Charles River Laboratories International (CRL) 10-K 14 Feb 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2016	Jan. 27, 2017	Jun. 25, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	CHARLES RIVER LABORATORIES INTERNATIONAL INC
Entity Central Index Key	1,100,682
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		47,372,995
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 3,735,593,230

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Income Statement [Abstract]
Service revenue	$ 1,130,733	$ 858,244	$ 797,765
Product revenue	550,699	505,058	499,897
Total revenue	1,681,432	1,363,302	1,297,662
Costs and expenses:
Cost of services provided (excluding amortization of intangible assets)	757,732	568,227	558,578
Cost of products sold (excluding amortization of intangible assets)	277,034	263,983	266,424
Selling, general and administrative	367,548	300,414	269,033
Amortization of intangible assets	41,699	24,229	25,957
Operating income	237,419	206,449	177,670
Other income (expense):
Interest income	1,314	1,043	1,154
Interest expense	(27,709)	(15,072)	(11,950)
Other income (expense), net	11,897	3,008	10,721
Income from continuing operations, before income taxes	222,921	195,428	177,595
Provision for income taxes	66,835	43,391	47,671
Income from continuing operations, net of income taxes	156,086	152,037	129,924
Income (loss) from discontinued operations, net of income taxes	280	(950)	(1,726)
Net income	156,366	151,087	128,198
Less: Net income attributable to noncontrolling interests	1,601	1,774	1,500
Net income attributable to common shareholders	$ 154,765	$ 149,313	$ 126,698
Basic:
Continuing operations attributable to common shareowners (in dollars per share)	$ 3.28	$ 3.23	$ 2.76
Discontinued operations (in dollars per share)	0.01	(0.02)	(0.04)
Net income attributable to common shareowners (in dollars per share)	3.29	3.21	2.72
Diluted:
Continuing operations attributable to common shareowners (in dollars per share)	3.22	3.15	2.70
Discontinued operations (in dollars per share)	0.01	(0.02)	(0.04)
Net income attributable to common shareowners (in dollars per share)	$ 3.23	$ 3.13	$ 2.66

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 156,366	$ 151,087	$ 128,198
Other comprehensive income (loss):
Foreign currency translation adjustment and other	(73,243)	(61,982)	(48,955)
Cumulative translation adjustment related to intercompany loan forgiveness	0	(2,341)	0
Pension and other post-retirement benefit plans (Note 10):
Prior service cost and gains (losses) arising during the period	(60,678)	(302)	(42,236)
Amortization of net gains (losses) and prior service benefit included in net periodic pension cost	1,711	2,617	1,234
Comprehensive income, before income taxes	24,156	89,079	38,241
Income tax expense (benefit) related to items of other comprehensive income (Note 8)	(12,369)	530	(9,897)
Comprehensive income, net of income taxes	36,525	88,549	48,138
Less: Comprehensive income (loss) related to noncontrolling interests, net of income taxes	(24)	537	1,044
Comprehensive income attributable to common shareholders, net of income taxes	$ 36,549	$ 88,012	$ 47,094

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Current assets:
Cash and cash equivalents	$ 117,626	$ 117,947
Trade receivables, net	364,050	270,068
Inventories	95,833	93,735
Prepaid assets	34,315	30,198
Other current assets	45,008	47,286
Total current assets	656,832	559,234
Property, plant and equipment, net	755,827	677,959
Goodwill	787,517	438,829
Intangible assets, net	394,448	280,804
Deferred tax assets	28,746	40,028
Other assets	88,430	71,643
Total assets	2,711,800	2,068,497
Current liabilities:
Current portion of long-term debt and capital leases	27,313	17,033
Accounts payable	68,485	36,675
Accrued compensation	93,471	72,832
Deferred revenue	127,731	81,343
Accrued liabilities	84,470	89,494
Other current liabilities	26,500	12,544
Current liabilities of discontinued operations	1,623	1,840
Total current liabilities	429,593	311,761
Long-term debt, net and capital leases	1,207,696	845,997
Deferred tax liabilities	55,717	48,223
Other long-term liabilities	159,239	89,062
Long-term liabilities of discontinued operations	5,771	7,890
Total liabilities	1,858,016	1,302,933
Commitments and contingencies (Notes 2, 7, 9, 10, 13, and 17)
Redeemable noncontrolling interest	14,659	28,008
Equity:
Preferred stock, $0.01 par value; 20,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.01 par value; 120,000 shares authorized; 86,301 shares issued and 47,363 shares outstanding as of December 31, 2016 and 85,464 shares issued and 46,698 shares outstanding as of December 26, 2015	863	855
Additional paid-in capital	2,477,371	2,397,960
Retained earnings	165,303	10,538
Treasury stock, at cost, 38,938 shares and 38,766 shares as of December 31, 2016 and December 26, 2015, respectively	(1,553,005)	(1,540,738)
Accumulated other comprehensive loss	(253,764)	(135,548)
Total equity attributable to common shareholders	836,768	733,067
Noncontrolling interests	2,357	4,489
Total equity	839,125	737,556
Total liabilities, redeemable noncontrolling interest and equity	2,711,800	2,068,497
Client relationships, net
Current assets:
Intangible assets, net	320,157	213,374
Other intangible assets, net
Current assets:
Intangible assets, net	$ 74,291	$ 67,430

CONSOLIDATED BALANCE SHEETS Bal

CONSOLIDATED BALANCE SHEETS Balance Sheets Parenthetical - $ / shares	Dec. 31, 2016	Dec. 26, 2015
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	120,000,000	120,000,000
Common stock, shares issued (in shares)	86,301,000	85,464,000
Common Stock, shares outstanding (in shares)	47,363,000	46,698,000
Treasury stock, shares (in shares)	38,938,000	38,766,000

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Cash flows relating to operating activities
Net income	$ 156,366	$ 151,087	$ 128,198
Less: Income (loss) from discontinued operations, net of income taxes	280	(950)	(1,726)
Income from continuing operations, net of income taxes	156,086	152,037	129,924
Adjustments to reconcile net income from continuing operations to net cash provided by operating activities:
Depreciation and amortization	126,658	94,881	96,445
Amortization of debt issuance costs and discounts	2,831	2,380	1,725
Stock-based compensation	43,642	40,122	31,035
Deferred income taxes	1,945	2,689	7,060
Gain on venture capital investments	(10,284)	(3,823)	(9,301)
Gain on bargain purchase	16	(9,837)	0
Other, net	9,499	168	(982)
Changes in assets and liabilities:
Trade receivables, net	(52,780)	(16,963)	(28,088)
Inventories	(4,021)	3,364	(2,956)
Other assets	(6,215)	850	(5,145)
Accounts payable	22,076	1,174	4,599
Accrued compensation	9,298	8,414	13,631
Deferred revenue	14,580	6,274	22,244
Accrued liabilities	(11,487)	14,069	8,284
Taxes payable and prepaid taxes	(1,800)	(3,906)	(7,090)
Other liabilities	331	(3,659)	(9,253)
Net cash provided by operating activities	300,375	288,234	252,132
Cash flows relating to investing activities
Acquisition of businesses and assets, net of cash acquired	(648,482)	(247,651)	(234,267)
Capital expenditures	(55,288)	(63,252)	(56,925)
Purchases of investments	(40,248)	(34,235)	(26,648)
Proceeds from sale of investments and distributions from venture capital investments	53,954	27,072	21,000
Other, net	3,694	(2,221)	(1,150)
Net cash used in investing activities	(686,370)	(320,287)	(297,990)
Cash flows relating to financing activities
Proceeds from long-term debt and revolving credit facility	1,044,666	492,514	298,920
Proceeds from exercises of stock options	23,197	39,367	73,688
Payments on long-term debt, revolving credit facility, and capital lease obligations	(656,636)	(417,331)	(194,536)
Purchase of treasury stock	(12,267)	(117,478)	(122,018)
Other, net	(8,234)	7,476	5,360
Net cash provided by financing activities	390,726	4,548	61,414
Discontinued operations
Net cash used in operating activities from discontinued operations	(2,056)	(1,876)	(1,081)
Effect of exchange rate changes on cash and cash equivalents	(2,996)	(12,695)	(10,379)
Net change in cash and cash equivalents	(321)	(42,076)	4,096
Cash and cash equivalents, beginning of period	117,947	160,023	155,927
Cash and cash equivalents, end of period	117,626	117,947	160,023
Supplemental cash flow information:
Cash paid for income taxes	42,868	24,436	29,704
Cash paid for interest	22,756	11,101	10,199
Non-cash investing and financing activities:
Capitalized interest	4	424	1,032
Additions to property, plant and equipment, net	5,333	6,720	4,355
Assets acquired under capital lease	$ 1,335	$ 10,281	$ 18,690

CONSOLIDATED STATEMENT OF CHANG

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Total Equity Attributable to Common Shareholders	Noncontrolling Interests
Beginning balance at Dec. 28, 2013	$ 644,077	$ 825	$ 2,206,155	$ (265,473)	$ 5,357	$ (1,305,880)	$ 640,984	$ 3,093
Beginning balance (in shares) at Dec. 28, 2013		82,523				34,969
Increase (Decrease) in Stockholders' Equity
Net income	127,343			126,698			126,698	645
Other comprehensive loss	(79,618)				(79,604)		(79,604)	(14)
Adjustment of redeemable noncontrolling interest to fair value	(7,425)		(7,425)				(7,425)
Tax benefit associated with stock issued under employee compensation plans	4,301		4,301				4,301
Issuance of stock under employee compensation plans	73,594	$ 20	73,574				73,594
Issuance of stock under employee compensation plans (in shares)		1,980
Acquisition of treasury shares	(117,380)					$ (117,380)	(117,380)
Acquisition of treasury shares (in shares)						2,207
Stock-based compensation	31,035		31,035				31,035
Ending balance at Dec. 27, 2014	675,927	$ 845	2,307,640	(138,775)	(74,247)	$ (1,423,260)	672,203	3,724
Ending balance (in shares) at Dec. 27, 2014		84,503				37,176
Increase (Decrease) in Stockholders' Equity
Net income	150,249			149,313			149,313	936
Other comprehensive loss	(61,472)				(61,301)		(61,301)	(171)
Adjustment of redeemable noncontrolling interest to fair value	183		183				183
Tax benefit associated with stock issued under employee compensation plans	10,608		10,608				10,608
Issuance of stock under employee compensation plans	39,417	$ 10	39,407				39,417
Issuance of stock under employee compensation plans (in shares)		961
Acquisition of treasury shares	(117,478)					$ (117,478)	(117,478)
Acquisition of treasury shares (in shares)						1,590
Stock-based compensation	40,122		40,122				40,122
Ending balance at Dec. 26, 2015	737,556	$ 855	2,397,960	10,538	(135,548)	$ (1,540,738)	733,067	4,489
Ending balance (in shares) at Dec. 26, 2015		85,464				38,766
Increase (Decrease) in Stockholders' Equity
Net income	155,689			154,765			154,765	924
Other comprehensive loss	(118,370)				(118,216)		(118,216)	(154)
Adjustment of redeemable noncontrolling interest to fair value	1,690		1,690				1,690
Dividends declared to noncontrolling interests	(2,902)							(2,902)
Purchase of additional equity in redeemable noncontrolling interest	1,593		1,593				1,593
Tax benefit associated with stock issued under employee compensation plans	9,274		9,274				9,274
Issuance of stock under employee compensation plans	23,220	$ 8	23,212				23,220
Issuance of stock under employee compensation plans (in shares)		837
Acquisition of treasury shares	(12,267)					$ (12,267)	(12,267)
Acquisition of treasury shares (in shares)						172
Stock-based compensation	43,642		43,642				43,642
Ending balance at Dec. 31, 2016	$ 839,125	$ 863	$ 2,477,371	$ 165,303	$ (253,764)	$ (1,553,005)	$ 836,768	$ 2,357
Ending balance (in shares) at Dec. 31, 2016		86,301				38,938

