Dorman Products (DORM) 10-K 26 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 29, 2018	Feb. 18, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 29, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	DORM
Entity Registrant Name	Dorman Products, Inc.
Entity Central Index Key	868,780
Current Fiscal Year End Date	--12-29
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		32,994,991
Entity Public Float			$ 1,588,586,757

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Income Statement [Abstract]
Net sales	$ 973,705	$ 903,221	$ 859,604
Cost of goods sold	600,424	544,572	521,530
Gross profit	373,281	358,649	338,074
Selling, general and administrative expenses	202,138	182,409	169,473
Income from operations	171,143	176,240	168,601
Other (expense) income, net	(8)	348	(241)
Income before income taxes	171,135	176,588	168,360
Provision for income taxes	37,533	69,989	62,311
Net income	$ 133,602	$ 106,599	$ 106,049
Earnings per share:
Basic	$ 4.04	$ 3.14	$ 3.07
Diluted	$ 4.02	$ 3.13	$ 3.07
Weighted average shares outstanding:
Basic	33,097	33,964	34,516
Diluted	33,207	34,052	34,598

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017
Current assets:
Cash and cash equivalents	$ 43,458	$ 71,691
Accounts receivable, less allowance for doubtful accounts and customer credits of $91,531 and $97,193 in 2018 and 2017, respectively	310,114	241,880
Inventories	270,504	212,149
Prepaids and other current assets	5,652	7,129
Total current assets	629,728	532,849
Property, plant and equipment, net	98,647	92,692
Goodwill	72,606	65,999
Intangible assets, net	25,164	22,158
Deferred tax asset, net	6,228	7,884
Other assets	55,184	44,342
Total	887,557	765,924
Current liabilities:
Accounts payable	109,096	80,218
Accrued compensation	14,515	12,162
Other accrued liabilities	17,979	18,401
Total current liabilities	141,590	110,781
Other long-term liabilities	13,550	13,732
Deferred tax liabilities, net	4,794	6,604
Commitments and contingencies (Note 11)
Shareholders' equity:
Common stock, par value $0.01; authorized 50,000,000 shares; issued and outstanding 33,004,861 and 33,571,524 shares in 2018 and 2017, respectively	330	336
Additional paid-in capital	47,861	44,812
Retained earnings	679,432	589,659
Total shareholders' equity	727,623	634,807
Total	$ 887,557	$ 765,924

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts and customer credits	$ 91,531	$ 97,193
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	33,004,861	33,571,524
Common stock, shares outstanding	33,004,861	33,571,524

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]
Beginning Balance at Dec. 26, 2015	$ 518,036	$ 349	$ 42,799	$ 474,888
Beginning Balance, Shares at Dec. 26, 2015		34,863,396
Compensation expense under Incentive Stock Plan	2,380		2,380
Purchase and cancellation of common stock	$ (24,678)	$ (5)	(846)	(23,827)
Purchase and cancellation of common stock, Shares	(38,970)	(469,836)
Issuance of non-vested stock, net of cancellations		$ 1	(1)
Issuance of non-vested stock, net of cancellations, Shares		131,123
Other stock related activity, net of tax	$ (145)		(145)
Other stock related activity, net of tax, Shares		(7,050)
Net income	106,049			106,049
Ending Balance at Dec. 31, 2016	601,642	$ 345	44,187	557,110
Ending Balance, Shares at Dec. 31, 2016		34,517,633
Exercise of stock options	31		31
Exercise of stock options, shares		29,750
Compensation expense under Incentive Stock Plan	3,162		3,162
Purchase and cancellation of common stock	$ (76,129)	$ (10)	(1,848)	(74,271)
Purchase and cancellation of common stock, Shares	(19,110)	(1,025,475)
Issuance of non-vested stock, net of cancellations	$ 675	$ 1	674
Issuance of non-vested stock, net of cancellations, Shares		65,317
Other stock related activity, net of tax	(1,173)		(1,394)	221
Other stock related activity, net of tax, Shares		(15,701)
Net income	106,599			106,599
Ending Balance at Dec. 30, 2017	$ 634,807	$ 336	44,812	589,659
Ending Balance, Shares at Dec. 30, 2017	33,571,524	33,571,524
Exercise of stock options	$ 200		200
Exercise of stock options, shares		10,572
Compensation expense under Incentive Stock Plan	3,460		3,460
Purchase and cancellation of common stock	$ (45,351)	$ (7)	(1,167)	(44,177)
Purchase and cancellation of common stock, Shares	(26,280)	(648,503)
Issuance of non-vested stock, net of cancellations	$ 1,799	$ 1	1,798
Issuance of non-vested stock, net of cancellations, Shares		83,891
Other stock related activity, net of tax	(894)		(1,242)	348
Other stock related activity, net of tax, Shares		(12,623)
Net income	133,602			133,602
Ending Balance at Dec. 29, 2018	$ 727,623	$ 330	$ 47,861	$ 679,432
Ending Balance, Shares at Dec. 29, 2018	33,004,861	33,004,861

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Cash Flows from Operating Activities:
Net income	$ 133,602	$ 106,599	$ 106,049
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation, amortization and accretion	28,391	22,224	18,907
Provision for doubtful accounts	(570)	299	1,221
Provision (benefit) from deferred income tax	(58)	4,676	(4,888)
Provision for non-cash stock compensation	3,460	3,162	2,380
Changes in assets and liabilities:
Accounts receivable	(66,403)	(5,709)	(27,824)
Inventories	(46,835)	(25,147)	24,874
Prepaids and other current assets	(853)	(3,748)	(790)
Other assets	(3,897)	(4,908)	(4,590)
Accounts payable	26,957	3,718	8,662
Accrued compensation and other liabilities	4,318	(6,925)	(2,462)
Cash provided by operating activities	78,112	94,241	121,539
Cash Flows from Investing Activities:
Acquisitions, net of cash acquired	(28,040)	(59,987)
Property, plant and equipment additions	(26,106)	(24,450)	(20,059)
Purchase of equity investments	(5,000)	(10,000)	(6,195)
Cash used in investing activities	(59,146)	(94,437)	(26,254)
Cash Flows from Financing Activities:
Contingent consideration payments	(2,036)
Other stock related activity	249	(1,173)	(145)
Proceeds from exercise of stock options	201	31
Purchase and cancellation of common stock	(45,352)	(76,129)	(24,678)
Cash used in financing activities	(46,938)	(77,271)	(24,823)
Effect of exchange rate changes on Cash and Cash Equivalents	(261)	37
Net Increase (Decrease) in Cash and Cash Equivalents	(28,233)	(77,430)	70,462
Cash and Cash Equivalents, Beginning of Period	71,691	149,121	78,659
Cash and Cash Equivalents, End of Period	43,458	71,691	149,121
Supplemental Cash Flow Information
Cash paid for interest expense	250	291	266
Cash paid for income taxes	$ 30,453	$ 74,647	$ 62,348

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 29, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	1. Summary of Significant Accounting Policies Dorman Products, Inc. ("Dorman", the "Company", “we”, “us”, or “our”) is a leading supplier of Original Equipment (“OE”) Dealer "Exclusive" automotive replacement parts, automotive hardware and brake products to the Automotive Aftermarket and Mass Merchandise markets. Dorman parts are marketed under the OE Solutions™, Dorman Premium Chassis, HELP! ® ® ® ® We operate on a fifty-two, fifty-three week period ending on the last Saturday of the calendar year. The fiscal years ended December 29, 2018 (“fiscal 2018”) and December 30, 2017 (“fiscal 2017”) were fifty-two week periods. The fiscal year ended December 31, 2016 (“fiscal 2016”) was a fifty-three week period. Principles of Consolidation . The Consolidated Financial Statements include our accounts and the accounts of our wholly-owned subsidiaries. All material intercompany accounts and transactions have been eliminated in consolidation. Use of Estimates in the Preparation of Financial Statements . The preparation of financial statements in accordance with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Reclassifications . Certain prior year amounts have been reclassified to conform with current-year presentation. Cash and Cash Equivalents . We consider all highly liquid short-term investments with original maturities of three months or less to be cash equivalents. Sales of Accounts Receivable . We have entered into several customer sponsored programs administered by unrelated financial institutions that permit us to sell certain accounts receivable at discounted rates to the financial institutions. Transactions under these agreements were accounted for as sales of accounts receivable and were removed from our Consolidated Balance Sheet at the time of the sales transactions. During fiscal 2018, fiscal 2017 and fiscal 2016, we sold $604.7 million, $582.9 million and $521.9 million, respectively, pursuant to these agreements. If receivables had not been sold, $378.5 million and $380.8 million of additional receivables would have been outstanding at December 29, 2018 and December 30, 2017, respectively, based on standard payment terms. Selling, general and administrative expenses include $14.5 million, $11.4 million and $8.9 million in fiscal 2018, fiscal 2017 and fiscal 2016, respectively, of financing costs associated with these accounts receivable sales programs. Inventories . Inventories are stated at the lower of cost or net realizable value. Cost is determined by the first-in, first-out method. Inventories include the cost of material, freight, direct labor and overhead utilized in the processing of our products. We provide reserves for discontinued and excess inventory based upon historical demand, forecasted usage, estimated customer requirements and product line updates. Property, Plant and Equipment . Property, plant and equipment are recorded at cost and depreciated over their estimated useful lives, which range from three to thirty-nine years, using the straight-line method for financial statement reporting purposes and accelerated methods for income tax purposes. The costs of maintenance and repairs are expensed as incurred. Renewals and betterments are capitalized. Gains and losses on disposals are included in operating results. Estimated useful lives by major asset category are as follows: Buildings and building improvements 10 to 39 years Machinery, equipment and tooling 3 to 10 years Software and computer equipment 3 to 10 years Furniture, fixtures and leasehold improvements 3 to 15 years Long-Lived Assets Including Goodwill and Other Acquired Intangible Assets . Long-lived assets, including property, plant, and equipment and amortizable identifiable intangibles, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. The impairment review is a two-step process. First, recoverability is measured by comparing the carrying amount of an asset to the estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount exceeds the estimated undiscounted future cash flows, the second step of the impairment test is performed and an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds its fair value. Assets to be disposed of would be separately presented in the balance sheet and reported at the lower of the carrying amount or fair value less costs to sell, and are no longer depreciated. The assets and liabilities of a disposal group classified as held for sale would be presented separately in the appropriate asset and liability sections of the balance sheet. Goodwill is reviewed for impairment on an annual basis or whenever events or changes in circumstances indicate the carrying value of the goodwill may be impaired. In regards to the annual test, we have the option to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If we determine it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing the two-step impairment test is unnecessary. Purchase Accounting . The purchase price of an acquired business is allocated to the underlying tangible and intangible assets acquired and liabilities assumed based upon their respective fair market values, with the excess recorded as goodwill. Such fair market value assessments require judgments and estimates which may change over time and may cause the final amounts to differ materially from their original estimates. These adjustments to fair value assessments are recorded to goodwill over the purchase price allocation period which cannot exceed twelve months. Other Assets . Other assets include primarily long-term core inventory, deposits, and equity method investments. Certain products we sell contain parts that can be recycled, or as more commonly referred to in our industry, remanufactured. We refer to these parts as cores. A used core is remaufactured and sold to the customer as a replacement for a unit inside a vehicle. Customers and end-users that purchase remanufactured products will generally return the used core to us, which we then use in the remanufacturing process to make another finished good. Our core inventory consists of used cores purchased and held in our facilities, used cores that are in the process of being returned from our customers and end-users, and remanufactured cores held in finished goods inventory at our facilities. Our products that utilize a core primarily include instrument clusters, hybrid batteries, radios, and climate control modules. Long-term core inventory was $28.1 million and $20.2 million as of December 29, 2018 and December 30, 2017, respectively. Long-term core inventory is recorded at the lower of cost or net realizable value. Cost is determined based on actual purchases of core inventory. We believe that the most appropriate classification of core inventory is a long-term asset. According to guidance provided under the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification(“ASC”), current assets are defined as “assets or resources commonly identified as those which are reasonably expected to be realized in cash or sold or consumed during the normal operating cycle of the business.” The determination of the long-term classification is based on our view that the value of the cores is not expected to be consumed or realized in cash during our normal annual operating cycle. We also have investments that we account for according to the equity method of accounting. The total book value of these investments was $18.4 million as of December 29, 2018 and $21.1 million as of December 30, 2017 and these investments provided us $2.2 million and $3.3 million of income during fiscal 2018 and fiscal 2017, respectively. Additionally, in fiscal 2018 we purchased an investment that we account for according to the cost method of accounting. The book value of this investment was $5.0 million as of December 29, 2018. Other Accrued Liabilities. Other accrued liabilities include primarily accrued customer rebates which we expect to settle in cash of $6.3 million as of December 29, 2018 and $6.8 million as of December 30, 2017. Also included are accrued commissions, accrued income taxes, insurance liabilities, product warranties, and other current liabilities. We warrant our products against certain defects in material and workmanship when used as designed on the vehicle on which it was originally installed. We offer a limited lifetime warranty on most of our products. Our warranty limits the end-user’s remedy to the repair or replacement of the part that is defective. Product warranty reserves, which were $0.6 million as of December 29, 2018 and $0.5 million as of December 30, 2017, are based upon actual experience and forecasts using the best historical and current claim information available. Provisions and payments related to product warranty reserves were not material in fiscal 2018, fiscal 2017 or fiscal 2016. Revenue Recognition and Allowance for Customer Credits . Revenue is recognized from product sales when goods are shipped, title and risk of loss and control have been transferred to the customer and collection is reasonably assured. We record estimates for cash discounts, product returns, promotional rebates, core return deposits, and other discounts in the period of the sale ("Customer Credits"). The provision for Customer Credits is recorded as a reduction from gross sales and reserves for Customer Credits are shown as a reduction of accounts receivable. Accrued customer credits which we expect to settle in cash are classified as other accrued liabilities. Actual Customer Credits have not differed materially from estimated amounts. Amounts billed to customers for shipping and handling are included in net sales. Costs associated with shipping and handling are included in cost of goods sold. As noted above, Customer Credits include core return deposits which are an estimate of the amount we believe we will refund to our customers when used cores are returned to us. The price we invoice to customers for remanufactured cores contain both the amount we charge to remanufacture the part and a deposit for the core. We charge a core deposit to encourage the customer to return the used core to us so that it can be used in our remanufacturing process. We allow our customers up to twenty-four months to return the used core to us. Core return deposits are reserved based on the expected deposits to be issued to customers based on historical returns. Research and Development . Research and development costs are expensed as incurred. Research and development costs totaling $20.1 million in fiscal 2018, $20.0 million in fiscal 2017 and $18.9 million in fiscal 2016 have been recorded in selling, general and administrative expenses in the Consolidated Statements of Operations. Stock-Based Compensation . At December 29, 2018 and December 30, 2017, we had one stock-based employee compensation plan, which is described more fully in Note 13, Capital Stock. We record compensation expense for all awards granted. The value of restricted stock issued is based on the fair value of our common stock on the grant date. The fair value of stock options granted was determined using the Black-Scholes option valuation model. Income Taxes . We follow the asset and liability method of accounting for deferred income taxes. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities. Deferred tax assets or liabilities at the end of each period are determined using the enacted tax rate expected to be in effect when taxes are actually paid or recovered. Unrecognized income tax benefits represent income tax positions taken on income tax returns that have not been recognized in the consolidated financial statements. The Company recognizes the benefit of an income tax position only if it is more likely than not (greater than 50%) that the tax position will be sustained upon tax examination, based solely on the technical merits of the tax position. Otherwise, no benefit is recognized. The tax benefits recognized are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. Additionally, we accrue interest and related penalties, if applicable, on all tax exposures for which reserves have been established consistent with jurisdictional tax laws. Interest and penalties are classified as income tax expense in the Consolidated Statements of Operations. The Company does not anticipate material changes in the amount of unrecognized income tax benefits over the next year. Concentrations of Risk . Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash equivalents and accounts receivable. All cash equivalents are managed within established guidelines which limit the amount which may be invested with one issuer. A significant percentage of our accounts receivable have been, and will continue to be, concentrated among a relatively small number of automotive retailers and warehouse distributors in the United States. Our five largest customers accounted for 79% of net accounts receivable as of December 29, 2018 and 85% of net accounts receivable as of December 30, 2017. We continually monitor the credit terms and credit limits to these and other customers. In fiscal 2018, approximately 77% of our products were purchased from suppliers located in a variety of foreign countries, with the largest portion coming from China. Fair Value Disclosures . The carrying value of financial instruments such as cash and cash equivalents, accounts receivable, accounts payable, and other current assets and liabilities approximate their fair value based on the short-term nature of these instruments. Additionally, the fair value of assets acquired and liabilities assumed are determined at the date of acquisition. We did not hold any foreign currency forward contracts at December 29, 2018 or December 30, 2017.

