Continental Building Products (CBPX) 10-Q 4 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 01, 2018
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	CBPX
Entity Registrant Name	CONTINENTAL BUILDING PRODUCTS, INC.
Entity Central Index Key	1,592,480
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding (shares)		36,967,770

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Net sales	$ 116,802	$ 120,615
Costs, expenses and other income:
Cost of goods sold	86,616	89,624
Selling and administrative	9,424	9,304
Total costs and operating expenses	96,040	98,928
Operating income	20,762	21,687
Other expense, net	(140)	(644)
Interest expense, net	(2,720)	(2,916)
Income before losses from equity method investment and provision for income taxes	17,902	18,127
Losses from equity method investment	(364)	(170)
Income before provision for income taxes	17,538	17,957
Provision for income taxes	(3,892)	(5,730)
Net income	$ 13,646	$ 12,227
Net income per share:
Basic (usd per share)	$ 0.36	$ 0.31
Diluted (usd per share)	$ 0.36	$ 0.31
Weighted average shares outstanding:
Basic (shares)	37,432,782	39,576,268
Diluted (shares)	37,604,953	39,702,126

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 13,646	$ 12,227
Foreign currency translation adjustment	(481)	124
Net unrealized gains on derivatives, net of taxes	1,045	20
Other comprehensive income	564	144
Comprehensive income	$ 14,210	$ 12,371

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets:
Cash and cash equivalents	$ 63,848	$ 72,521
Receivables, net	46,246	38,769
Inventories, net	27,725	24,882
Prepaid and other current assets	11,014	11,267
Total current assets	148,833	147,439
Property, plant and equipment, net	293,902	294,003
Customer relationships and other intangibles, net	68,433	70,807
Goodwill	119,945	119,945
Equity method investment	9,071	9,263
Debt issuance costs	432	477
Total Assets	640,616	641,934
Liabilities:
Accounts payable	31,215	30,809
Accrued and other liabilities	10,682	11,940
Notes payable, current portion	1,680	1,702
Total current liabilities	43,577	44,451
Deferred taxes and other long-term liabilities	15,888	15,847
Notes payable, non-current portion	263,242	263,610
Total Liabilities	322,707	323,908
Shareholders' Equity:
Undesignated preferred stock, par value $0.001 per share; 10,000,000 shares authorized, no shares issued and outstanding	0	0
Common stock, $0.001 par value per share; 190,000,000 shares authorized; 44,408,395 and 44,321,776 shares issued and 37,088,978 and 37,532,959 shares outstanding as of March 31, 2018 and December 31, 2017, respectively	44	44
Additional paid-in capital	325,615	325,391
Less: Treasury stock	(157,907)	(143,357)
Accumulated other comprehensive loss	(2,085)	(2,649)
Accumulated earnings	152,242	138,597
Total Shareholders' Equity	317,909	318,026
Total Liabilities and Shareholders' Equity	$ 640,616	$ 641,934

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Undesignated preferred stock, par value (usd per share)	$ 0.001	$ 0.001
Undesignated preferred stock, shares authorized	10,000,000	10,000,000
Undesignated preferred stock, shares issued	0	0
Undesignated preferred stock, shares outstanding	0	0
Common stock, par value (usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized	190,000,000	190,000,000
Common stock, shares issued	44,408,395	44,321,776
Common stock, shares outstanding	37,088,978	37,532,959

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 13,646	$ 12,227
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	10,581	11,286
Amortization of debt issuance costs and debt discount	334	291
Losses from equity method investment	364	170
Debt related expenses	0	686
Share-based compensation	600	724
Deferred taxes	0	92
Change in assets and liabilities:
Receivables	(7,562)	(9,323)
Inventories	(2,913)	(1,279)
Prepaid expenses and other current assets	1,144	1,994
Accounts payable	(1,353)	1,714
Accrued and other current liabilities	(1,042)	100
Other long-term liabilities	(56)	(146)
Net cash provided by operating activities	13,743	18,536
Cash flows from investing activities:
Capital expenditures	(5,955)	(5,359)
Software purchased or developed	(482)	(1)
Capital contributions to equity method investment	(251)	(524)
Distributions from equity method investment	78	214
Net cash used in investing activities	(6,610)	(5,670)
Cash flows from financing activities:
Proceeds from exercise of stock options	11	168
Tax withholdings on share-based compensation	(421)	(209)
Proceeds from debt refinancing	0	273,625
Disbursements for debt refinancing	0	(273,625)
Payments of financing costs	0	(649)
Principal payments for debt	(679)	(684)
Payments to repurchase common stock	(14,550)	(5,237)
Net cash used in financing activities	(15,639)	(6,611)
Effect of foreign exchange rates on cash and cash equivalents	(167)	117
Net change in cash and cash equivalents	(8,673)	6,372
Cash, beginning of period	72,521	51,536
Cash, end of period	$ 63,848	$ 57,908

Background and Nature of Operat

Background and Nature of Operations	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background and Nature of Operations	BACKGROUND AND NATURE OF OPERATIONS Description of Business Continental Building Products, Inc. (the "Company") is a Delaware corporation. Prior to the acquisition of the gypsum division of Lafarge North America Inc. ("Lafarge N.A.") described below, the Company had no operating activity. The Company manufactures gypsum wallboard related products for commercial and residential buildings and houses. The Company operates a network of three highly efficient wallboard facilities, all located in the eastern United States, and produces joint compound at one plant in the United States and at another plant in Canada. The Acquisition On June 24, 2013 , Lone Star Fund VIII (U.S.), L.P., (along with its affiliates and associates, but excluding the companies that it owns as a result of its investment activity, "Lone Star"), entered into a definitive agreement with Lafarge N.A. to purchase the assets of its North American gypsum division for an aggregate purchase price of approximately $703 million (the "Acquisition") in cash. The closing of the Acquisition occurred on August 30, 2013 . Secondary Public Offerings On March 18, 2016, following a series of secondary offerings, LSF8 Gypsum Holdings, L.P. ("LSF8") sold its remaining 5,106,803 shares of the Company's common stock at a price per share of $16.10 . Following the March 18, 2016 transaction and the concurrent repurchase by the Company of 900,000 shares of Company's common stock from LSF8, to the best of the Company's knowledge, neither LSF8 nor any other affiliate of Lone Star held any shares of Company common stock (See Note 11, Treasury Stock).