DESCRIPTION OF BUSINESS AND SUM

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Description of Business Charles River Laboratories International, Inc. (the Company), together with its subsidiaries, is a full service, early-stage contract research organization (CRO). The Company has built upon its core competency of laboratory animal medicine and science (research model technologies) to develop a diverse portfolio of discovery and safety assessment services, both Good Laboratory Practice (GLP) and non-GLP, which are able to support its clients from target identification through non-clinical development. The Company also provides a suite of products and services to support its clients’ manufacturing activities. Principles of Consolidation The Company’s consolidated financial statements reflect its financial statements and those of its subsidiaries in which the Company holds a controlling financial interest. For consolidated entities in which the Company owns or is exposed to less than 100% of the economics, the Company records net income (loss) attributable to noncontrolling interests in its consolidated statements of income equal to the percentage of the economic or ownership interest retained in such entities by the respective noncontrolling parties. Intercompany balances and transactions are eliminated in consolidation. The Company’s fiscal year is typically based on 52-week s , with each quarter comp osed of 13 weeks ending on the last Saturday on, or closest to, March 31, June 30, September 30, and December 31. A 53 rd week was included in fiscal year 2016, which is occasionally necessary to align with a December 31 calendar year-end. The additional week was included in the fourth quarter. Reclassifications Certain reclassifications have been made to prior year statements to conform to the current year presentation. These reclassifications have no impact on period reported net income or cash flow. Segment Reporting The Company reports its results in three reportable segments: Research Models and Services (RMS), Discovery and Safety Assessment (DSA), and Manufacturing Support (Manufacturing). The Company aggregates its operating segments into a reportable segment if (a) they have similar economic characteristics; (b) they are similar in the in the nature of the products or services, nature of the production process, type or class of customer for their products and services, methods used to distribute their products and services and nature of the regulatory environment; and (c) the aggregation helps users better understand the Company’s performance. During the second quarter of 2016 , the Company acquired WRH, Inc. (WIL Research), a provider of safety assessment and contract development and manufacturing (CDMO) services. WIL Research’s safety assessment business is reported in the Company’s DSA reportable segment and its CDMO business created a new operating segment, Contract Manufacturing, that is reported as part of the Company’s Manufacturing reportable segment. On February 10, 2017 , the Company divested the CDMO business. In addition, amounts due to changes in the Company’s market strategy for certain services and resulting information provided to the Chief Operating Decision Maker were reclassified from the Company’s RMS reportable segment to its Manufacturing reportable segment, including revenue of $2.8 million and $3.7 million for fiscal years 2015 and 2014 , respectively, and operating income of $0.5 million and $0.6 million for fiscal years 2015 and 2014 , respectively. The Company reported segment results on this basis for all periods presented. The revised reportable segments are as follows: Research Models and Services Discovery and Safety Assessment Manufacturing Support Research Models Discovery Services Microbial Solutions Research Model Services Safety Assessment Avian Biologics Contract Manufacturing Use of Estimates The preparation of consolidated financial statements in accordance with generally accepted accounting principles in the United States (U.S. GAAP) requires that the Company makes estimates and judgments that may affect the reported amounts of assets, liabilities, revenues, expenses, and related disclosure of contingent assets and liabilities. On an on-going basis, the Company evaluates its estimates, judgments and methodologies. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates under different assumptions or conditions. Changes in estimates are reflected in reported results in the period in which they become known. Cash and Cash Equivalents Cash equivalents include money market funds, time deposits and other investments with remaining maturities at the purchase date of three months or less. Investments Marketable securities are reported at fair value. Realized gains and losses on marketable securities are included in other income (expense), net and are determined using the specific identification method. Unrealized gains and losses on available-for-sale marketable securities are included in accumulated other comprehensive income (loss). Time deposits with original maturities of greater than three months are reported as investments. Trade Receivables, Net The Company records trade receivables net of an allowance for doubtful accounts. An allowance for doubtful accounts is established based on historical collection information, a review of major client accounts receivable balances and current economic conditions in the geographies in which it operates. Amounts determined to be uncollectible are charged or written off against the allowance. Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, investments and trade receivables. The Company places cash and cash equivalents and investments in various financial institutions with high credit rating and limits the amount of credit exposure to any one financial institution. Trade receivables are primarily from clients in the pharmaceutical and biotechnology industries, as well as academic and government institutions. Concentrations of credit risk with respect to trade receivables, which are typically unsecured, are limited due to the wide variety of customers using the Company’s products and services as well as their dispersion across many geographic areas. No single client accounted for more than 5% of revenue or trade receivables for the periods ended December 31, 2016 and December 26, 2015 . Fair Value Measurements The accounting standard for fair value measurements defines fair value, establishes a framework for measuring fair value in accordance with U.S. GAAP, and requires certain disclosures about fair value measurements. Under this standard, fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy: • Level 1 - Fair values are determined utilizing prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access; • Level 2 - Fair values are determined by utilizing quoted prices for identical or similar assets and liabilities in active markets or other market observable inputs such as interest rates, yield curves and foreign currency spot rates; • Level 3 - Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable. The fair value hierarchy level is determined by asset, liability and redeemable noncontrolling interest class based on the lowest level of significant input. The observability of inputs may change for certain assets or liabilities. This condition could cause an asset or liability to be reclassified between levels. The Company recognizes transfers between levels within the fair value hierarchy, if any, at the end of each quarter. Valuation methodologies used for assets and liabilities measured or disclosed at fair value are as follows: • Cash equivalents - Valued at market prices determined through third-party pricing services; • Mutual funds - Valued at the unadjusted quoted net asset value of shares held by the Company; • Foreign currency forward contracts - Valued using readily observable market inputs, such as forward foreign exchange points and foreign exchanges rates; • Life insurance policies - Valued at cash surrender value based on the fair value of underlying investments; • Contingent consideration - Valued based on a probability weighting of the future cash flows associated with the potential outcomes; • Redeemable noncontrolling interest - Valued using the income approach based on estimated future cash flows of the underlying business discounted by a weighted average cost of capital. Inventories Inventories are stated at the lower of cost or net realizable value. Cost is determined on the average cost method for the small model business and first-in-first-out for the Company’s large model and Microbial Solutions businesses. For the small model business, cost includes direct materials such as feed and bedding, costs of personnel directly involved in the care of the models, and an allocation of facility overhead. For the large model business, cost is primarily the external cost paid to acquire the model. Certain businesses value inventory based on standard costs, which are periodically compared to and adjusted to actual costs. Inventory costs are charged to cost of revenue in the period the products are sold to an external party. The Company analyzes its inventory levels on a quarterly basis and writes down inventory that is determined to be damaged, obsolete or otherwise unmarketable, with a corresponding charge to cost of products sold. Property, Plant and Equipment, Net Property, plant and equipment, including improvements that significantly add to productive capacity or extend useful life, are carried at cost and are subject to review for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. The cost of normal, recurring, or periodic repairs and maintenance activities related to property, plant and equipment is expensed as incurred. In addition, the Company capitalizes certain internal use computer software development costs. Costs incurred during the preliminary project stage are expensed as incurred, while costs incurred during the application development stage are capitalized and amortized over the estimated useful life of the software. The Company also capitalizes costs related to specific upgrades and enhancements when it is probable the expenditures will result in additional functionality. Maintenance and training costs related to software obtained for internal use are expensed as incurred. Interest costs incurred during the construction of major capital projects are capitalized until the underlying asset is ready for its intended use, at which point the interest costs are amortized as depreciation expense over the life of the underlying asset. The Company generally depreciates the cost of its property, plant and equipment using the straight-line method over the estimated useful lives of the respective assets as follow: Estimated (in years) Land Indefinite Buildings 20 - 40 Machinery and equipment 3 - 20 Furniture and fixtures 5 - 10 Computer hardware and software 3 - 8 Vehicles 3 - 5 Leasehold improvements are amortized over the shorter of the estimated useful life of the asset or the lease term. Capital lease assets are amortized over the lease term, however, if ownership is transferred by the end of the capital lease, or there is a bargain purchase option, such capital lease assets are amortized over the useful life that would be assigned if such assets were owned. When the Company disposes of property, plant and equipment, it removes the associated cost and accumulated depreciation from the related accounts on its consolidated balance sheet and includes any resulting gain or loss in its consolidated statement of income. Business Acquisitions The Company accounts for acquisitions as business combinations under the acquisition method of accounting. The Company allocates the amounts that it pays for each acquisition to the assets it acquires and liabilities it assumes based on their fair values at the dates of acquisition, including identifiable intangible assets. The Company bases the fair value of identifiable intangible assets acquired in a business combination on valuations that use information and assumptions determined by management and which consider management’s best estimates of inputs and assumptions that a market participant would use. Contingent Consideration The consideration for the Company’s acquisitions often includes future payments that are contingent upon the occurrence of a particular event. The Company records an obligation for such contingent payments at fair value on the acquisition date. The Company estimates the fair value of contingent consideration obligations through valuation models that incorporate probability adjusted assumptions related to the achievement of the milestones and thus likelihood of making related payments. The Company revalues these contingent consideration obligations each reporting period. Changes in the fair value of the contingent consideration obligations are recognized in the Company’s consolidated statements of income as a component of selling, general and administrative expenses. Changes in the fair value of the contingent consideration obligations can result from changes to one or multiple inputs, including adjustments to the discount rates and changes in the assumed probabilities of successful achievement of certain financial targets. Discount rates in the Company’s valuation models represent a measure of the credit risk associated with settling the liability. The period over which the Company discounts its contingent obligations is typically based on when the contingent payments would be triggered. These fair value measurements are based on significant inputs not observable in the market. See Note 5, “Fair Value.” Goodwill and Intangible Assets Goodwill represents the difference between the purchase price and the fair value of the identifiable tangible and intangible net assets when accounted for using the purchase method of accounting. Goodwill is not amortized, but reviewed for impairment on an annual basis, during the fourth quarter, or more frequently if an event occurs or circumstances change that would more-likely-than-not reduce the fair value of the Company's reporting units below their carrying amounts. The Company has the option to first assess qualitative factors to determine whether it is necessary to perform the two-step impairment test. If the Company elects this option and believes, as a result of the qualitative assessment, that it is more-likely-than-not that the carrying value of goodwill is not recoverable, the quantitative two-step impairment test is required; otherwise, no further testing is required. Alternatively, the Company may elect to not first assess qualitative factors and immediately perform the quantitative two-step impairment test. In the first step, the Company compares the fair value of its reporting units to their carrying values. If the carrying values of the net assets assigned to the reporting units exceed the fair values of the reporting units, then the second step of the impairment test is performed in order to determine the implied fair value of the Company’s goodwill. If the carrying value of the reporting unit’s goodwill exceeds its implied fair value, then the Company would record an impairment loss equal to the difference. Definite-lived intangible assets, including client relationships, are amortized over the pattern in which the economic benefits of the intangible assets are utilized and reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets or asset group may not be recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset, which requires the use of customer attribution rates and other assumptions. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the definite-lived intangible assets, the definite-lived intangible assets are written-down to their fair values. Valuation and Impairment of Long-Lived Assets Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets or asset group may not be recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written-down to their fair values. Long-lived assets to be disposed of are carried at fair value less costs to sell. Venture Capital Investments The Company invests in several venture capital funds that invest in start-up companies primarily in the life sciences industry. The Company’s ownership interest in these funds ranges from 0.7% to 12.0% . The Company accounts for such investments in limited liability partnerships (LLP), which are variable interest entities, under the equity or cost method of accounting. The Company is not the primary beneficiary because it has no power to direct the activities that most significantly affect the LLPs’ economic performance. The Company accounts for the investments in limited liability companies, which are not variable interest entities, under the equity method of accounting. Under the equity method of accounting, the Company’s portion of the investment gains and losses, as reported in the fund’s financial statements on a quarterly lag each reporting period, is recorded in other income (expense), net. In addition, the Company adjusts the carrying value of these investments to reflect its estimate of changes to fair value since the fund’s financial statements based on information from the fund’s management team, market prices of known public holdings of the fund and other information. Under the cost method of accounting, the Company’s investment is initially measured at cost, with distributions recognized in other income (expense), net. Distributions received in excess of earnings subsequent to the date of investment are considered a return of investment and are recorded as reductions of cost of the investment. The Company reviews its cost method investments to determine whether a decline in fair value below the cost basis is other-than-temporary. If the decline in fair value is determined to be other-than-temporary, the cost basis of the investment is written down to fair value. Life Insurance Contracts Investments in life insurance contracts are recorded at cash surrender value. The initial investment at the transaction price is recognized and remeasured based on fair value of underlying investments or contractual value each reporting period. Investments in and redemptions of these life insurance contracts are reported as cash flows from investing activities in the consolidated statement of cash flows. As of December 31, 2016 and December 26, 2015 , the Company held 43 and 42 contracts, respectively, with a face value of $61.4 million and $60.5 million , respectively. Stock-Based Compensation The Company grants stock options, restricted stock, restricted stock units, and performance share units (PSUs) to employees and stock options, restricted stock, and restricted stock units to non-employee directors under stock-based compensation plans. Stock-based compensation is recognized as an expense in the consolidated financial statements based on the grant date fair value, adjusted for estimated forfeitures, over the requisite service period. For stock options, restricted stock and restricted stock units that vest based on service conditions, the Company uses the straight-line method to allocate compensation expense to reporting periods. Where awards are made with non-substantive vesting periods, where a portion of the award continues to vests after the employee’s retirement, the Company recognizes expense based on the period from the grant date to the date on which the employee is retirement eligible. The Company records the expense for PSU grants subject to performance and/or market conditions using the accelerated attribution method over the remaining service period when management determines that achievement of the performance-based milestone is probable. The fair value of stock options granted is calculated using the Black-Scholes option-pricing model and the fair value of PSUs is estimated using a lattice model with a Monte Carlo simulation, both of which require the use of subjective assumptions including volatility and expected term, among others. The expected volatility assumption is typically determined using the historical volatility of the Company’s common stock over the expected life of the stock-based award. The expected term is determined using historical option exercise activity. The fair value of restricted stock and restricted stock units is based on the market value of the Company’s common stock on the date of grant. Revenue Recognition The Company recognizes revenue when all of the following conditions are satisfied: persuasive evidence of an arrangement exists, delivery has occurred or services have been provided, the price to the customer is fixed or determinable, and collectibility is reasonably assured. Service revenue is generally evidenced by client contracts, which range in duration from a few weeks to a few years and typically take the form of an agreed upon rate per unit or fixed fee arrangements. Such contracts typically do not contain acceptance provisions based upon the achievement of certain study or laboratory testing results. Revenue of agreed upon rate per unit contracts is recognized as services are performed, based upon rates specified in the contract. In cases where performance spans reporting periods, revenue of fixed fee contracts is recognized as services are performed, measured on the ratio of outputs or performance obligations completed to the total contractual outputs or performance obligations to be provided. Changes in estimated effort to complete the fixed fee contract are reflected in the period in which the change becomes known. Changes in scope of work are common, especially under long-term contracts, and generally result in a change in contract value. Once the client has agreed to the changes in scope and renegotiated pricing terms, the contract value is amended and revenue is typically recognized as described above. Billing schedules and payment terms are generally negotiated on a contract-by-contract basis. Payments received in excess of revenue recognized are recorded as deferred revenue. As the contracted services are subsequently performed and the associated revenue is recognized, the deferred revenue balance is reduced by the amount of revenue recognized during the period. In other cases, services may be provided and revenue is recognized before the client is invoiced. In these cases, revenue recognized will exceed amounts billed and the difference, representing amounts which are currently unbillable to the customer pursuant to contractual terms, is recorded as an unbilled receivable. Once the client is invoiced, the unbilled receivable is reduced for the amount billed, and a corresponding trade receivable is recorded. Most contracts are terminable by the client, either immediately or upon notice. These contracts often require payment to the Company of expenses to wind down the project, fees earned to date or, in some cases, a termination fee. Such payments are included in revenues when earned. The Company recognizes product revenue net of allowances for estimated returns, rebates and discounts when title and risk of loss pass to customers. When the Company sells equipment with specified acceptance criteria, it assesses its ability to meet the acceptance criteria in order to determine the timing of revenue recognition. The Company would defer revenue until completion of customer acceptance testing if it is not able to demonstrate the ability to meet such acceptance criteria. A portion of the Company’s revenue is from multiple-element arrangements that include multiple products and/or services as deliverables in a single arrangement with each deliverable, or a combination of the deliverables, representing a separate unit of accounting. The Company allocates revenues to each element in a multiple-element arrangement based upon the relative selling price of each deliverable. Revenue allocated to each deliverable is then recognized when all revenue recognition criteria are met. Judgments as to the identification of deliverables, units of accounting, the allocation of consideration to the deliverable, and the appropriate timing of revenue recognition are critical with respect to these arrangements. At the inception of each arrangement that includes milestone payments, the Company evaluates whether each milestone is substantive. This evaluation includes an assessment of whether (a) the consideration is commensurate with either (1) the Company’s performance to achieve the milestone, or (2) the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the Company’s performance to achieve the milestone; (b) the consideration relates solely to past performance; and (c) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. If a substantive milestone is achieved and collection of the related receivable is reasonably assured, the Company recognizes revenue related to the milestone in its entirety in the period in which the milestone is achieved. In those circumstances where a milestone is not substantive, the Company recognizes as revenue, on the date the milestone is achieved, an amount equal to the applicable percentage of the performance period that had elapsed as of the date the milestone was achieved, with the balance being deferred and recognized over the remaining period of performance. As of December 31, 2016 , the Company had no significant milestones that were deemed substantive. The Company records shipping charges billed to customers in total revenue and records shipping costs in c ost of revenue (excluding amortization of intangible assets) for all periods presented. Advertising Costs Advertising costs are expensed as incurred. For fiscal years 2016 , 2015 and 2014 , advertising costs totaled $1.4 million , $1.2 million and $1.3 million , respectively. Income Taxes The provision for income taxes includes federal, state, local and foreign taxes. Income taxes are accounted for under the liability method. Deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statements carrying amounts and their respective tax basis. The Company measures deferred tax assets and liabilities using the enacted tax rates in effect when the temporary differences are expected to be settled. The Company evaluates the realizability of its deferred tax assets and establishes a valuation allowance when it is more likely than not that all or a portion of deferred tax assets will not be realized. The Company accounts for uncertain tax positions using a “more-likely-than-not” threshold for recognizing and resolving uncertain tax positions. The Company evaluates uncertain tax positions on a quarterly basis and considers various factors, including, but not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, information obtained during in process audit activities and changes in facts or circumstances related to a tax position. The Company also accrues for potential interest and penalties related to unrecognized tax benefits in income tax expense. Foreign Currency Contracts Foreign currency contracts are recorded at fair value in the Company’s consolidated balance sheet and are not designated as hedging instruments. Any gains or losses on such contracts are immediately recognized in other income (expense), net. Translation of Foreign Currencies For the Company’s subsidiaries that transact in a functional currency other than the U.S. dollar, assets and liabilities are translated at current rates of exchange as of the balance sheet date. Income and expense items are translated at the average foreign exchange rates for the period. Adjustments resulting from the translation of the financial statements of the Company’s foreign operations into U.S. dollars are excluded from the determination of net income and are recorded in accumulated other comprehensive income (loss), a separate component of equity. Pension and Other Post-Retirement Benefit Plans The Company recognizes the funded status of its defined benefit pension and other post-retirement benefit plans as an asset or liability. This amount is defined as the difference between the fair value of plan assets and the benefit obligation. The Company measures plan assets and benefit obligations as of its fiscal year end. The key assumptions used to calculate benefit obligations and related pension costs include expected long-term rate of return on plan assets, withdrawal and mortality rates, expected rate of increase in employee compensation levels and discount rate. Assumptions are determined based on the Company’s data and appropriate market indicators, and evaluated each year as of the plan’s measurement date. The expected long-term rate of return on plan assets reflects the average rate of earnings expected on the funds invested, or to be invested, to provide for the benefits included in the projected benefit obligations. In determining the expected long-term rate of return on plan assets, the Company considers the relative weighting of plan assets, the historical performance of total plan assets and individual asset classes and economic and other indicators of future performance. In fiscal year 2016, new mortality improvement scales were issued in the U.S. reflecting a decline in longevity projection from the 2015 releases that the Company adopted, which decreased the Company’s benefit obligations by $ 1.3 million as of December 31, 2016. In fiscal year 2015, new mortality improvement scales were issued in the U.S. and the United Kingdom (U.K.) reflecting a decline in longevity projection from the 2014 releases that the Company adopted, which decreased the Company’s benefit obligations by $3.3 million as of December 26, 2015. The discount rate reflects the rate the Company would have to pay to purchase high-quality investments that would provide cash sufficient to settle its current pension obligations. The rate of compensation increase reflects the expected annual salary increases for the plan participants based on historical experience and the current employee compensation strategy. The Company is required to recognize as a component of other comprehensive income, net of tax, the actuarial gains or losses and prior service costs or credits that arise but were not previously required to be recognized as components of net periodic benefit cost. Other comprehensive income is adjusted as these amounts are later recognized in income as components of net periodic benefit cost. Earnings Per Share Basic earnings per share are calculated by dividing net income attributable to common shareholders by the weighted average number of common shares outstanding during the period. Except where the result would be anti-dilutive to income from continuing operations, diluted earnings per share is computed using the treasury stock method, assuming the exercise of stock options and the vesting of restricted stock awards, restricted stock units, or PSUs, as well as their related income tax effects. Newly Adopted Accounting Pronouncements In July 2015, the Financial Accounting Standards Board (FASB) issu