New and Recently Adopted Accoun

New and Recently Adopted Accounting Pronouncements	12 Months Ended
	Dec. 29, 2018
Accounting Changes And Error Corrections [Abstract]
New and Recently Adopted Accounting Pronouncements	2. New and Recently Adopted Accounting Pronouncements On December 31, 2017, the beginning of our 2018 fiscal year, we adopted FASB ASU No. 2014-09, Revenue from Contracts with Customers, In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments – Overall In February 2016, the FASB issued ASU No. 2016-02, Leases In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment In June 2018, the FASB issued ASU 2018-07, Improvements to Nonemployee Share-Based Payment Accounting

Business Acquisitions and Inves

Business Acquisitions and Investments	12 Months Ended
	Dec. 29, 2018
Business Combinations [Abstract]
Business Acquisitions and Investments	3. Business Acquisitions and Investments Flight Systems Automotive Group LLC On August 31, 2018, we acquired 100% of the outstanding stock of Flight Systems Automotive Group LLC (“Flight Systems” or “Flight”), a privately-held manufacturer and remanufacturer of complex automotive electronics and diesel fuel system components, based in Lewisberry, Pennsylvania. The purchase price was $27.5 million. We believe complex electronics and diesel fuel system components represent important growth opportunities for us and Flight’s product portfolio delivers valuable alternatives to aftermarket professionals. The transaction was accounted for as a business combination under the acquisition method of accounting. Accordingly, the assets acquired and liabilities assumed were recorded at fair value, with the remaining purchase price recorded as goodwill. In connection with this acquisition, we preliminary recorded $5.5 million in goodwill, $5.3 million of identified intangibles, and $16.7 million of other net assets, primarily $2.0 million of accounts receivables, $9.1 million of inventory, $4.4 million of fixed assets, and $1.2 million of net other assets and liabilities. The estimated fair value of the Flight assets acquired and liabilities assumed are provisional as of December 29, 2018 and are based on information that is currently available to the Company. Additional information about conditions that existed as of the date of acquisition are being gathered to finalize these provisional measurements, particularly with respect to net working capital, intangible assets, deferred income taxes and tax liabilities. Accordingly, the measurement of Flight’s assets acquired and liabilities assumed may change significantly upon finalization of the Company’s valuations and completion of the purchase price allocation, both of which are expected to occur no later than one year from the acquisition date. The valuation of the intangible assets acquired and related amortization periods are as follows: (in thousands) Valuation Amortization Period (in years) Customer relationships $ 3,080 8 Tradenames 1,990 15 Other 240 5 Total $ 5,310 The preliminary fair values of the Customer relationships and Tradenames were estimated using a discounted present value income approach. The goodwill recognized is attributable primarily to strategic and synergistic opportunities related to existing automotive aftermarket businesses, the assembled workforce of Flight and other factors. The goodwill is expected to be deductible for tax purposes. The financial results of the acquisition have been included in the Consolidated Financial Statements since the date of acquisition. Flight generated $7.8 million of net sales and an immaterial amount of net income since the date of acquisition. MAS Automotive Distribution Inc. On October 26, 2017, we acquired 100% of the outstanding stock of MAS Automotive Distribution Inc. (“MAS Industries” or “MAS”), a privately-held manufacturer of premium chassis and control arms based in Montreal, Canada. The purchase price was $67.2 million net of $3.3 million of cash acquired and including contingent consideration and other purchase price adjustments. The Company believes MAS is complementary to our business and growth strategy. We see opportunities to leverage MAS’ existing presence in the automotive aftermarket, as well as our product development capabilities and financial resources to accelerate the growth of MAS’ premium chassis and control arms. We have included the results of MAS in our Consolidated Financial Statements since the acquisition date of October 26, 2017. The Consolidated Statement of Operations for the year ended December 29, 2018 includes $40.3 million of net sales and an immaterial amount of net income related to MAS. The Consolidated Balance Sheets as of December 29, 2018 and December 30, 2017 reflect the acquisition of MAS Industries, effective October 26, 2017. The following table summarizes the preliminary fair value of the total consideration at October 26, 2017: (in thousands) Total Acquisition Date Fair Value Cash consideration (net of $3.3 million cash received) $ 56,859 Contingent cash consideration 7,982 Seller liability assumed 896 Working capital adjustment 1,486 Total consideration assigned to net assets acquired $ 67,223 Included in the table above is $8.0 million of estimated contingent payments which represents the fair value of the estimated payments which will become due if certain sales thresholds are achieved through December 2020. The fair value of the contingent cash consideration was estimated by using an option pricing model framework, which represents our own assumptions and data, and is based on our best available information. As of December 29, 2018, we had $7.9 million recorded which includes $0.3 million of accretion which was included in Selling, General and Administrative expenses in fiscal 2018, related to this payment. The maximum contingent payment would be $11.7 million. Additionally, during fiscal 2018, we finalized working capital and other purchase price adjustments based on the MAS standalone audited 2017 financial statements, resulting in a payment to the former shareholder of $1.5 million. This amount had previously been accrued on our Consolidated Balance Sheet. The transaction was accounted for as a business combination under the acquisition method of accounting. Accordingly, the assets acquired and liabilities assumed were recorded at fair value, with the remaining purchase price recorded as goodwill. The following table summarizes the fair values of the assets acquired and liabilities assumed as of October 26, 2017 (in thousands): (in thousands) October 26, 2017 (As initially reported) Measurement period adjustments October 26, 2017 (As adjusted) Current assets (net of $3.3 million cash received) $ 21,756 $ 90 $ 21,846 Property, plant and equipment 1,615 - 1,615 Intangible assets 20,440 - 20,440 Goodwill 35,624 (193 ) 35,431 Total assets acquired 79,435 (103 ) 79,332 Current liabilities 5,691 (50 ) 5,641 Long-term liabilities 6,468 - 6,468 Total liabilities assumed 12,159 (50 ) 12,109 Net assets acquired $ 67,276 $ (53 ) $ 67,223 Our measurement period adjustments for MAS were complete as of September 29, 2018. The valuation of the intangible assets acquired and related amortization periods are as follows: (in thousands) Valuation Amortization Period (in years) Customer relationships $ 14,840 8-12 Tradenames 5,600 15 Total $ 20,440 The fair values of the Customer relationships and Tradenames were estimated using a discounted present value income approach. Under this method, an intangible asset’s fair value is equal to the present value of the incremental after-tax cash flows (excess earnings) attributable solely to the intangible asset over its remaining useful life. To calculate fair value, we used cash flows discounted at rates ranging from 15% to 17%, which were considered appropriate given the inherent risks associated with each type of asset. We believe that the level and timing of cash flows appropriately reflect market participant assumptions. The goodwill recognized is attributable primarily to strategic and synergistic opportunities related to existing automotive aftermarket businesses, the assembled workforce of MAS and other factors. The goodwill is expected to be deductible for tax purposes. On January 27, 2017 we acquired a 33% minority equity interest in a supplier for $10.0 million. We are accounting for our interest using the equity method of accounting, as our investment gives us the ability to exercise significant influence, but not control, over the investee. On January 6, 2017, we acquired certain assets of Ingalls Engineering Company, Inc., a chassis and suspension business, primarily to expand our product portfolio. The purchase price was $4.8 million, comprised of $3.1 million of cash and $1.7 million of estimated contingent payments as of the date of acquisition. The contingent payment arrangement is based upon future net sales of the acquired business. In connection with this acquisition, we have completed our purchase price allocation procedures and recorded $2.8 million in goodwill and other intangible assets and $2.0 million of other net assets. All of the intangible assets resulting from the asset purchase are expected to be deductible for tax purposes. The financial results of the acquisition have been included in the Consolidated Financial Statements since the acquisition date.

Inventories

Inventories	12 Months Ended
	Dec. 29, 2018
Inventory Disclosure [Abstract]
Inventories	4. Inventories Inventories were as follows: (in thousands) December 29, 2018 December 30, 2017 Bulk product $ 122,111 $ 82,010 Finished product 144,897 126,827 Packaging materials 3,496 3,312 Total $ 270,504 $ 212,149

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 29, 2018
Property Plant And Equipment [Abstract]
Property, Plant and Equipment	5. Property, Plant and Equipment Property, plant and equipment include the following: (in thousands) December 29, 2018 December 30, 2017 Buildings $ 34,943 $ 32,623 Machinery, equipment and tooling 115,656 97,701 Furniture, fixtures and leasehold improvements 6,199 4,319 Software and computer equipment 79,349 77,618 Total 236,147 212,261 Less-accumulated depreciation and amortization (137,500 ) (119,569 ) Property, plant and equipment, net $ 98,647 $ 92,692 Depreciation and amortization expenses associated with property, plant, and equipment were $25.4 million, $21.5 million, and $18.7 million in fiscal 2018, fiscal 2017, and fiscal 2016, respectively.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 29, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	6. Goodwill and Intangible Assets Goodwill Goodwill included the following: (in thousands) December 29, 2018 December 30, 2017 Balance at beginning of period $ 65,999 $ 28,146 Goodwill acquired 6,800 37,853 Measurement period adjustment (193 ) - Balance at end of period $ 72,606 $ 65,999 Intangible Assets Intangible assets, subject to amortization, included the following: December 29, 2018 December 30, 2017 (dollars in thousands) Weighted Average Amortization Period (years) Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value Intangible assets subject to amortization Tradenames 14.1 $ 7,590 $ 516 $ 7,074 $ 5,600 $ 62 $ 5,538 Customer relationships 8.9 20,130 2,582 17,548 17,049 772 16,277 Technology 13.0 367 49 318 367 24 343 Other 4.7 240 16 224 - - - Total $ 28,327 $ 3,163 $ 25,164 $ 23,016 $ 858 $ 22,158 Amortization expense was $2.3 million in fiscal 2018 and $0.5 million in each of fiscal 2017 and $0.1 million in fiscal 2016. The estimated future amortization expense for intangible assets is summarized as follows: (in thousands) 2019 $ 2,679 2020 2,679 2021 2,679 2022 2,679 2023 2,663 Thereafter 11,785 Total $ 25,164

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 29, 2018
Debt Disclosure [Abstract]
Long-Term Debt	7. Long-Term Debt In December 2017, we entered into a credit agreement which will expire in December 2022. This agreement provides for an initial revolving credit facility of $100.0 million and gives us the ability to request increases of up to an incremental $100.0 million. This agreement replaces our previous $30.0 million credit agreement. Borrowings under the facility are on an unsecured basis with interest rates ranging from LIBOR plus 65 basis points to LIBOR plus 125 basis points based upon the ratio of consolidated funded debt to consolidated EBITDA, as defined by the credit agreement. The interest rate at December 29, 2018 was LIBOR plus 65 basis points (3.17%). The credit agreement also contains other covenants, including those related to the ratio of certain consolidated fixed charges to consolidated EBITDA, capital expenditures, and share repurchases, each as defined by the credit agreement. The new credit agreement also requires us to pay an unused fee of 0.10% on the average daily unused portion of the facility. As of December 29, 2018, we were in compliance with all financial covenants contained in the credit agreement. As of December 29, 2018, there were no borrowings under the facility and we had two outstanding letters of credit for approximately $0.8 million in the aggregate which were issued to secure ordinary course of business transactions. Net of these letters of credit, we had approximately $99.2 million available under the facility at December 29, 2018.

