $ 331,975 $ 363,339 Industrial and Infrastructure Products 203,455 225,691 273,987 Renewable Energy and Conservation 219,806 207,241 215,211 Unallocated corporate assets 209,286 153,338 37,235 $ 991,385 $ 918,245 $ 889,772 Capital expenditures Residential Products $ 5,236 $ 5,182 $ 3,328 Industrial and Infrastructure Products 2,094 2,060 4,846 Renewable Energy and Conservation 3,648 3,160 3,871 Unallocated corporate expenditures 421 377 328 $ 11,399 $ 10,779 $ 12,373
Net Sales by Region or Origin and Long-Lived Assets by Region of Domicile	Net sales by region or origin and long-lived assets by region of domicile for the years ended and as of December 31 are as follows (in thousands): 2017 2016 2015 Net sales North America $ 977,942 $ 963,797 $ 968,414 Europe 1,131 19,447 48,216 Asia 7,845 24,737 24,243 Total $ 986,918 $ 1,007,981 $ 1,040,873 Long-lived assets North America $ 97,956 $ 108,334 $ 110,571 Europe 3,222 2,900 11,084 Asia 601 992 1,292 Total $ 101,779 $ 112,226 $ 122,947

Supplemental Financial Inform48

Supplemental Financial Information (Tables)	12 Months Ended
Supplemental Financial Information (Tables)	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Consolidating Statements of Operations	GIBRALTAR INDUSTRIES, INC. CONSOLIDATING STATEMENT OF OPERATIONS YEAR ENDED DECEMBER 31, 2016 (in thousands) Gibraltar Guarantor Non-Guarantor Eliminations Total Net sales $ — $ 950,945 $ 78,184 $ (21,148 ) $ 1,007,981 Cost of sales — 722,315 62,729 (21,825 ) 763,219 Gross profit — 228,630 15,455 677 244,762 Selling, general, and administrative expense 14,302 137,343 9,454 — 161,099 Intangible asset impairment — 7,980 2,195 — 10,175 (Loss) income from operations (14,302 ) 83,307 3,806 677 73,488 Interest expense (income) 13,609 1,042 (74 ) — 14,577 Other expense (income) 8,716 512 (300 ) — 8,928 (Loss) income before taxes (36,627 ) 81,753 4,180 677 49,983 (Benefit of) provision for income taxes (11,768 ) 27,551 481 — 16,264 (Loss) income from continuing operations (24,859 ) 54,202 3,699 677 33,719 Discontinued operations: Loss before taxes — (70 ) — — (70 ) Benefit of income taxes — (26 ) — — (26 ) Loss from discontinued operations — (44 ) — — (44 ) Equity in earnings from subsidiaries 57,857 3,699 — (61,556 ) — Net income $ 32,998 $ 57,857 $ 3,699 $ (60,879 ) $ 33,675 GIBRALTAR INDUSTRIES, INC. CONSOLIDATING STATEMENT OF OPERATIONS YEAR ENDED DECEMBER 31, 2015 (in thousands)
Consolidated Statements of Comprehensive Income	GIBRALTAR INDUSTRIES, INC. CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (in thousands) Gibraltar Industries, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Total Year ended December 31, 2017 Net income (loss) $ 63,584 $ 72,261 $ (943 ) $ (72,342 ) $ 62,560 Other comprehensive income: Foreign currency translation adjustment — — 3,150 — 3,150 Adjustment to retirement benefit liability, net of tax — (9 ) — — (9 ) Adjustment to post-retirement healthcare benefit liability, net of tax — 214 — — 214 Other comprehensive income — 205 3,150 — 3,355 Total comprehensive income $ 63,584 $ 72,466 $ 2,207 $ (72,342 ) $ 65,915 Gibraltar Industries, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Total Year ended December 31, 2016 Net income $ 32,998 $ 57,857 $ 3,699 $ (60,879 ) $ 33,675 Other comprehensive income: Foreign currency translation adjustment — — 6,945 — 6,945 Adjustment to retirement benefit liability, net of tax — 55 — — 55 Adjustment to post-retirement healthcare benefit liability, net of tax — 695 — — 695 Other comprehensive income — 750 6,945 — 7,695 Total comprehensive income $ 32,998 $ 58,607 $ 10,644 $ (60,879 ) $ 41,370 Gibraltar Industries, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Total Year ended December 31, 2015 Net income (loss) $ 27,036 $ 36,401 $ (1,213 ) $ (38,776 ) $ 23,448 Other comprehensive income (loss): Foreign currency translation adjustment — — (6,228 ) — (6,228 ) Adjustment to retirement benefit liability, net of tax — 34 15 — 49 Adjustment to post-retirement healthcare benefit liability, net of tax — 171 — — 171 Unrealized loss on cash flow hedges, net of tax — 143 — — 143 Other comprehensive income (loss) — 348 (6,213 ) — (5,865 ) Total comprehensive income (loss) $ 27,036 $ 36,749 $ (7,426 ) $ (38,776 ) $ 17,583
Consolidating Balance Sheets	GIBRALTAR INDUSTRIES, INC. CONSOLIDATING BALANCE SHEET DECEMBER 31, 2017 (in thousands) Gibraltar Industries, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Total Assets Current assets: Cash and cash equivalents $ — $ 192,604 $ 29,676 $ — $ 222,280 Accounts receivable, net — 138,903 6,482 — 145,385 Intercompany balances 324 4,166 (4,490 ) — — Inventories — 82,457 3,915 — 86,372 Other current assets 5,415 (368 ) 3,680 — 8,727 Total current assets 5,739 417,762 39,263 — 462,764 Property, plant, and equipment, net — 93,906 3,192 — 97,098 Goodwill — 298,258 22,816 — 321,074 Acquired intangibles — 97,171 8,597 — 105,768 Other assets — 4,681 — — 4,681 Investment in subsidiaries 739,970 61,746 — (801,716 ) — $ 745,709 $ 973,524 $ 73,868 $ (801,716 ) $ 991,385 Liabilities and Shareholders’ Equity Current liabilities: Accounts payable $ — $ 77,786 $ 4,601 $ — $ 82,387 Accrued expenses 5,469 67,746 2,252 — 75,467 Billings in excess of cost — 9,840 2,939 — 12,779 Current maturities of long-term debt — 400 — — 400 Total current liabilities 5,469 155,772 9,792 — 171,033 Long-term debt 208,521 1,100 — — 209,621 Deferred income taxes — 28,907 2,330 — 31,237 Other non-current liabilities — 47,775 — — 47,775 Shareholders’ equity 531,719 739,970 61,746 (801,716 ) 531,719 $ 745,709 $ 973,524 $ 73,868 $ (801,716 ) $ 991,385 GIBRALTAR INDUSTRIES, INC. CONSOLIDATING BALANCE SHEET DECEMBER 31, 2016 (in thousands) Gibraltar Guarantor Non-Guarantor Eliminations Total Assets Current assets: Cash and cash equivalents $ — $ 143,826 $ 26,351 $ — $ 170,177 Accounts receivable, net — 117,526 6,546 — 124,072 Intercompany balances (615 ) 6,152 (5,537 ) — — Inventories — 85,483 4,129 — 89,612 Other current assets 13,783 (10,070 ) 3,623 — 7,336 Total current assets 13,168 342,917 35,112 — 391,197 Property, plant, and equipment, net — 104,642 3,662 — 108,304 Goodwill — 282,300 21,732 — 304,032 Acquired intangibles — 101,520 9,270 — 110,790 Other assets — 3,922 — — 3,922 Investment in subsidiaries 663,118 58,477 — (721,595 ) — $ 676,286 $ 893,778 $ 69,776 $ (721,595 ) $ 918,245 Liabilities and Shareholders’ Equity Current liabilities: Accounts payable $ — $ 66,363 $ 3,581 $ — $ 69,944 Accrued expenses 7,369 60,004 3,019 — 70,392 Billings in excess of cost — 9,301 2,051 — 11,352 Current maturities of long-term debt — 400 — — 400 Total current liabilities 7,369 136,068 8,651 — 152,088 Long-term debt 208,037 1,200 — — 209,237 Deferred income taxes — 35,354 2,648 — 38,002 Other non-current liabilities — 58,038 — — 58,038 Shareholders’ equity 460,880 663,118 58,477 (721,595 ) 460,880 $ 676,286 $ 893,778 $ 69,776 $ (721,595 ) $ 918,245
Condensed Consolidating Statements of Cash Flows	GIBRALTAR INDUSTRIES, INC. CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS DECEMBER 31, 2017 (in thousands) Gibraltar Industries, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Total Cash Flows from Operating Activities Net cash (used in) provided by operating activities $ (15,172 ) $ 83,114 $ 2,128 $ — $ 70,070 Cash Flows from Investing Activities Purchases of property, plant, and equipment — (11,026 ) (373 ) — (11,399 ) Acquisitions, net of cash acquired — (18,494 ) — — (18,494 ) Net proceeds from sale of property and equipment — 12,905 191 — 13,096 Net cash used in investing activities — (16,615 ) (182 ) — (16,797 ) Cash Flows from Financing Activities Long-term debt payments — (400 ) — — (400 ) Purchase of treasury stock at market prices (2,872 ) — — — (2,872 ) Intercompany financing 17,370 (17,321 ) (49 ) — — Net proceeds from issuance of common stock 674 — — — 674 Net cash provided by (used in) financing activities 15,172 (17,721 ) (49 ) — (2,598 ) Effect of exchange rate changes on cash — — 1,428 — 1,428 Net increase in cash and cash equivalents — 48,778 3,325 — 52,103 Cash and cash equivalents at beginning of year — 143,826 26,351 — 170,177 Cash and cash equivalents at end of year $ — $ 192,604 $ 29,676 $ — $ 222,280 GIBRALTAR INDUSTRIES, INC. CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS DECEMBER 31, 2016 (in thousands) Gibraltar Guarantor Non-Guarantor Eliminations Total Cash Flows from Operating Activities Net cash (used in) provided by operating activities $ (34,243 ) $ 140,890 $ 17,340 $ — $ 123,987 Cash Flows from Investing Activities Purchases of property, plant, and equipment — (10,321 ) (458 ) — (10,779 ) Acquisitions, net of cash acquired — (23,412 ) — — (23,412 ) Net proceeds from sale of property and equipment — 230 723 — 953 Net proceeds from sale of business — — 8,250 — 8,250 Other, net — 1,118 — — 1,118 Net cash (used in) provided by investing activities — (32,385 ) 8,515 — (23,870 ) Cash Flows from Financing Activities Long-term debt payments — (400 ) — — (400 ) Payment of debt issuance costs — (54 ) — — (54 ) Purchase of treasury stock at market prices (1,539 ) — — — (1,539 ) Intercompany financing 32,441 (3,822 ) (28,619 ) — — Net proceeds from issuance of common stock 3,341 — — — 3,341 Net cash provided by (used in) financing activities 34,243 (4,276 ) (28,619 ) — 1,348 Effect of exchange rate changes on cash — — (146 ) — (146 ) Net increase (decrease) in cash and cash equivalents — 104,229 (2,910 ) — 101,319 Cash and cash equivalents at beginning of year — 39,597 29,261 — 68,858 Cash and cash equivalents at end of year $ — $ 143,826 $ 26,351 $ — $ 170,177 GIBRALTAR INDUSTRIES, INC. CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS DECEMBER 31, 2015 (in thousands) Gibraltar Guarantor Non-Guarantor Eliminations Total Cash Flows from Operating Activities Net cash (used in) provided by operating activities $ (13,309 ) $ 94,977 $ 5,553 $ — $ 87,221 Cash Flows from Investing Activities Purchases of property, plant, and equipment — (11,754 ) (619 ) — (12,373 ) Acquisitions, net of cash acquired — (114,145 ) (26,476 ) — (140,621 ) Net proceeds from sale of property and equipment — 26,500 — — 26,500 Other, net — 1,154 1,154 Net cash used in investing activities — (98,245 ) (27,095 ) — (125,340 ) Cash Flows from Financing Activities Long-term debt payments — (73,642 ) — — (73,642 ) Proceeds from long-term debt — 73,242 73,242 Payment of debt issuance costs — (1,166 ) — — (1,166 ) Purchase of treasury stock at market prices (956 ) — — — (956 ) Intercompany financing 12,464 (47,035 ) 34,571 — — Net proceeds from issuance of common stock 1,801 — — — 1,801 Net cash provided by (used in) financing activities 13,309 (48,601 ) 34,571 — (721 ) Effect of exchange rate changes on cash — — (2,912 ) — (2,912 ) Net (decrease) increase in cash and cash equivalents — (51,869 ) 10,117 — (41,752 ) Cash and cash equivalents at beginning of year — 91,466 19,144 — 110,610 Cash and cash equivalents at end of year $ — $ 39,597 $ 29,261 $ — $ 68,858