BUSINESS ACQUISITIONS

BUSINESS ACQUISITIONS	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
BUSINESS ACQUISITIONS	BUSINESS ACQUISITIONS Agilux On September 28, 2016 , the Company acquired Agilux Laboratories, Inc. (Agilux), a CRO that provides a suite of integrated discovery small and large molecule bioanalytical services, drug metabolism and pharmacokinetic services, and pharmacology services. The acquisition supports the Company’s strategy to offer clients a broader, integrated portfolio that provides services continuously from the earliest stages of drug research through the non-clinical development process. The purchase price for Agilux was $64.9 million in cash and was funded by borrowings on the Company’s revolving credit facility. The business is reported as part of the Company’s DSA reportable segment. The purchase price allocation of $62.0 million , net of $2.9 million of cash acquired, was as follows: September 28, 2016 (in thousands) Trade receivables (contractual amount of $4,799) $ 4,799 Other current assets (excluding cash) 1,509 Property, plant and equipment 3,907 Other long-term assets 11 Definite-lived intangible assets 21,900 Goodwill 43,899 Current liabilities (3,987 ) Long-term liabilities (10,013 ) Total purchase price allocation $ 62,025 The purchase price allocations are subject to change as additional information becomes available concerning the fair value and tax basis of the assets acquired and liabilities assumed. Any additional adjustments to the purchase price allocation will be made as soon as practicable but no later than one year from the date of acquisition. The breakout of definite-lived intangible assets acquired was as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 16,700 17 Other intangible assets 5,200 4 Total definite-lived intangible assets $ 21,900 14 The goodwill resulting from the transaction is primarily attributable to the potential growth of the Company’s DSA businesses from customers and technology introduced through Agilux, and the assembled workforce of the acquired business. The goodwill attributable to Agilux is not deductible for tax purposes. The Company incurred transaction and integration costs of $1.7 million in connection with the acquisition during fiscal year 2016 , which were included in selling, general and administrative expenses. Pro forma financial information as well as actual revenue and operating income (loss) have not been included because Agilux’s financial results are non-significant when compared with the Company’s consolidated financial results. Blue Stream On June 27, 2016 , the Company acquired Blue Stream Laboratories, Inc. (Blue Stream), an analytical CRO supporting the development of complex biologics and biosimilars. Combining Blue Stream with the Company’s existing discovery, safety assessment, and biologics capabilities creates a leading CRO that has the ability to support biologic and biosimilar development from characterization through clinical testing and commercialization. The purchase price for Blue Stream was $11.7 million , including $3.0 million in contingent consideration, and was subject to certain customary adjustments. The acquisition was funded by borrowings on the Company’s revolving credit facility. The business is reported in the Company’s Manufacturing reportable segment. The contingent consideration is a one-time payment that could become payable based on the achievement of a revenue target. If achieved, the payment will become due in the third quarter of fiscal year 2017. The aggregate, undiscounted amount of contingent consideration that the Company may pay is $3.0 million . The Company estimated the fair value of this contingent consideration based on a probability-weighted set of outcomes. The purchase price allocation of $11.7 million , net of a non-significant amount of cash acquired, was as follows: June 27, 2016 (in thousands) Trade receivables (contractual amount of $1,104) $ 1,104 Other current assets (excluding cash) 15 Property, plant and equipment 912 Other long-term assets 187 Definite-lived intangible assets 1,230 Goodwill 10,477 Current liabilities (1,132 ) Long-term liabilities (1,044 ) Total purchase price allocation $ 11,749 The purchase price allocations are subject to change as additional information becomes available concerning the fair value and tax basis of the assets acquired and liabilities assumed. From the date of the acquisition through December 31, 2016 , the Company recorded a measurement-period adjustment related to the acquisition that resulted in an immaterial change to the purchase price allocation. Any additional adjustments to the purchase price allocation will be made as soon as practicable but no later than one year from the date of acquisition. The breakout of definite-lived intangible assets acquired was as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 650 10 Other intangible assets 580 5 Total definite-lived intangible assets $ 1,230 7 The goodwill resulting from the transaction is primarily attributable to the potential growth of the Company’s Manufacturing business from customers and technology introduced through Blue Stream, the assembled workforce of the acquired business, expected synergies, and the development of future proprietary processes. The goodwill attributable to Blue Stream is not deductible for tax purposes. The Company incurred $0.6 million of transaction and integration costs in connection with the acquisition during fiscal year 2016 , which were included in selling, general and administrative expenses. Pro forma financial information as well as actual revenue and operating income (loss) have not been included because Blue Stream’s financial results are non-significant when compared with the Company’s consolidated financial results. WIL Research On April 4, 2016 , the Company acquired WIL Research, a provider of safety assessment and CDMO services to biopharmaceutical and agricultural and industrial chemical companies worldwide. The acquisition enhanced the Company’s position as a leading global early-stage CRO by strengthening its ability to partner with clients across the drug discovery and development continuum. The purchase price for WIL Research was $604.8 million , including assumed liabilities of $0.4 million . The purchase price includes payment for estimated working capital, which was subject to final adjustment based on the actual working capital of the acquired business. The acquisition was funded by cash on hand and borrowings on the Company’s amended credit facility. See Note 7, “Long-Term Debt and Capital Lease Obligations.” WIL Research’s safety assessment and CDMO businesses are reported in the Company’s DSA and Manufacturing reportable segments, respectively. The purchase price allocation of $577.4 million , net of $27.4 million of cash acquired, was as follows: April 4, 2016 (in thousands) Trade receivables (contractual amount of $48,625) $ 48,157 Inventories 2,296 Other current assets (excluding cash) 3,814 Property, plant and equipment 129,066 Other long-term assets 1,060 Definite-lived intangible assets 164,800 Goodwill 330,602 Deferred revenue (39,103 ) Other current liabilities (27,386 ) Long-term liabilities (35,915 ) Total purchase price allocation $ 577,391 The purchase price allocations are subject to change as additional information becomes available concerning the fair value and tax basis of the assets acquired and liabilities assumed. From the date of the acquisition through December 31, 2016 , the Company recorded measurement-period adjustments related to the acquisition that resulted in an immaterial change to the purchase price allocation on a consolidated basis. Any additional adjustments to the purchase price allocation will be made as soon as practicable but no later than one year from the date of acquisition. The breakout of definite-lived intangible assets acquired was as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 137,500 15 Developed technology 20,700 3 Backlog 6,600 1 Total definite-lived intangible assets $ 164,800 13 The goodwill resulting from the transaction, $19.0 million of which is deductible for tax purposes due to a prior asset acquisition, is primarily attributed to the potential growth of the Company’s DSA and Manufacturing businesses from clients introduced through WIL Research, the assembled workforce of the acquired business, and expected cost synergies. The Company incurred transaction and integration costs in connection with the acquisition of $15.5 million and $3.2 million during fiscal years 2016 and 2015 , respectively, which were included in selling, general and administrative expenses. WIL Research revenue and operating income from April 4, 2016 through December 31, 2016 was $176.1 million and $12.5 million , respectively. Beginning on April 4, 2016 , WIL Research has been included in the operating results of the Company. The following selected unaudited pro forma consolidated results of operations are presented as if the WIL Research acquisition had occurred as of the beginning of the period immediately preceding the period of acquisition after giving effect to certain adjustments. For fiscal year 2016 , these adjustments included additional amortization of intangible assets and depreciation of fixed assets of $0.4 million , reversal of interest expense on borrowings of $2.6 million , elimination of intercompany activity and other one-time costs, and the tax impacts of these adjustments. For fiscal year 2015 , these adjustments included additional amortization of intangible assets and depreciation of fixed assets of $13.6 million , reversal of interest expense on borrowings of $10.5 million , inclusion of acquisition-related transaction costs of $11.5 million , elimination of intercompany activity and other one-time costs, and the tax impacts of these adjustments. Fiscal Year 2016 2015 (in thousands, except per share amounts) (unaudited) Revenue $ 1,741,964 $ 1,578,133 Net income attributable to common shareholders 175,779 153,974 Earnings per common share: Basic $ 3.74 $ 3.31 Diluted $ 3.67 $ 3.23 These unaudited pro forma results of operations have been prepared for comparative purposes only, and they do not purport to be indicative of the results of operations that actually would have resulted had the acquisition occurred on the date indicated or that may result in the future. No effect has been given for synergies, if any, that may have been realized through the acquisition. Oncotest On November 18, 2015 , the Company acquired Oncotest GmbH (Oncotest) , a German CRO providing discovery services for oncology, one of the largest therapeutic areas for biopharmaceutical research and development spending. With this acquisition, the Company has expanded its oncology services capabilities, enabling it to provide clients with access to a more comprehensive portfolio of technologies, including patient-derived xenograft (PDX) and syngeneic models. The purchase price for Oncotest was $36.0 million , including $0.3 million in contingent consideration. The acquisition was funded by borrowings on the Company's revolving credit facility. The business is reported in the Company’s DSA reportable segment. The contingent consideration earn-out period ended in the fourth quarter of 2016. As a result, the related contingent consideration liability was reversed and a gain of $0.3 million was recorded in selling, general and administrative expenses, as no payments were expected to be made. The contingent consideration was a one-time payment that could have become payable based on the achievement of a revenue target for fiscal year 2016. If achieved, the payment would have become due in the first quarter of fiscal year 2017. The aggregate, undiscounted amount of contingent consideration that the Company could have paid was €2.0 million ( $2.1 million as of December 31, 2016 ). The Company estimated the fair value of this contingent consideration based on a probability-weighted set of outcomes. The purchase price allocation of $35.4 million , net of $0.6 million of cash acquired, was as follows: November 18, 2015 (in thousands) Trade receivables (contractual amount of $3,546) $ 3,520 Inventories 129 Other current assets (excluding cash) 706 Property, plant and equipment 2,528 Definite-lived intangible assets 13,330 Goodwill 22,894 Other long-term assets 250 Current liabilities (3,456 ) Long-term liabilities (4,470 ) Total purchase price allocation $ 35,431 The breakout of definite-lived intangible assets acquired was as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 7,146 19 Developed technology 5,960 19 Other intangible assets 224 3 Total definite-lived intangible assets $ 13,330 19 The goodwill resulting from the transaction is primarily attributed to the potential growth in the Company's DSA businesses from customers and technology introduced through Oncotest, the assembled workforce of the acquired business and expected cost synergies. The goodwill attributable to Oncotest is not deductible for tax purposes. The Company incurred non-significant transaction and integration costs in connection with the acquisition during fiscal year 2016 and costs of $2.1 million during fiscal year 2015 , which were included in selling, general and administrative expenses. Pro forma financial information as well as actual revenue and operating income (loss) have not been included because Oncotest’s financial results are non-significant when compared with the Company’s consolidated financial results. Celsis On July 24, 2015 , the Company acquired Celsis Group Limited (Celsis), a leading provider of rapid testing systems for non-sterile bacterial contamination for the biopharmaceutical and consumer products industries. The purpose of this acquisition was to enhance the Company’s portfolio of rapid microbial detection products and services with the addition of a rapid bioburden testing product. The purchase price for Celsis was $214.5 million , including assumed debt and certain liabilities of $ 10.3 million . The acquisition was funded by cash on hand and borrowings on the Company’s revolving credit facility. The business is reported in the Company’s Manufacturing reportable segment. The purchase price allocation of $212.2 million , net of $2.3 million of cash acquired, was as follows: July 24, 2015 (in thousands) Trade receivables (contractual amount of $5,410) $ 5,288 Inventories 10,103 Other current assets (excluding cash) 13,269 Property, plant and equipment 4,639 Definite-lived intangible assets 118,140 Goodwill 105,550 Other long-term assets 537 Current debt (9,766 ) Other current liabilities (7,136 ) Long-term liabilities (28,388 ) Total purchase price allocation $ 212,236 The breakout of definite-lived intangible assets acquired was as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 71,000 16 Developed technology 39,140 14 Trademark and trade names 5,200 14 Non-compete 2,800 5 Total definite-lived intangible assets $ 118,140 15 The goodwill resulting from the transaction is primarily attributed to the potential growth of the Company’s Manufacturing business from clients introduced through Celsis, the assembled workforce of the acquired business and expected cost synergies. The goodwill attributable to Celsis is not deductible for tax purposes. The Company incurred transaction and integration costs in connection with the acquisition of $1.0 million and $8.8 million during fiscal years 2016 and 2015 , which were included in selling, general and administrative expenses. Celsis revenue and operating loss from July 24, 2015 through December 26, 2015 was $11.1 million and $6.1 million , respectively. Beginning on July 24, 2015 , Celsis has been included in the operating results of the Company. The following selected unaudited pro forma consolidated results of operations are presented as if the Celsis acquisition had occurred as of the beginning of the period immediately preceding the period of acquisition after giving effect to certain nonrecurring costs and other adjustments, resulting in a reversal of $0.6 million and additional expenses of $13.1 million for fiscal years 2015 and 2014 , respectively, related to depreciation and amortization of property, plant and equipment, inventory fair value adjustments and intangible assets. Fiscal Year 2015 2014 (in thousands, except per share amounts) (unaudited) Revenue $ 1,380,493 $ 1,329,025 Net income attributable to common shareholders 162,672 110,387 Earnings per common share: Basic $ 3.50 $ 2.37 Diluted $ 3.42 $ 2.32 These unaudited pro forma results of operations have been prepared for comparative purposes only, and they do not purport to be indicative of the results of operations that actually would have resulted had the acquisition occurred on the date indicated or that may result in the future. No effect has been given for synergies, if any, that may have been realized through the acquisition. Sunrise On May 5, 2015 , the Company acquired Sunrise Farms, Inc. (Sunrise), a producer of specific-pathogen-free fertile chicken eggs and chickens used in the manufacture of live viruses. The purpose of this business acquisition was to expand the capabilities of the Company’s existing Avian Vaccine Services business. The purchase price of the acquisition was $9.6 million and was funded by cash on hand and borrowings on the Company’s revolving credit facility. The business is reported in the Company’s Manufacturing reportable segment. The Company recorded a bargain purchase gain of $9.8 million , which represents the excess of the estimated fair value of the net assets acquired over the purchase price. The bargain purchase gain was recorded in other income (expense), net in the Company’s consolidated statement of income and was not recognized for tax purposes. The Company believes there were several factors that contributed to this transaction resulting in a bargain purchase gain, including the highly specialized nature of Sunrise’s business falling outside of the seller’s core activities and a limited pool of potential buyers. Before recognizing the gain from the bargain purchase, the Company reassessed its initial identification and valuation of assets acquired and liabilities assumed to validate that all assets and liabilities that the Company was able to identify at the acquisition date were properly recognized. The purchase price allocation of $9.6 million , net of less than $0.1 million of cash acquired, was as follows: May 5, 2015 (in thousands) Trade receivables (contractual amount of $995) $ 965 Inventories 1,518 Other current assets (excluding cash) 973 Property, plant and equipment 13,698 Definite-lived intangible assets 3,400 Current liabilities (925 ) Long-term liabilities (250 ) Fair value of net assets acquired 19,379 Bargain purchase gain (9,821 ) Total purchase price allocation $ 9,558 The identifiable definite-lived intangible assets acquired represent the client relationships intangible, which is being amortized over the weighted average estimated useful life of approximately 15 years . The Company incurred non-significant transaction and integration costs in connection with the acquisition during fiscal year 2016 and costs of $1.5 million during fiscal year 2015 , which were included in selling, general and administrative expenses. Pro forma financial information as well as actual revenue and operating income (loss) have not been included because Sunrise’s financial results are non-significant when compared with the Company’s consolidated financial results. ChanTest On October 29, 2014 , the Company acquired ChanTest Corporation (ChanTest), a leading provider of ion channel testing services to the biopharmaceutical industry. The acquisition augments the Company’s early discovery capabilities and enhances the Company’s ability to support clients’ target discovery and lead optimization efforts. The purchase price of the acquisition was $59.2 million , including $0.3 million in contingent consideration, and was funded by borrowings on the Company’s revolving credit facility and cash on hand. The business is reported in the Company’s DSA reportable segment. The contingent consideration earn-out period ended in the fourth quarter of 2015. As a result, the related contingent consideration liability was reversed and a gain of $0.3 million was recorded in selling, general and administrative expenses, as no payments were expected to be made. The aggregate, undiscounted amount of contingent consideration that could have become payable was $ 2.0 million . The Company estimated the fair value of this contingent consideration based on a probability-weighted set of outcomes. The purchase price allocation of $52.0 million , net of $7.2 million in cash acquired, is as follows: October 29, 2014 (in thousands) Current assets (excluding cash) $ 4,669 Property, plant and equipment 1,637 Definite-lived intangible assets 23,920 Goodwill 34,775 Current liabilities (3,486 ) Long-term liabilities (9,486 ) Total purchase price allocation $ 52,029 The breakout of definite-lived intangible assets acquired is as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 19,000 13 Other intangible assets 4,920 9 Total definite-lived intangible assets $ 23,920 12 The definite-lived intangibles are largely attributed to the expected cash flows related to client relationships existing at the acquisition closing date. The goodwill resulting from the transaction is primarily attributed to the potential growth of the business and is not deductible for tax purposes. The Company incurred non-significant transaction and integration costs in connection with the acquisition during both fiscal years 2016 and 2015 , and costs of $1.1 million during fiscal year 2014 , which were included in selling, general and administrative expenses. Pro forma financial information as well as actual revenue and operating income (loss) have not been included because ChanTest’s financial results are non-significant when compared with the Company’s consolidated financial results. VivoPath On June 16, 2014, the Company acquired substantially all of the assets of VivoPath LLC (VivoPath), a discovery services company specializing in the rapid, in vivo compound evaluation of molecules in the therapeutic areas of metabolism, inflammation and oncology. The purchase price was $2.3 million , including $1.6 million in contingent consideration, and was allocated primarily to the intangible assets acquired. The Company estimated the fair value of this contingent consideration based on a probability-weighted set of outcomes. The undiscounted total amount of contingent consideration was a maximum of $2.4 million , payable over three years based on the achievement of revenue growth targets and other contractual requirements. During fiscal year 2016 , the Company paid the second year tranche of the contingent consideration of $0.2 million . During fiscal year 2015 , the Company paid the first year tranche of the contingent consideration of $0.6 million and recorded a gain of $0.8 million , primarily due to a decrease in the expected future contingent consideration payments. As of December 31, 2016 , the remaining contingent consideration payable is a maximum of $0.2 million . The business is reported in the Company’s DSA reportable segment. Argenta and BioFocus On April 1, 2014, the Company acquired (1) 100% of the shares of the U.K. based entities Argenta and BioFocus, and (2) certain Dutch assets. These businesses have formed the core of the Company’s Early Discovery business. With this acquisition, the Company has enhanced its position as a full service, early-stage CRO, with integrated in vitro and in vivo capabilities from target discovery through non-clinical development. The purchase price of the acquisition was $191.8 million , including $0.9 million in contingent consideration. The acquisition was funded by cash on hand and borrowings on the Company’s revolving credit facility. The businesses are reported in the Company’s DSA reportable segment. The contingent consideration earn-out period ended on April 1, 2015. As a result, the related contingent consideration liability, as adjusted for subsequent changes in fair value, was reversed and a gain of $0.8 million was recorded in selling, general and administrative expenses during fiscal year 2015, as no payments were expected to be made. The contingent consideration was a one-time payment that could have become payable in the second quarter of 2015 based on the achievement of a certain revenue target for the twelve-month period following the acquisition. The aggregate, undiscounted amount of contingent consideration that the Company could have paid was € 5.0 million ( $5.3 million as of December 31, 2016 ). The Company estimated the fair value of this contingent consideration based on a probability-weighted set of outcomes. The purchase price allocation of $183.6 million , net of $8.2 million of cash acquired, was as follows: April 1, 2014 (in thousands) Current assets (excluding cash) $ 31,682 Property, plant and equipment 21,008 Other long-term assets 11,140 Definite-lived intangible assets 104,470 Goodwill 65,235 Current liabilities (13,139 ) Long-term liabilities (36,802 ) Total purchase price allocation $ 183,594 The breakout of definite-lived intangible assets acquired was as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 94,000 18 Backlog 5,900 1 Trademark and trade names 1,170 3 Leasehold interests 1,000 13 Other intangible assets 2,400 19 Total definite-lived intangible assets $ 104,470 17 The goodwill resulting from the transaction is primarily attributed to the potential growth of the Company’s DSA businesses from clients introduced through Argenta and BioFocus, the assembled workforce of the acquired businesses and expected cost synergies. The goodwill attributable to Argenta and BioFocus is not deductible for tax purposes. The Company incurred non-significant transaction and integration costs in connection with the acquisition during both fiscal years 2016 and 2015 , and costs of $5.3 million during fiscal year 2014 , which were included in selling, general and administrative expenses. Argenta and BioFocus revenue and operating income for fiscal year 2014 were $71.4 million and $1.8 million , respectively. Beginning on April 1, 2014, Argenta and BioFocus have been included in the operating results of the Company. The following selected unaudited pro forma consolidated results of operations are presented as if the Argenta and BioFocus acquisition had occurred as of the beginning of the period immediately preceding the period of acquisition after giving effect to certain adjustments, including amortization of intangible assets and depreciation of fixed assets of $ 3.7 million and other nonrecurring costs. Fiscal Year 2014 (in thousands, except per share amounts) (unaudited) Revenue $ 1,322,771 Net income attributable to common shareholders 128,195 Earnings per common share: Basic $ 2.75 Diluted $ 2.70 These unaudited pro forma results of operations have been prepared for comparative purposes only, and they do not purport to be indicative of the results of operations that actually would have resulted had the acquisition occurred on the date indicated or that may result in the future. No effect has been given for synergies, if any, that may have been realized through the acquisition.

SUPPLEMENTAL BALANCE SHEET INFO

SUPPLEMENTAL BALANCE SHEET INFORMATOIN	12 Months Ended
	Dec. 31, 2016
Supplemental Balance Sheet Information [Abstract]
SUPPLEMENTAL BALANCE SHEET INFORMATION	SUPPLEMENTAL BALANCE SHEET INFORMATION The composition of trade receivables, net is as follows: December 31, 2016 December 26, 2015 (in thousands) Client receivables $ 283,997 $ 230,010 Unbilled revenue 82,203 45,996 Total 366,200 276,006 Less: Allowance for doubtful accounts (2,150 ) (5,938 ) Trade receivables, net $ 364,050 $ 270,068 Recoveries to the allowance for doubtful accounts in fiscal year 2016 were $0.5 million . Provisions to the allowance for doubtful accounts in fiscal years 2015 and 2014 were $1.8 million and $0.5 million , respectively. The composition of inventories is as follows: December 31, 2016 December 26, 2015 (in thousands) Raw materials and supplies $ 18,893 $ 15,998 Work in process 13,681 12,101 Finished products 63,259 65,636 Inventories $ 95,833 $ 93,735 The composition of other current assets is as follows: December 31, 2016 December 26, 2015 (in thousands) Investments $ 3,771 $ 20,516 Prepaid income tax 40,705 26,350 Restricted cash 532 271 Other — 149 Other current assets $ 45,008 $ 47,286 The composition of property, plant and equipment, net is as follows: December 31, 2016 December 26, 2015 (in thousands) Land $ 47,392 $ 39,846 Buildings (1) 784,129 713,841 Machinery and equipment 403,123 362,695 Leasehold improvements 47,071 41,477 Furniture and fixtures 24,148 21,783 Computer hardware and software 127,283 113,466 Vehicles 4,118 3,819 Construction in progress 24,703 25,845 Total 1,461,967 1,322,772 Less: Accumulated depreciation (706,140 ) (644,813 ) Property, plant and equipment, net $ 755,827 $ 677,959 (1) The balances as of December 31, 2016 and December 26, 2015 include capital lease buildings. See Note 7, “Long-Term Debt and Capital Lease Obligations.” Depreciation expense in fiscal years 2016 , 2015 and 2014 was $85.0 million , $70.7 million and $70.5 million , respectively. The composition of other assets is as follows: December 31, 2016 December 26, 2015 (in thousands) Life insurance policies $ 29,456 $ 27,554 Venture capital investments 45,331 32,730 Restricted cash 1,736 1,745 Other 11,907 9,614 Other assets $ 88,430 $ 71,643 The composition of other current liabilities is as follows: December 31, 2016 December 26, 2015 (in thousands) Accrued income taxes $ 25,621 $ 12,168 Other 879 376 Other current liabilities $ 26,500 $ 12,544 The composition of other long-term liabilities is as follows: December 31, 2016 December 26, 2015 (in thousands) Long-term pension liability $ 89,984 $ 34,604 Accrued executive supplemental life insurance retirement plan and deferred compensation plan 32,880 30,188 Other 36,375 24,270 Other long-term liabilities $ 159,239 $ 89,062

VENTURE CAPITAL INVESTMENTS AND

VENTURE CAPITAL INVESTMENTS AND MARKETABLE SECURITIES	12 Months Ended
	Dec. 31, 2016
Marketable Securities and Equity-Method Affiliates [Abstract]
VENTURE CAPITAL INVESTMENTS AND MARKETABLE SECURITIES	VENTURE CAPITAL INVESTMENTS AND MARKETABLE SECURITIES Venture Capital Investments During fiscal years 2016 , 2015 , and 2014 , the Company recognized gains related to the venture capital investments of $10.3 million , $3.8 million and $9.3 million , respectively. The Company’s total commitment to these entities as of December 31, 2016 was $84.8 million , of which the Company had funded $38.2 million as of December 31, 2016 . During fiscal years 2016 , 2015 , and 2014 , the Company received dividends totaling $7.1 million , $7.3 million , and $7.4 million , respectively. As of December 31, 2016 and December 26, 2015 , the Company’s consolidated retained earnings (accumulated deficit) included $4.4 million and $2.4 million , respectively, of the undistributed earnings related to these entities. Marketable Securities The Company held no marketable securities as of December 31, 2016 . The following is a summary of the Company’s marketable securities, all of which are classified as available-for-sale, as of December 26, 2015 : Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Mutual fund $ 4,650 $ — $ (141 ) $ 4,509 Total $ 4,650 $ — $ (141 ) $ 4,509 During fiscal year 2016 , the Company realized non-significant losses and received proceeds of $ 4.6 million from the sale of its available-for-sale securities. There were no sales of available-for-sale securities during fiscal year 2015 .