Operating Lease Commitments and

Operating Lease Commitments and Rent Expense	12 Months Ended
	Dec. 29, 2018
Leases [Abstract]
Operating Lease Commitments and Rent Expense	8. Operating Lease Commitments and Rent Expense We lease certain equipment and operating facilities, including our primary operating facility which is leased from a partnership described in Note 9, Related Party Transactions, under non-cancelable operating leases. Approximate future minimum rental payments as of December 29, 2018 under these leases are summarized as follows: (in thousands) 2019 $ 5,489 2020 5,416 2021 4,972 2022 4,599 2023 3,013 Thereafter 24,297 Total $ 47,786 Rent expense, including payments for short-term equipment and storage rentals, was $6.9 million in fiscal 2018, $5.4 in fiscal 2017, and $4.2 million in fiscal 2016.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 29, 2018
Related Party Transactions [Abstract]
Related Party Transactions	9. Related Party Transactions We have a non-cancelable operating lease for our primary operating facility from a partnership in which Steven L. Berman, our Executive Chairman, and his family members are partners. Total rental payments each year to the partnership under the lease arrangement were $1.6 million in each of fiscal 2018, fiscal 2017 and fiscal 2016. This lease was renewed during November 2016, effective as of January 1, 2018, and will expire on December 31, 2022. In the opinion of our Audit Committee, the terms and rates of this lease were no less favorable than those which could have been obtained from an unaffiliated party when the lease was renewed during November 2016. Additionally, we have a non-cancelable operating lease for our Canadian operating facility from a corporation of which an employee and his family members are owners. Total rental payments to the corporation under the lease agreement were $0.7 million in fiscal 2018 and $0.1 million in fiscal 2017. We did not We are a partner in a joint venture with one of our suppliers and we own a minority interest in two other companies. Purchases from these companies, since we acquired our investment interests were $20.3 million in fiscal 2018 and $16.5 million in fiscal 2017 and $13.6 million in fiscal 2016.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 29, 2018
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes U.S. Tax Reform: Tax Cuts and Jobs Act On December 22, 2017, the Tax Cuts and Jobs Act (the "TCJA") was enacted in the United States. The TCJA represents sweeping changes in U.S. tax law. Among the numerous changes in tax law, the TCJA permanently reduces the U.S. corporate income tax rate to 21% beginning in 2018; allows 100% expensing for qualified property placed in service after September 27, 2017; imposes a one-time transition tax on deferred foreign earnings; establishes a participation exemption system by allowing a 100% dividends received deduction on qualifying dividends paid by foreign subsidiaries; limits deductions for net interest expense; and expands the U.S. taxation of foreign earned income to include "global intangible low taxed income". The TCJA represents the first significant change in U.S. tax law in over 30 years. In response to the TCJA, the Staff of the U.S. Securities and Exchange Commission issued Staff Accounting Bulletin No. 118 ("SAB No. 118") to provide guidance to registrants in applying ASC Topic 740 in connection with the TCJA. SAB No. 118 provides that in the period of enactment, the income tax effects of the TCJA may be reported as a provisional amount based on a reasonable estimate (to the extent a reasonable estimate can be determined), which would be subject to adjustment during a "measurement period". The measurement period begins in the reporting period of the TCJA's enactment and ends when a registrant has obtained, prepared, and analyzed the information that was needed in order to complete the accounting requirements under ASC Topic 740. SAB No. 118 also describes supplemental disclosures that should accompany the provisional amounts. As permitted by SAB No. 118, the net tax expense recorded in our financial statements for the fourth fiscal quarter of 2017 due to the enactment of the TCJA is considered "provisional," based on reasonable estimates. As of December 29, 2018 we have finalized our analysis of the TCJA and no material adjustments to the provisional amounts have been recorded. We continue to assess the impacts of the TCJA on future years and monitor the Internal Revenue Service guidance intended to interpret the TCJA provisions. We recognized tax expense of $4.4 million in fiscal 2017 to remeasure our net deferred tax assets at the lower 21% rate. The TCJA transitions the U.S. from a worldwide tax system to a territorial tax system. Under previous law, companies could indefinitely defer U.S. income taxation on unremitted foreign earnings. The TCJA imposed a one-time transition tax on deferred foreign earnings of 15.5% for liquid assets and 8% for illiquid assets, payable in defined increments over eight years. We did not recognize any transition tax expense due to having no accumulated earnings and profits in our non-U.S. subsidiaries. The components of the income tax provision (benefit) are as follows: (in thousands) 2018 2017 2016 Current: Federal $ 33,362 $ 56,641 $ 61,251 State 2,618 8,293 5,948 Foreign 1,611 379 - 37,591 65,313 67,199 Deferred: Federal 1,398 4,582 (4,563 ) State 186 343 (325 ) Foreign (1,642 ) (249 ) - (58 ) 4,676 (4,888 ) Total $ 37,533 $ 69,989 $ 62,311 The following is a reconciliation of income taxes at the statutory tax rate to the Company's effective tax rate: 2018 2017 2016 Federal taxes at statutory rate 21.0 % 35.0 % 35.0 % State taxes, net of federal tax benefit 1.3 3.4 2.2 Research and development tax credit (0.4 ) (0.3 ) (0.2 ) Federal permanent items (0.1 ) (0.4 ) — Tax reform — 2.5 — Other 0.1 (0.6 ) — Effective tax rate 21.9 % 39.6 % 37.0 % At December 29, 2018, we had $2.4 million of unrecognized tax benefits, $2.1 million of which would affect our effective tax rate if recognized. The following table summarizes the change in uncertain tax benefits for the three years ended December 29, 2018: (in thousands) 2018 2017 2016 Balance at beginning of year $ 2,301 $ 3,567 $ 1,855 Reductions due to lapses in statutes of limitations (95 ) (181 ) — Reductions due to tax positions settled (368 ) (4,543 ) (109 ) Reductions due to reversals of prior year positions (4 ) — (212 ) Additions based on tax positions taken during the prior period — 3,005 — Additions based on tax positions taken during the current period 556 453 2,033 Balance at end of year $ 2,390 $ 2,301 $ 3,567 We recognize interest and penalties related to uncertain tax positions in income tax expense. As of December 29, 2018, we had approximately $0.6 million of accrued interest and penalties related to uncertain tax positions. Deferred income taxes result from timing differences in the recognition of revenue and expense for tax and financial statement purposes. The sources of temporary differences are as follows: (in thousands) December 29, 2018 December 30, 2017 Assets: Inventories $ 9,006 $ 7,335 Accounts receivable 11,052 11,732 Accrued expenses 1,792 1,664 Foreign tax credits 1,050 — Other — 261 Total deferred tax assets 22,900 20,992 Valuation allowance (1,050 ) — Net deferred tax assets 21,850 20,992 Liabilities: Depreciation 9,094 7,936 Goodwill and intangible assets 11,310 11,776 Other 12 — Gross deferred tax liabilities 20,416 19,712 Net deferred tax assets $ 1,434 $ 1,280 Based on our history of taxable income and our projection of future earnings, we believe that it is more likely than not that sufficient taxable income will be generated in the foreseeable future to realize the remaining net deferred tax assets. We file income tax returns in the United States, India, China, Canada and Mexico. All years before 2015 are closed for federal tax purposes. Tax years before 2014 are closed for the states in which we file. Tax years before 2015 are closed for tax purposes in China and Canada. All tax years remain open for Mexico and all tax years are closed for Sweden.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 29, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	11. Commitments and Contingencies Shareholders’ Agreement . A shareholders’ agreement was entered into in September 1990 and amended and restated on July 1, 2006. Under the agreement, each of the late Richard Berman, Steven Berman, Jordan Berman, Marc Berman, Fred Berman, Deanna Berman and additional shareholders named in the agreement has, among other things, granted the others of them rights of first refusal, exercisable on a pro rata basis or in such other proportions as the exercising shareholders may agree, to purchase shares of our common stock which any of them, or upon their deaths their respective estates, proposes to sell to third parties. We have agreed with these shareholders that, upon their deaths, to the extent that any of their shares are not purchased by any of these surviving shareholders and may not be sold without registration under the Securities Act of 1933, as amended (the "1933 Act"), we will use our best efforts to cause those shares to be registered under the 1933 Act. The expenses of any such registration will be borne by the estate of the deceased shareholder. The additional shareholders that are a party to the agreement are trusts affiliated with the late Richard Berman, Steven Berman, Jordan Berman, Marc Berman or Fred Berman, or each person’s respective spouse or children. Legal Proceedings . We are a party to or otherwise involved in legal proceedings that arise in the ordinary course of business, such as various claims and legal actions involving contracts, competitive practices, intellectual property infringement, product liability claims and other matters arising out of the conduct of our business. In the opinion of management, none of the actions, individually or in the aggregate, would likely have a material financial impact on us and we believe the range of reasonably possible losses from current matters is immaterial.

Revenue Recognition

Revenue Recognition	12 Months Ended
	Dec. 29, 2018
Revenue From Contract With Customer [Abstract]
Revenue Recognition	12. Revenue Recognition The FASB issued an accounting standard update in May 2014 regarding the accounting for and disclosure of revenue. Specifically, the update outlined a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. As part of our impact assessment of the implementation of the new revenue recognition guidance, we reviewed our historical accounting policies and practices to identify potential differences with the requirements of the new revenue recognition standard, as it related to our contracts and sales arrangements, as well as technical considerations for our future transaction accounting, financial reporting, and disclosure requirements. We adopted the guidance in the first quarter of 2018, as required, electing to use a modified retrospective adoption approach. Comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. In addition, we elected to apply certain of the permitted practical expedients within the revenue recognition guidance and make certain accounting policy elections including those related to significant financing components, sales taxes and shipping and handling activities. Adoption of the revenue recognition standard did not have a material impact on our reported earnings, cash flows, or balance sheet, however, adoption did increase the amount and level of disclosures concerning our net sales. The impact of adoption of the new revenue recognition guidance and the impact of the new revenue recognition guidance as compared to the historical revenue recognition guidance was immaterial for fiscal 2018. Business Description We are a supplier of replacement parts and fasteners for passenger cars, light trucks, and heavy duty trucks in the automotive aftermarket. We group our products into four major classes: power-train, automotive body, chassis, and hardware. Our products are sold primarily in the United States through automotive aftermarket retailers, national and regional local warehouse distributors and specialty markets, and salvage yards. We also distribute automotive replacement parts internationally, with sales primarily into Canada, Mexico, Europe, the Middle East, and Australia. We warrant our products against certain defects in material and workmanship when used as designed on the vehicle on which it was originally installed. We offer a limited lifetime warranty on most of our products. Our warranty limits the customer’s remedy to the repair or replacement of the part that is defective. Our primary source of revenue is from contracts with and purchase orders from customers. Revenue is recognized from product sales when goods are shipped, title and risk of loss and control have been transferred to the customer, and collection is reasonably assured. We estimate the transaction price at the inception of a contract or upon fulfilling a purchase order, including any variable consideration, and will update the estimate for changes in circumstances. We utilize the most likely amount method consistently to estimate the effect of uncertainty on the amount of variable consideration to which we would be entitled. The most likely amount method considers the single most likely amount from a range of possible consideration amounts. This method is utilized for all of our variable consideration. We record estimates for cash discounts, product returns, promotional rebates, core return deposits and other discounts in the period the related product revenue is recognized (“Customer Credits”). The provision for Customer Credits is recorded as a reduction from gross sales and reserves for Customer Credits are shown as a reduction of accounts receivable. Accrued customer rebates which we expect to settle in cash are classified as other accrued liabilities. Actual Customer Credits have not differed materially from estimated amounts for each period presented. Amounts billed to customers for shipping and handling are included in net sales. Costs associated with shipping and handling are included in cost of goods sold. We have concluded that our estimates of variable consideration are not constrained according to the definition in the new standard. All of our revenue was recognized under the point of time approach in accordance with the revenue standard during fiscal 2018. Also, we do not have significant financing arrangements with our customers, as our credit terms are all less than one year. Lastly, we do not receive noncash consideration (such as materials or equipment) from our customers to facilitate the fulfillment of our contracts. Five-step model We apply the FASB’s guidance on revenue recognition, which requires us to recognize the amount of revenue and consideration which we expect to receive in exchange for goods or services transferred to our customers. To do this, we apply the five-step model prescribed by the FASB, which requires us to: (i) identify the contract with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when, or as, we satisfy a performance obligation. A summary of our application of the five-step model is as follows: (i) In most instances, our contract with a customer is the customer’s purchase order. Upon acceptance of the purchase order, a contract exists with a customer as a sales agreement indicates approval and commitment of the parties, identifies the rights of both parties, identifies the payment terms, has commercial substance, and it is probable that we will collect the consideration to which we will be entitled in exchange for the goods transferred to the customer. For certain customers, we may also enter into a sales agreement which outlines pricing considerations as well as the framework of terms and conditions which apply to future purchase orders for that customer. In these situations, our contract with the customer is both the sales agreement as well as the specific customer purchase order. As our contract with a customer is typically for a single transaction or customer purchase order, the duration of the contract is typically one year or less. As a result, we have elected to apply certain practical expedients and omit certain disclosures of remaining performance obligations for contracts which have an initial term of one year or less as permitted by the FASB. (ii) We identify a performance obligation in a contract for each distinct good or service promised that are separately identifiable from other promises in the contract. (iii) We identify the transaction price as the amount of consideration including variable consideration that we expect to be entitled in exchange for transferring control of goods and/or services to our customers. (iv) We allocate the transaction price to each performance obligation on the basis of the amount of consideration to which we expect to be entitled in exchange for satisfying each performance obligation. (v) We recognize revenue when we satisfy a performance obligation by transferring control of the promised goods. Practical Expedients and Accounting Policy Elections In accordance with the guidance on revenue recognition and as permitted by the FASB, we have elected to use certain practical expedients and policy elections. - We have elected to not adjust the promised amount of consideration for the effects of a significant financing component as we expect, at contract inception, that the period between when we transfer a promised good or service to the customer and when the customer pays for that good or service will be one year or less. - We have elected to expense costs to obtain a contract as incurred when the expected period of benefit, and therefore the amortization period, is one year or less. - We have elected to exclude from the measurement of the transaction price all taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction and collected by the entity for a customer, including sales, use, value-added, excise and various other taxes. - We have elected to account for shipping and handling activities that occur after the customer has obtained control of a good as a fulfilment activity rather than a separate performance obligation. Contract Assets and Liabilities We recognize a receivable or contract asset when we perform a service or transfer a good in advance of receiving consideration. - A receivable is recorded when our right to consideration is unconditional and only the passage of time is required before payment of that consideration is due. - A contract asset is recorded when our right to consideration in exchange for good or services that we have transferred to a customer is conditional on something other than the passage of time. We did not have any contract assets recorded as of December 29, 2018 or December 30, 2017. We recognize a contract liability when we receive consideration, or if we have the unconditional right to receive consideration, in advance of satisfying the performance obligation. A contract liability is our obligation to transfer goods or services to a customer for which we have received consideration, or an amount of consideration is due from the customer. We did not have any contract liabilities recorded as of December 29, 2018 or December 30, 2017. Disaggregated Revenue The following tables present our disaggregated net sales by Type of Major Good / Product Line, and Geography. (in thousands) 2018 2017 2016 Powertrain $ 393,979 $ 374,372 $ 351,423 Chassis 278,584 238,239 218,645 Automotive Body 256,344 245,869 244,465 Hardware 44,798 44,741 45,071 Net Sales $ 973,705 $ 903,221 $ 859,604 (in thousands) 2018 2017 2016 Net Sales to U.S. Customers $ 913,181 $ 847,394 $ 810,969 Net Sales to Non-U.S. Customers 60,524 55,827 48,635 Net Sales $ 973,705 $ 903,221 $ 859,604