Quarterly Unaudited Financial49

Quarterly Unaudited Financial Data (Tables)	12 Months Ended
Quarterly Unaudited Financial Data (Tables)	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Unaudited Financial Information	GIBRALTAR INDUSTRIES, INC. QUARTERLY UNAUDITED FINANCIAL DATA (in thousands, except per share data) 2017 Quarters Ended March 31 June 30 September 30 December 31 Total Net sales $ 206,605 $ 247,627 $ 274,574 $ 258,112 $ 986,918 Gross profit $ 49,255 $ 61,825 $ 68,735 $ 56,729 $ 236,544 Income from operations $ 9,679 $ 24,930 $ 35,693 $ 22,547 $ 92,849 Interest expense $ 3,576 $ 3,550 $ 3,486 $ 3,420 $ 14,032 Net income from continuing operations $ 3,996 $ 13,174 $ 20,619 $ 25,176 $ 62,965 Net loss from discontinued operations $ — $ (405 ) $ — $ — $ (405 ) Total net income $ 3,996 $ 12,769 $ 20,619 $ 25,176 $ 62,560 Income per share from continuing operations: Basic $ 0.13 $ 0.41 $ 0.65 $ 0.79 $ 1.98 Diluted $ 0.12 $ 0.41 $ 0.64 $ 0.78 $ 1.95 Loss per share from discontinued operations: Basic $ — $ (0.01 ) $ — $ — $ (0.01 ) Diluted $ — $ (0.01 ) $ — $ — $ (0.01 ) 2016 Quarters Ended March 31 June 30 September 30 December 31 Total Net sales $ 237,671 $ 265,738 $ 272,734 $ 231,838 $ 1,007,981 Gross profit $ 54,150 $ 68,843 $ 67,887 $ 53,882 $ 244,762 Income from operations $ 17,761 $ 28,576 $ 26,522 $ 629 $ 73,488 Interest expense $ 3,691 $ 3,666 $ 3,625 $ 3,595 $ 14,577 Net income (loss) from continuing operations $ 9,029 $ 18,612 $ 13,786 $ (7,708 ) $ 33,719 Net loss from discontinued operations $ — $ — $ — $ (44 ) $ (44 ) Total net income (loss) $ 9,029 $ 18,612 $ 13,786 $ (7,752 ) $ 33,675 Income (loss) per share from continuing operations: Basic $ 0.29 $ 0.59 $ 0.44 $ (0.24 ) $ 1.07 Diluted $ 0.28 $ 0.58 $ 0.43 $ (0.24 ) $ 1.05 Loss per share from discontinued operations: Basic $ — $ — $ — $ — $ — Diluted $ — $ — $ — $ — $ —

Summary of Significant Accoun50

Summary of Significant Accounting Policies (Narrative) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 01, 2018
Sale Leaseback Transaction [Line Items]
Revenue recognized under the percentage-of-completion method		28.00%	25.80%
Advertising costs		$ 4,900,000	$ 5,100,000	$ 4,700,000
Research and development cost		2,900,000	2,200,000	900,000
Net cash provided by operating activities		70,070,000	123,987,000	87,221,000
Net cash (used in) provided by financing activities		(2,598,000)	1,348,000	(721,000)
Selling, General and Administrative Expense		$ (143,448,000)	$ (161,099,000)	$ (133,381,000)
Minimum \| Land, Buildings and Improvements
Sale Leaseback Transaction [Line Items]
Estimated useful lives		15 years
Minimum \| Machinery and Equipment
Sale Leaseback Transaction [Line Items]
Estimated useful lives		3 years
Maximum \| Land, Buildings and Improvements
Sale Leaseback Transaction [Line Items]
Estimated useful lives		40 years
Maximum \| Machinery and Equipment
Sale Leaseback Transaction [Line Items]
Estimated useful lives		20 years
Residential Products \| Home Improvement Retail Company \| Accounts Receivable
Sale Leaseback Transaction [Line Items]
Concentrations of credit risk		13.60%	13.70%
Residential Products \| Home Improvement Retail Company \| Net sales
Sale Leaseback Transaction [Line Items]
Concentrations of credit risk		12.00%	11.00%	11.00%
First quarter 2015 Sale Leaseback
Sale Leaseback Transaction [Line Items]
Sale price	$ 26,400,000
Period of lease	5 years
Net present value of future minimum lease payments	$ 5,800,000
Deferred gain on sale	13,100,000
Gain above minimum lease payments fair value	7,400,000
Minimum lease payment for first year	1,378,000,000
Minimum lease payments year 2	1,378,000,000
Minimum lease payments year 3	1,378,000,000
Minimum lease payments year 4	1,378,000,000
Minimum lease payments year 5	$ 1,378,000,000
Accounting Standards Update 2016-09
Sale Leaseback Transaction [Line Items]
Net cash provided by operating activities			$ 1,249,000	$ 537,000
Net cash (used in) provided by financing activities			1,249,000	573,000
Accounting Standards Update 2016-09 \| Additional Paid-In Capital
Sale Leaseback Transaction [Line Items]
Cumulative effect of new accounting principle in period of adoption			254,000
Subsequent Event \| Accounting Standards Update 2014-09
Sale Leaseback Transaction [Line Items]
Cumulative effect of new accounting principle in period of adoption					$ 750,000
Pro Forma \| Accounting Standards Update 2017-07
Sale Leaseback Transaction [Line Items]
Selling, General and Administrative Expense			524,000	647,000
Other Expenses			$ 524,000	$ 647,000

Summary of Significant Accoun51

Summary of Significant Accounting Policies (Summary of Activity Recorded within the Allowance for Doubtful Accounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning balance	$ 5,272	$ 4,868	$ 4,280
Bad debt expense	1,253	2,519	1,404
Accounts written off and other adjustments	(91)	(2,115)	(816)
Ending balance	$ 6,434	$ 5,272	$ 4,868

Summary of Significant Accoun52

Summary of Significant Accounting Policies (Summary of Interest Capitalized and Depreciation Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Capitalized interest	$ 137	$ 138	$ 166
Depreciation expense	$ 12,929	$ 14,477	$ 17,869

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Receivables [Abstract]
Trade accounts receivable	$ 78,858	$ 81,193
Contract receivables:
Amounts billed	61,351	41,569
Costs in excess of billings	11,610	6,582
Total contract receivables	72,961	48,151
Total accounts receivable	151,819	129,344
Less allowance for doubtful accounts	(6,434)	(5,272)	$ (4,868)	$ (4,280)
Accounts receivable	$ 145,385	$ 124,072

Inventories (Schedule of Invent

Inventories (Schedule of Inventories) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw material	$ 42,661	$ 41,758
Work-in-process	10,598	12,268
Finished goods	33,113	35,586
Total inventories	$ 86,372	$ 89,612

Inventories (Summary of Activit

Inventories (Summary of Activity within the Reserve for Excess, Obsolete, and Slow Moving Inventory) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Inventory [Roll Forward]
Beginning balance	$ 3,801	$ 7,428	$ 5,575
Excess, obsolete and slow moving inventory expense	1,276	(239)	1,539
Scrapped inventory and other adjustments	(1,382)	(3,388)	314
Ending balance	$ 3,695	$ 3,801	$ 7,428

Property, Plant, and Equipmen56

Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Land and land improvements	$ 6,301	$ 7,102
Building and improvements	46,562	50,283
Machinery and equipment	195,301	212,774
Construction in progress	8,522	2,202
Property, plant, and equipment, gross	256,686	272,361
Less: accumulated depreciation	(159,588)	(164,057)
Property, plant, and equipment, net	$ 97,098	$ 108,304

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details) - USD ($) $ in Thousands	Feb. 22, 2017	Dec. 31, 2016	Jun. 09, 2015	Mar. 31, 2017	Dec. 31, 2017	Oct. 11, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill		$ 304,032			$ 321,074		$ 292,390
Adjustments to prior year acquisitions					$ (832)
Package Concierge
Business Acquisition [Line Items]
Acquisition purchase price	$ 18,900
Goodwill	16,790
Fair value of purchase consideration	$ 18,917
Nexus
Business Acquisition [Line Items]
Acquisition purchase price		23,800
Goodwill						$ 11,451
Purchase adjustment to be paid		$ 1,000
Working capital adjustment				$ 200
Adjustments to prior year acquisitions				$ 800
Fair value of purchase consideration						$ 23,762
Rough Brothers Incorporated
Business Acquisition [Line Items]
Acquisition purchase price			$ 147,600
Goodwill			57,180
Tax deductible goodwill			38,000
Indemnification assets			3,000
Fair value of purchase consideration			$ 147,585

Acquisitions (Schedule of Alloc

Acquisitions (Schedule of Allocation of the Purchase Price Consideration of the Fair Value of Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Feb. 22, 2017	Dec. 31, 2016	Oct. 11, 2016	Dec. 31, 2015	Jun. 09, 2015
Business Acquisition [Line Items]
Goodwill	$ 321,074		$ 304,032		$ 292,390
Package Concierge
Business Acquisition [Line Items]
Cash		$ 590
Working capital		(1,998)
Property, plant, and equipment		55
Acquired intangible assets		3,600
Other assets		8
Deferred income taxes		(128)
Goodwill		16,790
Fair value of purchase consideration		$ 18,917
Nexus
Business Acquisition [Line Items]
Cash				$ 2,495
Working capital				(1,109)
Property, plant, and equipment				4,702
Acquired intangible assets				6,200
Other assets				23
Goodwill				11,451
Fair value of purchase consideration				$ 23,762
Rough Brothers Incorporated
Business Acquisition [Line Items]
Cash						$ 4,651
Working capital						21,436
Property, plant, and equipment						12,797
Acquired intangible assets						56,392
Other assets						3,049
Deferred income taxes						(4,892)
Other liabilities						(3,028)
Goodwill						57,180
Fair value of purchase consideration						$ 147,585