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES (a) Basis of Presentation The accompanying consolidated financial statements for the Company have been prepared in accordance with accounting principles generally accepted in the United States ("U.S. GAAP"). The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions have been eliminated. (b) Basis of Presentation for Interim Periods Certain information and footnote disclosures normally included for the annual financial statements prepared in accordance with U.S. GAAP have been condensed or omitted for the interim periods presented. Management believes that the unaudited interim financial statements include all adjustments (which are normal and recurring in nature) necessary to present fairly the financial position of the Company and the results of operations and cash flows for the periods presented. The results of operations for the periods presented are not necessarily indicative of the results that may be expected for the year ending December 31, 2018. Seasonal changes and other conditions can affect the sales volumes of the Company's products. Therefore, the financial results for any interim period do not necessarily indicate the expected results for the year. The financial statements should be read in conjunction with Company's audited consolidated financial statements and the notes thereto for the year ended December 31, 2017 included in the Company's Annual Report on Form 10-K for the fiscal year then ended (the "2017 10-K"). The Company has continued to follow the accounting policies set forth in those financial statements. (c) Revenue Disclosure Revenue from the sale of gypsum products is recognized when control of the promised products is transferred to the Company's customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those products (the transaction price). A performance obligation is a promise in a contract to transfer a distinct product to a customer and is the unit of account under ASC 606. Control transfers to the customer at a point in time. To indicate the transfer of control, the Company must have a present right to payment, legal title must have passed to the customer and the customer must have the significant risks and rewards of ownership. Generally, the Company satisfies its performance obligations within a number of days from the time the contract is executed. The Company records estimated reductions to revenue for customer programs and incentive offerings, including promotions and other volume-based incentives, in the period in which the sale occurs. Amounts billed to a customer at the transaction price are included in "Net sales," and costs incurred for shipping and handling are treated as fulfillment costs and are classified as "Cost of goods sold" in the Consolidated Statements of Operations. See Note 17, Segment reporting, for disaggregation of revenue by segment. As of March 31, 2018 , accounts receivables were $46.2 million . The Company had no material contract assets, contract liabilities or deferred contract costs recorded on the Consolidated Balance Sheets as of March 31, 2018 . We do not have any material payment terms as payment is received shortly after the point of sale. (d) Supplemental Cash Flow Disclosure Table 2.1: Certain Cash Transactions and Other Activity For the Three Months Ended March 31, 2018 March 31, 2017 (in thousands) Cash paid during the period for: Interest paid on term loan, net $ 2,396 $ 2,457 Income taxes paid, net — 216 Other activity: Amounts in accounts payable for capital expenditures 1,789 915 (e) Recent Accounting Pronouncements Accounting Standards Adopted During the Period In May 2014, the FASB issued ASU No. 2014-9, "Revenue from Contracts with Customers (Topic 606)," which provides accounting guidance for all revenue arising from contracts with customers and affects all entities that enter into contracts to provide goods or services to their customers. In August 2015, the FASB issued ASU No. 2015-14, "Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date," which deferred the effective date of ASU No. 2014-9 for all entities by one year to annual reporting periods beginning after December 15, 2017. The ASU requires retroactive application on either a full or modified basis. The Company adopted the standard on January 1, 2018 using the modified retrospective approach. Based on evaluation, the Company has concluded it has one revenue stream and the adoption of this new guidance did not have a material impact on its Consolidated Financial Statements. The Company included the disclosures required by this ASU above. In August 2016, the FASB issued ASU 2016-15, "Classification of Certain Cash Receipts and Cash Payments." This ASU reduces existing diversity in the classification of certain cash receipts and cash payments on the statements of cash flows. ASU 2016-15 is effective for fiscal years beginning after December 15, 2017, and for interim periods within those fiscal years. The adoption of this standard did not have a material impact on the Company's Consolidated Financial Statements. In October 2016, the FASB issued ASU 2016-16, "Intra-Entity Transfers of Assets Other Than Inventory." The new standard requires companies to recognize the income tax effects of intercompany sales or transfers of assets, other than inventory, in the income statement as income tax expense (or benefit) in the period the sales or transfer occurs. The standard requires companies to apply a modified retrospective approach with a cumulative catch-up adjustment to opening retained earnings in the period of adoption. The provisions of this standard are effective for fiscal years beginning after December 15, 2017, and early adoption is permitted. The adoption of this standard did not have a material impact on the Company's Consolidated Financial Statements. Accounting Standards Not Yet Adopted In February 2016, the FASB issued ASU 2016-02, "Leases." ASU 2016-02 requires lessees to recognize a lease liability and a right-of-use asset on the balance sheet. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is in the process of evaluating the impact of adoption, which is not expected to have a material impact on its Consolidated Financial Statements. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments." This ASU is intended to introduce a revised approach to the recognition and measurement of credit losses, emphasizing an updated model based on expected losses rather than incurred losses. The provisions of this standard are effective for reporting periods beginning after December 15, 2019 and early adoption is permitted. The Company is currently evaluating the impact that this guidance may have on its Consolidated Financial Statements. In August 2017, the FASB issued ASU 2017-12, "Derivatives and Hedging (Topic 815), Targeted Improvements to Accounting for Hedging Activities." This ASU expands an entity's ability to hedge non-financial and financial risk components and reduce complexity in fair value hedges of interest rate risk. The guidance eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires the entire change in the fair value of a hedging instrument to be presented in the same income statement line as the hedged item. The provisions of this standard are effective in 2019 for calendar-year public business entities and in 2020 for all other calendar-year companies. Early adoption of the standard is permitted. The Company is currently evaluating when it will adopt the ASU and the expected impact to its Consolidated Financial Statements. In February 2018, the FASB issued ASU 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220), Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income." This ASU 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 reporting periods beginning after December 15, 2018 and early adoption is permitted. The Company is currently evaluating the impact that this guidance may have on its Consolidated Financial Statements. (f) Reclassifications Certain reclassifications of prior year information were made to conform to the 2018 presentation. These reclassifications had no material impact on the Company's Consolidated Financial Statements.

Receivables, Net

Receivables, Net	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Receivables, Net	RECEIVABLES, NET Table 3: Details of Receivables, Net March 31, 2018 December 31, 2017 (in thousands) Trade receivables, gross $ 46,961 $ 39,577 Allowance for cash discounts and doubtful accounts (715 ) (808 ) Receivables, net $ 46,246 $ 38,769 Trade receivables are recorded net of credit memos issued during the normal course of business.

Inventories, Net

Inventories, Net	3 Months Ended
	Mar. 31, 2018
Inventory Disclosure [Abstract]
Inventories	INVENTORIES, NET Table 4: Details of Inventories, Net March 31, 2018 December 31, 2017 (in thousands) Finished products $ 6,128 $ 5,893 Raw materials 14,463 11,663 Supplies and other 7,134 7,326 Inventories, net $ 27,725 $ 24,882

Property, Plant and Equipment,

Property, Plant and Equipment, Net	3 Months Ended
	Mar. 31, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Net	PROPERTY, PLANT AND EQUIPMENT, NET Table 5: Details of Property, Plant and Equipment, Net March 31, 2018 December 31, 2017 (in thousands) Land $ 13,187 $ 13,187 Buildings 114,193 114,051 Plant machinery 282,732 281,786 Mobile equipment 10,565 10,366 Construction in progress 26,789 20,291 Property, plant and equipment, at cost 447,466 439,681 Accumulated depreciation (153,564 ) (145,678 ) Property, plant and equipment, net $ 293,902 $ 294,003 Depreciation expense was $8.1 million for both the three months ended March 31, 2018 and 2017 .

Customer Relationships and Othe

Customer Relationships and Other Intangibles, Net	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Customer Relationships and Other Intangibles, Net	CUSTOMER RELATIONSHIPS AND OTHER INTANGIBLES, NET Table 6.1: Details of Customer Relationships and Other Intangibles, Net March 31, 2018 December 31, 2017 Gross Accumulated Amortization Net Gross Accumulated Amortization Net (in thousands) Customer relationships $ 116,531 $ (59,855 ) $ 56,676 $ 116,711 $ (57,811 ) $ 58,900 Purchased and internally developed software 6,483 (5,015 ) 1,468 6,226 (4,871 ) 1,355 Trademarks 14,816 (4,527 ) 10,289 14,839 (4,287 ) 10,552 Total $ 137,830 $ (69,397 ) $ 68,433 $ 137,776 $ (66,969 ) $ 70,807 Amortization expense was $2.5 million and $3.2 million for the three months ended March 31, 2018 and 2017 , respectively. Table 6.2: Details of Future Amortization Expense of Customer Relationships and Other Intangibles As of March 31, 2018 (in thousands) April 1, 2018 through December 31, 2018 $ 7,344 2019 8,753 2020 7,869 2021 7,178 2022 6,605 Thereafter 30,684 Total $ 68,433

Investment in Seven Hills

Investment in Seven Hills	3 Months Ended
	Mar. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Investment in Seven Hills	INVESTMENT IN SEVEN HILLS The Company is a party with an unaffiliated third party to a paperboard liner venture named Seven Hills Paperboard, LLC ("Seven Hills") that provides the Company with a continuous supply of high-quality recycled paperboard liner to meet its ongoing production requirements. The Company has evaluated the characteristics of its investment and determined that Seven Hills is a variable interest entity, but that it does not have the power to direct the principal activities most impacting the economic performance of Seven Hills, and is thus not the primary beneficiary. As such, the Company accounts for this investment in Seven Hills under the equity method of accounting. Paperboard liner purchased from Seven Hills was $12.2 million and $12.0 million for the three months ended March 31, 2018 and 2017 , respectively. As of March 31, 2018 , the Company had certain purchase commitments for paper totaling $35.1 million through 2021 .