Capital Stock

Capital Stock	12 Months Ended
	Dec. 29, 2018
Equity [Abstract]
Capital Stock	13. Capital Stock Controlling Interest by Officers, Directors and Family Members . As of December 29, 2018, Steven Berman, the Executive Chairman of the Company, and members of his family beneficially own approximately 18% of the outstanding shares of our common stock and can influence the election of our Board of Directors, the outcome of most corporate actions requiring shareholder approval (including certain fundamental transactions) and the affairs of the Company. Undesignated Stock . We have 50,000,000 shares authorized of undesignated capital stock for future issuance. The designation, rights and preferences of such shares will be determined by our Board of Directors. Incentive Stock Plan . On May 16, 2018, our shareholders approved our 2018 Stock Option and Stock Incentive Plan (the “2018 Plan” or the “Plan”), which supersedes our 2008 Stock Option and Stock Incentive Plan. All future stock compensation grants will be issued under the 2018 Plan. Under the terms of the Plan, our Board of Directors may grant up to 1,200,000 shares of common stock in the form of shares of restricted stock, restricted stock units, stock appreciation rights and stock options or combinations thereof to officers, directors, employees, important consultants and advisors. Grants under the Plan must be made within ten years of the date the Plan was approved. Stock options are exercisable upon the terms set forth in each grant agreement approved by the Board of Directors, but in no event more than ten years from the date of grant. Restricted stock and restricted stock units vest in accordance with the terms set forth in each applicable award agreement approved by our Board of Directors. At December 29, 2018, 1,162,398 shares were available for grant under the Plan. Restricted Stock We grant restricted stock to certain employees and members of our Board of Directors. The value of restricted stock issued is based on the fair value of our common stock on the grant date. Vesting of restricted stock is based on continued employment or service for a specified period and, in certain circumstances, the attainment of financial goals. Compensation cost related to the stock is recognized on a straight-line basis over the vesting period. We retain the restricted stock, and any dividends paid thereon, until the vesting provisions have been met. For awards with a service condition only, compensation cost related to the stock is recognized on a straight-line basis over the vesting period. For awards that have a service condition and require the attainment of financial goals, compensation cost related to the stock is recognized over the vesting period if it is probable that the financial goals will be attained. Compensation cost related to restricted stock was $2.6 million, $2.8 million and $2.3 million in fiscal 2018, fiscal 2017 and fiscal 2016, respectively. The compensation costs were classified as selling, general and administrative expense in the Consolidated Statements of Operations. No cost was capitalized during fiscal 2018, fiscal 2017 or fiscal 2016. The following table summarizes our restricted stock activity for the three years ended December 29, 2018: Shares Weighted Average Price Balance at December 26, 2015 43,242 $ 34.49 Granted 133,794 $ 49.45 Vested (29,002 ) $ 29.74 Cancelled (2,671 ) $ 33.79 Balance at December 31, 2016 145,363 $ 49.22 Granted 70,611 $ 78.27 Vested (56,953 ) $ 56.03 Cancelled (5,294 ) $ 51.56 Balance at December 30, 2017 153,727 $ 59.96 Granted 89,798 $ 73.51 Vested (45,707 ) $ 62.56 Cancelled (27,081 ) $ 75.39 Balance at December 29, 2018 170,737 $ 63.94 As of December 29, 2018, there was approximately $5.9 million of unrecognized compensation cost related to nonvested restricted stock, which is expected to be recognized over a weighted-average period of approximately 2.3 years. Cash flows resulting from tax deductions in excess of the tax effect of compensation cost recognized in the financial statements are classified as operating cash flows. In accordance with ASU 2016-09 (see Note 2), t he excess tax benefit generated from restricted shares which vested was $0.1 million in fiscal 2018 and $0.4 million in fiscal 2017 and was credited to income tax expense. The excess tax benefit generated from restricted shares which vested was $0.3 million in fiscal 2016 and was credited to additional paid-in capital. Stock Options We grant stock options to certain employees and members of our Board of Directors. We expense the grant-date fair value of stock options. Compensation cost is recognized over the vesting or performance period. Compensation cost charged against income was $0.5 million in fiscal 2018 and $0.3 million in fiscal 2017 and $0.1 million in fiscal 2016, respectively We used the Black-Scholes option valuation model to estimate the fair value of stock options granted in fiscal 2018, fiscal 2017 and fiscal 2016. Expected volatility and expected dividend yield are based on the actual historical experience of our common stock. The expected life represents the period of time that options granted are expected to be outstanding and was calculated using historical option exercise data. The risk-free rate is based on the U.S. Treasury security with terms equal to the expected time of exercise as of the grant date. The weighted-average grant-date fair value of options granted during fiscal 2018 was $15.88, fiscal 2017 was $15.81 and fiscal 2016 was $8.40 per option. The following table summarizes the weighted average valuation assumptions used to calculate the fair value of options granted: 2018 2017 2016 Expected dividend yield 0 % 0 % 0 % Expected stock price volatility 27 % 27 % 26 % Risk-free interest rate 2.6 % 1.5 % 0.9 % Expected life of options 3.0 years 3.0 years 3.0 years The following table summarizes our stock option activity for the three years ended December 29, 2018: Shares Option Price per Share Weighted Average Price Weighted Average Remaining Terms (years) Aggregate Intrinsic Value Balance at December 26, 2015 40,000 $5.67 – $7.74 $ 6.86 Granted 61,084 $41.59 – $53.32 $ 44.36 Balance at December 31, 2016 101,084 $5.67 – $53.32 $ 29.52 Granted 58,024 $69.02 – $82.59 $ 78.58 Exercised (32,751 ) $6.90 – $41.59 $ 7.69 Cancelled (3,810 ) $41.59 – $78.64 $ 56.72 Balance at December 30, 2017 122,547 $5.67 – $82.59 $ 57.74 Granted 81,995 $68.93 – $82.94 $ 73.84 Exercised (15,113 ) $5.67 – $78.64 $ 39.38 Cancelled (960 ) $ 72.55 $ 72.55 Balance at December 29, 2018 188,469 $7.74 – $82.94 $ 66.14 3.6 $ 4,186,151 Options exercisable at December 29, 2018 35,966 $7.74 – $82.59 $ 51.57 2.4 $ 1,323,007 As of December 29, 2018, there was approximately $1.8 million of unrecognized compensation cost related to nonvested stock options, which is expected to be recognized over a weighted-average period of approximately 2.8 years. The following table summarizes information concerning currently outstanding and exercisable options at December 29, 2018: Options Outstanding Options Exercisable Range of Exercise Price Number Outstanding Weighted Average Remaining Contractual Life (years) Weighted Average Exercise Price Number Exercisable Weighted Average Exercise Price $7.74 - $24.66 4,000 0.9 $ 7.74 4,000 $ 7.74 $24.67 - $41.60 35,544 2.1 $ 41.59 13,706 $ 41.59 $41.61 - $69.01 21,900 4.8 $ 58.67 7,200 $ 53.32 $69.02 - $77.99 62,184 4.2 $ 72.43 326 $ 69.02 $78.00 - $82.94 64,841 3.5 $ 79.69 10,734 $ 78.93 Balance at December 29, 2018 188,469 3.6 $ 66.14 35,966 $ 51.57 Cash received from option exercises was $0.2 million in fiscal 2018 and was less than $0.1 million in fiscal 2017. There were no option exercises during fiscal 2016. There was no excess tax benefit generated from option exercise in 2018. In accordance with ASU No.2016-09 (see Note 2), the excess tax benefit generated from option exercises was $0.6 million in fiscal 2017 and was credited to income tax expense. There was no excess tax benefit generated from stock option exercises in fiscal 2016. Performance-Based Long Term Award Program. The Compensation Committee of our Board of Directors has approved the Performance-Based Long Term Award Program (the “Program”) which connects compensation for certain of our executives to the three-year compound annual growth in our pre-tax income as defined in the Program. For the three-year periods ending in 2016 and 2017, the Compensation Committee had the discretion to settle the long term bonus in either cash or equity. These are liability-classified awards. The Compensation Committee elected to settle the award in equity for the three-year periods ending in fiscal 2017 and cash for three-year periods ending in fiscal 2016. In fiscal 2016, the Compensation Committee modified the Program to settle the awards earned in the three-year periods ending in fiscal 2018 and beyond in equity alone. These awards are equity-classified. Any equity issued related to the Program will be from the 2018 Plan. Employee Stock Purchase Plan. In May 2017, our shareholders’ approved the Dorman Products, Inc. Employee Stock Purchase Plan (the ‘ESPP”), which makes available 1,000,000 shares of our common stock for sale to eligible employees. The purpose of this plan, which is qualified under Section 423 of the Internal Revenue Service Code of 1986, as amended, is to encourage stock ownership through payroll deductions and limited cash contributions by our employees. These contributions are used to purchase shares of the Company’s common stock at a 15% discount from the lower of the market price at the beginning or end of the purchase window. Share purchases under the plan are made twice annually, beginning in March 2018. There were 21,173 shares purchased under this plan during fiscal 2018. There were no shares purchased under this plan during fiscal 2017. Compensation cost under the ESPP plan was $0.4 million in fiscal 2018 and $0.1 million in fiscal 2017. 401(k) Retirement Plan . The Dorman Products, Inc. 401(k) Retirement Plan and Trust (the “401(k) Plan”) is a defined contribution profit sharing and 401(k) plan covering substantially all of our employees as of December 29, 2018. Annual contributions under the 401(k) Plan are determined by the Compensation Committee of our Board of Directors. Total expense related to the 401(k) Plan was $4.3 million in fiscal 2018, $2.7 million in fiscal 2017 and $2.5 million in fiscal 2016. At December 29, 2018, the 401(k) Plan held 243,348 shares of our common stock. Common Stock Repurchases. We periodically repurchase, at the then current market price, and cancel common stock issued to the 401(k) Plan. Shares are generally purchased from the 401(k) Plan when participants sell units as permitted by the 401(k) Plan or elect to leave the 401(k) Plan upon retirement, termination or other reasons. During fiscal 2018 our Board of Directors approved the repurchase and cancellation of 26,280 shares of our common stock for $2.0 million at an average price of $74.79 per share. During fiscal 2017, our Board of Directors approved the repurchase and cancellation of 19,110 shares of our common stock for $1.4 million at an average price of $73.34 per share. During fiscal 2016, our Board of Directors approved the repurchase and cancellation of 38,970 shares of our common stock for $2.2 million at an average price of $56.66 per share. Share Repurchase Program . On December 12, 2013 we announced that our Board of Directors authorized a share repurchase program, authorizing the repurchase of up to $10 million of our outstanding common stock by the end of 2014. Through several expansions and extensions, our Board of Directors has expanded the program to $400 million and extended the program through December 31, 2021. Under this program, share repurchases may be made from time to time depending on market conditions, share price, share availability and other factors at our discretion. The share repurchase program does not obligate us to acquire any specific number of shares. We repurchased 622,223 common shares for $43.4 million at an average price of $69.73 under this program during fiscal 2018. We repurchased 1,006,365 common shares for $74.7 million at an average price of $74.26 under this program during fiscal 2017. We repurchased 430,866 common shares for $22.5 million at an average price of $52.15 under this program during fiscal 2016. At December 29, 2018, $183.3 million was available for repurchase under this program.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 29, 2018
Earnings Per Share [Abstract]
Earnings Per Share	14. Earnings Per Share Basic earnings per share was calculated by dividing our net income by the weighted average number of common shares outstanding during the period, excluding nonvested restricted stock which is considered to be contingently issuable. To calculate diluted earnings per share, common share equivalents are added to the weighted average number of common shares outstanding. Common share equivalents are calculated using the treasury stock method and are computed based on outstanding stock-based awards. Stock-based awards of approximately 116,000 shares, 106,000 shares and 50,000 shares were excluded from the calculation of diluted earnings per share as of December 29, 2018, December 30, 2017 and December 31, 2016, respectively, as their effect would have been anti-dilutive. The following table sets forth the computation of basic earnings per share and diluted earnings per share: (in thousands, except per share data) 2018 2017 2016 Numerator: Net income $ 133,602 $ 106,599 $ 106,049 Denominator: Weighted average basic shares outstanding 33,097 33,964 34,516 Effect of compensation awards 110 88 82 Weighted average diluted shares outstanding 33,207 34,052 34,598 Earnings Per Share: Basic $ 4.04 $ 3.14 $ 3.07 Diluted $ 4.02 $ 3.13 $ 3.07

Business Segments

Business Segments	12 Months Ended
	Dec. 29, 2018
Segment Reporting [Abstract]
Business Segments	15. Business Segments We have determined that our business comprises a single reportable operating segment, namely, the sale of replacement parts for the automotive aftermarket. During fiscal 2018, fiscal 2017 and fiscal 2016, four of our customers (Advance Auto Parts, Inc., AutoZone, Inc., Genuine Parts Co. – NAPA, and O’Reilly Automotive, Inc.) each accounted for more than 10% of net sales and in aggregate accounted for 63% of net sales in fiscal 2018, 61% in fiscal 2017 and 60% in fiscal 2016. Net sales to countries outside the United States, primarily to Canada and Mexico, and to a lesser extent into Europe, the Middle East, and Australia in fiscal 2018, fiscal 2017 and fiscal 2016 were $60.5 million, $55.8 million and $48.6 million, respectively.