FAIR VALUE

FAIR VALUE	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
FAIR VALUE	FAIR VALUE Assets, liabilities, and redeemable noncontrolling interest measured at fair value on a recurring basis are summarized below: December 31, 2016 Level 1 Level 2 Level 3 Total (in thousands) Cash equivalents $ — $ 21 $ — $ 21 Other assets: Life insurance policies — 22,121 — 22,121 Total assets measured at fair value $ — $ 22,142 $ — $ 22,142 Other current liabilities: Contingent consideration $ — $ — $ 3,621 $ 3,621 Total liabilities measured at fair value $ — $ — $ 3,621 $ 3,621 December 26, 2015 Level 1 Level 2 Level 3 Total (in thousands) Cash equivalents $ — $ 190 $ — $ 190 Other current assets: Marketable securities 4,509 — — 4,509 Foreign currency forward contracts — 15 — 15 Other assets: Life insurance policies — 20,364 — 20,364 Total assets measured at fair value $ 4,509 $ 20,569 $ — $ 25,078 Other current liabilities: Contingent consideration $ — $ — $ 1,172 $ 1,172 Other long-term liabilities: Contingent consideration — — 198 198 Redeemable noncontrolling interest — — 28,008 28,008 Total liabilities and redeemable noncontrolling interest measured at fair value $ — $ — $ 29,378 $ 29,378 During fiscal years 2016 and 2015 , there were no transfers between fair value levels. Contingent Consideration The following table provides a rollforward of the contingent consideration related to previous business acquisitions. See Note 2, “Business Acquisitions.” Fiscal Year 2016 2015 (in thousands) Beginning balance $ 1,370 $ 2,828 Additions 3,600 973 Payments (872 ) (600 ) Total gains or losses (realized/unrealized): Reversal of previously recorded contingent liability and change in fair value (477 ) (1,831 ) Ending balance $ 3,621 $ 1,370 The unobservable inputs used in the fair value measurement of the Company’s contingent consideration are the probabilities of successful achievement of certain financial targets and a discount rate. Increases or decreases in any of the probabilities of success would result in a higher or lower fair value measurement, respectively. Increases or decreases in the discount rate would result in a lower or higher fair value measurement, respectively. Debt Instruments The book value of the Company’s term and revolving loans, which are variable rate loans carried at amortized cost, approximates their fair value based on current market pricing of similar debt. As the fair value is based on significant other observable inputs, including current interest and foreign currency exchange rates, it is deemed to be Level 2 within the fair value hierarchy. Redeemable Noncontrolling Interest The Company’s redeemable noncontrolling interest resulted from the acquisition of an interest in Vital River in January 2013 and July 2016. The following table provides a rollforward of the fair value of the Company’s redeemable noncontrolling interest for fiscal year 2015 : Redeemable Noncontrolling Interest (in thousands) December 27, 2014 $ 28,419 Total gains or losses (realized/unrealized): Net income attributable to noncontrolling interest 838 Foreign currency translation (1,066 ) Change in fair value, included in additional paid-in capital (183 ) December 26, 2015 28,008 Total gains or losses (realized/unrealized): Net income attributable to noncontrolling interest 320 Foreign currency translation (653 ) Change in fair value, included in additional paid-in capital (1,690 ) July 7, 2016 $ 25,985 Since July 7, 2016, the redeemable noncontrolling interest is no longer reported at fair value. See Note 8, “Equity and Redeemable Noncontrolling Interest.”

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	GOODWILL AND INTANGIBLE ASSETS Goodwill The following table provides a rollforward of the Company’s goodwill: Adjustments to Goodwill Adjustments to Goodwill December 27, 2014 Acquisitions Foreign Exchange December 26, 2015 Acquisitions Transfers Foreign Exchange December 31, 2016 (in thousands) RMS $ 59,196 $ — $ (1,029 ) $ 58,167 $ — $ (342 ) $ (1,428 ) $ 56,397 DSA 1,234,302 22,146 (4,398 ) 1,252,050 337,872 — (21,446 ) 1,568,476 Manufacturing 32,579 105,567 (4,534 ) 133,612 46,859 342 (13,169 ) 167,644 Gross carrying amount 1,326,077 1,443,829 1,792,517 Accumulated impairment loss - DSA (1,005,000 ) — — (1,005,000 ) — — — (1,005,000 ) Goodwill $ 321,077 $ 438,829 $ 787,517 During the second quarter of 2016, the Company revised the composition of its reportable segments to align with the view of the business following its acquisition of WIL Research. See Note 1, "Description of Business and Summary of Significant Accounting Policies." As a result, goodwill was allocated from the Company's RMS reportable segment to its Manufacturing reportable segment, as shown in the preceding table within "transfers." The allocation was based on the fair value of each business group within its original reporting unit relative to the fair value of that reporting unit. In addition, the Company completed an assessment of any potential goodwill impairment for all reporting units immediately prior to the reallocation and determined that no impairment existed. Based on the Company’s step one goodwill impairment test for fiscal years 2016 , 2015 and 2014 , the fair value of each reporting unit exceeded the reporting unit’s book value and, therefore, goodwill was not impaired. Intangible Assets, Net The following table displays intangible assets, net by major class: December 31, 2016 December 26, 2015 Gross Accumulated Net Gross Accumulated Net (in thousands) Backlog $ 8,370 $ (6,390 ) $ 1,980 $ 50,568 $ (50,554 ) $ 14 Technology 71,425 (14,314 ) 57,111 60,350 (5,911 ) 54,439 Trademarks and trade names 8,177 (4,124 ) 4,053 11,495 (5,944 ) 5,551 Other 16,775 (5,628 ) 11,147 14,711 (7,285 ) 7,426 Other intangible assets 104,747 (30,456 ) 74,291 137,124 (69,694 ) 67,430 Client relationships 519,123 (198,966 ) 320,157 396,537 (183,163 ) 213,374 Intangible assets $ 623,870 $ (229,422 ) $ 394,448 $ 533,661 $ (252,857 ) $ 280,804 During fiscal year 2016, the Company determined that the carrying values of certain DSA intangible assets were not recoverable and recorded an impairment charge of $ 1.9 million , which was included in costs of services provided (excluding amortization of intangible assets). Amortization expense of definite-lived intangible assets, including client relationships, for fiscal years 2016 , 2015 and 2014 was $41.7 million , $24.2 million and $26.0 million , respectively. Estimated amortization expense for intangible assets for each of the next five fiscal years is expected to be as follows: Fiscal Year Amortization Expense (in thousands) 2017 $ 42,525 2018 40,731 2019 34,995 2020 34,382 2021 32,994

LONG-TERM DEBT AND CAPITAL LEAS

LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS	LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS Long-Term Debt Long-term debt, net consists of the following: December 31, 2016 December 26, 2015 (in thousands) Term loans $ 633,750 $ 390,000 Revolving credit facility 578,759 446,041 Other long-term debt 185 193 Total debt 1,212,694 836,234 Less: Current portion of long-term debt (24,560 ) (15,193 ) Long-term debt 1,188,134 821,041 Debt discount and debt issuance costs (7,633 ) (6,805 ) Long-term debt, net $ 1,180,501 $ 814,236 As of December 31, 2016 and December 26, 2015 , the weighted average interest rate on the Company’s debt was 1.89% and 1.33% , respectively. In April 2015, the Company amended and restated the $ 970M Credit Facility, creating a $ 1.3 billion facility ($ 1.3B Credit Facility) that provides for a $ 400.0 million term loan facility and a $ 900.0 million multi-currency revolving facility. The interest rates applicable to term loans and revolving loans under the Company’s $ 1.3B Credit Facility were, at the Company’s option, equal to either the alternate base rate (which is the higher of (1) the prime rate, (2) the federal funds rate plus 0.5% or (3) the one-month adjusted LIBOR rate plus 1% ) or the adjusted LIBOR rate, plus an interest rate margin based upon the Company’s leverage ratio. On March 30, 2016, the Company amended and restated its $ 1.3B credit facility creating a $ 1.65 billion credit facility ($ 1.65B Credit Facility) which (1) extends the maturity date for the credit facility and (2) makes certain other amendments in connection with the Company’s acquisition of WIL Research. The amendment was accounted for as a debt modification with a partial extinguishment of debt. In connection with the transaction, the Company capitalized approximately $3.3 million and expensed approximately $1.4 million of debt issuance costs. The $ 1.65B Credit Facility provides for a $ 650.0 million term loan and a $ 1.0 billion multi-currency revolving facility. The term loan facility matures in 19 quarterly installments with the last installment due March 30, 2021. The revolving facility matures on March 30, 2021, and requires no scheduled payment before that date. Under specified circumstances, the Company has the ability to increase the term loan and/or revolving line of credit by up to $ 500 million in the aggregate. The interest rates applicable to term loan and revolving loans under the $ 1.65B Credit Facility are, at the Company’s option, equal to either the base rate (which is the higher of (1) the prime rate, (2) the federal funds rate plus 0.50% , or (3) the one-month adjusted LIBOR rate plus 1% ) or the adjusted LIBOR rate, plus an interest rate margin based upon the Company’s leverage ratio. The $ 1.65B Credit Facility includes certain customary representations and warranties, events of default, notices of material adverse changes to the Company’s business and negative and affirmative covenants. These covenants include (1) maintenance of a ratio of consolidated earnings before interest, taxes, depreciation and amortization (EBITDA) less capital expenditures to consolidated cash interest expense, for any period of four consecutive fiscal quarters, of no less than 3.50 to 1.0 as well as (2) maintenance of a ratio of consolidated indebtedness to consolidated EBITDA for any period of four consecutive fiscal quarters, of no more than 4.25 to 1.0 with step downs to 3.50 to 1.0 by the last day of the fourth quarter of 2017. As of December 31, 2016 , the Company was compliant with all covenants. The obligations of the Company under the $ 1.65B Credit Facility are collateralized by substantially all of the assets of the Company. Principal maturities of existing debt for the periods set forth in the table below, are as follows: Principal (in thousands) 2017 $ 24,560 2018 36,563 2019 52,813 2020 81,250 2021 1,017,508 Total $ 1,212,694 Letters of Credit As of both December 31, 2016 and December 26, 2015 , the Company had $4.9 million outstanding under letters of credit. Capital Lease Obligations The Company acquired a build-to-suit lease as part of its acquisition of Argenta and BioFocus. In accordance with accounting guidance applicable to entities involved with the construction of an asset that will be leased when the construction is completed, the Company was considered the owner, for accounting purposes, of this property during the construction period. Accordingly, the Company recorded an asset and a corresponding financing obligation on its consolidated balance sheet for the amount of total project costs incurred related to the construction in progress for this property through completion of the construction period. Upon completion of the construction during the second quarter of fiscal year 2015, the Company determined that it was no longer considered the owner of the property because it did not have continuing involvement. Consequently, the Company recorded a successful sale leaseback and derecognized the property and the associated financing obligation from the Company’s consolidated balance sheet and recorded a capital lease asset and a corresponding liability of $ 35.8 million . As of December 31, 2016 , the minimum lease payments under capital leases for each of the next five years and total thereafter were as follows: Minimum Lease Payments (in thousands) 2017 $ 4,097 2018 3,503 2019 3,005 2020 2,385 2021 2,250 Thereafter 27,974 Total $ 43,214