Acquisitions (Schedule of Acqui

Acquisitions (Schedule of Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	Feb. 22, 2017	Oct. 11, 2016	Jun. 09, 2015	Dec. 31, 2017
Package Concierge
Business Acquisition [Line Items]
Fair Value	$ 3,600
Package Concierge \| Trademarks
Business Acquisition [Line Items]
Fair Value	600
Package Concierge \| Technology
Business Acquisition [Line Items]
Fair Value	$ 1,300
Estimated Useful Life	10 years
Package Concierge \| Customer relationships
Business Acquisition [Line Items]
Fair Value	$ 1,700
Estimated Useful Life	7 years
Nexus
Business Acquisition [Line Items]
Fair Value		$ 6,200
Estimated Useful Life				3 months
Nexus \| Trademarks
Business Acquisition [Line Items]
Fair Value		3,200
Nexus \| Technology
Business Acquisition [Line Items]
Fair Value		1,300
Estimated Useful Life				15 years
Nexus \| Customer relationships
Business Acquisition [Line Items]
Fair Value		800
Estimated Useful Life				11 years
Nexus \| Backlog
Business Acquisition [Line Items]
Fair Value		$ 900
Rough Brothers Incorporated
Business Acquisition [Line Items]
Fair Value			$ 56,392
Rough Brothers Incorporated \| Trademarks
Business Acquisition [Line Items]
Fair Value			13,550
Rough Brothers Incorporated \| Technology
Business Acquisition [Line Items]
Fair Value			3,550
Rough Brothers Incorporated \| Customer relationships
Business Acquisition [Line Items]
Fair Value			32,892
Rough Brothers Incorporated \| Non-compete agreements
Business Acquisition [Line Items]
Fair Value			1,300
Rough Brothers Incorporated \| Backlog
Business Acquisition [Line Items]
Fair Value			$ 5,100
Rough Brothers Incorporated \| Maximum \| Technology
Business Acquisition [Line Items]
Estimated Useful Life			15 years
Rough Brothers Incorporated \| Maximum \| Customer relationships
Business Acquisition [Line Items]
Estimated Useful Life			17 years
Rough Brothers Incorporated \| Minimum \| Technology
Business Acquisition [Line Items]
Estimated Useful Life			7 years
Rough Brothers Incorporated \| Minimum \| Customer relationships
Business Acquisition [Line Items]
Estimated Useful Life			11 years
Rough Brothers Incorporated \| Minimum \| Non-compete agreements
Business Acquisition [Line Items]
Estimated Useful Life			5 years
Rough Brothers Incorporated \| Minimum \| Backlog
Business Acquisition [Line Items]
Estimated Useful Life			6 months

Acquisitions (Pro Forma Informa

Acquisitions (Pro Forma Information) (Details) - Rough Brothers Incorporated - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Net sales	$ 1,128,915	$ 1,026,014
Net income (loss)	$ 33,587	$ (46,714)
Net income (loss) per share - Basic	$ 1.08	$ (1.50)
Net income (loss) per share - Diluted	$ 1.06	$ (1.50)

Acquisitions (Acquisition Relat

Acquisitions (Acquisition Related Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Total acquisition related costs	$ 146	$ 309	$ 962
Selling, general and administrative costs
Business Acquisition [Line Items]
Total acquisition related costs	146	228	732
Cost of sales
Business Acquisition [Line Items]
Total acquisition related costs	$ 0	$ 81	$ 230

Goodwill and Related Intangib62

Goodwill and Related Intangible Assets (Schedule of Changes in Carrying Amount of Goodwill) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Balance at	$ 304,032,000	$ 292,390,000
Acquired goodwill	16,790,000	12,283,000
Adjustments to prior year acquisitions	(832,000)
Impairment	0	(929,000)
Foreign currency translation	1,084,000	288,000
Balance at	321,074,000	304,032,000
Residential Products
Goodwill [Roll Forward]
Balance at	181,285,000	181,285,000
Acquired goodwill	16,790,000	0
Adjustments to prior year acquisitions	0
Impairment		0
Foreign currency translation	0	0
Balance at	198,075,000	181,285,000
Industrial and Infrastructure Products
Goodwill [Roll Forward]
Balance at	53,884,000	53,704,000
Acquired goodwill	0	0
Adjustments to prior year acquisitions	0
Impairment		0
Foreign currency translation	396,000	180,000
Balance at	54,280,000	53,884,000
Renewable Energy & Conservation
Goodwill [Roll Forward]
Balance at	68,863,000	57,401,000
Acquired goodwill	0	12,283,000
Adjustments to prior year acquisitions	(832,000)
Impairment		(929,000)
Foreign currency translation	688,000	108,000
Balance at	$ 68,719,000	$ 68,863,000

Goodwill and Related Intangib63

Goodwill and Related Intangible Assets (Narrative) (Details)	Oct. 31, 2017reporting_unit	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Goodwill [Line Items]
Goodwill		$ 321,074,000	$ 304,032,000	$ 292,390,000
Accumulated impairment losses		235,400,000	255,530,000
Number of reporting units tested \| reporting_unit	11
Goodwill impairment		0	(929,000)
Impairment of indefinite-lived intangibles		247,000	9,048,000	4,863,000
Impairment of definite-lived intangibles		0	198,000	0
Industrial and Infrastructure Products
Goodwill [Line Items]
Impairment of indefinite-lived intangibles		0	7,980,000	4,423,000
Impairment of definite-lived intangibles		0	0	0
Residential Products
Goodwill [Line Items]
Impairment of indefinite-lived intangibles		0	0	440,000
Impairment of definite-lived intangibles		0	$ 0	$ 0
Solar \| Residential Products
Goodwill [Line Items]
Goodwill impairment		$ (900,000)

Goodwill and Related Intangib64

Goodwill and Related Intangible Assets (Schedule of Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Finite-lived intangible assets	$ 116,339	$ 113,646
Total acquired intangible assets, Gross Carrying Amount	161,446	158,366
Accumulated Amortization, Finite-lived intangible assets	55,678	47,576
Total acquired intangible assets, Accumulated Amortization	55,678	47,576
Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Finite-lived intangible assets	5,876	5,808
Accumulated Amortization, Finite-lived intangible assets	3,062	2,427
Unpatented technology and patents
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Finite-lived intangible assets	28,107	26,720
Accumulated Amortization, Finite-lived intangible assets	12,033	10,041
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Finite-lived intangible assets	80,707	78,569
Accumulated Amortization, Finite-lived intangible assets	39,652	33,585
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Finite-lived intangible assets	1,649	1,649
Accumulated Amortization, Finite-lived intangible assets	931	623
Backlog
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Finite-lived intangible assets	0	900
Accumulated Amortization, Finite-lived intangible assets	0	900
Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Indefinite-lived intangible assets	45,107	44,720
Accumulated Amortization, Indefinite-lived intangible assets	$ 0	$ 0
Minimum \| Trademarks
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	5 years
Minimum \| Unpatented technology and patents
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	5 years
Minimum \| Customer relationships
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	5 years
Minimum \| Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	4 years
Minimum \| Backlog
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	6 months
Maximum \| Trademarks
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	15 years
Maximum \| Unpatented technology and patents
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	20 years
Maximum \| Customer relationships
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	17 years
Maximum \| Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	10 years
Maximum \| Backlog
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	2 years

Goodwill and Related Intangib65

Goodwill and Related Intangible Assets (Schedule of Impairment Charges) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Impairment of indefinite-lived intangibles	$ 247	$ 9,048	$ 4,863
Impairment of definite-lived intangibles	0	198	0
Residential Products
Finite-Lived Intangible Assets [Line Items]
Impairment of indefinite-lived intangibles	0	0	440
Impairment of definite-lived intangibles	0	0	0
Industrial and Infrastructure Products
Finite-Lived Intangible Assets [Line Items]
Impairment of indefinite-lived intangibles	0	7,980	4,423
Impairment of definite-lived intangibles	0	0	0
Renewable Energy & Conservation
Finite-Lived Intangible Assets [Line Items]
Impairment of indefinite-lived intangibles	247	1,068	0
Impairment of definite-lived intangibles	$ 0	$ 198	$ 0

Goodwill and Related Intangib66

Goodwill and Related Intangible Assets (Schedule of Amortization Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of Intangible Assets	$ 8,761	$ 9,637	$ 12,679

Goodwill and Related Intangib67

Goodwill and Related Intangible Assets (Schedule of Future Amortization Expense) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2,018	$ 8,289
2,019	7,618
2,020	7,106
2,021	6,504
2,022	$ 6,093

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Liabilities, Current [Abstract]
Compensation	$ 34,752	$ 27,669
Interest and taxes	8,002	13,102
Customer rebates	10,517	10,303
Insurance	7,261	7,584
Other	14,935	11,734
Total accrued expenses	$ 75,467	$ 70,392

Debt (Schedule of Long-Term Deb

Debt (Schedule of Long-Term Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Jan. 31, 2013
Debt Instrument [Line Items]
Total debt	$ 210,021	$ 209,637
Unamortized original issue discount	(2,379)	(3,163)
Less current maturities	400	400
Total long-term debt	209,621	209,237
Senior Subordinated 6.25% Notes
Debt Instrument [Line Items]
Total debt	$ 210,000	$ 210,000
Senior Subordinated Notes, interest rate	6.25%	6.25%	6.25%
Other debt
Debt Instrument [Line Items]
Total debt	$ 2,400	$ 2,800

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($)	Dec. 09, 2015	Jan. 31, 2013	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Standby letters of credit			$ 11,200,000
Availability amount			$ 288,800,000	$ 287,200,000
Senior Subordinated 6.25% Notes
Debt Instrument [Line Items]
Notes issued		$ 210,000,000
Interest rate		6.25%	6.25%	6.25%
Revolving Credit Facility \| Senior Credit Agreement
Debt Instrument [Line Items]
Current borrowing capacity	$ 300,000,000
Maximum borrowing capacity under the revolving credit facility	$ 500,000,000
Revolving Credit Facility \| Senior Credit Agreement \| Minimum
Debt Instrument [Line Items]
Annual commitment fee	0.20%
Revolving Credit Facility \| Senior Credit Agreement \| Minimum \| LIBOR
Debt Instrument [Line Items]
LIBOR floor, plus	1.25%
Revolving Credit Facility \| Senior Credit Agreement \| Maximum
Debt Instrument [Line Items]
Annual commitment fee	0.30%
Revolving Credit Facility \| Senior Credit Agreement \| Maximum \| LIBOR
Debt Instrument [Line Items]
LIBOR floor, plus	2.25%
Term Loan \| Senior Credit Agreement
Debt Instrument [Line Items]
Term loan (up to)	$ 200,000,000

Debt (Schedule of Aggregate Mat

Debt (Schedule of Aggregate Maturities of Long-Term Debt) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Long-term Debt, Unclassified [Abstract]
2,018	$ 400
2,019	400
2,020	400
2,021	210,400
2,022	400
Thereafter	$ 400

Debt (Schedule of Cash Paid for

Debt (Schedule of Cash Paid for Interest) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Long-term Debt, Unclassified [Abstract]
Cash paid for interest	$ 13,385	$ 13,906	$ 15,374

Employee Retirement Plans (Sche

Employee Retirement Plans (Schedule of Funded Status) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation at	$ 1,377	$ 1,685
Interest cost	46	59	$ 66
Actuarial losses (gains)	7	5
Benefits paid	(360)	(372)
Projected benefit obligation at	1,070	1,377	$ 1,685
Fair value of plan assets	0	0
Under funded status	(1,070)	(1,377)
Unamortized prior service cost	2	4
Unrecognized actuarial gain	(173)	(200)
Net amount recognized	$ (1,241)	$ (1,573)

Employee Retirement Plans (Sc74

Employee Retirement Plans (Schedule of Defined Benefit Plan, Amounts Recognized in Consolidated Financial Statements) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan [Abstract]
Accrued pension liability: Current portion	$ 327	$ 360
Accrued pension liability: Long term portion	743	1,016
Pre-tax accumulated other comprehensive income – retirement benefit liability adjustment	171	197
Net amount recognized	$ 1,241	$ 1,573