Quarterly Results of Operations

Quarterly Results of Operations (Unaudited)	12 Months Ended
	Dec. 29, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations (Unaudited)	16. Quarterly Results of Operations (Unaudited) The following is a summary of the unaudited quarterly Results of Operations for the fiscal years ended December 29, 2018 and December 30, 2017: First Quarter Second Quarter Third Quarter Fourth Quarter (in thousands, except per share amounts) 2018 Net sales* $ 227,262 $ 238,147 $ 247,954 $ 260,341 Income from operations* 39,994 42,780 43,733 44,637 Net income 30,647 34,339 34,017 34,599 Diluted earnings per share 0.93 1.03 1.03 1.05 First Quarter Second Quarter Third Quarter Fourth Quarter (in thousands, except per share amounts) 2017 Net sales $ 221,625 $ 229,262 $ 224,615 $ 227,719 Income from operations 45,042 44,999 42,790 43,409 Net income 29,187 28,437 27,008 21,967 Diluted earnings per share 0.85 0.83 0.80 0.65 *Quarterly information does not add to year to date information due to rounding

Schedule II_ Valuation and Qual

Schedule II: Valuation and Qualifying Accounts	12 Months Ended
	Dec. 29, 2018
Valuation And Qualifying Accounts [Abstract]
Schedule II: Valuation and Qualifying Accounts	For the Year Ended (in thousands) December 29, 2018 December 30, 2017 December 31, 2016 Allowance for doubtful accounts: Balance, beginning of period $ 1,656 $ 1,345 $ 4,503 Provision (570 ) 299 1,212 Charge-offs (151 ) 12 (4,370 ) Acquisitions and other 47 - - Balance, end of period $ 982 $ 1,656 $ 1,345 Allowance for customer credits: Balance, beginning of period $ 95,537 $ 98,650 $ 82,483 Provision 203,677 187,422 175,260 Credits issued (208,665 ) (193,753 ) (159,093 ) Acquisitions and other - 3,218 - Balance, end of period $ 90,549 $ 95,537 $ 98,650

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 29, 2018
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation . The Consolidated Financial Statements include our accounts and the accounts of our wholly-owned subsidiaries. All material intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates in the Preparation of Financial Statements	Use of Estimates in the Preparation of Financial Statements . The preparation of financial statements in accordance with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Reclassifications	Reclassifications . Certain prior year amounts have been reclassified to conform with current-year presentation.
Cash and Cash Equivalents	Cash and Cash Equivalents . We consider all highly liquid short-term investments with original maturities of three months or less to be cash equivalents.
Sales of Accounts Receivable	Sales of Accounts Receivable . We have entered into several customer sponsored programs administered by unrelated financial institutions that permit us to sell certain accounts receivable at discounted rates to the financial institutions. Transactions under these agreements were accounted for as sales of accounts receivable and were removed from our Consolidated Balance Sheet at the time of the sales transactions. During fiscal 2018, fiscal 2017 and fiscal 2016, we sold $604.7 million, $582.9 million and $521.9 million, respectively, pursuant to these agreements. If receivables had not been sold, $378.5 million and $380.8 million of additional receivables would have been outstanding at December 29, 2018 and December 30, 2017, respectively, based on standard payment terms. Selling, general and administrative expenses include $14.5 million, $11.4 million and $8.9 million in fiscal 2018, fiscal 2017 and fiscal 2016, respectively, of financing costs associated with these accounts receivable sales programs.
Inventories	Inventories . Inventories are stated at the lower of cost or net realizable value. Cost is determined by the first-in, first-out method. Inventories include the cost of material, freight, direct labor and overhead utilized in the processing of our products. We provide reserves for discontinued and excess inventory based upon historical demand, forecasted usage, estimated customer requirements and product line updates.
Property, Plant and Equipment	Property, Plant and Equipment . Property, plant and equipment are recorded at cost and depreciated over their estimated useful lives, which range from three to thirty-nine years, using the straight-line method for financial statement reporting purposes and accelerated methods for income tax purposes. The costs of maintenance and repairs are expensed as incurred. Renewals and betterments are capitalized. Gains and losses on disposals are included in operating results. Estimated useful lives by major asset category are as follows: Buildings and building improvements 10 to 39 years Machinery, equipment and tooling 3 to 10 years Software and computer equipment 3 to 10 years Furniture, fixtures and leasehold improvements 3 to 15 years
Long-Lived Assets Including Goodwill and Other Acquired Intangible Assets	Long-Lived Assets Including Goodwill and Other Acquired Intangible Assets . Long-lived assets, including property, plant, and equipment and amortizable identifiable intangibles, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. The impairment review is a two-step process. First, recoverability is measured by comparing the carrying amount of an asset to the estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount exceeds the estimated undiscounted future cash flows, the second step of the impairment test is performed and an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds its fair value. Assets to be disposed of would be separately presented in the balance sheet and reported at the lower of the carrying amount or fair value less costs to sell, and are no longer depreciated. The assets and liabilities of a disposal group classified as held for sale would be presented separately in the appropriate asset and liability sections of the balance sheet. Goodwill is reviewed for impairment on an annual basis or whenever events or changes in circumstances indicate the carrying value of the goodwill may be impaired. In regards to the annual test, we have the option to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If we determine it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing the two-step impairment test is unnecessary.
Purchase Accounting	Purchase Accounting . The purchase price of an acquired business is allocated to the underlying tangible and intangible assets acquired and liabilities assumed based upon their respective fair market values, with the excess recorded as goodwill. Such fair market value assessments require judgments and estimates which may change over time and may cause the final amounts to differ materially from their original estimates. These adjustments to fair value assessments are recorded to goodwill over the purchase price allocation period which cannot exceed twelve months.
Other Assets	Other Assets . Other assets include primarily long-term core inventory, deposits, and equity method investments. Certain products we sell contain parts that can be recycled, or as more commonly referred to in our industry, remanufactured. We refer to these parts as cores. A used core is remaufactured and sold to the customer as a replacement for a unit inside a vehicle. Customers and end-users that purchase remanufactured products will generally return the used core to us, which we then use in the remanufacturing process to make another finished good. Our core inventory consists of used cores purchased and held in our facilities, used cores that are in the process of being returned from our customers and end-users, and remanufactured cores held in finished goods inventory at our facilities. Our products that utilize a core primarily include instrument clusters, hybrid batteries, radios, and climate control modules. Long-term core inventory was $28.1 million and $20.2 million as of December 29, 2018 and December 30, 2017, respectively. Long-term core inventory is recorded at the lower of cost or net realizable value. Cost is determined based on actual purchases of core inventory. We believe that the most appropriate classification of core inventory is a long-term asset. According to guidance provided under the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification(“ASC”), current assets are defined as “assets or resources commonly identified as those which are reasonably expected to be realized in cash or sold or consumed during the normal operating cycle of the business.” The determination of the long-term classification is based on our view that the value of the cores is not expected to be consumed or realized in cash during our normal annual operating cycle. We also have investments that we account for according to the equity method of accounting. The total book value of these investments was $18.4 million as of December 29, 2018 and $21.1 million as of December 30, 2017 and these investments provided us $2.2 million and $3.3 million of income during fiscal 2018 and fiscal 2017, respectively. Additionally, in fiscal 2018 we purchased an investment that we account for according to the cost method of accounting. The book value of this investment was $5.0 million as of December 29, 2018.
Other Accrued Liabilities	Other Accrued Liabilities. Other accrued liabilities include primarily accrued customer rebates which we expect to settle in cash of $6.3 million as of December 29, 2018 and $6.8 million as of December 30, 2017. Also included are accrued commissions, accrued income taxes, insurance liabilities, product warranties, and other current liabilities. We warrant our products against certain defects in material and workmanship when used as designed on the vehicle on which it was originally installed. We offer a limited lifetime warranty on most of our products. Our warranty limits the end-user’s remedy to the repair or replacement of the part that is defective. Product warranty reserves, which were $0.6 million as of December 29, 2018 and $0.5 million as of December 30, 2017, are based upon actual experience and forecasts using the best historical and current claim information available. Provisions and payments related to product warranty reserves were not material in fiscal 2018, fiscal 2017 or fiscal 2016.
Revenue Recognition and Allowance for Customer Credits	Revenue Recognition and Allowance for Customer Credits . Revenue is recognized from product sales when goods are shipped, title and risk of loss and control have been transferred to the customer and collection is reasonably assured. We record estimates for cash discounts, product returns, promotional rebates, core return deposits, and other discounts in the period of the sale ("Customer Credits"). The provision for Customer Credits is recorded as a reduction from gross sales and reserves for Customer Credits are shown as a reduction of accounts receivable. Accrued customer credits which we expect to settle in cash are classified as other accrued liabilities. Actual Customer Credits have not differed materially from estimated amounts. Amounts billed to customers for shipping and handling are included in net sales. Costs associated with shipping and handling are included in cost of goods sold. As noted above, Customer Credits include core return deposits which are an estimate of the amount we believe we will refund to our customers when used cores are returned to us. The price we invoice to customers for remanufactured cores contain both the amount we charge to remanufacture the part and a deposit for the core. We charge a core deposit to encourage the customer to return the used core to us so that it can be used in our remanufacturing process. We allow our customers up to twenty-four months to return the used core to us. Core return deposits are reserved based on the expected deposits to be issued to customers based on historical returns.
Research and Development	Research and Development . Research and development costs are expensed as incurred. Research and development costs totaling $20.1 million in fiscal 2018, $20.0 million in fiscal 2017 and $18.9 million in fiscal 2016 have been recorded in selling, general and administrative expenses in the Consolidated Statements of Operations.
Stock-Based Compensation	Stock-Based Compensation . At December 29, 2018 and December 30, 2017, we had one stock-based employee compensation plan, which is described more fully in Note 13, Capital Stock. We record compensation expense for all awards granted. The value of restricted stock issued is based on the fair value of our common stock on the grant date. The fair value of stock options granted was determined using the Black-Scholes option valuation model.
Income Taxes	Income Taxes . We follow the asset and liability method of accounting for deferred income taxes. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities. Deferred tax assets or liabilities at the end of each period are determined using the enacted tax rate expected to be in effect when taxes are actually paid or recovered. Unrecognized income tax benefits represent income tax positions taken on income tax returns that have not been recognized in the consolidated financial statements. The Company recognizes the benefit of an income tax position only if it is more likely than not (greater than 50%) that the tax position will be sustained upon tax examination, based solely on the technical merits of the tax position. Otherwise, no benefit is recognized. The tax benefits recognized are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. Additionally, we accrue interest and related penalties, if applicable, on all tax exposures for which reserves have been established consistent with jurisdictional tax laws. Interest and penalties are classified as income tax expense in the Consolidated Statements of Operations. The Company does not anticipate material changes in the amount of unrecognized income tax benefits over the next year.
Concentrations of Risk	Concentrations of Risk . Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash equivalents and accounts receivable. All cash equivalents are managed within established guidelines which limit the amount which may be invested with one issuer. A significant percentage of our accounts receivable have been, and will continue to be, concentrated among a relatively small number of automotive retailers and warehouse distributors in the United States. Our five largest customers accounted for 79% of net accounts receivable as of December 29, 2018 and 85% of net accounts receivable as of December 30, 2017. We continually monitor the credit terms and credit limits to these and other customers. In fiscal 2018, approximately 77% of our products were purchased from suppliers located in a variety of foreign countries, with the largest portion coming from China.
Fair Value Disclosures	Fair Value Disclosures . The carrying value of financial instruments such as cash and cash equivalents, accounts receivable, accounts payable, and other current assets and liabilities approximate their fair value based on the short-term nature of these instruments. Additionally, the fair value of assets acquired and liabilities assumed are determined at the date of acquisition. We did not hold any foreign currency forward contracts at December 29, 2018 or December 30, 2017.
New and Recently Adopted Accounting Pronouncements	On December 31, 2017, the beginning of our 2018 fiscal year, we adopted FASB ASU No. 2014-09, Revenue from Contracts with Customers, In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments – Overall In February 2016, the FASB issued ASU No. 2016-02, Leases In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment In June 2018, the FASB issued ASU 2018-07, Improvements to Nonemployee Share-Based Payment Accounting

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 29, 2018
Accounting Policies [Abstract]
Estimated Useful Lives by Major Asset	Estimated useful lives by major asset category are as follows: Buildings and building improvements 10 to 39 years Machinery, equipment and tooling 3 to 10 years Software and computer equipment 3 to 10 years Furniture, fixtures and leasehold improvements 3 to 15 years

Business Acquisitions and Inv_2

Business Acquisitions and Investments (Tables)	12 Months Ended
	Dec. 29, 2018
Schedule of Valuation of Intangible Assets Acquired and Related Amortization Periods	The valuation of the intangible assets acquired and related amortization periods are as follows: (in thousands) Valuation Amortization Period (in years) Customer relationships $ 14,840 8-12 Tradenames 5,600 15 Total $ 20,440
Summary of Preliminary Fair Value of Total Consideration	The following table summarizes the preliminary fair value of the total consideration at October 26, 2017: (in thousands) Total Acquisition Date Fair Value Cash consideration (net of $3.3 million cash received) $ 56,859 Contingent cash consideration 7,982 Seller liability assumed 896 Working capital adjustment 1,486 Total consideration assigned to net assets acquired $ 67,223
Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed	The following table summarizes the fair values of the assets acquired and liabilities assumed as of October 26, 2017 (in thousands): (in thousands) October 26, 2017 (As initially reported) Measurement period adjustments October 26, 2017 (As adjusted) Current assets (net of $3.3 million cash received) $ 21,756 $ 90 $ 21,846 Property, plant and equipment 1,615 - 1,615 Intangible assets 20,440 - 20,440 Goodwill 35,624 (193 ) 35,431 Total assets acquired 79,435 (103 ) 79,332 Current liabilities 5,691 (50 ) 5,641 Long-term liabilities 6,468 - 6,468 Total liabilities assumed 12,159 (50 ) 12,109 Net assets acquired $ 67,276 $ (53 ) $ 67,223
Flight Systems Automotive Group LLC [Member]
Schedule of Valuation of Intangible Assets Acquired and Related Amortization Periods	The valuation of the intangible assets acquired and related amortization periods are as follows: (in thousands) Valuation Amortization Period (in years) Customer relationships $ 3,080 8 Tradenames 1,990 15 Other 240 5 Total $ 5,310