EQUITY AND REDEEMABLE NONCONTRO

EQUITY AND REDEEMABLE NONCONTROLLING INTEREST	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
EQUITY AND REDEEMABLE NONCONTROLLING INTEREST	EQUITY AND REDEEMABLE NONCONTROLLING INTEREST Earnings Per Share The following table reconciles the numerator and denominator in the computations of basic and diluted earnings per share: Fiscal Year 2016 2015 2014 (in thousands) Numerator: Income from continuing operations, net of income taxes $ 156,086 $ 152,037 $ 129,924 Income (loss) from discontinued operations, net of income taxes 280 (950 ) (1,726 ) Less: Net income attributable to noncontrolling interests 1,601 1,774 1,500 Net income attributable to common shareholders $ 154,765 $ 149,313 $ 126,698 Denominator: Weighted-average shares outstanding—Basic 47,014 46,496 46,627 Effect of dilutive securities: Stock options, restricted stock units, performance share units and restricted stock 944 1,138 931 Weighted-average shares outstanding—Diluted 47,958 47,634 47,558 Options to purchase approximately 0.8 million shares, 0.5 million shares, and 0.6 million shares for fiscal years 2016 , 2015 and 2014 , respectively, as well as a non-significant number of restricted stock, restricted stock units (RSUs), and performance share units (PSUs), were not included in computing diluted earnings per share because their inclusion would have been anti-dilutive. Basic weighted average shares outstanding for fiscal years 2016 , 2015 and 2014 excluded the impact of approximately 1.1 million shares, 1.1 million shares, and 1.2 million shares, respectively, of non-vested restricted stock, restricted stock units, and PSUs. Treasury Shares In July 2010 , the Company’s Board of Directors authorized a $500.0 million stock repurchase program, and subsequently approved increases to the stock repurchase program of $250.0 million in 2010 , $250.0 million in 2013 and $150.0 million in 2014, for an aggregate authorization of $1,150.0 million . Under its authorized stock repurchase program, the Company did not repurchase any shares in fiscal year 2016 , and repurchased approximately 1.5 million shares for $ 108.8 million and approximately 2.1 million shares for $ 110.6 million in fiscal years 2015 and 2014 , respectively. As of December 31, 2016 , the Company had $69.7 million remaining on the authorized stock repurchase program. In addition, the Company’s stock-based compensation plans permit the netting of common stock upon vesting of restricted stock, restricted stock units and performance share units in order to satisfy individual minimum statutory tax withholding requirements. The Company acquired approximately 0.2 million shares for $12.3 million , approximately 0.1 million shares for $8.7 million , and approximately 0.1 million shares for $6.8 million in fiscal years 2016 , 2015 and 2014 , respectively, to satisfy individual minimum statutory tax withholding requirements. Accumulated Other Comprehensive Income (Loss) Changes to each component of accumulated other comprehensive income (loss), net of income taxes, are as follows: Foreign Currency Translation and Other (3) Pension and Other Post-Retirement Benefit Plans Total (in thousands) December 27, 2014 $ (19,891 ) $ (54,356 ) $ (74,247 ) Other comprehensive loss before reclassifications (1) (60,745 ) (302 ) (61,047 ) Amounts reclassified from accumulated other comprehensive income (loss) (2,341 ) 2,617 276 Net current period other comprehensive income (loss) (63,086 ) 2,315 (60,771 ) Income tax expense — 530 530 December 26, 2015 (82,977 ) (52,571 ) (135,548 ) Other comprehensive loss before reclassifications (2) (71,618 ) (60,678 ) (132,296 ) Amounts reclassified from accumulated other comprehensive income (loss) — 1,711 1,711 Net current period other comprehensive income (loss) (71,618 ) (58,967 ) (130,585 ) Income tax expense (benefit) — (12,369 ) (12,369 ) December 31, 2016 $ (154,595 ) $ (99,169 ) $ (253,764 ) (1) The impact of the foreign currency translation adjustment to other comprehensive income (loss) before reclassifications for fiscal year 2015 was primarily due to the effect of changes in foreign currency exchange rates of the Euro and Canadian Dollar and to a lesser extent due to the impact of changes in the British Pound. (2) The impact of the foreign currency translation adjustment to other comprehensive income (loss) before reclassifications for fiscal year 2016 was primarily due to the effect of changes in foreign currency exchange rates of the Euro, British Pound, and Canadian Dollar and to a lesser extent due to the impact of changes in the Chinese Yuan Renminbi and Japanese Yen. (3) Foreign currency translation and other includes a non-significant amount of unrealized gains (losses) on available-for-sale marketable securities. Nonredeemable Noncontrolling Interests The Company has investments in several entities, whose financial results are consolidated in the Company’s financial statements, as it has the ability to exercise control over these entities. The interests of the respective noncontrolling parties in these entities have been recorded as nonredeemable noncontrolling interests. Redeemable Noncontrolling Interest In January 2013, the Company acquired a 75% ownership interest of Vital River, a commercial provider of research models and related services in China, for $ 24.2 million , net of $ 2.7 million of cash acquired. Concurrent with the acquisition, the Company entered into an agreement with the noncontrolling interest holders that provided the Company with the right to purchase, and the noncontrolling interest holders with the right to sell, the remaining 25% of the entity for cash at its fair value beginning in January 2016. On July 7, 2016, the Company purchased an additional 12% equity interest in Vital River for $10.8 million , resulting in total ownership of 87% . The Company recorded a $1.6 million gain in equity equal to the excess fair value of the 12% equity interest over the purchase price. Concurrent with the transaction, the original agreement was amended providing the Company with the right to purchase, and the noncontrolling interest holders with the right to sell, the remaining 13% equity interest at a contractually defined redemption value, subject to a redemption floor (embedded derivative). These rights are exercisable beginning in 2019 and are accelerated in certain events. The Company recorded a charge of $1.5 million in other income (expense), net, equal to the excess fair value of the hybrid instrument (equity interest with an embedded derivative) over the fair value of the 13% equity interest. The redeemable noncontrolling interest is measured at the greater of the amount that would be paid if settlement occurred as of the balance sheet date based on the contractually defined redemption value ( $14.1 million as of December 31, 2016 ) and its carrying amount adjusted for net income (loss) attributable to the noncontrolling interest. As the noncontrolling interest holders have the ability to require the Company to purchase the remaining 13% interest, the noncontrolling interest is classified in the mezzanine section of the consolidated balance sheet, which is presented above the equity section and below liabilities. The agreement does not limit the amount that the Company could be required to pay to purchase the remaining 13% equity interest. The following table provides a rollforward of the Company’s redeemable noncontrolling interest subsequent to the acquisition of the additional 12% equity interest on July 7, 2016: Redeemable Noncontrolling Interest (in thousands) July 7, 2016 $ 25,985 Purchase of 12% equity interest (12,360 ) Total gains or losses (realized/unrealized): Net income attributable to noncontrolling interest 357 Foreign currency translation (818 ) Modification of 13% purchase option 1,495 December 31, 2016 $ 14,659 See Note 5, “Fair Value,” for the activity within the redeemable noncontrolling interest prior to July 7, 2016.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The components of income from continuing operations before income taxes and the related provision for income taxes are presented below: Fiscal Year 2016 2015 2014 (in thousands) Income from continuing operations before income taxes: U.S. $ 59,255 $ 76,157 $ 71,002 Non-U.S. 163,666 119,271 106,593 $ 222,921 $ 195,428 $ 177,595 Income tax provision: Current: Federal $ 18,592 $ 23,687 $ 13,733 Foreign 39,829 8,572 20,364 State 5,263 6,819 4,746 Total current 63,684 39,078 38,843 Deferred: Federal 7,206 1,790 12,982 Foreign (4,024 ) 3,064 (4,672 ) State (31 ) (541 ) 518 Total deferred 3,151 4,313 8,828 $ 66,835 $ 43,391 $ 47,671 The components of deferred tax assets and liabilities are as follows: December 31, 2016 December 26, 2015 (in thousands) Deferred tax assets: Compensation $ 70,863 $ 55,259 Accruals and reserves 8,103 8,941 Inventory reserves and valuations 3,447 2,022 Financing related — 902 Net operating loss and credit carryforwards 58,081 35,233 Other 2,921 2,593 Valuation allowance (10,101 ) (6,112 ) Total deferred tax assets 133,314 98,838 Deferred tax liabilities: Goodwill and other intangibles (121,256 ) (73,208 ) Financing related (854 ) — Depreciation related (32,271 ) (23,664 ) Venture capital investments (5,084 ) (3,570 ) Foreign withholding taxes (821 ) (6,590 ) Total deferred tax liabilities (160,286 ) (107,032 ) Net deferred taxes $ (26,972 ) $ (8,194 ) Reconciliations of the statutory U.S. Federal income tax rate to effective tax rates are as follows: Fiscal Year 2016 2015 2014 U.S. statutory income tax rate 35.0 % 35.0 % 35.0 % Foreign tax rate differences (10.3 )% (8.6 )% (9.4 )% State income taxes, net of Federal tax benefit 1.6 % 1.9 % 1.9 % Research tax credits and enhanced deductions (3.5 )% (2.6 )% (4.1 )% Enacted tax rate changes (0.8 )% (1.5 )% — % Impact of tax uncertainties 0.2 % (5.2 )% (0.7 )% Foreign withholding taxes 2.0 % 3.4 % — % Impact of acquisitions and restructuring 1.8 % (2.0 )% 1.6 % Other 4.0 % 1.8 % 2.5 % Effective income tax rate 30.0 % 22.2 % 26.8 % The tax rate benefit for enacted tax rate changes is primarily associated with a reduction in the U.K.’s statutory tax rates. As of December 31, 2016 , the Company had foreign net operating loss and tax credit carryforwards of $58.5 million , as compared to $34.6 million as of December 26, 2015 . Of this amount, $5.2 million will expire beginning after 2016, $40.5 million will begin to expire in 2028 and beyond, and the remainder of $12.8 million can be carried forward indefinitely. In accordance with Canadian Federal tax law, the Company claims Scientific Research and Experimental Development (SR&ED) credits on qualified research and development costs incurred in its Safety Assessment facility in Montreal, and currently maintains $16.8 million in credit carryforwards, which will begin to expire in 2033. Additionally, the Company records a benefit to operating income for research and development credits in both Quebec and the U.K. related to its Safety Assessment and Early Discovery facilities. The Company has fully recognized its deferred tax assets on the belief that it is more likely than not that they will be realized. The only exceptions relate to deferred tax assets primarily for net operating losses in France, Hong Kong, Luxembourg, the Netherlands and Germany, capital losses in the U.S., and fixed assets in the U.K. The valuation allowance increased by $4.0 million from $6.1 million as of December 26, 2015 to $10.1 million as of December 31, 2016 . A reconciliation of the Company’s beginning and ending unrecognized income tax benefits is as follows: Fiscal Year 2016 2015 2014 (in thousands) Beginning balance $ 23,338 $ 34,627 $ 18,475 Additions to tax positions for current year 2,194 2,362 1,700 Additions to tax positions for prior years 2,035 3,028 18,502 Reductions to tax positions for current year — — — Reductions to tax positions for prior years (1,866 ) (3,991 ) (3,722 ) Settlements (918 ) (1,946 ) (308 ) Expiration of statute of limitations (597 ) (10,742 ) (20 ) Ending balance $ 24,186 $ 23,338 $ 34,627 The $0.8 million increase in unrecognized income tax benefits during fiscal year 2016 is primarily attributable to pre-acquisition tax positions taken by WIL Research, as well as an additional year of Canadian SR&ED credit, offset by a settlement related to the tax year ended 2014 for Canadian SR&ED credits and favorable foreign exchange movement. The amount of unrecognized income tax benefits that, if recognized, would favorably impact the effective tax rate was $ 21.4 million as of December 31, 2016 and $ 20.1 million as of December 26, 2015 . The $1.3 million increase is primarily pre-acquisition tax positions taken by WIL Research, as well as an additional year of Canadian SR&ED credit, offset by favorable foreign exchange movement. It is reasonably possible as of December 31, 2016 that the liability for unrecognized tax benefits for the uncertain tax position will decrease by $ 4.6 million over the next twelve month period, primarily as a result of the outcome of a pending tax ruling and competent authority proceedings. The Company continues to recognize interest and penalties related to unrecognized income tax benefits in income tax expense. The total amount of accrued interest related to unrecognized income tax benefits as of December 31, 2016 and December 26, 2015 was $ 1.7 million and $ 1.0 million , respectively. The total amount of accrued penalties related to unrecognized income tax benefits as of December 31, 2016 was $ 0.2 million . The Company conducts business in a number of tax jurisdictions. As a result, it is subject to tax audits on a regular basis including, but not limited to, such major jurisdictions as the U.S., the U.K., China, Japan, France, Germany, and Canada. With few exceptions, the Company is no longer subject to U.S. and international income tax examinations for years before 2013. The Company and certain of its subsidiaries have ongoing tax controversies in the U.S., Canada, Germany, and France. The Company does not anticipate resolution of these audits will have a material impact on its financial statements. During 2015, the Company applied with the Internal Revenue Service (IRS) and Canadian Revenue Authority (CRA) for relief pursuant to the competent authority procedure provided in the tax treaty between the U.S. and Canada for transfer pricing tax assessments related to the tax years 2008 through 2012. The Company believes that the controversy will likely be ultimately settled via the competent authority process and accordingly have recorded both a Canadian liability and a U.S. receivable. The actual amounts of the liability for Canadian taxes and the asset for the correlative relief in the U.S. could be different based upon the agreement reached between the IRS and the CRA. In accordance with the Company’s policy, the undistributed earnings of the Company’s non-U.S. subsidiaries remain indefinitely reinvested outside of the U.S. as of the end of 2016 as they are required to fund needs outside the U.S. and cannot be repatriated in a manner that is substantially tax free. As of December 31, 2016 , the earnings of non-U.S. subsidiaries considered to be indefinitely reinvested totaled $ 704.6 million . No provision for U.S. income taxes has been provided herein. Determination of the amount of unrecognized deferred income tax liabilities on these earnings is not practicable because of the complexities with the hypothetical calculation. Additionally, the amount of liability is dependent on circumstances existing if and when remittance occurs. On December 18, 2015, the U.S. enacted the Consolidated Appropriations Act, which provides for a reinstatement and extension of the controlled foreign corporation look-through rules. This rule allows the Company to access Chinese and Canadian cash in a more tax-efficient manner and utilize the cash outside of the U.S. without triggering residual U.S. tax. As such, in 2016 the Company accrued $4.5 million of foreign withholding taxes.

EMPLOYEE BENEFIT PLANS

EMPLOYEE BENEFIT PLANS	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
EMPLOYEE BENEFIT PLANS	EMPLOYEE BENEFIT PLANS Pension Plans The Charles River Laboratories, Inc. Pension Plan (CRL Pension Plan) is a qualified, non-contributory defined benefit plan covering certain U.S. employees. Effective 2002, the plan was amended to exclude new participants from joining and in 2008 the accrual of benefits was frozen. The Charles River Pension Plan is a defined contribution and defined benefit pension plan covering certain U.K. employees. Benefits are based on participants’ final pensionable salary and years of service. Participants’ rights vest immediately. Effective December 31, 2002, the plan was amended to exclude new participants from joining the defined benefit section of the plan and a defined contribution section was established for new entrants. Contributions under the defined contribution plan are determined as a percentage of gross salary. In the fourth quarter of 2015, the Charles River Pension Plan was amended such that the members of the defined benefit section of the plan ceased to accrue additional benefits; however, their benefits continue to be adjusted for changes in their final pensionable salary or a specified inflation index, as applicable. In addition, the Company has several defined benefit plans in certain other countries in which it maintains an operating presence, including Japan, Canada, France and the Netherlands. Charles River Laboratories Deferred Compensation Plan and Executive Supplemental Life Insurance Retirement Plan The Company maintains a non-qualified deferred compensation plan, known as the Charles River Laboratories Deferred Compensation Plan (DCP), which allows a select group of eligible employees to defer a portion of their compensation. At the present time, no contributions are credited to the DCP, except as set forth below. Participants must specify the distribution date for deferred amounts at the time of deferral, in accordance with applicable IRS regulations. Generally, amounts may be paid in lump sum or installments upon retirement or termination of employment, or later if the employee terminates employment after age 55 and before age 65. Amounts may also be distributed during employment, subject to a minimum deferral requirement of three years. The Company provides certain active employees an annual contribution into their DCP account of 10% of the employee’s base salary plus the lesser of their target annual bonus or actual annual bonus. In addition to the DCP, certain officers and key employees also participate, or in the past participated, in the Company’s Executive Supplemental Life Insurance Retirement Plan (ESLIRP), which is a non-funded, non-qualified arrangement. Annual benefits under this plan will equal a percentage of the highest five consecutive years of compensation, offset by amounts payable under the CRL Pension Plan and Social Security. In connection with the establishment of the DCP, certain active ESLIRP participants, who agreed to convert their accrued ESLIRP benefit to a comparable deferred compensation benefit, discontinued their direct participation in the ESLIRP. Instead, the present values of the accrued benefits of ESLIRP participants were credited to their DCP accounts, and future accruals are converted to present values and credited to their DCP accounts annually. The costs associated with these plans, including the ESLIRP, for fiscal years 2016 , 2015 and 2014 totaled $2.2 million , $ 2.6 million and $3.3 million , respectively. The Company has invested in several corporate-owned key-person life insurance policies with the intention of using these investments to fund the ESLIRP and the DCP. Participants have no interest in any such investments. As of December 31, 2016 and December 26, 2015 , the cash surrender value of these life insurance policies were $29.5 million and $27.6 million , respectively. The following table provides a reconciliation of benefit obligations and plan assets of the Company’s pension, DCP and ESLIRP plans: December 31, 2016 December 26, 2015 (in thousands) Change in projected benefit obligations: Benefit obligation at beginning of year $ 345,220 $ 359,130 Service cost 2,453 4,293 Interest cost 12,046 12,974 Benefit payments (13,383 ) (8,191 ) Curtailment (279 ) — Settlements (5,499 ) — Plan amendments 188 — Transfer in from acquisition 5,271 — Actuarial loss (gain) 71,006 (10,362 ) Administrative expenses paid (605 ) (411 ) Effect of foreign exchange (36,476 ) (12,213 ) Benefit obligation at end of year $ 379,942 $ 345,220 Change in fair value of plan assets: Fair value of plan assets at beginning of year $ 275,480 $ 281,290 Actual return on plan assets 23,388 6,263 Employer contributions 10,551 6,762 Settlements (5,499 ) — Transfer in from acquisition 508 — Benefit payments (13,383 ) (8,191 ) Administrative expenses paid (605 ) (411 ) Effect of foreign exchange (33,537 ) (10,233 ) Fair value of plan assets at end of year $ 256,903 $ 275,480 Net balance sheet liability $ 123,039 $ 69,740 Amounts recognized in balance sheet: Noncurrent assets $ — $ 261 Current liabilities 1,120 6,133 Noncurrent liabilities 121,919 63,868 Amounts recognized in accumulated other comprehensive loss related to the Company’s pension, DCP and ESLIRP plans are as follows: Fiscal Year 2016 2015 (in thousands) Net actuarial loss $ 123,743 $ 73,412 Net prior service cost (credit) (3,300 ) (4,584 ) Net amount recognized $ 120,443 $ 68,828 The accumulated benefit obligation and fair value of plan assets for the Company’s pension, DCP and ESLIRP plans with accumulated benefit obligations in excess of plan assets are as follows: December 31, 2016 December 26, 2015 (in thousands) Accumulated benefit obligation $ 346,122 $ 306,433 Fair value of plan assets 242,172 253,225 The projected benefit obligation and fair value of plan assets for the Company’s pension, DCP and ESLIRP plans with projected benefit obligations in excess of plan assets are as follows: December 31, 2016 December 26, 2015 (in thousands) Projected benefit obligation $ 379,942 $ 336,155 Fair value of plan assets 256,903 266,154 The amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit cost over the next fiscal year are as follows: December 31, 2016 (in thousands) Amortization of net actuarial loss $ 3,867 Amortization of net prior service credit (475 ) Components of net periodic benefit cost for the Company’s pension, DCP and ESLIRP plans are as follows: Fiscal Year 2016 2015 2014 (in thousands) Service cost $ 2,453 $ 4,293 $ 4,155 Interest cost 12,046 12,974 13,831 Expected return on plan assets (14,164 ) (16,987 ) (17,444 ) Amortization of prior service cost (credit) (292 ) (581 ) 1,211 Amortization of net loss (gain) 2,003 3,198 23 Curtailment (279 ) — — Settlements 788 — — Net periodic cost (benefit) $ 2,555 $ 2,897 $ 1,776 Assumptions Weighted-average assumptions used to determine projected benefit obligations are as follows: December 31, 2016 December 26, 2015 Discount rate 3.01 % 3.89 % Rate of compensation increase 3.25 % 3.17 % Weighted-average assumptions used to determine net periodic benefit cost are as follows: December 31, 2016 December 26, 2015 December 27, 2014 Discount rate 3.89 % 3.75 % 4.44 % Expected long-term return on plan assets 5.83 % 6.24 % 6.41 % Rate of compensation increase 3.17 % 3.18 % 3.36 % A 0.5% decrease in the expected rate of return would increase annual pension expense by $1.3 million . Plan assets The Company invests its pension assets with the objective of achieving a total long-term rate of return sufficient to fund future pension obligations and to minimize future pension contributions. The Company is willing to tolerate a commensurate level of risk to achieve this objective. The Company controls its risk by maintaining a diversified portfolio of assets classes. Plan assets did not include any of the Company’s common stock as of December 31, 2016 or December 26, 2015 . The weighted-average target asset allocations are approximately 45.0% to equity securities, approximately 31.5% to fixed income securities and approximately 23.5% to other securities. The fair value of the Company’s pension plan assets by asset category are as follows: December 31, 2016 December 26, 2015 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (in thousands) Cash $ 108 $ — $ — $ 108 $ 92 $ — $ — $ 92 Equity securities (1) 63,348 6,252 — 69,600 65,890 5,941 — 71,831 Debt securities (2) 59,294 3,269 — 62,563 68,489 2,822 — 71,311 Mutual funds (3) 64,698 56,596 — 121,294 63,689 65,725 — 129,414 Other 1,318 586 1,434 3,338 1,021 49 1,762 2,832 Total $ 188,766 $ 66,703 $ 1,434 $ 256,903 $ 199,181 $ 74,537 $ 1,762 $ 275,480 (1) This category comprises equity securities held by non-U.S. pension plans valued at the quoted closing price, and translated into U.S. dollars using a foreign currency exchange rate at year end. (2) This category comprises debt securities held by non-U.S. pension plans valued at the quoted closing price, and translated into U.S. dollars using a foreign currency exchange rate at year end. (3) This category comprises mutual funds valued at the net asset value of shares held at year end. The activity within the Level 3 pension plan assets was non-significant during the periods presented. During fiscal year 2016 , the Company contributed $4.0 million to the pension plans and expects to contribute $4.0 million to its pension plans in fiscal year 2017 . Expected benefit payments are estimated using the same assumptions used in determining the Company’s benefit obligation as of December 31, 2016 . Benefit payments will depend on future employment and compensation levels, among other factors, and changes in any of these factors could significantly affect these estimated future benefit payments. Estimated future benefit payments during the next five years and in the aggregate for fiscal years thereafter, are as follows: Fiscal Year Pension Plans (in thousands) 2017 $ 8,610 2018 8,818 2019 9,682 2020 10,014 2021 30,717 Thereafter 57,705 Post-Retirement Health and Life Insurance Plans The Company’s Canadian location offers post-retirement life insurance benefits to its employees and post-retirement medical and dental insurance coverage to certain executives. The plan is non-contributory and unfunded. As of December 31, 2016 and December 26, 2015 , the accumulated benefit obligation related to the plan was $1.2 million and $0.9 million , respectively. The amounts included in other accumulated comprehensive income as well as expenses related to the plan were non-significant for fiscal years 2016 , 2015 , and 2014 . Charles River Laboratories Employee Savings Plan The Charles River Laboratories Employee Savings Plan is a defined contribution plan in the form of a qualified 401(k) plan in which substantially all U.S. employees are eligible to participate upon employment. The plan contains a provision whereby the Company matches a percentage of employee contributions. During fiscal years 2016 , 2015 and 2014 , the costs associated with this defined contribution plan totaled $6.2 million , $5.3 million and $4.9 million , respectively.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION The Company has stock-based compensation plans under which employees and non-employee directors may be granted stock-based awards such as stock options, restricted stock, restricted stock units and PSUs. During fiscal years 2016 , 2015 and 2014 , the primary share-based awards and their general terms and conditions are as follows: • Stock options, which entitle the holder to purchase a specified number of shares of common stock at an exercise price equal to the closing market price of common stock on the date of grant; typically vest over 4 years; and typically expire 5 to 7 years from date of grant. • Restricted stock units, which represent an unsecured promise to grant at no cost a set number of shares of common stock upon the completion of the vesting schedule, and typically vest over 2 to 4 years. With respect to restricted stock units, recipients are not entitled to cash dividends and have no voting rights on the stock during the vesting period. • Restricted stock, which is an award of common stock issued on the grant date and subject to vesting, typically over 2 to 4 years. Recipients cannot sell or transfer the shares until the restriction period has lapsed, but are entitled to forfeitable cash dividends and to vote their respective shares upon grant. • PSUs, which entitle the holder to receive at no cost, a specified number of shares of common stock within a range of shares from zero to a specified maximum and typically vest over 3 years. Payout of this award is contingent upon achievement of certain performance and market conditions. In May 2007, the Company’s shareholders approved the 2007 Incentive Plan, which was amended in 2009, 2011, 2013 and 2015 (2007 Plan). The 2007 Plan provided no further awards to be granted under preexisting stock option and incentive plans; provided, however, that any shares that have been forfeited or canceled in accordance with the terms of the applicable award under a preexisting plan may be subsequently awarded in accordance with the terms of the preexisting plan. The 2007 Plan allows a maximum of 18.7 million shares to be awarded, of which restricted stock grants, restricted stock units, and performance based stock awards count as 2.3 shares and stock options count as 1.0 shares. Any stock options and other share-based awards that were granted under prior plans and were outstanding in May 2007 continue in accordance with the terms of the respective plans. In May 2016, the Company’s shareholders approved the 2016 Incentive Plan (2016 Plan). The 2016 Plan provided no further awards to be granted under preexisting stock option and incentive plans; provided, however, that any shares that have been forfeited or canceled in accordance with the terms of the applicable award under a preexisting plan may be subsequently awarded in accordance with the terms of the preexisting plan. The 2016 Plan allows a maximum of 6.1 million shares to be awarded, of which restricted stock grants, restricted stock units and performance based stock awards count as 2.3 shares and stock options count as 1.0 shares. Any stock options and other share-based awards that were granted under prior plans and were outstanding in May 2016 continue in accordance with the terms of the respective plans. As of December 31, 2016 , approximately 7.3 million shares were authorized for future grants under the Company’s share-based compensation plans. The Company settles employee share-based compensation awards with newly issued shares. The following table provides the financial statement line items in which stock-based compensation is reflected: Fiscal Year 2016 2015 2014 (in thousands) Cost of revenue (excluding amortization of intangible assets) $ 6,508 $ 6,511 $ 5,382 Selling, general and administrative 37,134 33,611 25,653 Stock-based compensation expense, before income taxes 43,642 40,122 31,035 Provision for income taxes (15,548 ) (14,225 ) (11,006 ) Stock-based compensation, net of income taxes $ 28,094 $ 25,897 $ 20,029 During fiscal year 2015, the Company modified certain stock-based awards granted in previous years as part of executive retirement transitions. For the stock-based awards granted to employees during and subsequent to fiscal year 2015 , the Company introduced a new retirement provision, which allows for continued vesting of such awards after the employee’s retirement if certain eligibility conditions are met. The introduction of the new retirement provision and stock-based award modifications increased the Company’s stock-based compensation expense for 2015 by $4.5 million . The Company capitalized no stock-based compensation related costs for fiscal years 2016 , 2015 and 2014 . The Company’s pool of excess tax benefits, which is computed in accordance with the long form method, was $32.2 million as of December 31, 2016 , $22.3 million as of December 26, 2015 , and $10.8 million as of December 27, 2014 . During fiscal year 2016 , the Company recorded a tax benefit of $9.3 million to additional paid-in capital related to the exercise of stock options and vesting of restricted shares and restricted stock units, compared to a tax benefit of $10.6 million in fiscal year 2015 . Stock Options The following table summarizes stock option activities under the Company’s stock-based compensation plans: Number of shares Weighted Average Weighted Average Aggregate (in thousands, except per share amounts) Options outstanding as of December 26, 2015 2,066 $ 50.62 Options granted 588 $ 74.13 Options exercised (601 ) $ 38.52 Options canceled (83 ) $ 62.66 Options outstanding as of December 31, 2016 1,970 $ 60.82 3.4 $ 30,638 Options exercisable as of December 31, 2016 746 $ 48.34 2.6 $ 20,817 Options expected to vest as of December 31, 2016 1,202 $ 68.40 3.8 $ 9,690 The fair value of stock options granted was estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions: Fiscal Year 2016 2015 2014 Expected life (in years) 3.6 3.6 4.2 Expected volatility 25 % 28 % 30 % Risk-free interest rate 1.2 % 1.1 % 1.5 % Expected dividend yield 0 % 0 % 0 % The weighted-average grant date fair value of stock options granted was $15.12 , $17.24 and $15.19 for fiscal years 2016 , 2015 and 2014 , respectively. As of December 31, 2016 , the unrecognized compensation cost related to unvested stock options expected to vest was $10.8 million . This unrecognized compensation will be recognized over an estimated weighted-average amortization period of 2.2 years . The total intrinsic value of options exercised during fiscal years 2016 , 2015 and 2014 was $23.0 million , $28.3 million and $30.5 million , respectively, with intrinsic value defined as the difference between the market price on the date of exercise and the exercise price. Restricted Stock and Restricted Stock Units The following table summarizes the restricted stock and restricted stock units activity for fiscal year 2016 : Restricted Stock and Restricted Stock Units Weighted (in thousands) December 26, 2015 607 $ 55.52 Granted 236 $ 75.10 Vested (296 ) $ 49.29 Canceled (32 ) $ 63.36 December 31, 2016 515 $ 67.62 As of December 31, 2016 , the unrecognized compensation cost related to shares of unvested restricted stock and restricted stock units expected to vest was $19.2 million , which is expected to be recognized over an estimated weighted-average amortization period of 1.2 years . The total fair value of restricted stock and restricted stock unit grants that vested during fiscal years 2016 , 2015 and 2014 was $14.6 million , $15.7 million and $13.9 million , respectively. Performance Based Stock Award Program The Company issues PSUs to certain corporate officers. The number of shares of common stock issued for each PSU is adjusted based on a performance condition linked to the Company’s financial performance. Certain awards are further adjusted based on a market condition, which is calculated based on the Company’s stock performance relative to a peer group over the three-year vesting period. The fair value of the market condition is reflected in the fair value of the award at grant date. The Company utilizes a Monte Carlo simulation valuation model to value these awards. Information pertaining to the Company’s PSUs and the related estimated weighted-average assumptions used to calculate their fair value were as follows: Fiscal Year 2016 2015 2014 PSUs granted 190,628 148,900 214,823 Weighted average per share fair value $ 80.38 $ 88.62 $ 67.82 Key Assumptions: Expected volatility 24 % 23 % 29 % Risk-free interest rate 0.91 % 0.96 % 0.63 % Expected dividend yield — % — % — % 20 trading day average stock price on grant date (4.8 )% 20.6 % 13.1 % The maximum amount of common shares to be issued upon vesting of PSUs is approximately 0.3 million . For fiscal years 2016 , 2015 and 2014 , the Company recognized stock-based compensation related to PSUs of $19.7 million , $14.7 million and $8.5 million , respectively. The total fair value of PSUs that vested during fiscal years 2016 and 2015 was $ 18.0 million and $ 6.6 million , respectively. In fiscal year 2016 , the Company also issued approximately 18,000 PSUs using a weighted average fair value per share of $73.70 . These PSUs vest upon the achievement of financial targets and other performance measures.