Employee Retirement Plans (Comp

Employee Retirement Plans (Components of Net Periodic Pension and Other Post-Retirement Benefit Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost	$ 46	$ 59	$ 66
Amortization of unrecognized prior service cost	2	6	14
Gain amortization	19	13	0
Net periodic pension cost	$ 29	$ 52	$ 80
Discount rate	3.55%	3.81%	3.94%

Employee Retirement Plans (Sc76

Employee Retirement Plans (Schedule of Expected Benefit Payments) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2,018	$ 327
2,019	228
2,020	137
2,021	100
2,022	100
Years 2023 - 2027	$ 292

Employee Retirement Plans (Narr

Employee Retirement Plans (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)agreementemployee	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 1,070	$ 1,377	$ 1,685
Pre-tax accumulated other comprehensive loss - retirement benefit liability adjustment	(171)	(197)
Net liability	$ 1,241	$ 1,573
Number of employees \| employee	2,022
Employees represented by unions through CBAs, percentage	11.00%
Number of CBA's to be negotiated \| agreement	3
Number of CBA's \| agreement	6
Company's maximum contribution percentage	5.00%
National Integrated Group Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
CBAs expiration date	Apr. 30, 2018

Employee Retirement Plans (Sc78

Employee Retirement Plans (Schedule of Multiemployer Plans) (Details) - Pension	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
National Integrated Group Pension Plan [Member]
Multiemployer Plans [Line Items]
EIN	226,190,618
Pension Plan Number	1
PPA Zone Status		Red	Red
Surcharge Imposed	Yes
Sheet Metal Workers National Pension Plan [Member]
Multiemployer Plans [Line Items]
EIN	526,112,463
Pension Plan Number	1
PPA Zone Status		Yellow	Yellow
Surcharge Imposed	Yes
Sheet Metal Workers Pension Plan Of Northern California
Multiemployer Plans [Line Items]
EIN	516,115,939
Pension Plan Number	1
PPA Zone Status		Red	Red
Surcharge Imposed	Yes

Employee Retirement Plans (Sc79

Employee Retirement Plans (Schedule of Contributions Made by the Company to Each Multiemployer Plan) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Contributions	$ 292	$ 296	$ 333
National Integrated Group Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	220	218	246
Sheet Metal Workers National Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	42	50	56
Sheet Metal Workers Pension Plan Of Northern California
Defined Benefit Plan Disclosure [Line Items]
Contributions	$ 30	$ 28	$ 31

Employee Retirement Plans (Sc80

Employee Retirement Plans (Schedule of Total Expense for All Retirement Plans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan [Abstract]
Total retirement plan expense	$ 3,044	$ 2,887	$ 2,934

Accumulated Other Comprehensi86

Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at begging of period	$ (8,801)	$ (16,926)
Other Comprehensive Income (Loss), before Tax	(315)	(1,180)
Balance at end of period	(5,336)	(8,801)	$ (16,926)
Tax (Benefit) Expense
Balance at beginning of period	(1,080)	(1,510)
Minimum pension and post retirement health care plan adjustments	110	430
Balance at end of period	(970)	(1,080)	(1,510)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	(7,721)	(15,416)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax	205	750
Other Comprehensive Income (Loss), Net of Tax	(3,355)	(7,695)	5,865
Balance at end of period	(4,366)	(7,721)	(15,416)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at begging of period	(5,848)	(12,793)
Other Comprehensive Income (Loss), before Tax	3,150	6,945
Balance at end of period	(2,698)	(5,848)	(12,793)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax	3,150	6,945
Accumulated Defined Benefit Plans Adjustment \| Minimum Pension Liability Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at begging of period	197	118
Other Comprehensive Income (Loss), before Tax	26	(79)
Balance at end of period	171	197	118
Accumulated Defined Benefit Plans Adjustment \| Unamortized Post-Retirement Health Care Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at begging of period	(3,150)	(4,251)
Other Comprehensive Income (Loss), before Tax	(341)	(1,101)
Balance at end of period	$ (2,809)	$ (3,150)	$ (4,251)

Equity-Based Compensation (Narr

Equity-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		12 Months Ended
	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market price of common stock, per share				$ 33
Unrecognized compensation cost				$ 9.2
Weighted average cost recognition period, in years				2 years 1 day
Accrued equity based compensation				$ 48	$ 45.5
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Typical vesting period, in years				4 years
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Typical vesting period, in years				3 years
Shares awarded (in shares)				108,748	0	396,714
Award performance period				1 year
Forfeited in period (in shares)				25,000
Performance stock units outstanding (in shares)				480,462	396,714
Equity Based Compensation Percent Of Targeted Performance Stock Units Earned				200.00%	200.00%
Units vested (in shares)				256,000	438,000
Number of days trailing for closing price							90 days
2015 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for issuance under the Plan				354,000
2015 Equity Incentive Plan \| Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares awarded (in shares)	75,000	321,714
Award performance period	3 years
Performance stock units outstanding (in shares)				50,000
Non-Employee Directors Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for issuance under the Plan				73,000
June 2015 \| 2015 Equity Incentive Plan \| Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forfeited in period (in shares)				25,000
Based on actual return on invested capital \| February 2017 \| Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares awarded (in shares)				78,482
Based on actual return on invested capital \| April 2017 \| Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares awarded (in shares)				5,266
Based on total shareholder return vs S&P Small Cap Industrial Sector \| February and April 2017 \| Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares awarded (in shares)				25,000
Non Current Liabilities
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accrued equity based compensation				$ 29.3	$ 40.2
Scenario, Forecast \| 2015 Equity Incentive Plan \| Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares awarded (in shares)			321,714

Equity-Based Compensation (Summ

Equity-Based Compensation (Summary of Compensation Expense Connection with Awards) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation [Abstract]
Expense recognized under the Prior Plan	$ 1,059	$ 1,937	$ 1,953
Expense recognized under the Plan	5,643	3,993	1,938
Expense recognized under the Non-Employee Directors Plan	420	443	0
Total stock compensation expense	7,122	6,373	3,891
Tax benefits recognized related to stock compensation expense	$ 2,133	$ 2,485	$ 1,518

Equity-Based Compensation (Sche

Equity-Based Compensation (Schedule of Number of Awards and Weighted Average Grant Date Fair Value) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Awards (in shares)	25,000	0	37,500
Weighted Average Grant DAte Fair Value (in USD per share)	$ 12.85	$ 0	$ 7.67
Deferred stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Awards (in shares)	10,170	11,945	0
Weighted Average Grant Date Fair Value (in USD per share)	$ 34.42	$ 29.30	$ 0
Restricted shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Awards (in shares)	2,034	3,185	21,318
Weighted Average Grant Date Fair Value (in USD per share)	$ 34.42	$ 29.30	$ 17.48
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Awards (in shares)	133,548	141,982	212,419
Weighted Average Grant Date Fair Value (in USD per share)	$ 36.56	$ 25.44	$ 17.78
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Awards (in shares)	108,748	0	396,714
Weighted Average Grant Date Fair Value (in USD per share)	$ 42.72	$ 0	$ 19.78

Equity-Based Compensation (Weig

Equity-Based Compensation (Weighted Average Assumptions Used to Measure Fair Value of Stock Options) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Fair Value	$ 12.85	$ 7.67
Expected Life (in years)	4 years	4 years
Expected Stock Volatility	35.70%	35.70%
Risk-free Interest Rate	1.70%	1.50%
Expected Dividend Yield	0.00%	0.00%

Equity-Based Compensation (Su91

Equity-Based Compensation (Summary of Ranges of Outstanding and Exercisable Options) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding	247,666	277,224	458,349	569,319
Weighted Average Remaining Contractual Life (in years)	5 years 3 months 7 days
Weighted Average Exercise Price	$ 16.02	$ 19.08	$ 15.13
Options Exercisable	197,666
$8.90 – $9.32
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	$ 8.90
Exercise Price Range, Upper Range Limit	$ 9.32
Options Outstanding	28,750
Weighted Average Remaining Contractual Life (in years)	2 years 8 months 12 days
Weighted Average Exercise Price	$ 8.90
Options Exercisable	28,750
Weighted Average Exercise Price	$ 8.90
$9.33 – $11.73
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	9.33
Exercise Price Range, Upper Range Limit	$ 11.73
Options Outstanding	92,441
Weighted Average Remaining Contractual Life (in years)	3 years 8 months 12 days
Weighted Average Exercise Price	$ 9.74
Options Exercisable	92,441
Weighted Average Exercise Price	$ 9.74
$11.74 – $17.94
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	11.74
Exercise Price Range, Upper Range Limit	$ 17.94
Options Outstanding	39,475
Weighted Average Remaining Contractual Life (in years)	1 year 8 months 12 days
Weighted Average Exercise Price	$ 13.72
Options Exercisable	39,475
Weighted Average Exercise Price	$ 13.72
$17.95 – $23.80
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	17.95
Exercise Price Range, Upper Range Limit	$ 23.80
Options Outstanding	37,000
Weighted Average Remaining Contractual Life (in years)	8 months 9 days
Weighted Average Exercise Price	$ 22.16
Options Exercisable	37,000
Weighted Average Exercise Price	$ 22.16
$23.81 – $43.05
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	23.81
Exercise Price Range, Upper Range Limit	$ 43.05
Options Outstanding	50,000
Weighted Average Remaining Contractual Life (in years)	8 years 6 months 26 days
Weighted Average Exercise Price	$ 33.90
Options Exercisable	0
Weighted Average Exercise Price	$ 0

Equity-Based Compensation (Su92

Equity-Based Compensation (Summary of Stock Option Transactions) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Options (in shares):
Beginning balance (in shares)	277,224	458,349	569,319
Granted (in shares)	25,000	0	37,500
Exercised (in shares)	(42,058)	(175,125)	(119,096)
Forfeited (in shares)	(12,500)	(6,000)	(29,374)
Ending balance (in shares)	247,666	277,224	458,349
Weighted Average Exercise Price (in dollars per share)
Begininng balance (in dollars per share)	$ 14.95	$ 16.57	$ 15.88
Granted (in dollars per share)	42.35		25.44
Exercised (in dollars per share)	16.02	19.08	15.13
Forfeited (in dollars per share)	25.44	18.22	20.28
Ending balance (in dollars per share)	$ 17.01	$ 14.95	$ 16.57
Weighted Average Remaining Contractual Life (in years)	5 years 3 months 7 days
Aggregate Intrinsic Value	$ 4,194