Accrued and Other Liabilities

Accrued and Other Liabilities	3 Months Ended
	Mar. 31, 2018
Payables and Accruals [Abstract]
Accrued and Other Liabilities	ACCRUED AND OTHER LIABILITIES Table 8: Details of Accrued and Other Liabilities March 31, 2018 December 31, 2017 (in thousands) Employee-related costs $ 3,828 $ 9,258 Income taxes 3,764 — Other taxes 1,665 938 Other 1,425 1,744 Accrued and other liabilities $ 10,682 $ 11,940

Debt

Debt	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt	DEBT Table 9.1: Details of Debt March 31, 2018 December 31, 2017 (in thousands) First Lien Credit Agreement ( 1 ) $ 270,894 $ 271,573 Less: Original issue discount (net of amortization) (1,575 ) (1,681 ) Less: Debt issuance costs (4,397 ) (4,580 ) Total debt 264,922 265,312 Less: Current portion of long-term debt (1,680 ) (1,702 ) Long-term debt $ 263,242 $ 263,610 (1) As of March 31, 2018 and December 31, 2017, the Amended and Restated Credit Agreement, as amended, had a maturity date of August 18, 2023 and an interest rate of LIBOR (with a 0.75% floor) plus 2.25% . On August 18, 2016, the Company, Continental Building Products Operating Company, LLC ("OpCo") and Continental Building Products Canada Inc. and the lenders party thereto and Credit Suisse, as Administrative Agent, entered into an Amended and Restated Credit Agreement amending and restating the Company's First Lien Credit Agreement (the "Amended and Restated Credit Agreement"). The Amended and Restated Credit Agreement provides for a $275 million senior secured first lien term loan facility and a $75 million senior secured revolving credit facility (the "Revolver"), which mature on August 18, 2023 and August 18, 2021, respectively. Related to this debt refinancing, the Company incurred $4.7 million of discount and debt issuance costs, of which $2.5 million was recorded in Other expense, net on the Consolidated Statements of Operations in 2016, and $2.2 million will be amortized over the term of the Amended and Restated Credit Agreement. Upon completion of this debt refinancing, the Company recognized an additional expense of $3.3 million related to losses resulting from debt extinguishment which was also reported in Other expense, net on the Consolidated Statements of Operations in 2016. The interest rate under the Amended and Restated Credit Agreement remained floating but was reduced to a spread over LIBOR of 2.75% and floor of 0.75% . On February 21, 2017 , the Company repriced its term loan under the Amended and Restated Credit Agreement lowering its interest rate by 25 basis points to LIBOR plus 2.50% . Subsequently, on December 6, 2017 , the Company further repriced its term loan under the Amended and Restated Credit Agreement lowering its interest rate by an additional 25 basis points to LIBOR plus 2.25% . The Company may further reduce its interest rate to LIBOR plus 2.00% based on the attainment of a total leverage ratio of 1.1 or better. All other terms and conditions under the Amended and Restated Credit Agreement remained the same. During both the three months ended March 31, 2018 and 2017 , the Company made $0.7 million of ordinary scheduled mandatory principal payments. As of March 31, 2018 , the annual effective interest rate, including original issue discount and amortization of debt issuance costs, was 4.6% . There were no amounts outstanding under the Revolver as of March 31, 2018 or 2017 . During the three months ended March 31, 2018 and 2017 the Company did not have any draws under the Revolver. Interest under the Revolver is floating, based on LIBOR plus 2.25% . In addition, the Company pays a facility fee of 50 basis points per annum on the total capacity under the Revolver. Availability under the Revolver as of March 31, 2018 , based on draws and outstanding letters of credit and absence of violations of covenants, was $73.4 million . Table 9.2: Details of Future Minimum Principal Payments Due Under the Amended and Restated Credit Agreement Amount Due (in thousands) April 1, 2018 through December 31, 2018 $ 2,037 2019 2,716 2020 2,716 2021 2,716 2022 2,716 Thereafter 257,993 Total Payments $ 270,894 Under the terms of the Amended and Restated Credit Agreement, the Company is required to comply with certain covenants, including among others, the limitation of indebtedness, limitation on liens, and limitations on certain cash distributions. One single financial covenant governs all of the Company's debt and only applies if the outstanding borrowings of the Revolver plus outstanding letters of credit are greater than $22.5 million as of the end of the quarter. The financial covenant is a total leverage ratio calculation, in which total debt less outstanding cash is divided by adjusted earnings before interest, taxes, depreciation and amortization. As the sum of outstanding borrowings under the Revolver and outstanding letters of credit were less than $22.5 million at March 31, 2018 , the total leverage ratio of no greater than 5.0 under the financial covenant was not applicable at March 31, 2018 . The Company was in compliance with all applicable covenants under the Amended and Restated Credit Agreement as of March 31, 2018 .

Derivative Instruments

Derivative Instruments	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	DERIVATIVE INSTRUMENTS Commodity Derivative Instruments As of March 31, 2018 , the Company had 2.9 million mmBTUs (millions of British Thermal Units) in aggregate notional amount outstanding natural gas swap contracts to manage commodity price exposures. All of these contracts mature by December 31, 2018 . The Company elected to designate these derivative instruments as cash flow hedges in accordance with ASC 815-20, "Derivatives – Hedging" . No ineffectiveness was recorded on these contracts during the three months ended March 31, 2018 and 2017 . Interest Rate Derivative Instrument In September 2016, the Company entered into interest rate swap agreements for a combined notional amount of $100.0 million with a term of four years , which hedged the floating LIBOR on a portion of the term loan under the Amended and Restated Credit Agreement to an average fixed rate of 1.323% and LIBOR floor of 0.75% . The Company elected to designate these interest rate swaps as cash flow hedges for accounting purposes. No ineffectiveness was recorded on these contracts during the three months ended March 31, 2018 and 2017 . On March 29, 2018, the Company terminated its interest rate swap agreements that were previously designated as a cash flow hedge and received $3.2 million in cash, the fair value of the swap on the termination date. The unrealized gain at termination remains in accumulated other comprehensive income and will be amortized into interest expense over the life of the original hedged instrument. On the same date, the Company entered into new interest rate swap agreements for a combined notional amount of $100.0 million , which expire on September 30, 2020 and hedge the floating LIBOR on a portion of the term loan under the Amended and Restated Credit Agreement to an average fixed rate of 2.46% and LIBOR floor of 0.75% . The Company elected to designate these interest rate swaps as cash flow hedges for accounting purposes. Table 10.1: Details of Derivatives Fair Value March 31, 2018 December 31, 2017 (in thousands) Assets Interest rate swap $ — $ 2,148 Commodity hedges 9 11 Total assets $ 9 $ 2,159 Liabilities Interest rate swap $ 108 $ — Commodity hedges 339 613 Total liabilities $ 447 $ 613 Table 10.2: Gains/(Losses) on Derivatives For the Three Months Ended March 31, 2018 March 31, 2017 March 31, 2018 March 31, 2017 Gain/(loss) recognized in Other comprehensive income on derivatives (effective portion), net of tax Gain/(loss) reclassified from Accumulated other comprehensive loss into income (effective portion), net of tax (in thousands) Interest rate swap $ 831 $ (2 ) $ 70 $ 82 Commodity hedges 241 (66 ) (97 ) 6 Total $ 1,072 $ (68 ) $ (27 ) $ 88 Counterparty Risk The Company is exposed to credit losses in the event of nonperformance by the counterparties to the Company's derivative instruments. As of March 31, 2018 , the Company's derivatives were in a $0.4 million net liability position and recorded in Other current liabilities. All of the Company's counterparties have investment grade credit ratings; accordingly, the Company anticipates that the counterparties will be able to fully satisfy their obligations under the contracts. The Company's agreements outline the conditions upon which it or the counterparties are required to post collateral. As of March 31, 2018 , the Company had no collateral posted with its counterparties related to the derivatives.

Treasury Stock

Treasury Stock	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Treasury Stock	TREASURY STOCK On November 4, 2015 , the Company announced that the Board of Directors approved a new stock repurchase program authorizing the Company to repurchase up to $50 million of its common stock, at such times and prices as determined by management as market conditions warrant, through December 31, 2016 . Pursuant to this authorization, the Company has repurchased shares of its common stock in the open market and in the March 2016 private transaction with LSF8 described above. During 2016 , 2017 and 2018 , the Company announced three expansions of its stock repurchase program. The most recent authorization on February 21, 2018 expanded the program to a total of $300 million and also extended the expiration date to December 31, 2019 . All repurchased shares are held in treasury, reducing the number of shares of common stock outstanding and used in the Company's earnings per share calculation. Table 11: Details of Treasury Stock Activity March 31, 2018 March 31, 2017 Shares Amount (1) Average Share Price (1) Shares Amount (1) Average Share Price (1) (in thousands, except share data) Beginning Balance 6,788,817 $ 143,357 $ 21.12 4,499,655 $ 88,756 $ 19.73 Repurchases on open market 530,600 14,550 27.42 217,123 5,237 24.12 Ending Balance 7,319,417 $ 157,907 $ 21.57 4,716,778 $ 93,993 $ 19.93 ( 1 ) Includes commissions paid for repurchases on open market.