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 29, 2018
Inventory Disclosure [Abstract]
Inventories	Inventories were as follows: (in thousands) December 29, 2018 December 30, 2017 Bulk product $ 122,111 $ 82,010 Finished product 144,897 126,827 Packaging materials 3,496 3,312 Total $ 270,504 $ 212,149

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 29, 2018
Property Plant And Equipment [Abstract]
Property, Plant and Equipment	Property, plant and equipment include the following: (in thousands) December 29, 2018 December 30, 2017 Buildings $ 34,943 $ 32,623 Machinery, equipment and tooling 115,656 97,701 Furniture, fixtures and leasehold improvements 6,199 4,319 Software and computer equipment 79,349 77,618 Total 236,147 212,261 Less-accumulated depreciation and amortization (137,500 ) (119,569 ) Property, plant and equipment, net $ 98,647 $ 92,692

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 29, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	Goodwill Goodwill included the following: (in thousands) December 29, 2018 December 30, 2017 Balance at beginning of period $ 65,999 $ 28,146 Goodwill acquired 6,800 37,853 Measurement period adjustment (193 ) - Balance at end of period $ 72,606 $ 65,999
Schedule of Intangible Assets	Intangible Assets Intangible assets, subject to amortization, included the following: December 29, 2018 December 30, 2017 (dollars in thousands) Weighted Average Amortization Period (years) Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value Intangible assets subject to amortization Tradenames 14.1 $ 7,590 $ 516 $ 7,074 $ 5,600 $ 62 $ 5,538 Customer relationships 8.9 20,130 2,582 17,548 17,049 772 16,277 Technology 13.0 367 49 318 367 24 343 Other 4.7 240 16 224 - - - Total $ 28,327 $ 3,163 $ 25,164 $ 23,016 $ 858 $ 22,158
Schedule of Estimated Future Amortization Expense	The estimated future amortization expense for intangible assets is summarized as follows: (in thousands) 2019 $ 2,679 2020 2,679 2021 2,679 2022 2,679 2023 2,663 Thereafter 11,785 Total $ 25,164

Operating Lease Commitments a_2

Operating Lease Commitments and Rent Expense (Tables)	12 Months Ended
	Dec. 29, 2018
Leases [Abstract]
Summary of Future Minimum Rental Payments under Leases	Approximate future minimum rental payments as of December 29, 2018 under these leases are summarized as follows: (in thousands) 2019 $ 5,489 2020 5,416 2021 4,972 2022 4,599 2023 3,013 Thereafter 24,297 Total $ 47,786

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 29, 2018
Income Tax Disclosure [Abstract]
Components of Income Tax Provision (Benefit)	The components of the income tax provision (benefit) are as follows: (in thousands) 2018 2017 2016 Current: Federal $ 33,362 $ 56,641 $ 61,251 State 2,618 8,293 5,948 Foreign 1,611 379 - 37,591 65,313 67,199 Deferred: Federal 1,398 4,582 (4,563 ) State 186 343 (325 ) Foreign (1,642 ) (249 ) - (58 ) 4,676 (4,888 ) Total $ 37,533 $ 69,989 $ 62,311
Reconciliation of Income Taxes at Statutory Tax Rate to Company's Effective Tax Rate	The following is a reconciliation of income taxes at the statutory tax rate to the Company's effective tax rate: 2018 2017 2016 Federal taxes at statutory rate 21.0 % 35.0 % 35.0 % State taxes, net of federal tax benefit 1.3 3.4 2.2 Research and development tax credit (0.4 ) (0.3 ) (0.2 ) Federal permanent items (0.1 ) (0.4 ) — Tax reform — 2.5 — Other 0.1 (0.6 ) — Effective tax rate 21.9 % 39.6 % 37.0 %
Change in Uncertain Tax Benefits	The following table summarizes the change in uncertain tax benefits for the three years ended December 29, 2018: (in thousands) 2018 2017 2016 Balance at beginning of year $ 2,301 $ 3,567 $ 1,855 Reductions due to lapses in statutes of limitations (95 ) (181 ) — Reductions due to tax positions settled (368 ) (4,543 ) (109 ) Reductions due to reversals of prior year positions (4 ) — (212 ) Additions based on tax positions taken during the prior period — 3,005 — Additions based on tax positions taken during the current period 556 453 2,033 Balance at end of year $ 2,390 $ 2,301 $ 3,567
Reconciliation of Deferred Tax Assets and Liabilities	Deferred income taxes result from timing differences in the recognition of revenue and expense for tax and financial statement purposes. The sources of temporary differences are as follows: (in thousands) December 29, 2018 December 30, 2017 Assets: Inventories $ 9,006 $ 7,335 Accounts receivable 11,052 11,732 Accrued expenses 1,792 1,664 Foreign tax credits 1,050 — Other — 261 Total deferred tax assets 22,900 20,992 Valuation allowance (1,050 ) — Net deferred tax assets 21,850 20,992 Liabilities: Depreciation 9,094 7,936 Goodwill and intangible assets 11,310 11,776 Other 12 — Gross deferred tax liabilities 20,416 19,712 Net deferred tax assets $ 1,434 $ 1,280

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Dec. 29, 2018
Revenue From Contract With Customer [Abstract]
Summary of Disaggregated Net Sales	The following tables present our disaggregated net sales by Type of Major Good / Product Line, and Geography. (in thousands) 2018 2017 2016 Powertrain $ 393,979 $ 374,372 $ 351,423 Chassis 278,584 238,239 218,645 Automotive Body 256,344 245,869 244,465 Hardware 44,798 44,741 45,071 Net Sales $ 973,705 $ 903,221 $ 859,604 (in thousands) 2018 2017 2016 Net Sales to U.S. Customers $ 913,181 $ 847,394 $ 810,969 Net Sales to Non-U.S. Customers 60,524 55,827 48,635 Net Sales $ 973,705 $ 903,221 $ 859,604

Capital Stock (Tables)

Capital Stock (Tables)	12 Months Ended
	Dec. 29, 2018
Equity [Abstract]
Summary of Restricted Stock Activity	The following table summarizes our restricted stock activity for the three years ended December 29, 2018: Shares Weighted Average Price Balance at December 26, 2015 43,242 $ 34.49 Granted 133,794 $ 49.45 Vested (29,002 ) $ 29.74 Cancelled (2,671 ) $ 33.79 Balance at December 31, 2016 145,363 $ 49.22 Granted 70,611 $ 78.27 Vested (56,953 ) $ 56.03 Cancelled (5,294 ) $ 51.56 Balance at December 30, 2017 153,727 $ 59.96 Granted 89,798 $ 73.51 Vested (45,707 ) $ 62.56 Cancelled (27,081 ) $ 75.39 Balance at December 29, 2018 170,737 $ 63.94
Schedule of Weighted Average Valuation Assumptions Used to Calculate Fair Value of Options Granted	The following table summarizes the weighted average valuation assumptions used to calculate the fair value of options granted: 2018 2017 2016 Expected dividend yield 0 % 0 % 0 % Expected stock price volatility 27 % 27 % 26 % Risk-free interest rate 2.6 % 1.5 % 0.9 % Expected life of options 3.0 years 3.0 years 3.0 years
Summary of Stock Option Activity	The following table summarizes our stock option activity for the three years ended December 29, 2018: Shares Option Price per Share Weighted Average Price Weighted Average Remaining Terms (years) Aggregate Intrinsic Value Balance at December 26, 2015 40,000 $5.67 – $7.74 $ 6.86 Granted 61,084 $41.59 – $53.32 $ 44.36 Balance at December 31, 2016 101,084 $5.67 – $53.32 $ 29.52 Granted 58,024 $69.02 – $82.59 $ 78.58 Exercised (32,751 ) $6.90 – $41.59 $ 7.69 Cancelled (3,810 ) $41.59 – $78.64 $ 56.72 Balance at December 30, 2017 122,547 $5.67 – $82.59 $ 57.74 Granted 81,995 $68.93 – $82.94 $ 73.84 Exercised (15,113 ) $5.67 – $78.64 $ 39.38 Cancelled (960 ) $ 72.55 $ 72.55 Balance at December 29, 2018 188,469 $7.74 – $82.94 $ 66.14 3.6 $ 4,186,151 Options exercisable at December 29, 2018 35,966 $7.74 – $82.59 $ 51.57 2.4 $ 1,323,007
Summary of Information Concerning Currently Outstanding and Exercisable Options	The following table summarizes information concerning currently outstanding and exercisable options at December 29, 2018: Options Outstanding Options Exercisable Range of Exercise Price Number Outstanding Weighted Average Remaining Contractual Life (years) Weighted Average Exercise Price Number Exercisable Weighted Average Exercise Price $7.74 - $24.66 4,000 0.9 $ 7.74 4,000 $ 7.74 $24.67 - $41.60 35,544 2.1 $ 41.59 13,706 $ 41.59 $41.61 - $69.01 21,900 4.8 $ 58.67 7,200 $ 53.32 $69.02 - $77.99 62,184 4.2 $ 72.43 326 $ 69.02 $78.00 - $82.94 64,841 3.5 $ 79.69 10,734 $ 78.93 Balance at December 29, 2018 188,469 3.6 $ 66.14 35,966 $ 51.57

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 29, 2018
Earnings Per Share [Abstract]
Schedule of Computation of Basic Earnings per Share and Diluted Earnings per Share	The following table sets forth the computation of basic earnings per share and diluted earnings per share: (in thousands, except per share data) 2018 2017 2016 Numerator: Net income $ 133,602 $ 106,599 $ 106,049 Denominator: Weighted average basic shares outstanding 33,097 33,964 34,516 Effect of compensation awards 110 88 82 Weighted average diluted shares outstanding 33,207 34,052 34,598 Earnings Per Share: Basic $ 4.04 $ 3.14 $ 3.07 Diluted $ 4.02 $ 3.13 $ 3.07

Quarterly Results of Operatio_2

Quarterly Results of Operations (Unaudited) (Tables)	12 Months Ended
	Dec. 29, 2018
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Results of Operations	The following is a summary of the unaudited quarterly Results of Operations for the fiscal years ended December 29, 2018 and December 30, 2017: First Quarter Second Quarter Third Quarter Fourth Quarter (in thousands, except per share amounts) 2018 Net sales* $ 227,262 $ 238,147 $ 247,954 $ 260,341 Income from operations* 39,994 42,780 43,733 44,637 Net income 30,647 34,339 34,017 34,599 Diluted earnings per share 0.93 1.03 1.03 1.05 First Quarter Second Quarter Third Quarter Fourth Quarter (in thousands, except per share amounts) 2017 Net sales $ 221,625 $ 229,262 $ 224,615 $ 227,719 Income from operations 45,042 44,999 42,790 43,409 Net income 29,187 28,437 27,008 21,967 Diluted earnings per share 0.85 0.83 0.80 0.65 *Quarterly information does not add to year to date information due to rounding

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 29, 2018USD ($)CustomerContract	Dec. 30, 2017USD ($)CustomerContract	Dec. 31, 2016USD ($)
Significant Accounting Policies [Line Items]
Highly liquid short-term investments maturity date	three months or less
Sale of accounts receivable	$ 604.7	$ 582.9	$ 521.9
Additional receivables outstanding if receivables had not been sold	378.5	380.8
Factoring costs associated with the sales of accounts receivable	14.5	11.4	8.9
Long-term core inventory	28.1	20.2
Total book value of equity method investments	18.4	21.1
Income from equity method investments	2.2	3.3
Book value of cost method investments	5
Accrued customer rebates	6.3	6.8
Product warranty reserves	$ 0.6	$ 0.5
Number of largest customers | Customer	5	5
Number of foreign exchange forward contracts outstanding | Contract	0	0
Credit Concentration Risk [Member]
Significant Accounting Policies [Line Items]
Concentration risk percentage	79.00%	85.00%
Supplier Concentration Risk [Member]
Significant Accounting Policies [Line Items]
Concentration risk percentage	77.00%
Selling, General and Administrative Expenses [Member]
Significant Accounting Policies [Line Items]
Research and development costs	$ 20.1	$ 20	$ 18.9
Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of Property, Plant and Equipment	3 years
Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of Property, Plant and Equipment	39 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Estimated Useful Lives by Major Asset (Detail)	12 Months Ended
	Dec. 29, 2018
Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of Property, Plant and Equipment	3 years
Minimum [Member] | Buildings and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of Property, Plant and Equipment	10 years
Minimum [Member] | Machinery, Equipment and Tooling [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of Property, Plant and Equipment	3 years
Minimum [Member] | Software and Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of Property, Plant and Equipment	3 years
Minimum [Member] | Furniture, Fixtures and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of Property, Plant and Equipment	3 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of Property, Plant and Equipment	39 years
Maximum [Member] | Buildings and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of Property, Plant and Equipment	39 years
Maximum [Member] | Machinery, Equipment and Tooling [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of Property, Plant and Equipment	10 years
Maximum [Member] | Software and Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of Property, Plant and Equipment	10 years
Maximum [Member] | Furniture, Fixtures and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of Property, Plant and Equipment	15 years

New and Recently Adopted Acco_2

New and Recently Adopted Accounting Pronouncements - Additional Information (Detail) - ASU 2016-02 [Member] $ in Millions	Dec. 29, 2018USD ($)
Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use asset	$ 30
Lease liability	34
Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use asset	36
Lease liability	$ 40