Equity-Based Compensation (Su93

Equity-Based Compensation (Summary of Information about Restricted Stock Units and Weighted Average Grant Date Fair Value) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted stock units
Restricted Stock Units / Restricted Stock (in shares)
Balance at beginning of period (in shares)	536,164
Granted (in shares)	133,548	141,982	212,419
Vested (in shares)	(202,788)
Forfeited (in shares)	(25,108)
Balance at end of period (in shares)	441,816	536,164
Weighted Average Grant Date Fair Value (in dollars per share)
Balance at beginning of period (in USD per share)	$ 17.79
Granted (in USD per share)	36.56	$ 25.44	$ 17.78
Vested (in USD per share)	15.71
Forfeited (in USD per share)	25.88
Balance at end of period (in USD per share)	$ 23.96	$ 17.79
Restricted shares
Restricted Stock Units / Restricted Stock (in shares)
Balance at beginning of period (in shares)	7,361
Granted (in shares)	2,034	3,185	21,318
Vested (in shares)	(5,137)
Forfeited (in shares)	0
Balance at end of period (in shares)	4,258	7,361
Weighted Average Grant Date Fair Value (in dollars per share)
Balance at beginning of period (in USD per share)	$ 17.07
Granted (in USD per share)	34.42	$ 29.30	$ 17.48
Vested (in USD per share)	23.75
Forfeited (in USD per share)	0
Balance at end of period (in USD per share)	$ 17.30	$ 17.07
Performance stock units
Restricted Stock Units / Restricted Stock (in shares)
Balance at beginning of period (in shares)	396,714
Granted (in shares)	108,748	0	396,714
Vested (in shares)	0
Forfeited (in shares)	(25,000)
Balance at end of period (in shares)	480,462	396,714
Weighted Average Grant Date Fair Value (in dollars per share)
Balance at beginning of period (in USD per share)	$ 19.78
Granted (in USD per share)	42.72	$ 0	$ 19.78
Vested (in USD per share)	0
Forfeited (in USD per share)	25.44
Balance at end of period (in USD per share)	$ 24.68	$ 19.78
Deferred stock units
Restricted Stock Units / Restricted Stock (in shares)
Balance at beginning of period (in shares)	11,945
Granted (in shares)	10,170	11,945	0
Vested (in shares)	0
Forfeited (in shares)	0
Balance at end of period (in shares)	22,115	11,945
Weighted Average Grant Date Fair Value (in dollars per share)
Balance at beginning of period (in USD per share)	$ 29.30
Granted (in USD per share)	34.42	$ 29.30	$ 0
Vested (in USD per share)	0
Forfeited (in USD per share)	0
Balance at end of period (in USD per share)	$ 31.65	$ 29.30

Equity-Based Compensation (Aggr

Equity-Based Compensation (Aggregate Intrinsic Value of Options Exercised and Aggregate Fair Value of Restricted Stock Units and Restricted Shares that Vested) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of options exercised	$ 628	$ 2,439	$ 1,089
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value	6,756	4,368	6,578
Restricted shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value	70	247	111
Deferred stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value	$ 350	$ 443	$ 0

Equity-Based Compensation (Sc95

Equity-Based Compensation (Schedule of Compensation Expense Recognized from Change in Fair Value and Vesting of Performance Stock Units) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance stock unit compensation expense	$ 3,591	$ 10,377	$ 6,965

Equity-Based Compensation (PSUs

Equity-Based Compensation (PSUs Eligible for Conversion to Cash) (Details) - Performance stock units - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units (in shares)		128,000	219,000
Grant date fair value		$ 3,100	$ 4,039
Equity Based Compensation Percent Of Targeted Performance Stock Units Earned	200.00%	200.00%
Units vested (in shares)	256,000	438,000

Equity-Based Compensation (Cash

Equity-Based Compensation (Cash Paid to Settle Liability Awards) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
MSPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units credited	$ 6,058	$ 3,137	$ 1,901
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units credited	$ 84,299	$ 198,155	$ 94,047
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	389,189,000	646,669,000	519,668,000
Restricted stock units balance, vested and unvested	441,816	536,164
Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
MSPP expense, in thousands	$ 2,432	$ 8,565	$ 2,767

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Jan. 31, 2013
Extinguishment of Debt [Line Items]
Carrying value of outstanding debt	$ 210,021	$ 209,637
Senior Subordinated 6.25% Notes
Extinguishment of Debt [Line Items]
Carrying value of outstanding debt	$ 210,000	$ 210,000
Senior Subordinated Notes, interest rate	6.25%	6.25%	6.25%
Fair Value
Extinguishment of Debt [Line Items]
Fair value of debt, gross	$ 213,800	$ 219,900

Exit Activity Costs and Asset99

Exit Activity Costs and Asset Impairments (Narrative) (Details) $ in Thousands	Apr. 15, 2016USD ($)	Dec. 31, 2017USD ($)facility	Dec. 31, 2016USD ($)facility	Dec. 31, 2015USD ($)facility
Restructuring and Related Activities [Abstract]
Exit activity charges		$ 5,495	$ 13,747	$ 3,123
Restructuring impairment charges		(1,630)	7,530	8,504
Exit activity costs		$ 7,125	$ 6,217	$ 1,418
Number of consolidated facilities to be closed \| facility		3	7	4
Sale leaseback gain				$ 6,799
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 8,800
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Net of Tax	2,000
Net proceeds from sale of business	$ 8,300	$ 0	$ 8,250	$ 0

Exit Activity Costs and Asse100

Exit Activity Costs and Asset Impairments (Schedule Of Asset Impairment Charges Related To Restructuring Activities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment charges	$ (1,630)	$ 7,530	$ 8,504
Exit activity costs	7,125	6,217	1,418
Gain on sale leaseback			(6,799)
Total exit activity costs & asset impairments	5,495	13,747	3,123
Corporate
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment charges	0	0	0
Exit activity costs	261	58	0
Gain on sale leaseback			0
Total exit activity costs & asset impairments	261	58	0
Residential Products \| Operating Segments
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment charges	345	1,459	6,495
Exit activity costs	1,058	1,074	1,256
Gain on sale leaseback			(6,799)
Total exit activity costs & asset impairments	1,403	2,533	952
Industrial and Infrastructure Products \| Operating Segments
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment charges	(2,484)	4,221	2,009
Exit activity costs	2,820	4,546	162
Gain on sale leaseback			0
Total exit activity costs & asset impairments	$ 336	$ 8,767	$ 2,171

Exit Activity Costs and Asse101

Exit Activity Costs and Asset Impairments (Summary Of Exit Activity Costs And Asset Impairments by Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment charges	$ (1,630)	$ 7,530	$ 8,504
Exit activity costs	7,125	6,217	1,418
Gain on sale leaseback			(6,799)
Total exit activity costs & asset impairments	5,495	13,747	3,123
Corporate
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment charges	0	0	0
Exit activity costs	261	58	0
Gain on sale leaseback			0
Total exit activity costs & asset impairments	261	58	0
Residential Products \| Operating Segments
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment charges	345	1,459	6,495
Exit activity costs	1,058	1,074	1,256
Gain on sale leaseback			(6,799)
Total exit activity costs & asset impairments	1,403	2,533	952
Industrial and Infrastructure Products \| Operating Segments
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment charges	(2,484)	4,221	2,009
Exit activity costs	2,820	4,546	162
Gain on sale leaseback			0
Total exit activity costs & asset impairments	336	8,767	2,171
Renewable Energy & Conservation \| Operating Segments
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment charges	509	1,850	0
Exit activity costs	2,986	539	0
Gain on sale leaseback			0
Total exit activity costs & asset impairments	$ 3,495	$ 2,389	$ 0

Exit Activity Costs and Asse102

Exit Activity Costs and Asset Impairments (Summary Of Exit Activity Costs And Asset Impairments Recorded in the Consolidated Statements of Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Total exit activity costs & asset impairments	$ 5,495	$ 13,747	$ 3,123
Cost of sales
Restructuring Cost and Reserve [Line Items]
Total exit activity costs & asset impairments	911	9,922	9,381
Selling, general, and administrative expense
Restructuring Cost and Reserve [Line Items]
Total exit activity costs & asset impairments	$ 4,584	$ 3,825	$ (6,258)

Exit Activity Costs and Asse103

Exit Activity Costs and Asset Impairments (Reconciles Of Liability For Exit Activity Costs Relating To Facility Consolidation Efforts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Reserve [Roll Forward]
Balance as of	$ 3,744	$ 603
Exit activity costs recognized	7,125	6,217	$ 1,418
Cash payments	(9,908)	(3,076)
Balance as of	$ 961	$ 3,744	$ 603

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Income Taxes (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Provisional tax benefit from remeasurement of deferred tax liabilities	$ 16.2
Transition tax for foreign earnings	$ 3.7
Statutory tax rate, percentage	35.00%	35.00%	35.00%
Deferred tax assets, net of operating losses	$ 22.5
Deferred tax assets, net of operating losses	3.5
Undistributed earnings of foreign subsidiaries	27.2
Cash held in foreign operations	24.4
Unrecognized tax benefits that would affect the effective tax rate	$ 0.3	$ 0.6
Minimum
Operating Loss Carryforwards [Line Items]
Statute of limitations expiration period, in years	4 years
Maximum
Operating Loss Carryforwards [Line Items]
Statute of limitations expiration period, in years	10 years
RBI
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefits that would affect the effective tax rate	$ 3.2	$ 2.8

Income Taxes (Components of Inc

Income Taxes (Components of Income (Loss) before Taxes from Continuing Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Domestic	$ 78,468	$ 37,316	$ 40,176
Foreign	(560)	12,667	(3,076)
Income before taxes	$ 77,908	$ 49,983	$ 37,100

Income Taxes (Benefit of) Provi

Income Taxes (Benefit of) Provision for Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Benefit of income taxes	$ (239)	$ (26)	$ (16)
Deferred:
Total deferred	(7,105)	(4,893)	(2,051)
Provision for income taxes	14,943	16,264	13,624
Continuing Operations
Current:
U.S. Federal	16,882	14,703	12,294
State	2,479	2,987	2,010
Foreign	2,687	3,467	1,371
Total current	22,048	21,157	15,675
Deferred:
U.S. Federal	(7,466)	(5,404)	(178)
State	1,246	1,595	273
Foreign	(885)	(1,084)	(2,146)
Total deferred	(7,105)	(4,893)	(2,051)
Provision for income taxes	14,943	16,264	13,624
Discontinued Operations
Current:
U.S. Federal	219	24	15
State	20	2	1
Foreign	0	0	0
Benefit of income taxes	$ 239	$ 26	$ 16

Income Taxes (Provision for Inc

Income Taxes (Provision for Income Taxes from Continuing Operations Differs from the Federal Statutory Rate) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Statutory rate	$ 27,268	$ 17,494	$ 12,985
State taxes, less federal effect	2,442	3,033	1,845
Tax effect of Tax Reform Act	(12,535)	0	0
Domestic manufacturer's deduction	(1,578)	(1,363)	(795)
Excess tax benefit on stock based compensation	(1,415)	0	0
Federal tax credits	(373)	(439)	(242)
Uncertain tax positions	(148)	(154)	(344)
Change in valuation allowance	660	685	284
Non-deductible expenses	499	556	2
Foreign rate differential	2	(677)	(6)
Intangible asset impairment	0	341	0
Worthless stock deduction	0	(868)	0
Intercompany debt discharge	0	(2,389)	0
Other	121	45	(105)
Provision for income taxes	$ 14,943	$ 16,264	$ 13,624
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory rate	35.00%	35.00%	35.00%
State taxes, less federal effect	3.10%	6.10%	5.00%
Tax effect of Tax Reform Act	(16.10%)	0.00%	0.00%
Domestic manufacturer's deduction	(2.00%)	(2.70%)	(2.10%)
Excess tax benefit on stock based compensation	(1.80%)	(0.00%)	(0.00%)
Federal tax credits	(0.50%)	(0.90%)	(0.70%)
Uncertain tax positions	(0.20%)	(0.30%)	(0.90%)
Change in valuation allowance	0.80%	1.40%	0.70%
Non-deductible expenses	0.70%	1.10%	0.00%
Foreign rate differential	0.00%	(1.40%)	0.00%
Intangible asset impairment	0.00%	0.70%	0.00%
Worthless stock deduction	(0.00%)	(1.70%)	(0.00%)
Intercompany debt discharge	(0.00%)	(4.80%)	(0.00%)
Other	0.20%	0.00%	(0.30%)
Effective income tax rate, percentage	19.20%	32.50%	36.70%