Share-Based Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	SHARE-BASED COMPENSATION On February 20, 2018, the Company granted certain employees 51,012 Restricted Share Units ("RSUs") that vest ratably over four years from the grant date. All of these grants had a market price on the date of grant of $26.85 . Additionally, on February 21, 2018, the Company granted an employee and members of the Board of Directors 19,788 RSUs and 15,900 RSUs, respectively that vest ratably over a period of four years for the employee and one year for the members of the Board of Directors from the grant date and had a market price on the date of grant of $27.00 . On February 20, 2018 and February 21, 2018, the Company also granted certain employees 21,385 Performance Based RSUs ("PRSUs") and 19,788 PRSUs, respectively. The PRSUs vest on December 31, 2020, with the exact number of PRSUs vesting subject to the achievement of certain performance conditions through December 31, 2019. The number of PRSUs earned will vary from 0% to 240% of the number of PRSUs awarded, depending on the Company’s performance relative to a cumulative two year EBITDA target for fiscal years 2018 and 2019 and the Company's Total Shareholder Return ("TSR") relative to the TSRs of a pre-determined peer group. The market price on February 20, 2018 was $26.85 , and the market price on February 21, 2018 was $27.00 . For the three months ended March 31, 2018 and 2017 , the Company recognized share-based compensation expenses of $0.6 million and $0.7 million in expense, respectively. The expenses related to share-based compensation awards that were recorded in selling and administrative expenses. As of March 31, 2018 , there was $6.4 million of total unrecognized compensation cost related to non-vested stock options, restricted stock awards, RSUs and PRSUs. This cost is expected to be recognized over a weighted average period of 2.6 years .

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Accumulated Other Comprehensive Loss	ACCUMULATED OTHER COMPREHENSIVE LOSS Table 13: Details of Changes in Accumulated Other Comprehensive Loss by Category Foreign currency translation adjustment Net unrealized gain on derivatives, net of tax Total (in thousands) Balance as of December 31, 2017 $ (3,636 ) $ 987 $ (2,649 ) Other comprehensive (loss)/income before reclassifications (481 ) 1,072 591 Amounts reclassified from Accumulated other comprehensive loss — (27 ) (27 ) Net current period other comprehensive (loss)/income (481 ) 1,045 564 Balance as of March 31, 2018 $ (4,117 ) $ 2,032 $ (2,085 )

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The Company’s estimated annual effective tax rate is approximately 22.9% . Due to the timing of the enactment and the complexity involved in applying the provisions of the Tax Cuts and Jobs Act of 2017 (the "Act"), the Company calculated its best estimate of the impact of the Act in its 2017 year end income tax provision in accordance with its understanding of the Act and guidance available as of the date of its Annual Report on Form 10-K for fiscal year 2017 and as a result had recorded $9.2 million reduction in income tax expense in the fourth quarter of 2017. No adjustment was made to the provisional amount as a result of additional information obtained for the three months ended March 31, 2018 . The accounting is expected to be complete when the 2017 U.S. federal and state corporate income tax returns are filed in late 2018. The Company is subject to audit examinations at federal, state and local levels by tax authorities in those jurisdictions. In addition, the Canadian operations are subject to audit examinations at federal and provincial levels by tax authorities in those jurisdictions. The tax matters challenged by the tax authorities are typically complex; therefore, the ultimate outcome of any challenges would be subject to uncertainty. The Company has not identified any issues that did not meet the recognition threshold or would be impacted by the measurement provisions of the uncertain tax position guidance.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE The following table shows the weighted average number of shares used in computing earnings per share and the effect on the weighted average number of shares of potentially dilutive securities. Potentially dilutive common stock has no effect on income available to common stockholders. For the three months ended March 31, 2018 and 2017 respectively, approximately 62,949 and 84,456 share-based compensation awards were excluded from the weighted average shares outstanding because their impact would be anti-dilutive in the computation of dilutive earnings per share. Table 15: Details of Basic and Dilutive Earnings Per Share For the Three Months Ended March 31, 2018 March 31, 2017 (dollars in thousands, except for per share amounts) Net income $ 13,646 $ 12,227 Weighted average number of shares outstanding - basic 37,432,782 39,576,268 Effect of dilutive securities: Restricted stock awards 3,509 10,061 Restricted stock units 72,012 74,349 Performance restricted stock units 69,509 16,523 Stock options 27,141 24,925 Total effect of dilutive securities 172,171 125,858 Weighted average number of shares outstanding - diluted 37,604,953 39,702,126 Basic earnings per share $ 0.36 $ 0.31 Diluted earnings per share $ 0.36 $ 0.31

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Commitments The Company leases certain buildings and equipment. The Company's facility and equipment leases may provide for escalations of rent or rent abatements and payment of pro rata portions of building operating expenses. Minimum lease payments are recognized on a straight-line basis over the minimum lease term. The total expenses under operating leases for both the three months ended March 31, 2018 and 2017 was $0.8 million . The Company also has non-capital purchase commitments that primarily relate to gas, gypsum, paper and other raw materials. The total amounts purchased under such commitments were $22.4 million and $17.6 million for the three months ended March 31, 2018 and 2017 , respectively. Table 16: Details of Future Minimum Lease Payments Due Under Noncancellable Operating Leases and Purchase Commitments Future Minimum Lease Payments Purchase Commitments (in thousands) April 1, 2018 - December 31, 2018 $ 540 $ 23,932 2019 1,658 27,939 2020 48 27,054 2021 — 8,828 2022 — 5,410 2023 — 5,572 Thereafter — 53,621 Total $ 2,246 $ 152,356 Contingent obligations Under certain circumstances, the Company provides letters of credit related to its natural gas and other supply purchases. As of March 31, 2018 and December 31, 2017 , the Company had outstanding letters of credit of approximately $1.6 million . Legal Matters In the ordinary course of business, the Company executes contracts involving indemnifications standard in the industry. These indemnifications might include claims relating to any of the following: environmental and tax matters; intellectual property rights; governmental regulations and employment-related matters; customer, supplier, and other commercial contractual relationships; and financial matters. While the maximum amount to which the Company may be exposed under such agreements cannot be estimated, it is the opinion of management that these guarantees and indemnifications are not expected to have a material adverse effect on the Company's financial condition, results of operations or liquidity. In the ordinary course of business, the Company is involved in certain legal actions and claims, including proceedings under laws and regulations relating to environmental and other matters. Because such matters are subject to many uncertainties and the outcomes are not predictable with assurance, the total liability for these legal actions and claims cannot be determined with certainty. When the Company determines that it is probable that a liability for environmental matters, legal actions or other contingencies has been incurred and the amount of the loss is reasonably estimable, an estimate of the costs to be incurred is recorded as a liability in the financial statements. As of March 31, 2018 and December 31, 2017 , such liabilities were not expected to have a material adverse effect on the Company's financial condition, results of operations or liquidity. While management believes its accruals for such liabilities are adequate, the Company may incur costs in excess of the amounts provided. Although the ultimate amount of liability that may result from these matters or actions is not ascertainable, any amounts exceeding the recorded accruals are not expected to have a material adverse effect on the Company's financial condition, results of operations or liquidity.

Segment Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Segment Reporting	SEGMENT REPORTING Segment information is presented in accordance with ASC 280, Segment Reporting, which establishes standards for reporting information about operating segments. It also establishes standards for related disclosures about products and geographic areas. The Company's primary reportable segment is wallboard, which represented approximately 96.7% and 96.6% of the Company's revenues for the three months ended March 31, 2018 and 2017 , respectively. This segment produces wallboard for the commercial and residential construction sectors. The Company also manufactures finishing products, which complement the Company's full range of wallboard products. Revenues from the major products sold to external customers include gypsum wallboard and finishing products. The Company's two geographic areas consist of the United States and Canada for which it reports net sales, fixed assets and total assets. The Company evaluates operating performance based on profit or loss from operations before certain adjustments as shown below. Revenues are attributed to geographic areas based on the location of the customer generating the revenue. The Company did not provide asset information by segment as its Chief Operating Decision Maker does not use such information for purposes of allocating resources and assessing segment performance. Table 17.1: Segment Reporting For the Three Months Ended March 31, 2018 March 31, 2017 (in thousands) Net Sales: Wallboard $ 112,971 $ 116,476 Other 3,831 4,139 Total net sales $ 116,802 $ 120,615 Operating Income: Wallboard $ 21,030 $ 21,592 Other (268 ) 95 Total operating income $ 20,762 $ 21,687 Adjustments: Interest expense $ (2,720 ) $ (2,916 ) Losses from equity investment (364 ) (170 ) Other expense, net (140 ) (644 ) Income before provision for income taxes $ 17,538 $ 17,957 Depreciation and Amortization: Wallboard $ 10,305 $ 11,022 Other 276 264 Total depreciation and amortization $ 10,581 $ 11,286 Table 17.2: Details of Net Sales By Geographic Region For the Three Months Ended March 31, 2018 March 31, 2017 (in thousands) United States $ 109,975 $ 110,386 Canada 6,827 10,229 Net sales $ 116,802 $ 120,615 Table 17.3: Details of Assets By Geographic Region Fixed Assets Total Assets March 31, 2018 December 31, 2017 March 31, 2018 December 31, 2017 (in thousands) United States $ 290,371 $ 290,324 $ 621,878 $ 622,836 Canada 3,531 3,679 18,738 19,098 Total $ 293,902 $ 294,003 $ 640,616 $ 641,934