FOREIGN CURRENCY CONTRACTS

FOREIGN CURRENCY CONTRACTS	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
FOREIGN CURRENCY CONTRACTS	FOREIGN CURRENCY CONTRACTS The Company enters into foreign exchange forward contracts to limit its foreign currency exposure related to intercompany loans that are not of a long-term investment nature. These contracts are recorded at fair value in the Company’s consolidated balance sheet and are not designated as hedging instruments. Any gains or losses on such contracts are immediately recognized in other income (expense), net, and are largely offset by the remeasurement of the underlying intercompany loan balances. The Company did not have any foreign currency contracts open as of December 31, 2016 . The notional amount and fair value of the Company’s foreign currency forward contracts as of December 26, 2015 were as follows: Notional Amount Fair Value Balance Sheet Location (in thousands) $ 88,483 $ 15 Other current assets The following table summarizes gains (losses) recognized on foreign exchange forward contracts related to intercompany loans denominated in British Pounds and Euros on the Company’s consolidated statement of income: Fiscal Year Location of Gain (Loss) 2016 2015 (in thousands) Other income (expense), net $ 3,373 $ (4,917 ) The forward contracts outstanding as of December 26, 2015 had durations of approximately 3 months.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Operating Leases The Company rents laboratory and office space, land, vehicles and certain equipment under non-cancellable operating leases. These lease agreements contain various clauses for renewal at the Company’s option and, in certain cases, rent escalation clauses. Rental expense under these leases amounted to $21.8 million , $23.4 million and $14.2 million in fiscal years 2016 , 2015 and 2014 , respectively. In addition to rent, the leases may require the Company to pay additional amounts for taxes, insurance, maintenance and other operating expenses. As of December 31, 2016 , minimum rental commitments under non-cancellable leases, net of income from subleases, for each of the next five years and total thereafter were as follows: Minimum Lease Payments (in thousands) 2017 $ 23,410 2018 20,273 2019 17,119 2020 13,254 2021 8,104 Thereafter 19,116 Total $ 101,276 Insurance The Company maintains certain insurance policies that maintain large deductibles up to approximately $5.0 million , some with or without stop-loss limits, depending on market availability. Insurance policies at certain locations are based on a percentage of the insured assets, for which deductibles for certain property may exceed $5.0 million in the event of a catastrophic event. Litigation Various lawsuits, claims and proceedings of a nature considered normal to its business are pending against the Company. While the outcome of any of these proceedings cannot be accurately predicted, the Company does not believe the ultimate resolution of any of these existing matters would have a material adverse effect on the Company’s business or financial condition. In July 2015, IDEXX Laboratories, Inc. and IDEXX Distribution, Inc. (collectively, IDEXX) filed a complaint in the United States District Court for the District of Delaware alleging the Company has infringed three recently issued patents related to a blood spot sample collection method used in determining the presence or absence of an infectious disease in a population of rodents. On September 21, 2015, the Company timely filed a motion to dismiss the complaint on the grounds that all of the claims are directed to unpatentable subject matter and therefore are invalid. On October 7, 2015, IDEXX filed an amended complaint, which substantially asserted the same patents and infringement allegations as asserted in the original complaint, and on October 26, 2015, the Company timely filed a motion to dismiss this amended complaint. The hearing on the motion to dismiss was held on January 12, 2016. On July 1, 2016, the Court issued an opinion denying the motion to dismiss. The Company filed its answer to the complaint on July 21, 2016. In addition, on July 29, 2016, the Company initiated an inter partes review (IPR) procedure with the United States Patent and Trademark Office challenging the validity of the IDEXX patents. On February 6, 2017, we entered into a settlement agreement with IDEXX, which involved the withdrawal by IDEXX of their complaint and withdrawal by us of the IPR. In May 2013, the Company commenced an investigation into inaccurate billing with respect to certain government contracts. The Company promptly reported these matters to the relevant government contracting officers, the Department of Health and Human Services’ Office of the Inspector General, and the Department of Justice, and the Company is cooperating with these agencies to ensure the proper repayment and resolution of this matter. The Company previously identified approximately $ 1.5 million of excess amounts billed on these contracts since January 1, 2007, and recorded a liability for such amount. Based on its ongoing discussions with the government, the Company has recorded an additional charge of $ 0.3 million during the fiscal year 2016. The Company’s best estimate, which totals $ 1.8 million , may be subject to change based on the terms of any final settlement with the Department of Justice and the Department of Health and Human Services’ Office of the Inspector General. Guarantees The Company enters into certain agreements with other parties in the ordinary course of business that contain indemnification provisions. These typically include agreements with directors and officers, business partners, contractors, landlords, and customers. Under these provisions, the Company generally indemnifies and holds harmless the indemnified party for losses suffered or incurred by the indemnified party as a result of the Company’s activities. These indemnification provisions generally survive termination of the underlying agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification provisions is unlimited. However, to date the Company has not incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. As a result, the estimated fair value of these obligations is minimal. Purchase Obligations The Company enters into unconditional purchase obligations, in the ordinary course of business, that include agreements to purchase goods or services that are enforceable and legally binding and that specify all significant terms including: fixed or minimum quantities to be purchased; fixed, minimum or variable price provisions; and the approximate timing of the transaction. Purchase obligations exclude agreements that are cancellable at any time without penalty. The aggregate amount of the Company’s unconditional purchase obligations totaled $86.2 million as of December 31, 2016.

RESTRUCTURING AND ASSET IMPAIRM

RESTRUCTURING AND ASSET IMPAIRMENTS	12 Months Ended
	Dec. 31, 2016
Restructuring and Related Activities [Abstract]
RESTRUCTURING AND ASSET IMPAIRMENTS	RESTRUCTURING AND ASSET IMPAIRMENTS Workforce Reductions The Company periodically implements workforce reductions to improve operating efficiency at various sites. The following table provides a rollforward of the Company’s severance and retention costs liability: December 31, 2016 December 26, 2015 December 27, 2014 (in thousands) Balance, beginning of period $ 2,969 $ 2,666 $ 2,782 Expense 8,454 6,173 7,792 Payments / utilization (7,473 ) (5,820 ) (7,900 ) Foreign currency adjustments (270 ) (50 ) (8 ) Balance, end of period $ 3,680 $ 2,969 $ 2,666 As of December 31, 2016 and December 26, 2015 , $3.6 million and $2.6 million of severance and retention costs liability, respectively, was included in accrued compensation and $0.1 million and $0.3 million , respectively, was included in other long-term liabilities on the Company's consolidated balance sheets. The following table presents severance and retention costs by classification on the consolidated statements of income: Fiscal Year 2016 2015 2014 (in thousands) Cost of services provided and products sold (excluding amortization of intangible assets) $ 4,717 $ 735 $ 3,342 Selling, general and administrative 3,737 5,438 4,450 Total severance and retention costs $ 8,454 $ 6,173 $ 7,792 The following presents severance and retention costs by reportable segment: Fiscal Year 2016 2015 2014 (in thousands) RMS $ 759 $ 1,338 $ 4,593 DSA 7,689 1,068 2,912 Manufacturing 6 1,639 166 Unallocated corporate — 2,128 121 Total severance and retention costs $ 8,454 $ 6,173 $ 7,792 Facilities In fiscal year 2016 , the Company commenced a consolidation of small DSA facilities in the U.S., Ireland, and the United Kingdom. As a result, an asset impairment charge of $9.4 million was recorded related to the consolidation plans. In fiscal year 2015 , the Company commenced a consolidation of certain RMS facilities in the U.S., Europe, and Japan. As a result, an asset impairment charge of $1.8 million was recorded related to the consolidation plans. In fiscal year 2014 , the Company committed to plans to consolidate certain research model operations in the U.S., Japan, and Europe. As a result, the Company recorded $2.2 million of asset impairments and other charges and $4.3 million of accelerated depreciation related to certain facilities impacted by the consolidation plans. Also, in fiscal year 2014, the Company recorded a gain of $1.0 million on the sale of a European facility.

SEGMENT AND GEOGRAPHIC INFORMAT

SEGMENT AND GEOGRAPHIC INFORMATION	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
SEGMENT AND GEOGRAPHIC INFORMATION	SEGMENT AND GEOGRAPHIC INFORMATION The Company revised its reportable segments during fiscal year 2016 to align with its view of the business following its acquisition of WIL Research. See Note 1, “Description of Business and Summary of Significant Accounting Policies.” The Company reported segment results on this basis retrospectively for all comparable prior periods. Asset information on a reportable segment basis is not disclosed as this information is not separately identified and internally reported to the Company’s Chief Operating Decision Maker. The following table presents revenue and other financial information by reportable segment: Fiscal Year 2016 2015 2014 (in thousands) RMS Revenue $ 494,037 $ 470,411 $ 503,656 Operating income 136,365 120,973 120,736 Depreciation and amortization 20,853 22,526 27,309 Capital expenditures 11,642 17,398 18,669 DSA Revenue $ 836,593 $ 612,173 $ 538,218 Operating income 138,157 121,981 69,749 Depreciation and amortization 71,816 46,812 47,138 Capital expenditures 27,493 30,333 19,759 Manufacturing Revenue $ 350,802 $ 280,718 $ 255,788 Operating income 104,543 74,675 79,260 Depreciation and amortization 25,566 18,129 14,295 Capital expenditures 12,247 9,814 15,621 For fiscal years ended 2016 , 2015 and 2014 , reconciliations of segment operating income and capital expenditures to the respective consolidated amounts are as follows: Operating Income Capital Expenditures Fiscal Year Fiscal Year 2016 2015 2014 2016 2015 2014 (in thousands) Total reportable segments $ 379,065 $ 317,629 $ 269,745 $ 51,382 $ 57,545 $ 54,049 Unallocated corporate (141,646 ) (111,180 ) (92,075 ) 3,906 5,707 2,876 Total consolidated $ 237,419 $ 206,449 $ 177,670 $ 55,288 $ 63,252 $ 56,925 Revenue for each significant product or service offering is as follows : Fiscal Year 2016 2015 2014 (in thousands) RMS $ 494,037 $ 470,411 $ 503,656 DSA 836,593 612,173 538,218 Manufacturing 350,802 280,718 255,788 Total revenue $ 1,681,432 $ 1,363,302 $ 1,297,662 A summary of unallocated corporate overhead consists of the following : Fiscal Year 2016 2015 2014 (in thousands) Stock-based compensation expense $ 27,272 $ 25,751 $ 18,474 Salary, bonus, and fringe 39,189 33,026 30,838 Consulting, audit, and professional services 23,421 15,418 13,431 IT related expenses 13,233 8,400 6,528 Depreciation expense 8,423 7,414 7,703 Acquisition related adjustments 15,608 11,644 6,285 Other general unallocated corporate expenses 14,500 9,527 8,816 Total unallocated corporate overhead costs $ 141,646 $ 111,180 $ 92,075 Other general unallocated corporate expenses consist of various departmental costs including those associated with departments such as senior executives, corporate accounting, legal, tax, human resources, treasury, and investor relations. Revenue and long-lived assets by geographic area are as follows: U.S. Europe Canada Japan Other Non-U.S. Consolidated (in thousands) 2016 Revenue $ 850,422 $ 520,937 $ 194,210 $ 46,829 $ 69,034 $ 1,681,432 Long-lived assets 462,330 177,423 78,866 20,941 16,267 755,827 2015 Revenue $ 659,466 $ 435,491 $ 172,349 $ 40,520 $ 55,476 $ 1,363,302 Long-lived assets 402,238 159,445 77,535 22,348 16,393 677,959 2014 Revenue $ 588,531 $ 446,263 $ 163,490 $ 49,921 $ 49,457 $ 1,297,662 Long-lived assets 386,624 153,203 95,272 23,896 17,802 676,797 Included in the other non-U.S. category above are operations located in China, Korea, Australia, Singapore, and India. Revenues represent sales originating in entities physically located in the identified geographic area. Long-lived assets include property, plant, and equipment and other long-lived assets.