Business Acquisitions and Inv_3

Business Acquisitions and Investments - Additional Information (Detail) - USD ($)	Aug. 31, 2018	Oct. 26, 2017	Jan. 06, 2017	Dec. 29, 2018		Sep. 29, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016	Jan. 27, 2017
Business Acquisition [Line Items]
Business acquisition, goodwill				$ 72,606,000								$ 65,999,000				$ 72,606,000	$ 65,999,000	$ 28,146,000
Net sales				$ 260,341,000	[1]	$ 247,954,000		$ 238,147,000		$ 227,262,000		$ 227,719,000	$ 224,615,000	$ 229,262,000	$ 221,625,000	973,705,000	$ 903,221,000	$ 859,604,000
Equity Method Investee [Member]
Business Acquisition [Line Items]
Equity method investment, ownership percentage																			33.00%
Equity method investment, cost																			$ 10,000,000
Minimum [Member]
Business Acquisition [Line Items]
Cash flows discounted at rates		15.00%
Maximum [Member]
Business Acquisition [Line Items]
Cash flows discounted at rates		17.00%
Flight Systems Automotive Group LLC [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of outstanding stock acquired	100.00%
Business acquisition, cash paid	$ 27,500,000
Business acquisition, goodwill	5,500,000
Business acquisition, identified intangibles	5,310,000
Business acquisition, other net assets	16,700,000
Business acquisition, accounts receivables	2,000,000
Business acquisition, inventory	9,100,000
Business acquisition, fixed assets	4,400,000
Business acquisition, other assets and liabilities net	1,200,000
Net sales	$ 7,800,000
MAS Automotive Distribution Inc [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of outstanding stock acquired		100.00%
Business acquisition, goodwill		$ 35,431,000
Business acquisition, identified intangibles		20,440,000
Business acquisition, fixed assets		1,615,000
Business acquisition, total purchase price consideration		67,223,000
Business acquisition, cash acquired		3,300,000
Net sales, included in consolidated statement of operations																40,300,000
Estimated contingent payments		7,982,000														7,900,000
Business combination maximum contingent consideration payment		$ 11,700,000
Business combination sales thresholds achievement maturity date		2020-12
Payment to former shareholder																1,500,000
MAS Automotive Distribution Inc [Member] | Selling, General and Administrative Expenses [Member]
Business Acquisition [Line Items]
Estimated contingent payments																$ 300,000
Ingalls Engineering Company, Inc., [Member]
Business Acquisition [Line Items]
Business acquisition, cash paid			$ 3,100,000
Business acquisition, other net assets			2,000,000
Business acquisition, total purchase price consideration			$ 4,800,000
Business acquisition date			Jan. 6, 2017
Business acquisition, estimated contingent payments			$ 1,700,000
Business acquisition of goodwill and other intangible assets			$ 2,800,000
[1]	Quarterly information does not add to year to date information due to rounding

Business Acquisitions and Inv_4

Business Acquisitions and Investments - Schedule of Valuation of Intangible Assets Acquired and Related Amortization Periods (Detail) - USD ($) $ in Thousands	Aug. 31, 2018	Oct. 26, 2017
Flight Systems Automotive Group LLC [Member]
Business Acquisition [Line Items]
Valuation,Intangible assets	$ 5,310
Flight Systems Automotive Group LLC [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Valuation,Intangible assets	$ 3,080
Amortization Period (in years)	8 years
Flight Systems Automotive Group LLC [Member] | Tradenames [Member]
Business Acquisition [Line Items]
Valuation,Intangible assets	$ 1,990
Amortization Period (in years)	15 years
Flight Systems Automotive Group LLC [Member] | Other [Member]
Business Acquisition [Line Items]
Valuation,Intangible assets	$ 240
Amortization Period (in years)	5 years
MAS Automotive Distribution Inc [Member]
Business Acquisition [Line Items]
Valuation,Intangible assets		$ 20,440
MAS Automotive Distribution Inc [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Valuation,Intangible assets		$ 14,840
MAS Automotive Distribution Inc [Member] | Customer Relationships [Member] | Minimum [Member]
Business Acquisition [Line Items]
Amortization Period (in years)		8 years
MAS Automotive Distribution Inc [Member] | Customer Relationships [Member] | Maximum [Member]
Business Acquisition [Line Items]
Amortization Period (in years)		12 years
MAS Automotive Distribution Inc [Member] | Tradenames [Member]
Business Acquisition [Line Items]
Valuation,Intangible assets		$ 5,600
Amortization Period (in years)		15 years

Business Acquisitions and Inv_5

Business Acquisitions and Investments - Summary of Preliminary Fair Value of Total Consideration (Detail) - USD ($) $ in Thousands	Oct. 26, 2017	Dec. 29, 2018	Dec. 30, 2017
Business Acquisition [Line Items]
Cash consideration (net of $3.3 million cash received)		$ 28,040	$ 59,987
MAS Automotive Distribution Inc [Member]
Business Acquisition [Line Items]
Cash consideration (net of $3.3 million cash received)	$ 56,859
Contingent cash consideration	7,982	$ 7,900
Seller liability assumed	896
Working capital adjustment	1,486
Total consideration assigned to net assets acquired	$ 67,223

Business Acquisitions and Inv_6

Business Acquisitions and Investments - Summary of Preliminary Fair Value of Total Consideration (Parenthetical) (Detail) $ in Millions	Oct. 26, 2017USD ($)
MAS Automotive Distribution Inc [Member]
Business Acquisition [Line Items]
Business acquisition, cash received	$ 3.3

Business Acquisitions and Inv_7

Business Acquisitions and Investments - Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017	Oct. 26, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill	$ 72,606	$ 65,999		$ 28,146
MAS Automotive Distribution Inc [Member]
Business Acquisition [Line Items]
Current assets (net of $3.3 million cash received)			$ 21,846
Property, plant and equipment			1,615
Intangible assets			20,440
Goodwill			35,431
Total assets acquired			79,332
Current liabilities			5,641
Long-term liabilities			6,468
Total liabilities assumed			12,109
Net assets acquired			67,223
MAS Automotive Distribution Inc [Member] | As initially reported [Member]
Business Acquisition [Line Items]
Current assets (net of $3.3 million cash received)			21,756
Property, plant and equipment			1,615
Intangible assets			20,440
Goodwill			35,624
Total assets acquired			79,435
Current liabilities			5,691
Long-term liabilities			6,468
Total liabilities assumed			12,159
Net assets acquired			67,276
MAS Automotive Distribution Inc [Member] | Measurement period adjustments [Member]
Business Acquisition [Line Items]
Current assets (net of $3.3 million cash received)			90
Goodwill			(193)
Total assets acquired			(103)
Current liabilities			(50)
Total liabilities assumed			(50)
Net assets acquired			$ (53)

Business Acquisitions and Inv_8

Business Acquisitions and Investments - Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed (Parenthetical) (Detail) $ in Millions	Oct. 26, 2017USD ($)
MAS Automotive Distribution Inc [Member]
Business Acquisition [Line Items]
Business acquisition, cash received	$ 3.3

Inventories - Inventories (Deta

Inventories - Inventories (Detail) - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017
Inventory Disclosure [Abstract]
Bulk product	$ 122,111	$ 82,010
Finished product	144,897	126,827
Packaging materials	3,496	3,312
Total	$ 270,504	$ 212,149

Property, Plant and Equipment -

Property, Plant and Equipment - Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017
Property, Plant and Equipment [Line Items]
Total	$ 236,147	$ 212,261
Less-accumulated depreciation and amortization	(137,500)	(119,569)
Property, plant and equipment, net	98,647	92,692
Buildings [Member]
Property, Plant and Equipment [Line Items]
Total	34,943	32,623
Machinery, Equipment and Tooling [Member]
Property, Plant and Equipment [Line Items]
Total	115,656	97,701
Furniture, Fixtures and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total	6,199	4,319
Software and Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Total	$ 79,349	$ 77,618

Property, Plant and Equipment_2

Property, Plant and Equipment - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Property Plant And Equipment [Abstract]
Depreciation and amortization expenses	$ 25.4	$ 21.5	$ 18.7

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Schedule of Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Balance at beginning of period	$ 65,999	$ 28,146
Goodwill acquired	6,800	37,853
Measurement period adjustment	(193)
Balance at end of period	$ 72,606	$ 65,999

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 28,327	$ 23,016
Accumulated Amortization	3,163	858
Net Carrying Value	$ 25,164	22,158
Tradenames [Member]
Finite Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (years)	14 years 1 month 6 days
Gross Carrying Value	$ 7,590	5,600
Accumulated Amortization	516	62
Net Carrying Value	$ 7,074	5,538
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (years)	8 years 10 months 24 days
Gross Carrying Value	$ 20,130	17,049
Accumulated Amortization	2,582	772
Net Carrying Value	$ 17,548	16,277
Technology [Member]
Finite Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (years)	13 years
Gross Carrying Value	$ 367	367
Accumulated Amortization	49	24
Net Carrying Value	$ 318	$ 343
Other [Member]
Finite Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (years)	4 years 8 months 12 days
Gross Carrying Value	$ 240
Accumulated Amortization	16
Net Carrying Value	$ 224

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense	$ 2.3	$ 0.5	$ 0.1

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Schedule of Estimated Future Amortization Expense (Detail) - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017
Finite Lived Intangible Assets [Line Items]
Net Carrying Value	$ 25,164	$ 22,158
MAS [Member]
Finite Lived Intangible Assets [Line Items]
2,019	2,679
2,020	2,679
2,021	2,679
2,022	2,679
2,023	2,663
Thereafter	11,785
Net Carrying Value	$ 25,164

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Detail)	12 Months Ended
	Dec. 29, 2018USD ($)LetterOfCredit	Dec. 30, 2017USD ($)	Nov. 30, 2017USD ($)
Debt Instrument [Line Items]
Number of letters of credit outstanding | LetterOfCredit	2
$100 million Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity		$ 100,000,000
Expiration date of credit facility		2022-12
Line of credit facility incremental borrowing capacity		$ 100,000,000
Line of credit facility unused fee percentage		0.10%
Interest rate of credit facility	3.17%
Borrowings under credit facility	$ 0
Amount available under credit facility, net of letters of credit	$ 99,200,000
$100 million Revolving Credit Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
LIBOR basis points	65.00%
$100 million Revolving Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
LIBOR basis points		125.00%
$30 million Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity			$ 30,000,000
Letters of Credit [Member]
Debt Instrument [Line Items]
Borrowings under credit facility	$ 800,000

Operating Lease Commitments a_3

Operating Lease Commitments and Rent Expense - Summary of Future Minimum Rental Payments under Leases (Detail) $ in Thousands	Dec. 29, 2018USD ($)
Leases [Abstract]
2,019	$ 5,489
2,020	5,416
2,021	4,972
2,022	4,599
2,023	3,013
Thereafter	24,297
Total	$ 47,786

Operating Lease Commitments a_4

Operating Lease Commitments and Rent Expense - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Leases [Abstract]
Rent expense, including payments for short-term equipment and storage rentals	$ 6.9	$ 5.4	$ 4.2

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail)	12 Months Ended
	Dec. 29, 2018USD ($)Supplier	Dec. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Related Party Transaction [Line Items]
Total annual rental payments to the partnership / corporation under the lease arrangement	$ 1,600,000	$ 1,600,000	$ 1,600,000
Lease expiration date	Dec. 31, 2022
Lease effective date	Jan. 1, 2018
Joint Venture [Member]
Related Party Transaction [Line Items]
Minority interests in number of companies | Supplier	2
Purchases from companies	$ 20,300,000	16,500,000	13,600,000
Canada [Member]
Related Party Transaction [Line Items]
Total annual rental payments to the partnership / corporation under the lease arrangement	$ 700,000	$ 100,000	$ 0
Lease expiration date	Feb. 28, 2019

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended			15 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016	Dec. 29, 2018	Dec. 26, 2015
Income Tax Disclosure [Abstract]
U.S. corporate income tax rate	21.00%	35.00%	35.00%
Percentage of expense qualified property placed in service				100.00%
Percentage of dividends received deduction on qualifying dividends paid by foreign subsidiaries				100.00%
First significant change in U.S. tax law, period	30 years
Provisional tax expense	$ 0
Provisional tax expense, net deferred tax assets		$ 4,400,000
Tax on deferred foreign earnings, liquid assets, percentage	15.50%
Tax on deferred foreign earnings, illiquid assets, percentage	8.00%
Defined increments minimum payment period	8 years
Transition tax expense on accumulated earnings and profits of non-U.S. subsidiaries	$ 0
Accumulated earnings and profits of non-U.S. subsidiaries	0			$ 0
Net unrecognized tax benefits	2,390,000	$ 2,301,000	$ 3,567,000	2,390,000	$ 1,855,000
Unrecognized tax benefits which would impact effective tax rate if recognized	2,100,000			2,100,000
Accrued interest and penalties related to uncertain tax positions	$ 600,000			$ 600,000

Income Taxes - Components of In

Income Taxes - Components of Income Tax Provision (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Current:
Federal	$ 33,362	$ 56,641	$ 61,251
State	2,618	8,293	5,948
Foreign	1,611	379
Current, Total	37,591	65,313	67,199
Deferred:
Federal	1,398	4,582	(4,563)
State	186	343	(325)
Foreign	(1,642)	(249)
Deferred, Total	(58)	4,676	(4,888)
Total	$ 37,533	$ 69,989	$ 62,311

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Taxes at Statutory Tax Rate to Company's Effective Tax Rate (Detail)	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal taxes at statutory rate	21.00%	35.00%	35.00%
State taxes, net of federal tax benefit	1.30%	3.40%	2.20%
Research and development tax credit	(0.40%)	(0.30%)	(0.20%)
Federal permanent items	(0.10%)	(0.40%)
Tax reform		2.50%
Other	0.10%	(0.60%)
Effective tax rate	21.90%	39.60%	37.00%

Income Taxes - Change in Uncert

Income Taxes - Change in Uncertain Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 2,301	$ 3,567	$ 1,855
Reductions due to lapses in statutes of limitations	(95)	(181)
Reductions due to tax positions settled	(368)	(4,543)	(109)
Reductions due to reversals of prior year positions	(4)		(212)
Additions based on tax positions taken during the prior period		3,005
Additions based on tax positions taken during the current period	556	453	2,033
Balance at end of year	$ 2,390	$ 2,301	$ 3,567

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017
Assets:
Inventories	$ 9,006	$ 7,335
Accounts receivable	11,052	11,732
Accrued expenses	1,792	1,664
Foreign tax credits	1,050
Other		261
Total deferred tax assets	22,900	20,992
Valuation allowance	(1,050)
Net deferred tax assets	21,850	20,992
Liabilities:
Depreciation	9,094	7,936
Goodwill and intangible assets	11,310	11,776
Other	12
Gross deferred tax liabilities	20,416	19,712
Net deferred tax assets	$ 1,434	$ 1,280