Fair Value Disclosures

Fair Value Disclosures	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Disclosures	FAIR VALUE DISCLOSURES The Company estimates the fair value of its debt by discounting the future cash flows of each instrument using estimated market rates of debt instruments with similar maturities and credit profiles. These inputs are classified as Level 3 within the fair value hierarchy. As of March 31, 2018 and December 31, 2017 , the carrying value reported in the consolidated balance sheet for the Company's notes payable approximated its fair value. The only assets or liabilities the Company had at March 31, 2018 that are recorded at fair value on a recurring basis are the natural gas hedges and interest rate swaps. Generally, the Company obtains its Level 2 pricing inputs from its counterparties. Substantially all of these assumptions are observable in the marketplace throughout the full term of the instrument, can be derived from observable data or are supported by observable levels at which transactions are executed in the marketplace. Assets and liabilities that are measured at fair value on a non-recurring basis include intangible assets and goodwill. These items are recognized at fair value when they are considered to be impaired. There were no fair value adjustments for assets and liabilities measured on a non-recurring basis. The Company discloses fair value information about financial instruments for which it is practicable to estimate that value. Table 18.1: Fair Value Hierarchy - 2018 As of March 31, 2018 Level 1 Level 2 Level 3 Balance (in thousands) Asset Interest rate swap $ — $ — $ — $ — Commodity derivatives — 9 — 9 Total assets $ — $ 9 $ — $ 9 Liabilities Interest rate swap $ — $ 108 $ — $ 108 Commodity derivatives — 339 — 339 Total liabilities $ — $ 447 $ — $ 447 Table 18.2: Fair Value Hierarchy - 2017 As of December 31, 2017 Level 1 Level 2 Level 3 Balance (in thousands) Asset Interest rate swap $ — $ 2,148 $ — $ 2,148 Commodity derivatives — 11 — 11 Total assets $ — $ 2,159 $ — $ 2,159 Liabilities Interest rate swap $ — $ — $ — $ — Commodity derivatives — 613 — 613 Total liabilities $ — $ 613 $ — $ 613

Significant Accounting Polici25

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements for the Company have been prepared in accordance with accounting principles generally accepted in the United States ("U.S. GAAP"). The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions have been eliminated.
Revenue Recognition	Revenue Disclosure Revenue from the sale of gypsum products is recognized when control of the promised products is transferred to the Company's customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those products (the transaction price). A performance obligation is a promise in a contract to transfer a distinct product to a customer and is the unit of account under ASC 606. Control transfers to the customer at a point in time. To indicate the transfer of control, the Company must have a present right to payment, legal title must have passed to the customer and the customer must have the significant risks and rewards of ownership. Generally, the Company satisfies its performance obligations within a number of days from the time the contract is executed. The Company records estimated reductions to revenue for customer programs and incentive offerings, including promotions and other volume-based incentives, in the period in which the sale occurs. Amounts billed to a customer at the transaction price are included in "Net sales," and costs incurred for shipping and handling are treated as fulfillment costs and are classified as "Cost of goods sold" in the Consolidated Statements of Operations. See Note 17, Segment reporting, for disaggregation of revenue by segment.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting Standards Adopted During the Period In May 2014, the FASB issued ASU No. 2014-9, "Revenue from Contracts with Customers (Topic 606)," which provides accounting guidance for all revenue arising from contracts with customers and affects all entities that enter into contracts to provide goods or services to their customers. In August 2015, the FASB issued ASU No. 2015-14, "Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date," which deferred the effective date of ASU No. 2014-9 for all entities by one year to annual reporting periods beginning after December 15, 2017. The ASU requires retroactive application on either a full or modified basis. The Company adopted the standard on January 1, 2018 using the modified retrospective approach. Based on evaluation, the Company has concluded it has one revenue stream and the adoption of this new guidance did not have a material impact on its Consolidated Financial Statements. The Company included the disclosures required by this ASU above. In August 2016, the FASB issued ASU 2016-15, "Classification of Certain Cash Receipts and Cash Payments." This ASU reduces existing diversity in the classification of certain cash receipts and cash payments on the statements of cash flows. ASU 2016-15 is effective for fiscal years beginning after December 15, 2017, and for interim periods within those fiscal years. The adoption of this standard did not have a material impact on the Company's Consolidated Financial Statements. In October 2016, the FASB issued ASU 2016-16, "Intra-Entity Transfers of Assets Other Than Inventory." The new standard requires companies to recognize the income tax effects of intercompany sales or transfers of assets, other than inventory, in the income statement as income tax expense (or benefit) in the period the sales or transfer occurs. The standard requires companies to apply a modified retrospective approach with a cumulative catch-up adjustment to opening retained earnings in the period of adoption. The provisions of this standard are effective for fiscal years beginning after December 15, 2017, and early adoption is permitted. The adoption of this standard did not have a material impact on the Company's Consolidated Financial Statements. Accounting Standards Not Yet Adopted In February 2016, the FASB issued ASU 2016-02, "Leases." ASU 2016-02 requires lessees to recognize a lease liability and a right-of-use asset on the balance sheet. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is in the process of evaluating the impact of adoption, which is not expected to have a material impact on its Consolidated Financial Statements. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments." This ASU is intended to introduce a revised approach to the recognition and measurement of credit losses, emphasizing an updated model based on expected losses rather than incurred losses. The provisions of this standard are effective for reporting periods beginning after December 15, 2019 and early adoption is permitted. The Company is currently evaluating the impact that this guidance may have on its Consolidated Financial Statements. In August 2017, the FASB issued ASU 2017-12, "Derivatives and Hedging (Topic 815), Targeted Improvements to Accounting for Hedging Activities." This ASU expands an entity's ability to hedge non-financial and financial risk components and reduce complexity in fair value hedges of interest rate risk. The guidance eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires the entire change in the fair value of a hedging instrument to be presented in the same income statement line as the hedged item. The provisions of this standard are effective in 2019 for calendar-year public business entities and in 2020 for all other calendar-year companies. Early adoption of the standard is permitted. The Company is currently evaluating when it will adopt the ASU and the expected impact to its Consolidated Financial Statements. In February 2018, the FASB issued ASU 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220), Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income." This ASU 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 reporting periods beginning after December 15, 2018 and early adoption is permitted. The Company is currently evaluating the impact that this guidance may have on its Consolidated Financial Statements.
Reclassifications	Reclassifications Certain reclassifications of prior year information were made to conform to the 2018 presentation. These reclassifications had no material impact on the Company's Consolidated Financial Statements.

Significant Accounting Polici26

Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	Table 2.1: Certain Cash Transactions and Other Activity For the Three Months Ended March 31, 2018 March 31, 2017 (in thousands) Cash paid during the period for: Interest paid on term loan, net $ 2,396 $ 2,457 Income taxes paid, net — 216 Other activity: Amounts in accounts payable for capital expenditures 1,789 915

Receivables, Net (Tables)

Receivables, Net (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Detail of Receivables, Net	Table 3: Details of Receivables, Net March 31, 2018 December 31, 2017 (in thousands) Trade receivables, gross $ 46,961 $ 39,577 Allowance for cash discounts and doubtful accounts (715 ) (808 ) Receivables, net $ 46,246 $ 38,769

Inventories, Net (Tables)

Inventories, Net (Tables)	3 Months Ended
	Mar. 31, 2018
Inventory Disclosure [Abstract]
Composition of Inventories	Table 4: Details of Inventories, Net March 31, 2018 December 31, 2017 (in thousands) Finished products $ 6,128 $ 5,893 Raw materials 14,463 11,663 Supplies and other 7,134 7,326 Inventories, net $ 27,725 $ 24,882

Property, Plant and Equipment29

Property, Plant and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment Details	Table 5: Details of Property, Plant and Equipment, Net March 31, 2018 December 31, 2017 (in thousands) Land $ 13,187 $ 13,187 Buildings 114,193 114,051 Plant machinery 282,732 281,786 Mobile equipment 10,565 10,366 Construction in progress 26,789 20,291 Property, plant and equipment, at cost 447,466 439,681 Accumulated depreciation (153,564 ) (145,678 ) Property, plant and equipment, net $ 293,902 $ 294,003