Income Taxes (Deferred Tax Liab

Income Taxes (Deferred Tax Liabilities (Assets)) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Depreciation	$ 9,563	$ 17,367
Goodwill	32,662	43,562
Intangible assets	10,928	14,731
Foreign withholding tax	1,014	0
Other	652	892
Gross deferred tax liabilities	54,819	76,552
Equity compensation	(12,577)	(21,439)
Other	(13,247)	(18,473)
Gross deferred tax assets	(25,824)	(39,912)
Valuation allowances	2,242	1,362
Deferred tax assets, net of valuation allowances	(23,582)	(38,550)
Net deferred tax liabilities	$ 31,237	$ 38,002

Income Taxes (Summary of Valuat

Income Taxes (Summary of Valuation Allowance) (Details) - Deferred Tax Valuation Allowance - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance as of January 1	$ 1,362	$ 766	$ 400
Cost charged to the tax provision	1,505	983	286
Currency translation	(820)	(338)	(78)
Currency translation	195	(49)	0
Balance as of December 31	$ 2,242	$ 1,362	$ 766

Income Taxes (Income Taxes Paid

Income Taxes (Income Taxes Paid, Net of Tax Refunds) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Payments made for income taxes, net	$ 26,186	$ 17,700	$ 11,879

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance as of January 1	$ 3,466	$ 3,876	$ 1,414
Additions for tax positions of the current year	99	33	148
Additions for tax positions of prior years	0	0	2,955
Settlements and changes in judgment	(422)	(256)	(331)
Lapses of applicable statute of limitations	0	0	(310)
Divestitures and foreign currency translation	393	(187)	0
Balance as of December 31	$ 3,536	$ 3,466	$ 3,876

Income Taxes (Interest (Net of

Income Taxes (Interest (Net of Federal Tax Benefit) and Penalties Recognized) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Interest and penalties recognized as income	$ 130	$ 122	$ 87

Earnings per Share (Narrative)

Earnings per Share (Narrative) (Details) - shares	12 Months Ended
Earnings per Share (Narrative) (Details) - shares	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive number of shares	468,000	653,000	643,000

Earnings per Share (Schedule of

Earnings per Share (Schedule of Computation of Basic and Diluted Earnings per Share) (Details) - USD ($) shares in Thousands, $ 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
Earnings Per Share [Abstract]
Income from continuing operations	$ 25,176	$ 20,619	$ 13,174	$ 3,996	$ (7,708)	$ 13,786	$ 18,612	$ 9,029	$ 62,965	$ 33,719	$ 23,476
Loss from discontinued operations	0	0	(405)	0	(44)	0	0	0	(405)	(44)	(28)
Net income	$ 25,176	$ 20,619	$ 12,769	$ 3,996	$ (7,752)	$ 13,786	$ 18,612	$ 9,029	$ 62,560	$ 33,675	$ 23,448
Weighted average shares outstanding (in shares)									31,701	31,536	31,233
Common stock options and restricted stock (in shares)									549	533	312
Weighted average shares and conversions (in shares)									32,250	32,069	31,545

Commitments and Contingencie115

Commitments and Contingencies (Schedule of Rent Expense under Operating Leases) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 11,964	$ 13,652	$ 13,959

Commitments and Contingencie116

Commitments and Contingencies (Schedule of Future Minimum Lease Payments under Non-Cancelable Operating Leases) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,018	$ 11,072
2,019	9,274
2,020	6,521
2,021	4,773
2,022	3,817
Thereafter	$ 5,211

Related Party Transactions (Nar

Related Party Transactions (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Officer \| Leased Real Estate Properties
Related Party Transaction [Line Items]
Related party lease expense	$ 1.1	$ 1

Segment Information (Narrative)

Segment Information (Narrative) (Details)	12 Months Ended
Segment Information (Narrative) (Details)	Dec. 31, 2017segment
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Number of reportable segments	3

Segment Information (Measuremen

Segment Information (Measurements Used by Management to Assess Performance of Segments) (Details) - 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, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales	$ 258,112	$ 274,574	$ 247,627	$ 206,605	$ 231,838	$ 272,734	$ 265,738	$ 237,671	$ 986,918	$ 1,007,981	$ 1,040,873
Income (loss) from operations:	22,547	$ 35,693	$ 24,930	$ 9,679	629	$ 26,522	$ 28,576	$ 17,761	92,849	73,488	48,732
Depreciation and amortization									21,690	24,114	30,548
Total assets	991,385				918,245				991,385	918,245	889,772
Capital expenditures									11,399	10,779	12,373
Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Income (loss) from operations:									30,218	43,214	12,659
Intersegment sales
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales:									(1,247)	(1,495)	(1,536)
Unallocated Corporate Expenses
Segment Reporting, Other Significant Reconciling Item [Line Items]
Income (loss) from operations:									(22,421)	(36,273)	(26,312)
Depreciation and amortization									321	377	662
Total assets	209,286				153,338				209,286	153,338	37,235
Capital expenditures									421	377	328
Residential Products \| Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales									466,603	430,938	475,653
Income (loss) from operations:									76,893	65,241	46,804
Depreciation and amortization									9,183	9,297	9,967
Total assets	358,838				331,975				358,838	331,975	363,339
Capital expenditures									5,236	5,182	3,328
Industrial and Infrastructure Products
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales									213,964	295,018	376,688
Industrial and Infrastructure Products \| Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales:									215,211	296,513	378,224
Income (loss) from operations:									8,159	1,306	15,581
Depreciation and amortization									6,529	8,237	12,108
Total assets	203,455				225,691				203,455	225,691	273,987
Capital expenditures									2,094	2,060	4,846
Renewable Energy & Conservation \| Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales									306,351	282,025	188,532
Depreciation and amortization									5,657	6,203	7,811
Total assets	$ 219,806				$ 207,241				219,806	207,241	215,211
Capital expenditures									$ 3,648	$ 3,160	$ 3,871

Segment Information (Net Sales

Segment Information (Net Sales by Region or Origin and Long-Lived Assets by Region of Domicile) (Details) - 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, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 258,112	$ 274,574	$ 247,627	$ 206,605	$ 231,838	$ 272,734	$ 265,738	$ 237,671	$ 986,918	$ 1,007,981	$ 1,040,873
Long-lived assets	101,779				112,226				101,779	112,226	122,947
North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									977,942	963,797	968,414
Long-lived assets	97,956				108,334				97,956	108,334	110,571
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									1,131	19,447	48,216
Long-lived assets	3,222				2,900				3,222	2,900	11,084
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									7,845	24,737	24,243
Long-lived assets	$ 601				$ 992				$ 601	$ 992	$ 1,292

Supplemental Financial Infor121

Supplemental Financial Information (Narrative) (Details)	Dec. 31, 2017	Dec. 31, 2016	Jan. 31, 2013
Senior Subordinated 6.25% Notes
Debt Instrument [Line Items]
Senior Subordinated Notes, interest rate	6.25%	6.25%	6.25%

Supplemental Financial Infor122

Supplemental Financial Information (Consolidating Statements of Operations) (Details) - 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, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Income Statements, Captions [Line Items]
Net sales	$ 258,112	$ 274,574	$ 247,627	$ 206,605	$ 231,838	$ 272,734	$ 265,738	$ 237,671	$ 986,918	$ 1,007,981	$ 1,040,873
Cost of sales									750,374	763,219	853,897
Gross profit	56,729	68,735	61,825	49,255	53,882	67,887	68,843	54,150	236,544	244,762	186,976
Selling, general, and administrative expense									143,448	161,099	133,381
Intangible asset impairment									247	10,175	4,863
Income from operations	22,547	35,693	24,930	9,679	629	26,522	28,576	17,761	92,849	73,488	48,732
Interest expense	3,420	3,486	3,550	3,576	3,595	3,625	3,666	3,691	14,032	14,577	15,003
Other expense (income)									909	8,928	(3,371)
Income before taxes									77,908	49,983	37,100
Provision for income taxes									14,943	16,264	13,624
Income from continuing operations	25,176	20,619	13,174	3,996	(7,708)	13,786	18,612	9,029	62,965	33,719	23,476
Loss before taxes									(644)	(70)	(44)
Benefit of income taxes									(239)	(26)	(16)
Loss from discontinued operations	0	0	(405)	0	(44)	0	0	0	(405)	(44)	(28)
Equity in earnings from subsidiaries									0	0	0
Net income	$ 25,176	$ 20,619	$ 12,769	$ 3,996	$ (7,752)	$ 13,786	$ 18,612	$ 9,029	62,560	33,675	23,448
Gibraltar Industries, Inc.
Condensed Income Statements, Captions [Line Items]
Net sales									0	0	0
Cost of sales									0	0	0
Gross profit									0	0	0
Selling, general, and administrative expense									147	14,302	133
Intangible asset impairment									0	0	0
Income from operations									(147)	(14,302)	(133)
Interest expense									13,609	13,609	13,609
Other expense (income)									0	8,716	50
Income before taxes									(13,756)	(36,627)	(13,792)
Provision for income taxes									(5,079)	(11,768)	(4,427)
Income from continuing operations									(8,677)	(24,859)	(9,365)
Loss before taxes									0	0	0
Benefit of income taxes									0	0	0
Loss from discontinued operations									0	0	0
Equity in earnings from subsidiaries									72,261	57,857	36,401
Net income									63,584	32,998	27,036
Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Net sales									947,604	950,945	960,614
Cost of sales									719,587	722,315	785,085
Gross profit									228,017	228,630	175,529
Selling, general, and administrative expense									133,409	137,343	115,882
Intangible asset impairment									200	7,980	4,863
Income from operations									94,408	83,307	54,784
Interest expense									512	1,042	1,469
Other expense (income)									500	512	(3,154)
Income before taxes									93,396	81,753	56,469
Provision for income taxes									19,787	27,551	18,827
Income from continuing operations									73,609	54,202	37,642
Loss before taxes									(644)	(70)	(44)
Benefit of income taxes									(239)	(26)	(16)
Loss from discontinued operations									(405)	(44)	(28)
Equity in earnings from subsidiaries									(943)	3,699	(1,213)
Net income									72,261	57,857	36,401
Non-Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Net sales									52,738	78,184	109,984
Cost of sales									43,187	62,729	94,949
Gross profit									9,551	15,455	15,035
Selling, general, and administrative expense									9,892	9,454	17,366
Intangible asset impairment									47	2,195	0
Income from operations									(388)	3,806	(2,331)
Interest expense									(89)	(74)	(75)
Other expense (income)									409	(300)	(267)
Income before taxes									(708)	4,180	(1,989)
Provision for income taxes									235	481	(776)
Income from continuing operations									(943)	3,699	(1,213)
Loss before taxes									0	0	0
Benefit of income taxes									0	0	0
Loss from discontinued operations									0	0	0
Equity in earnings from subsidiaries									0	0	0
Net income									(943)	3,699	(1,213)
Eliminations
Condensed Income Statements, Captions [Line Items]
Net sales									(13,424)	(21,148)	(29,725)
Cost of sales									(12,400)	(21,825)	(26,137)
Gross profit									(1,024)	677	(3,588)
Selling, general, and administrative expense									0	0	0
Intangible asset impairment									0	0	0
Income from operations									(1,024)	677	(3,588)
Interest expense									0	0	0
Other expense (income)									0	0	0
Income before taxes									(1,024)	677	(3,588)
Provision for income taxes									0	0	0
Income from continuing operations									(1,024)	677	(3,588)
Loss before taxes									0	0	0
Benefit of income taxes									0	0	0
Loss from discontinued operations									0	0	0
Equity in earnings from subsidiaries									(71,318)	(61,556)	(35,188)
Net income									$ (72,342)	$ (60,879)	$ (38,776)