SELECTED QUARTERLY FINANCIAL DA

SELECTED QUARTERLY FINANCIAL DATA (unaudited)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
SELECTED QUARTERLY FINANCIAL DATA (unaudited)	SELECTED QUARTERLY FINANCIAL DATA (unaudited) The following table contains quarterly financial information for fiscal years 2016 and 2015 . The operating results for any quarter are not necessarily indicative of future period results. First Quarter Second Quarter Third Quarter Fourth Quarter Fiscal Year 2016 (in thousands, except per share amounts) Total revenue $ 354,868 $ 434,055 $ 425,720 $ 466,789 Gross profit (1) 140,768 169,747 156,270 179,881 Operating income 51,472 58,061 58,795 69,091 Net income attributable to common shareholders 37,143 35,207 37,735 44,680 Earnings (loss) per common share Basic: Continuing operations attributable to common shareholders $ 0.80 $ 0.75 $ 0.79 $ 0.95 Discontinued operations $ — $ — $ 0.01 $ — Net income attributable to common shareholders $ 0.80 $ 0.75 $ 0.80 $ 0.95 Diluted: Continuing operations attributable to common shareholders $ 0.78 $ 0.73 $ 0.78 $ 0.93 Discontinued operations $ — $ — $ 0.01 $ — Net income attributable to common shareholders $ 0.78 $ 0.73 $ 0.79 $ 0.93 Fiscal Year 2015 Total revenue $ 320,414 $ 339,573 $ 349,465 $ 353,850 Gross profit (1) 119,660 132,783 138,075 140,574 Operating income 43,005 55,735 55,440 52,269 Net income attributable to common shareholders 31,541 48,509 37,379 31,884 Earnings (loss) per common share Basic: Continuing operations attributable to common shareholders $ 0.67 $ 1.04 $ 0.81 $ 0.71 Discontinued operations $ — $ — $ — $ (0.02 ) Net income attributable to common shareholders $ 0.67 $ 1.04 $ 0.81 $ 0.69 Diluted: Continuing operations attributable to common shareholders $ 0.66 $ 1.02 $ 0.79 $ 0.69 Discontinued operations $ — $ — $ — $ (0.02 ) Net income attributable to common shareholders $ 0.66 $ 1.02 $ 0.79 $ 0.67 (1) Gross profit is calculated as total revenues minus cost of revenue (excluding amortization of intangible assets). Full-year amounts may not sum due to rounding.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS On February 10, 2017 , the Company completed the divestiture of its CDMO business to Quotient Clinical Ltd., based in London, England, for $75.0 million in cash, subject to certain post-closing adjustments. The CDMO business, which represented approximately 1% of the Company’s 2016 consolidated revenue, was acquired in April 2016 as part of the acquisition of WIL Research. See Note 1, “Description of Business and Summary of Significant Accounting Policies” and Note 2, “Business Acquisitions.” Following a strategic review, the Company determined that the CDMO business was not optimized within the Company’s portfolio at its current scale, and that the capital could be better deployed in other long-term growth opportunities. The Company is in the process of evaluating the transaction and its impact on the financial statements, including evaluating the resulting gain (loss) that will be recognized. As of December 31, 2016 , the carrying amounts of the major classes of assets and liabilities associated with the CDMO business were as follows: December 31, 2016 (in thousands) Assets Current assets $ 4,270 Property, plant and equipment, net 11,313 Goodwill 35,857 Long-term assets 17,332 Total assets $ 68,772 Liabilities Current liabilities $ 5,840 Long-term liabilities 7,856 Total liabilities $ 13,696 As of December 31, 2016 , the assets and liabilities of the CDMO business were not classified as held-for-sale as management had not committed to a formal plan to sell the business and the sale was not deemed probable .

DESCRIPTION OF BUSINESS AND S25

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principles of Consolidation	Principles of Consolidation The Company’s consolidated financial statements reflect its financial statements and those of its subsidiaries in which the Company holds a controlling financial interest. For consolidated entities in which the Company owns or is exposed to less than 100% of the economics, the Company records net income (loss) attributable to noncontrolling interests in its consolidated statements of income equal to the percentage of the economic or ownership interest retained in such entities by the respective noncontrolling parties. Intercompany balances and transactions are eliminated in consolidation. The Company’s fiscal year is typically based on 52-week s , with each quarter comp osed of 13 weeks ending on the last Saturday on, or closest to, March 31, June 30, September 30, and December 31. A 53 rd week was included in fiscal year 2016, which is occasionally necessary to align with a December 31 calendar year-end. The additional week was included in the fourth quarter.
Reclassifications	Reclassifications Certain reclassifications have been made to prior year statements to conform to the current year presentation. These reclassifications have no impact on period reported net income or cash flow.
Segment Reporting	Segment Reporting The Company reports its results in three reportable segments: Research Models and Services (RMS), Discovery and Safety Assessment (DSA), and Manufacturing Support (Manufacturing). The Company aggregates its operating segments into a reportable segment if (a) they have similar economic characteristics; (b) they are similar in the in the nature of the products or services, nature of the production process, type or class of customer for their products and services, methods used to distribute their products and services and nature of the regulatory environment; and (c) the aggregation helps users better understand the Company’s performance. During the second quarter of 2016 , the Company acquired WRH, Inc. (WIL Research), a provider of safety assessment and contract development and manufacturing (CDMO) services. WIL Research’s safety assessment business is reported in the Company’s DSA reportable segment and its CDMO business created a new operating segment, Contract Manufacturing, that is reported as part of the Company’s Manufacturing reportable segment. On February 10, 2017 , the Company divested the CDMO business. In addition, amounts due to changes in the Company’s market strategy for certain services and resulting information provided to the Chief Operating Decision Maker were reclassified from the Company’s RMS reportable segment to its Manufacturing reportable segment, including revenue of $2.8 million and $3.7 million for fiscal years 2015 and 2014 , respectively, and operating income of $0.5 million and $0.6 million for fiscal years 2015 and 2014 , respectively. The Company reported segment results on this basis for all periods presented. The revised reportable segments are as follows: Research Models and Services Discovery and Safety Assessment Manufacturing Support Research Models Discovery Services Microbial Solutions Research Model Services Safety Assessment Avian Biologics Contract Manufacturing
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in accordance with generally accepted accounting principles in the United States (U.S. GAAP) requires that the Company makes estimates and judgments that may affect the reported amounts of assets, liabilities, revenues, expenses, and related disclosure of contingent assets and liabilities. On an on-going basis, the Company evaluates its estimates, judgments and methodologies. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates under different assumptions or conditions. Changes in estimates are reflected in reported results in the period in which they become known.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents include money market funds, time deposits and other investments with remaining maturities at the purchase date of three months or less.
Investments	Investments Marketable securities are reported at fair value. Realized gains and losses on marketable securities are included in other income (expense), net and are determined using the specific identification method. Unrealized gains and losses on available-for-sale marketable securities are included in accumulated other comprehensive income (loss). Time deposits with original maturities of greater than three months are reported as investments.
Trade Receivables, Net	Trade Receivables, Net The Company records trade receivables net of an allowance for doubtful accounts. An allowance for doubtful accounts is established based on historical collection information, a review of major client accounts receivable balances and current economic conditions in the geographies in which it operates. Amounts determined to be uncollectible are charged or written off against the allowance.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, investments and trade receivables. The Company places cash and cash equivalents and investments in various financial institutions with high credit rating and limits the amount of credit exposure to any one financial institution. Trade receivables are primarily from clients in the pharmaceutical and biotechnology industries, as well as academic and government institutions. Concentrations of credit risk with respect to trade receivables, which are typically unsecured, are limited due to the wide variety of customers using the Company’s products and services as well as their dispersion across many geographic areas. No single client accounted for more than 5% of revenue or trade receivables for the periods ended December 31, 2016 and December 26, 2015 .
Fair Value Measurements	Fair Value Measurements The accounting standard for fair value measurements defines fair value, establishes a framework for measuring fair value in accordance with U.S. GAAP, and requires certain disclosures about fair value measurements. Under this standard, fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy: • Level 1 - Fair values are determined utilizing prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access; • Level 2 - Fair values are determined by utilizing quoted prices for identical or similar assets and liabilities in active markets or other market observable inputs such as interest rates, yield curves and foreign currency spot rates; • Level 3 - Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable. The fair value hierarchy level is determined by asset, liability and redeemable noncontrolling interest class based on the lowest level of significant input. The observability of inputs may change for certain assets or liabilities. This condition could cause an asset or liability to be reclassified between levels. The Company recognizes transfers between levels within the fair value hierarchy, if any, at the end of each quarter. Valuation methodologies used for assets and liabilities measured or disclosed at fair value are as follows: • Cash equivalents - Valued at market prices determined through third-party pricing services; • Mutual funds - Valued at the unadjusted quoted net asset value of shares held by the Company; • Foreign currency forward contracts - Valued using readily observable market inputs, such as forward foreign exchange points and foreign exchanges rates; • Life insurance policies - Valued at cash surrender value based on the fair value of underlying investments; • Contingent consideration - Valued based on a probability weighting of the future cash flows associated with the potential outcomes; • Redeemable noncontrolling interest - Valued using the income approach based on estimated future cash flows of the underlying business discounted by a weighted average cost of capital.
Inventories	Inventories Inventories are stated at the lower of cost or net realizable value. Cost is determined on the average cost method for the small model business and first-in-first-out for the Company’s large model and Microbial Solutions businesses. For the small model business, cost includes direct materials such as feed and bedding, costs of personnel directly involved in the care of the models, and an allocation of facility overhead. For the large model business, cost is primarily the external cost paid to acquire the model. Certain businesses value inventory based on standard costs, which are periodically compared to and adjusted to actual costs. Inventory costs are charged to cost of revenue in the period the products are sold to an external party. The Company analyzes its inventory levels on a quarterly basis and writes down inventory that is determined to be damaged, obsolete or otherwise unmarketable, with a corresponding charge to cost of products sold.
Property, Plant and Equipment, Net	Property, Plant and Equipment, Net Property, plant and equipment, including improvements that significantly add to productive capacity or extend useful life, are carried at cost and are subject to review for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. The cost of normal, recurring, or periodic repairs and maintenance activities related to property, plant and equipment is expensed as incurred. In addition, the Company capitalizes certain internal use computer software development costs. Costs incurred during the preliminary project stage are expensed as incurred, while costs incurred during the application development stage are capitalized and amortized over the estimated useful life of the software. The Company also capitalizes costs related to specific upgrades and enhancements when it is probable the expenditures will result in additional functionality. Maintenance and training costs related to software obtained for internal use are expensed as incurred. Interest costs incurred during the construction of major capital projects are capitalized until the underlying asset is ready for its intended use, at which point the interest costs are amortized as depreciation expense over the life of the underlying asset. The Company generally depreciates the cost of its property, plant and equipment using the straight-line method over the estimated useful lives of the respective assets as follow: Estimated (in years) Land Indefinite Buildings 20 - 40 Machinery and equipment 3 - 20 Furniture and fixtures 5 - 10 Computer hardware and software 3 - 8 Vehicles 3 - 5 Leasehold improvements are amortized over the shorter of the estimated useful life of the asset or the lease term. Capital lease assets are amortized over the lease term, however, if ownership is transferred by the end of the capital lease, or there is a bargain purchase option, such capital lease assets are amortized over the useful life that would be assigned if such assets were owned. When the Company disposes of property, plant and equipment, it removes the associated cost and accumulated depreciation from the related accounts on its consolidated balance sheet and includes any resulting gain or loss in its consolidated statement of income.
Business Acquisitions	Business Acquisitions The Company accounts for acquisitions as business combinations under the acquisition method of accounting. The Company allocates the amounts that it pays for each acquisition to the assets it acquires and liabilities it assumes based on their fair values at the dates of acquisition, including identifiable intangible assets. The Company bases the fair value of identifiable intangible assets acquired in a business combination on valuations that use information and assumptions determined by management and which consider management’s best estimates of inputs and assumptions that a market participant would use. Contingent Consideration The consideration for the Company’s acquisitions often includes future payments that are contingent upon the occurrence of a particular event. The Company records an obligation for such contingent payments at fair value on the acquisition date. The Company estimates the fair value of contingent consideration obligations through valuation models that incorporate probability adjusted assumptions related to the achievement of the milestones and thus likelihood of making related payments. The Company revalues these contingent consideration obligations each reporting period. Changes in the fair value of the contingent consideration obligations are recognized in the Company’s consolidated statements of income as a component of selling, general and administrative expenses. Changes in the fair value of the contingent consideration obligations can result from changes to one or multiple inputs, including adjustments to the discount rates and changes in the assumed probabilities of successful achievement of certain financial targets. Discount rates in the Company’s valuation models represent a measure of the credit risk associated with settling the liability. The period over which the Company discounts its contingent obligations is typically based on when the contingent payments would be triggered. These fair value measurements are based on significant inputs not observable in the market. See Note 5, “Fair Value.”
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill represents the difference between the purchase price and the fair value of the identifiable tangible and intangible net assets when accounted for using the purchase method of accounting. Goodwill is not amortized, but reviewed for impairment on an annual basis, during the fourth quarter, or more frequently if an event occurs or circumstances change that would more-likely-than-not reduce the fair value of the Company's reporting units below their carrying amounts. The Company has the option to first assess qualitative factors to determine whether it is necessary to perform the two-step impairment test. If the Company elects this option and believes, as a result of the qualitative assessment, that it is more-likely-than-not that the carrying value of goodwill is not recoverable, the quantitative two-step impairment test is required; otherwise, no further testing is required. Alternatively, the Company may elect to not first assess qualitative factors and immediately perform the quantitative two-step impairment test. In the first step, the Company compares the fair value of its reporting units to their carrying values. If the carrying values of the net assets assigned to the reporting units exceed the fair values of the reporting units, then the second step of the impairment test is performed in order to determine the implied fair value of the Company’s goodwill. If the carrying value of the reporting unit’s goodwill exceeds its implied fair value, then the Company would record an impairment loss equal to the difference. Definite-lived intangible assets, including client relationships, are amortized over the pattern in which the economic benefits of the intangible assets are utilized and reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets or asset group may not be recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset, which requires the use of customer attribution rates and other assumptions. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the definite-lived intangible assets, the definite-lived intangible assets are written-down to their fair values.
Valuation and Impairment of Long-Lived Assets	Valuation and Impairment of Long-Lived Assets Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets or asset group may not be recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written-down to their fair values. Long-lived assets to be disposed of are carried at fair value less costs to sell.
Venture Capital Investments	Venture Capital Investments The Company invests in several venture capital funds that invest in start-up companies primarily in the life sciences industry. The Company’s ownership interest in these funds ranges from 0.7% to 12.0% . The Company accounts for such investments in limited liability partnerships (LLP), which are variable interest entities, under the equity or cost method of accounting. The Company is not the primary beneficiary because it has no power to direct the activities that most significantly affect the LLPs’ economic performance. The Company accounts for the investments in limited liability companies, which are not variable interest entities, under the equity method of accounting. Under the equity method of accounting, the Company’s portion of the investment gains and losses, as reported in the fund’s financial statements on a quarterly lag each reporting period, is recorded in other income (expense), net. In addition, the Company adjusts the carrying value of these investments to reflect its estimate of changes to fair value since the fund’s financial statements based on information from the fund’s management team, market prices of known public holdings of the fund and other information. Under the cost method of accounting, the Company’s investment is initially measured at cost, with distributions recognized in other income (expense), net. Distributions received in excess of earnings subsequent to the date of investment are considered a return of investment and are recorded as reductions of cost of the investment. The Company reviews its cost method investments to determine whether a decline in fair value below the cost basis is other-than-temporary. If the decline in fair value is determined to be other-than-temporary, the cost basis of the investment is written down to fair value.
Life Insurance Contracts	Life Insurance Contracts Investments in life insurance contracts are recorded at cash surrender value. The initial investment at the transaction price is recognized and remeasured based on fair value of underlying investments or contractual value each reporting period. Investments in and redemptions of these life insurance contracts are reported as cash flows from investing activities in the consolidated statement of cash flows.
Stock-Based Compensation	Stock-Based Compensation The Company grants stock options, restricted stock, restricted stock units, and performance share units (PSUs) to employees and stock options, restricted stock, and restricted stock units to non-employee directors under stock-based compensation plans. Stock-based compensation is recognized as an expense in the consolidated financial statements based on the grant date fair value, adjusted for estimated forfeitures, over the requisite service period. For stock options, restricted stock and restricted stock units that vest based on service conditions, the Company uses the straight-line method to allocate compensation expense to reporting periods. Where awards are made with non-substantive vesting periods, where a portion of the award continues to vests after the employee’s retirement, the Company recognizes expense based on the period from the grant date to the date on which the employee is retirement eligible. The Company records the expense for PSU grants subject to performance and/or market conditions using the accelerated attribution method over the remaining service period when management determines that achievement of the performance-based milestone is probable. The fair value of stock options granted is calculated using the Black-Scholes option-pricing model and the fair value of PSUs is estimated using a lattice model with a Monte Carlo simulation, both of which require the use of subjective assumptions including volatility and expected term, among others. The expected volatility assumption is typically determined using the historical volatility of the Company’s common stock over the expected life of the stock-based award. The expected term is determined using historical option exercise activity. The fair value of restricted stock and restricted stock units is based on the market value of the Company’s common stock on the date of grant.
Revenue Recognition	Revenue Recognition The Company recognizes revenue when all of the following conditions are satisfied: persuasive evidence of an arrangement exists, delivery has occurred or services have been provided, the price to the customer is fixed or determinable, and collectibility is reasonably assured. Service revenue is generally evidenced by client contracts, which range in duration from a few weeks to a few years and typically take the form of an agreed upon rate per unit or fixed fee arrangements. Such contracts typically do not contain acceptance provisions based upon the achievement of certain study or laboratory testing results. Revenue of agreed upon rate per unit contracts is recognized as services are performed, based upon rates specified in the contract. In cases where performance spans reporting periods, revenue of fixed fee contracts is recognized as services are performed, measured on the ratio of outputs or performance obligations completed to the total contractual outputs or performance obligations to be provided. Changes in estimated effort to complete the fixed fee contract are reflected in the period in which the change becomes known. Changes in scope of work are common, especially under long-term contracts, and generally result in a change in contract value. Once the client has agreed to the changes in scope and renegotiated pricing terms, the contract value is amended and revenue is typically recognized as described above. Billing schedules and payment terms are generally negotiated on a contract-by-contract basis. Payments received in excess of revenue recognized are recorded as deferred revenue. As the contracted services are subsequently performed and the associated revenue is recognized, the deferred revenue balance is reduced by the amount of revenue recognized during the period. In other cases, services may be provided and revenue is recognized before the client is invoiced. In these cases, revenue recognized will exceed amounts billed and the difference, representing amounts which are currently unbillable to the customer pursuant to contractual terms, is recorded as an unbilled receivable. Once the client is invoiced, the unbilled receivable is reduced for the amount billed, and a corresponding trade receivable is recorded. Most contracts are terminable by the client, either immediately or upon notice. These contracts often require payment to the Company of expenses to wind down the project, fees earned to date or, in some cases, a termination fee. Such payments are included in revenues when earned. The Company recognizes product revenue net of allowances for estimated returns, rebates and discounts when title and risk of loss pass to customers. When the Company sells equipment with specified acceptance criteria, it assesses its ability to meet the acceptance criteria in order to determine the timing of revenue recognition. The Company would defer revenue until completion of customer acceptance testing if it is not able to demonstrate the ability to meet such acceptance criteria. A portion of the Company’s revenue is from multiple-element arrangements that include multiple products and/or services as deliverables in a single arrangement with each deliverable, or a combination of the deliverables, representing a separate unit of accounting. The Company allocates revenues to each element in a multiple-element arrangement based upon the relative selling price of each deliverable. Revenue allocated to each deliverable is then recognized when all revenue recognition criteria are met. Judgments as to the identification of deliverables, units of accounting, the allocation of consideration to the deliverable, and the appropriate timing of revenue recognition are critical with respect to these arrangements. At the inception of each arrangement that includes milestone payments, the Company evaluates whether each milestone is substantive. This evaluation includes an assessment of whether (a) the consideration is commensurate with either (1) the Company’s performance to achieve the milestone, or (2) the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the Company’s performance to achieve the milestone; (b) the consideration relates solely to past performance; and (c) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. If a substantive milestone is achieved and collection of the related receivable is reasonably assured, the Company recognizes revenue related to the milestone in its entirety in the period in which the milestone is achieved. In those circumstances where a milestone is not substantive, the Company recognizes as revenue, on the date the milestone is achieved, an amount equal to the applicable percentage of the performance period that had elapsed as of the date the milestone was achieved, with the balance being deferred and recognized over the remaining period of performance. As of December 31, 2016 , the Company had no significant milestones that were deemed substantive. The Company records shipping charges billed to customers in total revenue and records shipping costs in c ost of revenue (excluding amortization of intangible assets) for all periods presented.
Advertising Costs	Advertising Costs Advertising costs are expensed as incurred.
Income Taxes	Income Taxes The provision for income taxes includes federal, state, local and foreign taxes. Income taxes are accounted for under the liability method. Deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statements carrying amounts and their respective tax basis. The Company measures deferred tax assets and liabilities using the enacted tax rates in effect when the temporary differences are expected to be settled. The Company evaluates the realizability of its deferred tax assets and establishes a valuation allowance when it is more likely than not that all or a portion of deferred tax assets will not be realized. The Company accounts for uncertain tax positions using a “more-likely-than-not” threshold for recognizing and resolving uncertain tax positions. The Company evaluates uncertain tax positions on a quarterly basis and considers various factors, including, but not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, information obtained during in process audit activities and changes in facts or circumstances related to a tax position. The Company also accrues for potential interest and penalties related to unrecognized tax benefits in income tax expense.
Foreign Currency	Foreign Currency Contracts Foreign currency contracts are recorded at fair value in the Company’s consolidated balance sheet and are not designated as hedging instruments. Any gains or losses on such contracts are immediately recognized in other income (expense), net. Translation of Foreign Currencies For the Company’s subsidiaries that transact in a functional currency other than the U.S. dollar, assets and liabilities are translated at current rates of exchange as of the balance sheet date. Income and expense items are translated at the average foreign exchange rates for the period. Adjustments resulting from the translation of the financial statements of the Company’s foreign operations into U.S. dollars are excluded from the determination of net income and are recorded in accumulated other comprehensive income (loss), a separate component of equity.
Pension and Other Post-Retirement Benefit Plans	Pension and Other Post-Retirement Benefit Plans The Company recognizes the funded status of its defined benefit pension and other post-retirement benefit plans as an asset or liability. This amount is defined as the difference between the fair value of plan assets and the benefit obligation. The Company measures plan assets and benefit obligations as of its fiscal year end. The key assumptions used to calculate benefit obligations and related pension costs include expected long-term rate of return on plan assets, withdrawal and mortality rates, expected rate of increase in employee compensation levels and discount rate. Assumptions are determined based on the Company’s data and appropriate market indicators, and evaluated each year as of the plan’s measurement date. The expected long-term rate of return on plan assets reflects the average rate of earnings expected on the funds invested, or to be invested, to provide for the benefits included in the projected benefit obligations. In determining the expected long-term rate of return on plan assets, the Company considers the relative weighting of plan assets, the historical performance of total plan assets and individual asset classes and economic and other indicators of future performance. In fiscal year 2016, new mortality improvement scales were issued in the U.S. reflecting a decline in longevity projection from the 2015 releases that the Company adopted, which decreased the Company’s benefit obligations by $ 1.3 million as of December 31, 2016. In fiscal year 2015, new mortality improvement scales were issued in the U.S. and the United Kingdom (U.K.) reflecting a decline in longevity projection from the 2014 releases that the Company adopted, which decreased the Company’s benefit obligations by $3.3 million as of December 26, 2015. The discount rate reflects the rate the Company would have to pay to purchase high-quality investments that would provide cash sufficient to settle its current pension obligations. The rate of compensation increase reflects the expected annual salary increases for the plan participants based on historical experience and the current employee compensation strategy. The Company is required to recognize as a component of other comprehensive income, net of tax, the actuarial gains or losses and prior service costs or credits that arise but were not previously required to be recognized as components of net periodic benefit cost. Other comprehensive income is adjusted as these amounts are later recognized in income as components of net periodic benefit cost.
Earnings Per Share	Earnings Per Share Basic earnings per share are calculated by dividing net income attributable to common shareholders by the weighted average number of common shares outstanding during the period. Except where the result would be anti-dilutive to income from continuing operations, diluted earnings per share is computed using the treasury stock method, assuming the exercise of stock options and the vesting of restricted stock awards, restricted stock units, or PSUs, as well as their related income tax effects.
New Accounting Pronouncements	. Newly Adopted Accounting Pronouncements In July 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2015-11, “Simplifying the Measurement of Inventory,” that simplifies the subsequent measurement of inventories by replacing the current lower of cost or market test with a lower of cost or net realizable value test. The ASU is effective for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption is permitted. During the fourth quarter of 2016, the Company adopted this standard, which had no impact on inventories as of December 31, 2016 . In August 2014, the FASB issued ASU 2014-15, “Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern.” The standard requires management to assess if there is substantial doubt about an entity’s ability to continue as a going concern within one year after the issuance date and, as applicable, provide additional disclosures on management’s plan to alleviate the substantial doubt. The ASU is effective for fiscal years ending after December 15, 2016, and interim periods within annual periods beginning after December 15, 2016. Early adoption is permitted. During the fourth quarter of 2016, the Company adopted this standard, which had no impact on the Company’s consolidated financial statements and related disclosures. Newly Issued Accounting Pronouncements In January 2017, the FASB issued ASU 2017-04, “Simplifying the Test for Goodwill Impairment.” The standard simplifies the accounting for goodwill impairment by removing Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. The ASU is effective for annual or interim goodwill impairment tests in fiscal years beginning after December 15, 2019, and should be applied on a prospective basis. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The adoption of this standard is not expected to have a material impact on the consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU 2017-01, “Clarifying the Definition of a Business.” The standard clarifies the definition of a business by adding guidance to assist entities in evaluating whether transactions should be accounted for as acquisitions of assets or businesses. The ASU is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted for certain transactions. The Company is still evaluating the impact this standard will have on its consolidated financial statements and related disclosures. In November 2016, the FASB issued ASU 2016-18, “Restricted Cash.” The standard addresses the classification and presentation of restricted cash and restricted cash equivalents within the statement of cash flows. The ASU is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted. The Company is still evaluating the impact this standard will have on its consolidated financial statements and related disclosures. In October 2016, the FASB issued ASU 2016-16, “Intra-Entity Transfers of Assets Other Than Inventory.” The standard requires the immediate recognition of tax effects for an intra-entity asset transfer other than inventory. The ASU is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted. The adoption of this standard is not expected to have a material impact on the consolidated financial statements and related disclosures. In August 2016, the FASB issued ASU 2016-15, “Classification of Certain Cash Receipts and Cash Payments.” The standard addresses the classification of certain transactions within the statement of cash flows, including cash payments for debt prepayment or debt extinguishment costs, contingent consideration payments made after a business combination, and distributions received from equity method investments. The ASU is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted. The Company is still evaluating the impact this standard will have on its consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU 2016-09, “Improvements to Employee Share-Based Payment Accounting.” The standard reduces complexity in several aspects of the accounting for employee share-based compensation, including the income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The ASU is effective for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption is permitted. The Company is still evaluating the impact this standard will have on its consolidated financial statements and related disclosures. In February 2016, the FASB issued ASU 2016-02, “Leases.” The standard established the principles that lessees and lessors will apply to report useful information to users of financial statements about the amount, timing and uncertainty of cash flows arising from a lease. The ASU is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted. The Company is still evaluating the full impact this standard will have on its consolidated financial statements and related disclosures but expects to recognize substantially all of its leases on the balance sheet, by recording a right-to-use asset and a corresponding lease liability. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers.” The standard, including subsequently issued amendments, will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective and permits the use of either the full retrospective or modified retrospective transition method. The standard will require an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The standard will be effective for annual and interim periods beginning after December 15, 2017. The Company has selected the modified retrospective transition method and is still evaluating the impact the adoption will have on its consolidated financial statements and related disclosures.