Customer Relationships and Ot30

Customer Relationships and Other Intangibles, Net (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Details of Customer Relationships and Other Intangibles, Net	Table 6.1: Details of Customer Relationships and Other Intangibles, Net March 31, 2018 December 31, 2017 Gross Accumulated Amortization Net Gross Accumulated Amortization Net (in thousands) Customer relationships $ 116,531 $ (59,855 ) $ 56,676 $ 116,711 $ (57,811 ) $ 58,900 Purchased and internally developed software 6,483 (5,015 ) 1,468 6,226 (4,871 ) 1,355 Trademarks 14,816 (4,527 ) 10,289 14,839 (4,287 ) 10,552 Total $ 137,830 $ (69,397 ) $ 68,433 $ 137,776 $ (66,969 ) $ 70,807
Future Amortization Expense of Customer Relationships and Other Intangibles	Table 6.2: Details of Future Amortization Expense of Customer Relationships and Other Intangibles As of March 31, 2018 (in thousands) April 1, 2018 through December 31, 2018 $ 7,344 2019 8,753 2020 7,869 2021 7,178 2022 6,605 Thereafter 30,684 Total $ 68,433

Accrued and Other Liabilities (

Accrued and Other Liabilities (Tables)	3 Months Ended
	Mar. 31, 2018
Payables and Accruals [Abstract]
Details of Accrued and Other Liabilities	Table 8: Details of Accrued and Other Liabilities March 31, 2018 December 31, 2017 (in thousands) Employee-related costs $ 3,828 $ 9,258 Income taxes 3,764 — Other taxes 1,665 938 Other 1,425 1,744 Accrued and other liabilities $ 10,682 $ 11,940

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Details of Debt	Table 9.1: Details of Debt March 31, 2018 December 31, 2017 (in thousands) First Lien Credit Agreement ( 1 ) $ 270,894 $ 271,573 Less: Original issue discount (net of amortization) (1,575 ) (1,681 ) Less: Debt issuance costs (4,397 ) (4,580 ) Total debt 264,922 265,312 Less: Current portion of long-term debt (1,680 ) (1,702 ) Long-term debt $ 263,242 $ 263,610
Future Minimum Principal Payments Due Under the Credit Agreements	Table 9.2: Details of Future Minimum Principal Payments Due Under the Amended and Restated Credit Agreement Amount Due (in thousands) April 1, 2018 through December 31, 2018 $ 2,037 2019 2,716 2020 2,716 2021 2,716 2022 2,716 Thereafter 257,993 Total Payments $ 270,894

Derivative Instruments (Tables)

Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	Table 10.1: Details of Derivatives Fair Value March 31, 2018 December 31, 2017 (in thousands) Assets Interest rate swap $ — $ 2,148 Commodity hedges 9 11 Total assets $ 9 $ 2,159 Liabilities Interest rate swap $ 108 $ — Commodity hedges 339 613 Total liabilities $ 447 $ 613
Derivative Instruments, Gain (Loss)	Table 10.2: Gains/(Losses) on Derivatives For the Three Months Ended March 31, 2018 March 31, 2017 March 31, 2018 March 31, 2017 Gain/(loss) recognized in Other comprehensive income on derivatives (effective portion), net of tax Gain/(loss) reclassified from Accumulated other comprehensive loss into income (effective portion), net of tax (in thousands) Interest rate swap $ 831 $ (2 ) $ 70 $ 82 Commodity hedges 241 (66 ) (97 ) 6 Total $ 1,072 $ (68 ) $ (27 ) $ 88

Treasury Stock (Tables)

Treasury Stock (Tables)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Treasury Stock Activity	All repurchased shares are held in treasury, reducing the number of shares of common stock outstanding and used in the Company's earnings per share calculation. Table 11: Details of Treasury Stock Activity March 31, 2018 March 31, 2017 Shares Amount (1) Average Share Price (1) Shares Amount (1) Average Share Price (1) (in thousands, except share data) Beginning Balance 6,788,817 $ 143,357 $ 21.12 4,499,655 $ 88,756 $ 19.73 Repurchases on open market 530,600 14,550 27.42 217,123 5,237 24.12 Ending Balance 7,319,417 $ 157,907 $ 21.57 4,716,778 $ 93,993 $ 19.93 ( 1 ) Includes commissions paid for repurchases on open market.

Accumulated Other Comprehensi35

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Changes in Accumulated Other Comprehensive (Loss)/Income by Category	Table 13: Details of Changes in Accumulated Other Comprehensive Loss by Category Foreign currency translation adjustment Net unrealized gain on derivatives, net of tax Total (in thousands) Balance as of December 31, 2017 $ (3,636 ) $ 987 $ (2,649 ) Other comprehensive (loss)/income before reclassifications (481 ) 1,072 591 Amounts reclassified from Accumulated other comprehensive loss — (27 ) (27 ) Net current period other comprehensive (loss)/income (481 ) 1,045 564 Balance as of March 31, 2018 $ (4,117 ) $ 2,032 $ (2,085 )

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Basic and Dilutive Earnings Per Share	The following table shows the weighted average number of shares used in computing earnings per share and the effect on the weighted average number of shares of potentially dilutive securities. Potentially dilutive common stock has no effect on income available to common stockholders. For the three months ended March 31, 2018 and 2017 respectively, approximately 62,949 and 84,456 share-based compensation awards were excluded from the weighted average shares outstanding because their impact would be anti-dilutive in the computation of dilutive earnings per share. Table 15: Details of Basic and Dilutive Earnings Per Share For the Three Months Ended March 31, 2018 March 31, 2017 (dollars in thousands, except for per share amounts) Net income $ 13,646 $ 12,227 Weighted average number of shares outstanding - basic 37,432,782 39,576,268 Effect of dilutive securities: Restricted stock awards 3,509 10,061 Restricted stock units 72,012 74,349 Performance restricted stock units 69,509 16,523 Stock options 27,141 24,925 Total effect of dilutive securities 172,171 125,858 Weighted average number of shares outstanding - diluted 37,604,953 39,702,126 Basic earnings per share $ 0.36 $ 0.31 Diluted earnings per share $ 0.36 $ 0.31

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Lease Payments Due Under Non-Cancelable Operating Leases and Purchase Commitments by Year	Table 16: Details of Future Minimum Lease Payments Due Under Noncancellable Operating Leases and Purchase Commitments Future Minimum Lease Payments Purchase Commitments (in thousands) April 1, 2018 - December 31, 2018 $ 540 $ 23,932 2019 1,658 27,939 2020 48 27,054 2021 — 8,828 2022 — 5,410 2023 — 5,572 Thereafter — 53,621 Total $ 2,246 $ 152,356

Segment Reporting (Tables)

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Segment Reporting	Table 17.1: Segment Reporting For the Three Months Ended March 31, 2018 March 31, 2017 (in thousands) Net Sales: Wallboard $ 112,971 $ 116,476 Other 3,831 4,139 Total net sales $ 116,802 $ 120,615 Operating Income: Wallboard $ 21,030 $ 21,592 Other (268 ) 95 Total operating income $ 20,762 $ 21,687 Adjustments: Interest expense $ (2,720 ) $ (2,916 ) Losses from equity investment (364 ) (170 ) Other expense, net (140 ) (644 ) Income before provision for income taxes $ 17,538 $ 17,957 Depreciation and Amortization: Wallboard $ 10,305 $ 11,022 Other 276 264 Total depreciation and amortization $ 10,581 $ 11,286
Net Sales By Geographic Region	Table 17.2: Details of Net Sales By Geographic Region For the Three Months Ended March 31, 2018 March 31, 2017 (in thousands) United States $ 109,975 $ 110,386 Canada 6,827 10,229 Net sales $ 116,802 $ 120,615
Assets By Geographic Region	Table 17.3: Details of Assets By Geographic Region Fixed Assets Total Assets March 31, 2018 December 31, 2017 March 31, 2018 December 31, 2017 (in thousands) United States $ 290,371 $ 290,324 $ 621,878 $ 622,836 Canada 3,531 3,679 18,738 19,098 Total $ 293,902 $ 294,003 $ 640,616 $ 641,934

Fair Value Disclosures (Tables)

Fair Value Disclosures (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	Table 18.1: Fair Value Hierarchy - 2018 As of March 31, 2018 Level 1 Level 2 Level 3 Balance (in thousands) Asset Interest rate swap $ — $ — $ — $ — Commodity derivatives — 9 — 9 Total assets $ — $ 9 $ — $ 9 Liabilities Interest rate swap $ — $ 108 $ — $ 108 Commodity derivatives — 339 — 339 Total liabilities $ — $ 447 $ — $ 447 Table 18.2: Fair Value Hierarchy - 2017 As of December 31, 2017 Level 1 Level 2 Level 3 Balance (in thousands) Asset Interest rate swap $ — $ 2,148 $ — $ 2,148 Commodity derivatives — 11 — 11 Total assets $ — $ 2,159 $ — $ 2,159 Liabilities Interest rate swap $ — $ — $ — $ — Commodity derivatives — 613 — 613 Total liabilities $ — $ 613 $ — $ 613