Supplemental Financial Infor123

Supplemental Financial Information (Consolidating Statements of Comprehensive Income) (Details) - 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, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Statement of Income Captions [Line Items]
Net income	$ 25,176	$ 20,619	$ 12,769	$ 3,996	$ (7,752)	$ 13,786	$ 18,612	$ 9,029	$ 62,560	$ 33,675	$ 23,448
Other comprehensive income:
Foreign currency translation adjustment									3,150	6,945	(6,228)
Unrealized loss on cash flow hedges, net of tax									0	0	143
Adjustment to retirement benefit liability, net of tax									(9)	55	49
Adjustment to post-retirement healthcare benefit liability, net of tax									214	695	171
Other comprehensive income (loss)									3,355	7,695	(5,865)
Total comprehensive income									65,915	41,370	17,583
Gibraltar Industries, Inc.
Condensed Statement of Income Captions [Line Items]
Net income									63,584	32,998	27,036
Other comprehensive income:
Foreign currency translation adjustment									0	0	0
Unrealized loss on cash flow hedges, net of tax											0
Adjustment to retirement benefit liability, net of tax									0	0	0
Adjustment to post-retirement healthcare benefit liability, net of tax									0	0	0
Other comprehensive income (loss)									0	0	0
Total comprehensive income									63,584	32,998	27,036
Guarantor Subsidiaries
Condensed Statement of Income Captions [Line Items]
Net income									72,261	57,857	36,401
Other comprehensive income:
Foreign currency translation adjustment									0	0	0
Unrealized loss on cash flow hedges, net of tax											143
Adjustment to retirement benefit liability, net of tax									(9)	55	34
Adjustment to post-retirement healthcare benefit liability, net of tax									214	695	171
Other comprehensive income (loss)									205	750	348
Total comprehensive income									72,466	58,607	36,749
Non-Guarantor Subsidiaries
Condensed Statement of Income Captions [Line Items]
Net income									(943)	3,699	(1,213)
Other comprehensive income:
Foreign currency translation adjustment									3,150	6,945	(6,228)
Unrealized loss on cash flow hedges, net of tax											0
Adjustment to retirement benefit liability, net of tax									0	0	15
Adjustment to post-retirement healthcare benefit liability, net of tax									0	0	0
Other comprehensive income (loss)									3,150	6,945	(6,213)
Total comprehensive income									2,207	10,644	(7,426)
Eliminations
Condensed Statement of Income Captions [Line Items]
Net income									(72,342)	(60,879)	(38,776)
Other comprehensive income:
Foreign currency translation adjustment									0	0	0
Unrealized loss on cash flow hedges, net of tax											0
Adjustment to retirement benefit liability, net of tax									0	0	0
Adjustment to post-retirement healthcare benefit liability, net of tax									0	0	0
Other comprehensive income (loss)									0	0	0
Total comprehensive income									$ (72,342)	$ (60,879)	$ (38,776)

Supplemental Financial Infor124

Supplemental Financial Information (Consolidating Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 222,280	$ 170,177	$ 68,858	$ 110,610
Accounts receivable, net	145,385	124,072
Intercompany balances	0	0
Inventories	86,372	89,612
Other current assets	8,727	7,336
Total current assets	462,764	391,197
Property, plant, and equipment, net	97,098	108,304
Goodwill	321,074	304,032	292,390
Acquired intangibles	105,768	110,790
Other assets	4,681	3,922
Investment in subsidiaries	0	0
Total assets	991,385	918,245	889,772
Current liabilities:
Accounts payable	82,387	69,944
Accrued expenses	75,467	70,392
Billings in Excess of Cost	12,779	11,352
Current maturities of long-term debt	400	400
Total current liabilities	171,033	152,088
Long-term debt	209,621	209,237
Deferred income taxes	31,237	38,002
Other non-current liabilities	47,775	58,038
Total shareholders’ equity	531,719	460,880	410,086	387,229
Total liabilities and shareholders' equity	991,385	918,245
Gibraltar Industries, Inc.
Current assets:
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	0	0
Intercompany balances	324	(615)
Inventories	0	0
Other current assets	5,415	13,783
Total current assets	5,739	13,168
Property, plant, and equipment, net	0	0
Goodwill	0	0
Acquired intangibles	0	0
Other assets	0	0
Investment in subsidiaries	739,970	663,118
Total assets	745,709	676,286
Current liabilities:
Accounts payable	0	0
Accrued expenses	5,469	7,369
Billings in Excess of Cost	0	0
Current maturities of long-term debt	0	0
Total current liabilities	5,469	7,369
Long-term debt	208,521	208,037
Deferred income taxes	0	0
Other non-current liabilities	0	0
Total shareholders’ equity	531,719	460,880
Total liabilities and shareholders' equity	745,709	676,286
Guarantor Subsidiaries
Current assets:
Cash and cash equivalents	192,604	143,826	39,597	91,466
Accounts receivable, net	138,903	117,526
Intercompany balances	4,166	6,152
Inventories	82,457	85,483
Other current assets	(368)	(10,070)
Total current assets	417,762	342,917
Property, plant, and equipment, net	93,906	104,642
Goodwill	298,258	282,300
Acquired intangibles	97,171	101,520
Other assets	4,681	3,922
Investment in subsidiaries	61,746	58,477
Total assets	973,524	893,778
Current liabilities:
Accounts payable	77,786	66,363
Accrued expenses	67,746	60,004
Billings in Excess of Cost	9,840	9,301
Current maturities of long-term debt	400	400
Total current liabilities	155,772	136,068
Long-term debt	1,100	1,200
Deferred income taxes	28,907	35,354
Other non-current liabilities	47,775	58,038
Total shareholders’ equity	739,970	663,118
Total liabilities and shareholders' equity	973,524	893,778
Non-Guarantor Subsidiaries
Current assets:
Cash and cash equivalents	29,676	26,351	29,261	19,144
Accounts receivable, net	6,482	6,546
Intercompany balances	(4,490)	(5,537)
Inventories	3,915	4,129
Other current assets	3,680	3,623
Total current assets	39,263	35,112
Property, plant, and equipment, net	3,192	3,662
Goodwill	22,816	21,732
Acquired intangibles	8,597	9,270
Other assets	0	0
Investment in subsidiaries	0	0
Total assets	73,868	69,776
Current liabilities:
Accounts payable	4,601	3,581
Accrued expenses	2,252	3,019
Billings in Excess of Cost	2,939	2,051
Current maturities of long-term debt	0	0
Total current liabilities	9,792	8,651
Long-term debt	0	0
Deferred income taxes	2,330	2,648
Other non-current liabilities	0	0
Total shareholders’ equity	61,746	58,477
Total liabilities and shareholders' equity	73,868	69,776
Eliminations
Current assets:
Cash and cash equivalents	0	0	$ 0	$ 0
Accounts receivable, net	0	0
Intercompany balances	0	0
Inventories	0	0
Other current assets	0	0
Total current assets	0	0
Property, plant, and equipment, net	0	0
Goodwill	0	0
Acquired intangibles	0	0
Other assets	0	0
Investment in subsidiaries	(801,716)	(721,595)
Total assets	(801,716)	(721,595)
Current liabilities:
Accounts payable	0	0
Accrued expenses	0	0
Billings in Excess of Cost	0	0
Current maturities of long-term debt	0	0
Total current liabilities	0	0
Long-term debt	0	0
Deferred income taxes	0	0
Other non-current liabilities	0	0
Total shareholders’ equity	(801,716)	(721,595)
Total liabilities and shareholders' equity	$ (801,716)	$ (721,595)

Supplemental Financial Infor125

Supplemental Financial Information (Condensed Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	Apr. 15, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities		$ 70,070	$ 123,987	$ 87,221
Cash Flows from Investing Activities
Purchases of property, plant, and equipment		(11,399)	(10,779)	(12,373)
Acquisitions, net of cash acquired		(18,494)	(23,412)	(140,621)
Net proceeds from sale of property and equipment		13,096	953	26,500
Net proceeds from sale of business	$ 8,300	0	8,250	0
Net cash used in investing activities		(16,797)	(23,870)	(125,340)
Other, net		0	1,118	1,154
Cash Flows from Financing Activities
Long-term debt payments		(400)	(400)	(73,642)
Proceeds from long-term debt		0	0	73,242
Payment of debt issuance costs		0	(54)	(1,166)
Purchase of treasury stock at market prices		(2,872)	(1,539)	(956)
Intercompany financing		0	0	0
Net proceeds from issuance of common stock		674	3,341	1,801
Net cash (used in) provided by financing activities		(2,598)	1,348	(721)
Effect of exchange rate changes on cash		1,428	(146)	(2,912)
Net increase (decrease) in cash and cash equivalents		52,103	101,319	(41,752)
Cash and cash equivalents at beginning of year		170,177	68,858	110,610
Cash and cash equivalents at end of year		222,280	170,177	68,858
Gibraltar Industries, Inc.
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities		(15,172)	(34,243)	(13,309)
Cash Flows from Investing Activities
Purchases of property, plant, and equipment		0	0	0
Acquisitions, net of cash acquired		0	0	0
Net proceeds from sale of property and equipment		0	0	0
Net proceeds from sale of business			0
Net cash used in investing activities		0	0	0
Other, net			0	0
Cash Flows from Financing Activities
Long-term debt payments		0	0	0
Proceeds from long-term debt				0
Payment of debt issuance costs			0	0
Purchase of treasury stock at market prices		(2,872)	(1,539)	(956)
Intercompany financing		17,370	32,441	12,464
Net proceeds from issuance of common stock		674	3,341	1,801
Net cash (used in) provided by financing activities		15,172	34,243	13,309
Effect of exchange rate changes on cash		0	0	0
Net increase (decrease) in cash and cash equivalents		0	0	0
Cash and cash equivalents at beginning of year		0	0	0
Cash and cash equivalents at end of year		0	0	0
Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities		83,114	140,890	94,977
Cash Flows from Investing Activities
Purchases of property, plant, and equipment		(11,026)	(10,321)	(11,754)
Acquisitions, net of cash acquired		(18,494)	(23,412)	(114,145)
Net proceeds from sale of property and equipment		12,905	230	26,500
Net proceeds from sale of business			0
Net cash used in investing activities		(16,615)	(32,385)	(98,245)
Other, net			1,118	1,154
Cash Flows from Financing Activities
Long-term debt payments		(400)	(400)	(73,642)
Proceeds from long-term debt				73,242
Payment of debt issuance costs			(54)	(1,166)
Purchase of treasury stock at market prices		0	0	0
Intercompany financing		(17,321)	(3,822)	(47,035)
Net proceeds from issuance of common stock		0	0	0
Net cash (used in) provided by financing activities		(17,721)	(4,276)	(48,601)
Effect of exchange rate changes on cash		0	0	0
Net increase (decrease) in cash and cash equivalents		48,778	104,229	(51,869)
Cash and cash equivalents at beginning of year		143,826	39,597	91,466
Cash and cash equivalents at end of year		192,604	143,826	39,597
Non-Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities		2,128	17,340	5,553
Cash Flows from Investing Activities
Purchases of property, plant, and equipment		(373)	(458)	(619)
Acquisitions, net of cash acquired		0	0	(26,476)
Net proceeds from sale of property and equipment		191	723	0
Net proceeds from sale of business			8,250
Net cash used in investing activities		(182)	8,515	(27,095)
Other, net			0
Cash Flows from Financing Activities
Long-term debt payments		0	0	0
Payment of debt issuance costs			0	0
Purchase of treasury stock at market prices		0	0	0
Intercompany financing		(49)	(28,619)	34,571
Net proceeds from issuance of common stock		0	0	0
Net cash (used in) provided by financing activities		(49)	(28,619)	34,571
Effect of exchange rate changes on cash		1,428	(146)	(2,912)
Net increase (decrease) in cash and cash equivalents		3,325	(2,910)	10,117
Cash and cash equivalents at beginning of year		26,351	29,261	19,144
Cash and cash equivalents at end of year		29,676	26,351	29,261
Eliminations
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities		0	0	0
Cash Flows from Investing Activities
Purchases of property, plant, and equipment		0	0	0
Acquisitions, net of cash acquired		0	0	0
Net proceeds from sale of property and equipment		0	0	0
Net proceeds from sale of business			0
Net cash used in investing activities		0	0	0
Other, net			0
Cash Flows from Financing Activities
Long-term debt payments		0	0	0
Payment of debt issuance costs			0	0
Purchase of treasury stock at market prices		0	0	0
Intercompany financing		0	0	0
Net proceeds from issuance of common stock		0	0	0
Net cash (used in) provided by financing activities		0	0	0
Effect of exchange rate changes on cash		0	0	0
Net increase (decrease) in cash and cash equivalents		0	0	0
Cash and cash equivalents at beginning of year		0	0	0
Cash and cash equivalents at end of year		$ 0	$ 0	$ 0