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017
Revenue From Contract With Customer [Line Items]
Revenue, performance obligation, description of good or service	We are a supplier of replacement parts and fasteners for passenger cars, light trucks, and heavy duty trucks in the automotive aftermarket. We group our products into four major classes: power-train, automotive body, chassis, and hardware.
Revenue, performance obligation, description of warranty	We warrant our products against certain defects in material and workmanship when used as designed on the vehicle on which it was originally installed. We offer a limited lifetime warranty on most of our products. Our warranty limits the customer’s remedy to the repair or replacement of the part that is defective.
Maximum credit terms allow to customers	1 year
Revenue, performance obligation satisfy, transfer of control goods or sevices, description	We identify the transaction price as the amount of consideration including variable consideration that we expect to be entitled in exchange for transferring control of goods and/or services to our customers.
Revenue, performance obligation satisfy, method of base, description	We allocate the transaction price to each performance obligation on the basis of the amount of consideration to which we expect to be entitled in exchange for satisfying each performance obligation.
Revenue, performance obligation, description of timing	We recognize revenue when we satisfy a performance obligation by transferring control of the promised goods.
Revenue, performance obligation, description of payment terms	A receivable is recorded when our right to consideration is unconditional and only the passage of time is required before payment of that consideration is due.
Contract assets	$ 0	$ 0
Contract liabilities	$ 0	$ 0
Maximum [Member]
Revenue From Contract With Customer [Line Items]
Customer purchase order duration of contract	1 year
Customer pays for good or service future duration	1 year
Expense costs to obtain as incurred, expected period of benefie, amortization period	1 year

Revenue Recognition - Additio_2

Revenue Recognition - Additional Information 1 (Detail)	Dec. 29, 2018
Maximum [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2018-12-29
Revenue From Contract With Customer [Line Items]
Revenue, remaining performance obligations for contract, initial term	1 year

Revenue Recognition - Summary o

Revenue Recognition - Summary of Disaggregated Net Sales (Detail) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 29, 2018	[1]	Sep. 29, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Disaggregation Of Revenue [Line Items]
Net Sales	$ 260,341		$ 247,954		$ 238,147		$ 227,262		$ 227,719	$ 224,615	$ 229,262	$ 221,625	$ 973,705	$ 903,221	$ 859,604
U.S. Customers [Member]
Disaggregation Of Revenue [Line Items]
Net Sales													913,181	847,394	810,969
Non-U.S. Customers [Member]
Disaggregation Of Revenue [Line Items]
Net Sales													60,524	55,827	48,635
Powertrain [Member]
Disaggregation Of Revenue [Line Items]
Net Sales													393,979	374,372	351,423
Chassis [Member]
Disaggregation Of Revenue [Line Items]
Net Sales													278,584	238,239	218,645
Automotive Body [Member]
Disaggregation Of Revenue [Line Items]
Net Sales													256,344	245,869	244,465
Hardware [Member]
Disaggregation Of Revenue [Line Items]
Net Sales													$ 44,798	$ 44,741	$ 45,071
[1]	Quarterly information does not add to year to date information due to rounding

Capital Stock - Additional Info

Capital Stock - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	May 31, 2017	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of outstanding shares owned by controlling family		18.00%
Shares authorized of undesignated capital stock for future issuance		50,000,000
Authorized number of common stock shares for grant		1,200,000
Date of plan approval		May 16, 2018
Maximum grant period from date of plan approval		10 years
Shares available for grant under the plan		1,162,398
Compensation cost related to restricted stock		$ 2,600,000	$ 2,800,000	$ 2,300,000
Compensation cost related to stock options		$ 500,000	$ 300,000	$ 100,000
Weighted-average grant-date fair value		$ 73.84	$ 78.58	$ 44.36
Cash received from stock option exercises under the plan		$ 201,000	$ 31,000
Stock options exercised		15,113	32,751
Total 401(K) expense		$ 4,300,000	$ 2,700,000	$ 2,500,000
Common stock, shares held by 401(K) plan		243,348
Repurchase and cancellation of shares		26,280	19,110	38,970
Common stock repurchased, average price		$ 74.79	$ 73.34	$ 56.66
Common stock repurchased, value		$ 2,000,000	$ 1,400,000	$ 2,200,000
Share Repurchase Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock repurchased, average price		$ 69.73	$ 74.26	$ 52.15
Common stock repurchased, value		$ 43,400,000	$ 74,700,000	$ 22,500,000
Share repurchase program shares authorized to be repurchased					$ 400,000,000	$ 10,000,000
Share repurchase program shares authorized to be repurchased expiration date		Dec. 31, 2021
Shares repurchased under share repurchase program		622,223	1,006,365	430,866
Authorized date of repurchase of outstanding common stock		Dec. 12, 2013
Shares available for repurchase under share repurchase program		183,300,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized number of common stock shares for grant	1,000,000
Rate of discount on shares of common stock available for sale to eligible employees	15.00%
Number of shares purchased		21,173	0
Compensation cost		$ 400,000	$ 100,000
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash received from stock option exercises under the plan			100,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Capitalized compensation cost		0	0	$ 0
Unrecognized compensation cost related to non-vested stock options		$ 5,900,000
Unrecognized compensation cost related to nonvested stock options, weighted-average period		2 years 3 months 18 days
Tax benefit generated from compensation cost and credited		$ 100,000	400,000	300,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Capitalized compensation cost		0	0	0
Unrecognized compensation cost related to non-vested stock options		$ 1,800,000
Unrecognized compensation cost related to nonvested stock options, weighted-average period		2 years 9 months 18 days
Tax benefit generated from compensation cost and credited		$ 0	$ 600,000	$ 0
Weighted-average grant-date fair value		$ 15.88	$ 15.81	$ 8.40
Stock options exercised				0
Performance-Based Long Term Award Program [Member] | Executives [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of compensation on compound annual growth in our pre-tax income		3 years

Capital Stock - Summary of Rest

Capital Stock - Summary of Restricted Stock Activity (Detail) - $ / shares	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Beginning Balance, Shares	153,727	145,363	43,242
Granted, Shares	89,798	70,611	133,794
Vested, Shares	(45,707)	(56,953)	(29,002)
Cancelled, Shares	(27,081)	(5,294)	(2,671)
Ending Balance, Shares	170,737	153,727	145,363
Beginning Balance, Weighted Average Price	$ 59.96	$ 49.22	$ 34.49
Granted, Weighted Average Price	73.51	78.27	49.45
Vested, Weighted Average Price	62.56	56.03	29.74
Cancelled, Weighted Average Price	75.39	51.56	33.79
Ending Balance, Weighted Average Price	$ 63.94	$ 59.96	$ 49.22

Capital Stock - Schedule of Wei

Capital Stock - Schedule of Weighted Average Valuation Assumptions Used to Calculate Fair Value of Options Granted (Detail)	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected dividend yield	0.00%	0.00%	0.00%
Expected stock price volatility	27.00%	27.00%	26.00%
Risk-free interest rate	2.60%	1.50%	0.90%
Expected life of options	3 years	3 years	3 years

Capital Stock - Summary of Stoc

Capital Stock - Summary of Stock Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, Shares	122,547	101,084	40,000
Granted, Shares	81,995	58,024	61,084
Exercised, Shares	(15,113)	(32,751)
Cancelled, Shares	(960)	(3,810)
Ending Balance, Shares	188,469	122,547	101,084
Options Exercisable, Shares	35,966
Option Price per Share, Cancelled	$ 72.55
Options Exercisable, Option Price per Share	51.57
Beginning Balance, Weighted Average Price	57.74	$ 29.52	$ 6.86
Granted, Weighted Average Price	73.84	78.58	44.36
Exercised, Weighted Average Price	39.38	7.69
Cancelled, Weighted Average Price	72.55	56.72
Ending Balance, Weighted Average Price	$ 66.14	57.74	29.52
Ending Balance, Weighted Average Remaining Terms (years)	3 years 7 months 6 days
Options Exercisable, Weighted Average Remaining Terms (years)	2 years 4 months 24 days
Ending Balance, Aggregate Intrinsic Value	$ 4,186,151
Options Exercisable, Aggregate Intrinsic Value	$ 1,323,007
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, Option Price per Share	$ 5.67	5.67	5.67
Option price per share, Granted	68.93	69.02	41.59
Option Price per Share, Exercised	5.67	6.90
Option Price per Share, Cancelled		41.59
Ending Balance, Option Price per Share	7.74	5.67	5.67
Options Exercisable, Option Price per Share	7.74
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, Option Price per Share	82.59	53.32	7.74
Option price per share, Granted	82.94	82.59	53.32
Option Price per Share, Exercised	78.64	41.59
Option Price per Share, Cancelled		78.64
Ending Balance, Option Price per Share	82.94	$ 82.59	$ 53.32
Options Exercisable, Option Price per Share	$ 82.59

Capital Stock - Summary of Info

Capital Stock - Summary of Information Concerning Currently Outstanding and Exercisable Options (Detail)	12 Months Ended
	Dec. 29, 2018$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding | shares	188,469
Weighted Average Remaining Contractual Life (Years)	3 years 7 months 6 days
Weighted Average Exercise Price	$ 66.14
Number Exercisable | shares	35,966
Options Exercisable, Weighted Average Exercise Price	$ 51.57
Range One [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Option Price per share, Minimum	7.74
Option Price per share, Maximum	$ 24.66
Number Outstanding | shares	4,000
Weighted Average Remaining Contractual Life (Years)	10 months 24 days
Weighted Average Exercise Price	$ 7.74
Number Exercisable | shares	4,000
Options Exercisable, Weighted Average Exercise Price	$ 7.74
Range Two [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Option Price per share, Minimum	24.67
Option Price per share, Maximum	$ 41.60
Number Outstanding | shares	35,544
Weighted Average Remaining Contractual Life (Years)	2 years 1 month 6 days
Weighted Average Exercise Price	$ 41.59
Number Exercisable | shares	13,706
Options Exercisable, Weighted Average Exercise Price	$ 41.59
Range Three [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Option Price per share, Minimum	41.61
Option Price per share, Maximum	$ 69.01
Number Outstanding | shares	21,900
Weighted Average Remaining Contractual Life (Years)	4 years 9 months 18 days
Weighted Average Exercise Price	$ 58.67
Number Exercisable | shares	7,200
Options Exercisable, Weighted Average Exercise Price	$ 53.32
Range Four [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Option Price per share, Minimum	69.02
Option Price per share, Maximum	$ 77.99
Number Outstanding | shares	62,184
Weighted Average Remaining Contractual Life (Years)	4 years 2 months 12 days
Weighted Average Exercise Price	$ 72.43
Number Exercisable | shares	326
Options Exercisable, Weighted Average Exercise Price	$ 69.02
Range Five [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Option Price per share, Minimum	78
Option Price per share, Maximum	$ 82.94
Number Outstanding | shares	64,841
Weighted Average Remaining Contractual Life (Years)	3 years 6 months
Weighted Average Exercise Price	$ 79.69
Number Exercisable | shares	10,734
Options Exercisable, Weighted Average Exercise Price	$ 78.93

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Stock-based awards considered as anti-dilutive	116,000	106,000	50,000

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Computation of Basic Earnings per Share and Diluted Earnings per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Numerator:
Net income	$ 34,599	$ 34,017	$ 34,339	$ 30,647	$ 21,967	$ 27,008	$ 28,437	$ 29,187	$ 133,602	$ 106,599	$ 106,049
Denominator:
Weighted average basic shares outstanding									33,097	33,964	34,516
Effect of compensation awards									110	88	82
Weighted average diluted shares outstanding									33,207	34,052	34,598
Earnings Per Share:
Basic									$ 4.04	$ 3.14	$ 3.07
Diluted	$ 1.05	$ 1.03	$ 1.03	$ 0.93	$ 0.65	$ 0.80	$ 0.83	$ 0.85	$ 4.02	$ 3.13	$ 3.07

Business Segments - Additional

Business Segments - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 29, 2018USD ($)Customer	Dec. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Product Information [Line Items]
Number of customers exceeding 10% of net sales | Customer	4
Total percentage of sales to customers exceeding 10% of sales	63.00%	61.00%	60.00%
Net sales outside of the U.S. | $	$ 60.5	$ 55.8	$ 48.6
Sales Revenue, Net [Member] | Customer Concentration Risk [Member]
Product Information [Line Items]
Percentage of net sales	10.00%	10.00%	10.00%

Quarterly Results of Operatio_3

Quarterly Results of Operations - Summary of Quarterly Results of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 29, 2018		Sep. 29, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 260,341	[1]	$ 247,954	[1]	$ 238,147	[1]	$ 227,262	[1]	$ 227,719	$ 224,615	$ 229,262	$ 221,625	$ 973,705	$ 903,221	$ 859,604
Income from operations	44,637	[1]	43,733	[1]	42,780	[1]	39,994	[1]	43,409	42,790	44,999	45,042	171,143	176,240	168,601
Net income	$ 34,599		$ 34,017		$ 34,339		$ 30,647		$ 21,967	$ 27,008	$ 28,437	$ 29,187	$ 133,602	$ 106,599	$ 106,049
Diluted earnings per share	$ 1.05		$ 1.03		$ 1.03		$ 0.93		$ 0.65	$ 0.80	$ 0.83	$ 0.85	$ 4.02	$ 3.13	$ 3.07
[1]	Quarterly information does not add to year to date information due to rounding

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts
Balance, beginning of period	$ 1,656	$ 1,345	$ 4,503
Provision	(570)	299	1,212
Charge-offs / Credits issued	(151)	12	(4,370)
Acquisitions and other	47
Balance, end of period	982	1,656	1,345
Allowance for Customer Credits [Member]
Valuation and Qualifying Accounts
Balance, beginning of period	95,537	98,650	82,483
Provision	203,677	187,422	175,260
Charge-offs / Credits issued	(208,665)	(193,753)	(159,093)
Acquisitions and other		3,218
Balance, end of period	$ 90,549	$ 95,537	$ 98,650