Background and Nature of Oper40

Background and Nature of Operations - Description of Business and Acquisition (Detail) $ in Millions	Aug. 30, 2013USD ($)	Mar. 31, 2018facility
Lone Star Fund VIII (U.S.), L.P. | Lafarge N.A.
Business Acquisition [Line Items]
Total purchase price | $	$ 703
Wallboard
Business Acquisition [Line Items]
Number of operating facilities (facility)		3
Joint Compound
Business Acquisition [Line Items]
Number of operating facilities (facility)		1

Background and Nature of Oper41

Background and Nature of Operations - Public Offerings (Detail) - Secondary Public Offerings - LSF8 Gypsum Holdings, L.P.	Mar. 18, 2016$ / sharesshares
Subsidiary, Sale of Stock [Line Items]
Shares issued at public offering (shares)	5,106,803
Offering price per share (usd per share) | $ / shares	$ 16.10
Repurchase from LSF8 in private transaction
Subsidiary, Sale of Stock [Line Items]
Shares repurchased (shares)	900,000

Significant Accounting Polici42

Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Accounts receivable	$ 46,246	$ 38,769

Significant Accounting Polici43

Significant Accounting Policies - Certain Cash and Non-Cash Transactions (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accounting Policies [Abstract]
Interest paid	$ 2,396	$ 2,457
Income taxes paid, net	0	216
Accounts payable for capital expenditures	$ 1,789	$ 915

Receivables, Net - Detail of Re

Receivables, Net - Detail of Receivables, Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Trade receivables, gross	$ 46,961	$ 39,577
Allowance for cash discounts and doubtful accounts	(715)	(808)
Receivables, net	$ 46,246	$ 38,769

Inventories, Net (Detail)

Inventories, Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Finished products	$ 6,128	$ 5,893
Raw materials	14,463	11,663
Supplies and other	7,134	7,326
Inventories, net	$ 27,725	$ 24,882

Property, Plant and Equipment46

Property, Plant and Equipment, Net - Property, Plant and Equipment Details (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 447,466	$ 439,681
Accumulated depreciation	(153,564)	(145,678)
Property, plant and equipment, net	293,902	294,003
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	13,187	13,187
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	114,193	114,051
Plant machinery
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	282,732	281,786
Mobile equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	10,565	10,366
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 26,789	$ 20,291

Property, Plant and Equipment47

Property, Plant and Equipment, Net - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 8.1

Investment in Seven Hills - Add

Investment in Seven Hills - Additional Information (Detail) - Seven Hills - Variable Interest Entity, Not Primary Beneficiary - Equity Method Investee - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Schedule of Equity Method Investments [Line Items]
Cost of paperboard	$ 12.2	$ 12
Purchase commitments	$ 35.1

Customer Relationships and Ot49

Customer Relationships and Other Intangibles, Net - Details of Customer Relationships and Other Intangibles, Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross	$ 137,830	$ 137,776
Accumulated Amortization	(69,397)	(66,969)
Net	68,433	70,807
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross	116,531	116,711
Accumulated Amortization	(59,855)	(57,811)
Net	56,676	58,900
Purchased and internally developed software
Finite-Lived Intangible Assets [Line Items]
Gross	6,483	6,226
Accumulated Amortization	(5,015)	(4,871)
Net	1,468	1,355
Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross	14,816	14,839
Accumulated Amortization	(4,527)	(4,287)
Net	$ 10,289	$ 10,552

Customer Relationships and Ot50

Customer Relationships and Other Intangibles, Net - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 2.5	$ 3.2

Customer Relationships and Ot51

Customer Relationships and Other Intangibles, Net - Future Amortization Expense of Customer Relationships and Other Intangibles (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
April 1, 2018 through December 31, 2018	$ 7,344
2,019	8,753
2,020	7,869
2,021	7,178
2,022	6,605
Thereafter	30,684
Net	$ 68,433	$ 70,807

Accrued and Other Liabilities52

Accrued and Other Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Employee-related costs	$ 3,828	$ 9,258
Income taxes	3,764	0
Other taxes	1,665	938
Other	1,425	1,744
Accrued and other liabilities	$ 10,682	$ 11,940

Debt - Details of Debt (Detail)

Debt - Details of Debt (Detail) - USD ($) $ in Thousands	Aug. 18, 2016	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
First Lien Credit Agreement (1)		$ 270,894
Less: Original issue discount (net of amortization)		(1,575)	$ (1,681)
Less: Debt issuance costs		(4,397)	(4,580)
Total debt		264,922	265,312
Less: Current portion of long-term debt		(1,680)	(1,702)
Long-term debt		263,242	263,610
Term Loan Facility | First Lien Credit Agreement
Debt Instrument [Line Items]
First Lien Credit Agreement (1)		$ 270,894	$ 271,573
Term Loan Facility | First Lien Credit Agreement | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Floor rate	0.75%	0.75%
Debt, variable interest rate (as a percent)	2.75%	2.25%

Debt - Additional Information (

Debt - Additional Information (Detail)	Dec. 06, 2017	Feb. 21, 2017	Aug. 18, 2016USD ($)	May 31, 2014	Mar. 31, 2018USD ($)covenant	Mar. 31, 2017USD ($)	Sep. 30, 2014	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Debt related expenses					$ 0	$ 686,000
Extinguishment of Debt, Amount					$ (700,000)	(700,000)
First Lien Credit Agreement
Debt Instrument [Line Items]
Debt related expenses			$ 3,300,000
Number of covenants | covenant					1
Debt covenant trigger, line of credit facility amount less letters of credit threshold					$ 22,500,000
First Lien Credit Agreement | Maximum
Debt Instrument [Line Items]
Leverage ratio (no greater than)					5
Amended and Restated Credit Agreement
Debt Instrument [Line Items]
Decrease in basis spread, percentage		0.25%
Leverage ratio (no greater than)	1.1
Amended and Restated Credit Agreement | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt, variable interest rate (as a percent)	2.25%	2.50%
Debt, variable interest rate if leverage ratio met	2.00%
Term Loan Facility | First Lien Credit Agreement
Debt Instrument [Line Items]
Debt principal amount			275,000,000
Discount and debt issuance costs			4,700,000		$ 2,200,000
Discount and debt issuance costs recorded in other expense, net			$ 2,500,000
Effective interest rate					4.60%
Term Loan Facility | First Lien Credit Agreement | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt, variable interest rate (as a percent)			2.75%		2.25%
Floor rate			0.75%		0.75%
Decrease in basis spread, percentage				0.50%
Term Loan Facility | First Lien Credit Agreement | Moody's, B2 Rating | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Decrease in basis spread, percentage							0.25%
Line of Credit | First Lien Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility borrowing capacity			$ 75,000,000
Debt, variable interest rate (as a percent)					2.25%
Outstanding amount					$ 0			$ 0
Proceeds from line of credit					$ 0	$ 0
Facility fee, basis points					0.50%
Remaining outstanding					$ 73,400,000
Line of Credit | First Lien Credit Agreement | Revolving Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt, variable interest rate (as a percent)					2.25%

Debt - Future Minimum Principal

Debt - Future Minimum Principal Payments Due Under the Credit Agreements (Detail) $ in Thousands	Mar. 31, 2018USD ($)
Long-term Debt, Fiscal Year Maturity [Abstract]
April 1, 2018 through December 31, 2018	$ 2,037
2,019	2,716
2,018	2,716
2,020	2,716
2,021	2,716
Thereafter	257,993
Total Payments	$ 270,894

Derivative Instruments - Additi

Derivative Instruments - Additional Information (Detail)	Mar. 29, 2018USD ($)	Sep. 30, 2016USD ($)	Mar. 31, 2018USD ($)MMBTU
Derivative [Line Items]
Proceeds from derivative hedges	$ 3,200,000
Derivatives, net liability position			$ (400,000)
Collateral posted with counterparties related to derivatives			$ 0
Natural Gas Swap | Cash Flow Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Aggregate notional amount outstanding (in mmBTUs) | MMBTU			2,895,000
Interest rate swap | Cash Flow Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Aggregate notional amount outstanding	$ 100,000,000	$ 100,000,000
Derivative instrument term (not beyond)		4 years
Average fixed rate (as a percent)	2.46%	1.323%
Interest rate swap | Cash Flow Hedging | Designated as Hedging Instrument | London Interbank Offered Rate (LIBOR)
Derivative [Line Items]
Floor rate (as a percent)	0.75%	0.75%