Quarterly Unaudited Financia126

Quarterly Unaudited Financial Data (Details) - 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	$ 258,112	$ 274,574	$ 247,627	$ 206,605	$ 231,838	$ 272,734	$ 265,738	$ 237,671	$ 986,918	$ 1,007,981	$ 1,040,873
Gross profit	56,729	68,735	61,825	49,255	53,882	67,887	68,843	54,150	236,544	244,762	186,976
Income (loss) from operations:	22,547	35,693	24,930	9,679	629	26,522	28,576	17,761	92,849	73,488	48,732
Interest expense	3,420	3,486	3,550	3,576	3,595	3,625	3,666	3,691	14,032	14,577	15,003
Income from continuing operations	25,176	20,619	13,174	3,996	(7,708)	13,786	18,612	9,029	62,965	33,719	23,476
Loss from discontinued operations	0	0	(405)	0	(44)	0	0	0	(405)	(44)	(28)
Net income	$ 25,176	$ 20,619	$ 12,769	$ 3,996	$ (7,752)	$ 13,786	$ 18,612	$ 9,029	$ 62,560	$ 33,675	$ 23,448
(Loss) income per share from continuing operations:
Basic (in dollars per share)	$ 0.79	$ 0.65	$ 0.41	$ 0.13	$ (0.24)	$ 0.44	$ 0.59	$ 0.29	$ 1.98	$ 1.07	$ 0.75
Diluted (in dollars per share)	0.78	0.64	0.41	0.12	(0.24)	0.43	0.58	0.28	1.95	1.05	0.74
Loss per share from discontinued operations:
Basic (in dollars per share)	0	0	(0.01)	0	0	0	0	0	(0.01)	0	0
Diluted (in dollars per share)	$ 0	$ 0	$ (0.01)	$ 0	$ 0	$ 0	$ 0	$ 0	$ (0.01)	$ 0	$ 0

Other Postretirement Benefits	12 Months Ended
Other Postretirement Benefits	Dec. 31, 2017
Other Postretirement Benefits [Abstract]
Other Postretirement Benefits	OTHER POSTRETIREMENT BENEFITS The Company has an unfunded postretirement healthcare plan which provides health insurance to certain employees and their spouses upon retirement. This plan has been frozen and no additional participants will be added to the plan in the future. The following table presents the changes in the accumulated postretirement benefit obligation related to the Company’s unfunded postretirement healthcare benefits at December 31 (in thousands): 2017 2016 Projected benefit obligation at January 1 $ 7,202 $ 8,149 Service cost 17 22 Interest cost 269 272 Actuarial gain (150 ) (923 ) Benefits paid, net of contributions (318 ) (318 ) Projected benefit obligation at December 31 7,020 7,202 Fair value of plan assets — — Under funded status (7,020 ) (7,202 ) Unamortized prior service cost 427 471 Unrecognized actuarial loss 2,382 2,679 Net amount recognized $ (4,211 ) $ (4,052 ) Amounts recognized in the consolidated financial statements consisted of (in thousands): 2017 2016 Accrued postretirement benefit liability Current portion $ 314 $ 294 Long term portion 6,706 6,908 Pre-tax accumulated other comprehensive loss – unamortized post-retirement healthcare costs (2,809 ) (3,150 ) Net amount recognized $ 4,211 $ 4,052 The measurement date used to determine postretirement benefit obligation measures was December 31. Components of net periodic postretirement benefit cost charged to expense for the years ended December 31 were as follows (in thousands): 2017 2016 2015 Service cost $ 17 $ 22 $ 26 Interest cost 269 272 300 Amortization of unrecognized prior service cost 44 44 44 Loss amortization ( 2 ) 146 134 197 Net periodic benefit cost $ 476 $ 472 $ 567 Assumptions used to calculate the benefit obligation: Discount rate 3.4 % 3.8 % 3.9 % Annual rate of increase in the per capita cost of: Medical costs before age 65 ( 1) 7.3 % 7.5 % 7.8 % Medical costs after age 65 ( 1) 6.3 % 6.5 % 6.8 % Prescription drug costs ( 1) 10.5 % 10.5 % 11.0 % (1) It was assumed that these rates would gradually decline to 4% by 2075. (2) Actuarial (gains)/losses are amortized utilizing the corridor approach. Differences between actual experience and the actuarial assumptions are reflected in (gain)/loss. If the total net (gain) or loss exceeds 10 percent of the greater of the accumulated postretirement benefit obligation or plan asset, this excess must be amortized over the average remaining service period of the active plan participants. If most of the plan participants are inactive, the amortization period is the expected future lifetime of inactive plan participants. A 1% change in the annual medical inflation rate issued would have the following impact on the amounts reported at December 31 as follows (in thousands): 2017 2016 Effect on accumulated postretirement benefit obligation 1% increase $ 950 $ 975 1% decrease $ (803 ) $ (824 ) Effect on annual service and interest costs 1% increase $ 41 $ 42 1% decrease $ (34 ) $ (35 ) Expected benefit payments from the plan for the years ended December 31 are as follows (in thousands): 2018 2019 2020 2021 2022 2023 - 2027 Expected benefit payments $ 314 $ 333 $ 353 $ 371 $ 389 $ 2,159

Other Postretirement Benefits (Tables)	12 Months Ended
Other Postretirement Benefits (Tables)	Dec. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Changes in the Accumulated Postretirement Benefit Obligation	The following table presents the changes in the plan’s projected benefit obligation, fair value of plan assets, and funded status for the years ended December 31 (in thousands): 2017 2016 Projected benefit obligation at January 1 $ 1,377 $ 1,685 Interest cost 46 59 Actuarial losses (gains) 7 5 Benefits paid (360 ) (372 ) Projected benefit obligation at December 31 1,070 1,377 Fair value of plan assets — — Under funded status (1,070 ) (1,377 ) Unamortized prior service cost 2 4 Unrecognized actuarial gain (173 ) (200 ) Net amount recognized $ (1,241 ) $ (1,573 )
Amounts Recognized in the Consolidated Financial Statements	Amounts recognized in the consolidated financial statements consisted of (in thousands): 2017 2016 Accrued postretirement benefit liability Current portion $ 314 $ 294 Long term portion 6,706 6,908 Pre-tax accumulated other comprehensive loss – unamortized post-retirement healthcare costs (2,809 ) (3,150 ) Net amount recognized $ 4,211 $ 4,052
Schedule of Net Periodic Pension and Other Post-Retirement Benefit Costs	Components of net periodic pension cost for the years ended December 31 were as follows (in thousands): 2017 2016 2015 Interest cost $ 46 $ 59 $ 66 Amortization of unrecognized prior service cost 2 6 14 Gain amortization (19 ) (13 ) — Net periodic pension cost $ 29 $ 52 $ 80 Assumptions used to calculate the benefit obligation: Discount rate 3.55 % 3.81 % 3.94 %
Expected Benefit Payments from the Plan	Expected benefit payments from the plan for the years ended December 31 are as follows (in thousands): 2018 2019 2020 2021 2022 2023 - 2027 Expected benefit payments $ 327 $ 228 $ 137 $ 100 $ 100 $ 292
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Changes in the Accumulated Postretirement Benefit Obligation	The following table presents the changes in the accumulated postretirement benefit obligation related to the Company’s unfunded postretirement healthcare benefits at December 31 (in thousands): 2017 2016 Projected benefit obligation at January 1 $ 7,202 $ 8,149 Service cost 17 22 Interest cost 269 272 Actuarial gain (150 ) (923 ) Benefits paid, net of contributions (318 ) (318 ) Projected benefit obligation at December 31 7,020 7,202 Fair value of plan assets — — Under funded status (7,020 ) (7,202 ) Unamortized prior service cost 427 471 Unrecognized actuarial loss 2,382 2,679 Net amount recognized $ (4,211 ) $ (4,052 )
Schedule of Net Periodic Pension and Other Post-Retirement Benefit Costs	Components of net periodic postretirement benefit cost charged to expense for the years ended December 31 were as follows (in thousands): 2017 2016 2015 Service cost $ 17 $ 22 $ 26 Interest cost 269 272 300 Amortization of unrecognized prior service cost 44 44 44 Loss amortization ( 2 ) 146 134 197 Net periodic benefit cost $ 476 $ 472 $ 567 Assumptions used to calculate the benefit obligation: Discount rate 3.4 % 3.8 % 3.9 % Annual rate of increase in the per capita cost of: Medical costs before age 65 ( 1) 7.3 % 7.5 % 7.8 % Medical costs after age 65 ( 1) 6.3 % 6.5 % 6.8 % Prescription drug costs ( 1) 10.5 % 10.5 % 11.0 % (1) It was assumed that these rates would gradually decline to 4% by 2075. (2) Actuarial (gains)/losses are amortized utilizing the corridor approach. Differences between actual experience and the actuarial assumptions are reflected in (gain)/loss. If the total net (gain) or loss exceeds 10 percent of the greater of the accumulated postretirement benefit obligation or plan asset, this excess must be amortized over the average remaining service period of the active plan participants. If most of the plan participants are inactive, the amortization period is the expected future lifetime of inactive plan participants.
Schedule of 1% Change in Annual Medical Inflation Rate Issued	A 1% change in the annual medical inflation rate issued would have the following impact on the amounts reported at December 31 as follows (in thousands): 2017 2016 Effect on accumulated postretirement benefit obligation 1% increase $ 950 $ 975 1% decrease $ (803 ) $ (824 ) Effect on annual service and interest costs 1% increase $ 41 $ 42 1% decrease $ (34 ) $ (35 )
Expected Benefit Payments from the Plan	Expected benefit payments from the plan for the years ended December 31 are as follows (in thousands): 2018 2019 2020 2021 2022 2023 - 2027 Expected benefit payments $ 314 $ 333 $ 353 $ 371 $ 389 $ 2,159

Gibraltar Industries (ROCK) 10-K27 Feb 182017 FY Annual reportFinancial data

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