Derivative Instruments - Deriva

Derivative Instruments - Derivatives at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative asset	$ 9	$ 2,159
Derivative liability	447	613
Interest rate swap
Derivative [Line Items]
Derivative asset	0	2,148
Derivative liability	108	0
Commodity derivatives
Derivative [Line Items]
Derivative asset	9	11
Derivative liability	$ 339	$ 613

Derivative Instruments - Gains

Derivative Instruments - Gains (losses) on derivatives (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(loss) recognized in Other comprehensive income on derivatives (effective portion), net of tax	$ 1,072	$ (68)
Gain/(loss) reclassified from Accumulated other comprehensive loss into income (effective portion), net of tax	(27)	88
Interest rate swap
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(loss) recognized in Other comprehensive income on derivatives (effective portion), net of tax	831	(2)
Gain/(loss) reclassified from Accumulated other comprehensive loss into income (effective portion), net of tax	70	82
Commodity derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(loss) recognized in Other comprehensive income on derivatives (effective portion), net of tax	241	(66)
Gain/(loss) reclassified from Accumulated other comprehensive loss into income (effective portion), net of tax	$ (97)	$ 6

Treasury Stock - Additional Inf

Treasury Stock - Additional Information (Detail)	27 Months Ended
	Mar. 31, 2018expansion	Feb. 21, 2018USD ($)	Nov. 04, 2015USD ($)
Equity [Abstract]
Stock repurchase program authorized amount (up to) | $		$ 300,000,000	$ 50,000,000
Number of expansions to stock repurchase program | expansion	3

Treasury Stock - Treasury Stock

Treasury Stock - Treasury Stock Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Treasury Stock [Roll Forward]
Beginning balance (shares)	6,788,817	4,499,655	4,499,655
Ending balance (shares)	7,319,417	4,716,778	6,788,817	4,499,655
Beginning balance	$ 143,357	$ 88,756	$ 88,756
Ending balance	$ 157,907	$ 93,993	$ 143,357	$ 88,756
Average share price (usd per share)	$ 21.57	$ 19.93	$ 21.12	$ 19.73
Repurchases on open market
Treasury Stock [Roll Forward]
Shares repurchased (shares)	530,600	217,123
Shares repurchased	$ 14,550	$ 5,237
Average share price (usd per share)	$ 27.42	$ 24.12

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Feb. 21, 2018	Feb. 20, 2018	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense			$ 0.6	$ 0.7
Unrecognized compensation expense related to non-vested restricted stock			$ 6.4
Restricted Share Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	19,788	51,012
Vesting period	4 years	4 years
Granted, Weighted average exercise price (in dollars per share)	$ 27	$ 26.85
Restricted Share Units (RSUs) | Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	15,900
Vesting period	1 year
Performance Based RSUs (PRSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	19,788	21,385
Granted, Weighted average exercise price (in dollars per share)	$ 27	$ 26.85
Performance Based RSUs (PRSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of PRSUs earned	0.00%
Performance Based RSUs (PRSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of PRSUs earned	240.00%
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unearned compensation expense, weighted average remaining period			2 years 6 months 20 days

Accumulated Other Comprehensi62

Accumulated Other Comprehensive Loss (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 318,026
Ending Balance	317,909
Foreign currency translation adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(3,636)
Other comprehensive (loss)/income before reclassifications	(481)
Amounts reclassified from Accumulated other comprehensive loss	0
Net current period other comprehensive (loss)/income	(481)
Ending Balance	(4,117)
Net unrealized gain on derivatives, net of tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	987
Other comprehensive (loss)/income before reclassifications	1,072
Amounts reclassified from Accumulated other comprehensive loss	(27)
Net current period other comprehensive (loss)/income	1,045
Ending Balance	2,032
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(2,649)
Other comprehensive (loss)/income before reclassifications	591
Amounts reclassified from Accumulated other comprehensive loss	(27)
Net current period other comprehensive (loss)/income	564
Ending Balance	$ (2,085)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Effective rate (as a percent)	22.90%
Reduction in income tax expense due to Tax Cuts and Jobs Act of 2017		$ 9.2

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Details) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based compensation awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	62,949	84,456

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income	$ 13,646	$ 12,227
Weighted average number of shares outstanding- basic (shares)	37,432,782	39,576,268
Effect of dilutive securities:
Total effect of dilutive securities (shares)	172,171	125,858
Weighted average number of shares outstanding - diluted (shares)	37,604,953	39,702,126
Basic earnings per share (usd per share)	$ 0.36	$ 0.31
Diluted earnings per share (usd per share)	$ 0.36	$ 0.31
Restricted stock awards
Effect of dilutive securities:
Effect of dilutive securities (shares)	3,509	10,061
Restricted stock units
Effect of dilutive securities:
Effect of dilutive securities (shares)	72,012	74,349
Performance restricted stock units
Effect of dilutive securities:
Effect of dilutive securities (shares)	69,509	16,523
Stock options
Effect of dilutive securities:
Effect of dilutive securities (shares)	27,141	24,925

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 0.8	$ 0.8
Letter of Credit
Long-term Purchase Commitment [Line Items]
Outstanding amount of letters of credit	1.6		$ 1.6
Gas, Gypsum, Paper, and Other Raw Materials
Long-term Purchase Commitment [Line Items]
Non capital purchased under commitments	$ 22.4	$ 17.6

Commitments and Contingencies67

Commitments and Contingencies - Future Minimum Lease Payments Due Under Non-Cancelable Operating Leases and Purchase Commitments by Year (Detail) $ in Thousands	Mar. 31, 2018USD ($)
Future Minimum Lease Payments
April 1, 2018 - December 31, 2018	$ 540
2,019	1,658
2,020	48
2,021	0
2,022	0
2,023	0
Thereafter	0
Total	2,246
Purchase Commitments
April 1, 2018 - December 31, 2018	23,932
2,019	27,939
2,020	27,054
2,021	8,828
2,022	5,410
2,023	5,572
Thereafter	53,621
Total	$ 152,356

Segment Reporting - Additional

Segment Reporting - Additional Information (Detail) - geographic_area	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Number of geographical areas (geographic area)	2
Wallboard | Sales Revenue, Net | Product Concentration Risk
Segment Reporting Information [Line Items]
Percentage of revenues	96.70%	96.60%

Segment Reporting - Segment Rep

Segment Reporting - Segment Reporting (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net Sales:
Net Sales	$ 116,802	$ 120,615
Operating Income:
Operating income	20,762	21,687
Adjustments:
Interest expense	(2,720)	(2,916)
Losses from equity investment	(364)	(170)
Other expense, net	(140)	(644)
Income before provision for income taxes	17,538	17,957
Depreciation and Amortization
Total depreciation and amortization	10,581	11,286
Operating Segments | Wallboard
Net Sales:
Net Sales	112,971	116,476
Operating Income:
Operating income	21,030	21,592
Depreciation and Amortization
Total depreciation and amortization	10,305	11,022
Operating Segments | Other
Net Sales:
Net Sales	3,831	4,139
Operating Income:
Operating income	(268)	95
Depreciation and Amortization
Total depreciation and amortization	276	264
Adjustments
Adjustments:
Interest expense	(2,720)	(2,916)
Losses from equity investment	(364)	(170)
Other expense, net	$ (140)	$ (644)

Segment Reporting - Net Sales b

Segment Reporting - Net Sales by Geographic Region (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 116,802	$ 120,615
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	109,975	110,386
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 6,827	$ 10,229

Segment Reporting - Assets by G

Segment Reporting - Assets by Geographic Region (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Fixed Assets	$ 293,902	$ 294,003
Total Assets	640,616	641,934
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Fixed Assets	290,371	290,324
Total Assets	621,878	622,836
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Fixed Assets	3,531	3,679
Total Assets	$ 18,738	$ 19,098

Fair Value Disclosures (Details

Fair Value Disclosures (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	$ 9	$ 2,159
Derivative liability	447	613
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	9	2,159
Derivative liability	447	613
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	0	0
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	9	2,159
Derivative liability	447	613
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	0	0
Interest rate swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	2,148
Derivative liability	108	0
Interest rate swap | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	2,148
Derivative liability	108	0
Interest rate swap | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	0	0
Interest rate swap | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	2,148
Derivative liability	108	0
Interest rate swap | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	0	0
Commodity derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	9	11
Derivative liability	339	613
Commodity derivatives | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	9	11
Derivative liability	339	613
Commodity derivatives | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	0	0
Commodity derivatives | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	9	11
Derivative liability	339	613
Commodity derivatives | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	$ 0	$ 0