DESCRIPTION OF BUSINESS AND S26

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Property, Plant, and Equipment Estimated Useful Lives	The Company generally depreciates the cost of its property, plant and equipment using the straight-line method over the estimated useful lives of the respective assets as follow: Estimated (in years) Land Indefinite Buildings 20 - 40 Machinery and equipment 3 - 20 Furniture and fixtures 5 - 10 Computer hardware and software 3 - 8 Vehicles 3 - 5

BUSINESS ACQUISITIONS (Tables)

BUSINESS ACQUISITIONS (Tables)	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition	The purchase price allocation of $52.0 million , net of $7.2 million in cash acquired, is as follows: October 29, 2014 (in thousands) Current assets (excluding cash) $ 4,669 Property, plant and equipment 1,637 Definite-lived intangible assets 23,920 Goodwill 34,775 Current liabilities (3,486 ) Long-term liabilities (9,486 ) Total purchase price allocation $ 52,029 The purchase price allocation of $212.2 million , net of $2.3 million of cash acquired, was as follows: July 24, 2015 (in thousands) Trade receivables (contractual amount of $5,410) $ 5,288 Inventories 10,103 Other current assets (excluding cash) 13,269 Property, plant and equipment 4,639 Definite-lived intangible assets 118,140 Goodwill 105,550 Other long-term assets 537 Current debt (9,766 ) Other current liabilities (7,136 ) Long-term liabilities (28,388 ) Total purchase price allocation $ 212,236 The purchase price allocation of $62.0 million , net of $2.9 million of cash acquired, was as follows: September 28, 2016 (in thousands) Trade receivables (contractual amount of $4,799) $ 4,799 Other current assets (excluding cash) 1,509 Property, plant and equipment 3,907 Other long-term assets 11 Definite-lived intangible assets 21,900 Goodwill 43,899 Current liabilities (3,987 ) Long-term liabilities (10,013 ) Total purchase price allocation $ 62,025 The purchase price allocation of $183.6 million , net of $8.2 million of cash acquired, was as follows: April 1, 2014 (in thousands) Current assets (excluding cash) $ 31,682 Property, plant and equipment 21,008 Other long-term assets 11,140 Definite-lived intangible assets 104,470 Goodwill 65,235 Current liabilities (13,139 ) Long-term liabilities (36,802 ) Total purchase price allocation $ 183,594 The purchase price allocation of $9.6 million , net of less than $0.1 million of cash acquired, was as follows: May 5, 2015 (in thousands) Trade receivables (contractual amount of $995) $ 965 Inventories 1,518 Other current assets (excluding cash) 973 Property, plant and equipment 13,698 Definite-lived intangible assets 3,400 Current liabilities (925 ) Long-term liabilities (250 ) Fair value of net assets acquired 19,379 Bargain purchase gain (9,821 ) Total purchase price allocation $ 9,558 The purchase price allocation of $577.4 million , net of $27.4 million of cash acquired, was as follows: April 4, 2016 (in thousands) Trade receivables (contractual amount of $48,625) $ 48,157 Inventories 2,296 Other current assets (excluding cash) 3,814 Property, plant and equipment 129,066 Other long-term assets 1,060 Definite-lived intangible assets 164,800 Goodwill 330,602 Deferred revenue (39,103 ) Other current liabilities (27,386 ) Long-term liabilities (35,915 ) Total purchase price allocation $ 577,391 The purchase price allocation of $11.7 million , net of a non-significant amount of cash acquired, was as follows: June 27, 2016 (in thousands) Trade receivables (contractual amount of $1,104) $ 1,104 Other current assets (excluding cash) 15 Property, plant and equipment 912 Other long-term assets 187 Definite-lived intangible assets 1,230 Goodwill 10,477 Current liabilities (1,132 ) Long-term liabilities (1,044 ) Total purchase price allocation $ 11,749 The purchase price allocation of $35.4 million , net of $0.6 million of cash acquired, was as follows: November 18, 2015 (in thousands) Trade receivables (contractual amount of $3,546) $ 3,520 Inventories 129 Other current assets (excluding cash) 706 Property, plant and equipment 2,528 Definite-lived intangible assets 13,330 Goodwill 22,894 Other long-term assets 250 Current liabilities (3,456 ) Long-term liabilities (4,470 ) Total purchase price allocation $ 35,431
Finite-Lived Intangible Assets Acquired as Part of Business Combination	The breakout of definite-lived intangible assets acquired was as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 94,000 18 Backlog 5,900 1 Trademark and trade names 1,170 3 Leasehold interests 1,000 13 Other intangible assets 2,400 19 Total definite-lived intangible assets $ 104,470 17 The breakout of definite-lived intangible assets acquired was as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 7,146 19 Developed technology 5,960 19 Other intangible assets 224 3 Total definite-lived intangible assets $ 13,330 19 The breakout of definite-lived intangible assets acquired was as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 137,500 15 Developed technology 20,700 3 Backlog 6,600 1 Total definite-lived intangible assets $ 164,800 13 The breakout of definite-lived intangible assets acquired is as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 19,000 13 Other intangible assets 4,920 9 Total definite-lived intangible assets $ 23,920 12 The breakout of definite-lived intangible assets acquired was as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 16,700 17 Other intangible assets 5,200 4 Total definite-lived intangible assets $ 21,900 14 The breakout of definite-lived intangible assets acquired was as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 650 10 Other intangible assets 580 5 Total definite-lived intangible assets $ 1,230 7 The breakout of definite-lived intangible assets acquired was as follows: Definite-Lived Intangible Assets Weighted Average Amortization Life (in thousands) (in years) Client relationships $ 71,000 16 Developed technology 39,140 14 Trademark and trade names 5,200 14 Non-compete 2,800 5 Total definite-lived intangible assets $ 118,140 15
Business Acquisition, Pro Forma Information	The following selected unaudited pro forma consolidated results of operations are presented as if the WIL Research acquisition had occurred as of the beginning of the period immediately preceding the period of acquisition after giving effect to certain adjustments. For fiscal year 2016 , these adjustments included additional amortization of intangible assets and depreciation of fixed assets of $0.4 million , reversal of interest expense on borrowings of $2.6 million , elimination of intercompany activity and other one-time costs, and the tax impacts of these adjustments. For fiscal year 2015 , these adjustments included additional amortization of intangible assets and depreciation of fixed assets of $13.6 million , reversal of interest expense on borrowings of $10.5 million , inclusion of acquisition-related transaction costs of $11.5 million , elimination of intercompany activity and other one-time costs, and the tax impacts of these adjustments. Fiscal Year 2016 2015 (in thousands, except per share amounts) (unaudited) Revenue $ 1,741,964 $ 1,578,133 Net income attributable to common shareholders 175,779 153,974 Earnings per common share: Basic $ 3.74 $ 3.31 Diluted $ 3.67 $ 3.23 The following selected unaudited pro forma consolidated results of operations are presented as if the Argenta and BioFocus acquisition had occurred as of the beginning of the period immediately preceding the period of acquisition after giving effect to certain adjustments, including amortization of intangible assets and depreciation of fixed assets of $ 3.7 million and other nonrecurring costs. Fiscal Year 2014 (in thousands, except per share amounts) (unaudited) Revenue $ 1,322,771 Net income attributable to common shareholders 128,195 Earnings per common share: Basic $ 2.75 Diluted $ 2.70 The following selected unaudited pro forma consolidated results of operations are presented as if the Celsis acquisition had occurred as of the beginning of the period immediately preceding the period of acquisition after giving effect to certain nonrecurring costs and other adjustments, resulting in a reversal of $0.6 million and additional expenses of $13.1 million for fiscal years 2015 and 2014 , respectively, related to depreciation and amortization of property, plant and equipment, inventory fair value adjustments and intangible assets. Fiscal Year 2015 2014 (in thousands, except per share amounts) (unaudited) Revenue $ 1,380,493 $ 1,329,025 Net income attributable to common shareholders 162,672 110,387 Earnings per common share: Basic $ 3.50 $ 2.37 Diluted $ 3.42 $ 2.32

SUPPLEMENTAL BALANCE SHEET IN28

SUPPLEMENTAL BALANCE SHEET INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2016
Supplemental Balance Sheet Information [Abstract]
Composition of Trade Receivables, Net	The composition of trade receivables, net is as follows: December 31, 2016 December 26, 2015 (in thousands) Client receivables $ 283,997 $ 230,010 Unbilled revenue 82,203 45,996 Total 366,200 276,006 Less: Allowance for doubtful accounts (2,150 ) (5,938 ) Trade receivables, net $ 364,050 $ 270,068
Composition of Inventories	The composition of inventories is as follows: December 31, 2016 December 26, 2015 (in thousands) Raw materials and supplies $ 18,893 $ 15,998 Work in process 13,681 12,101 Finished products 63,259 65,636 Inventories $ 95,833 $ 93,735
Composition of Other Current Assets	The composition of other current assets is as follows: December 31, 2016 December 26, 2015 (in thousands) Investments $ 3,771 $ 20,516 Prepaid income tax 40,705 26,350 Restricted cash 532 271 Other — 149 Other current assets $ 45,008 $ 47,286
Composition of Property, Plant and Equipment, Net	The composition of property, plant and equipment, net is as follows: December 31, 2016 December 26, 2015 (in thousands) Land $ 47,392 $ 39,846 Buildings (1) 784,129 713,841 Machinery and equipment 403,123 362,695 Leasehold improvements 47,071 41,477 Furniture and fixtures 24,148 21,783 Computer hardware and software 127,283 113,466 Vehicles 4,118 3,819 Construction in progress 24,703 25,845 Total 1,461,967 1,322,772 Less: Accumulated depreciation (706,140 ) (644,813 ) Property, plant and equipment, net $ 755,827 $ 677,959 (1) The balances as of December 31, 2016 and December 26, 2015 include capital lease buildings. See Note 7, “Long-Term Debt and Capital Lease Obligations.”
Composition of Other Assets	The composition of other assets is as follows: December 31, 2016 December 26, 2015 (in thousands) Life insurance policies $ 29,456 $ 27,554 Venture capital investments 45,331 32,730 Restricted cash 1,736 1,745 Other 11,907 9,614 Other assets $ 88,430 $ 71,643
Composition of Other Current Liabilities	The composition of other current liabilities is as follows: December 31, 2016 December 26, 2015 (in thousands) Accrued income taxes $ 25,621 $ 12,168 Other 879 376 Other current liabilities $ 26,500 $ 12,544
Schedule of Other Liabilities	The composition of other long-term liabilities is as follows: December 31, 2016 December 26, 2015 (in thousands) Long-term pension liability $ 89,984 $ 34,604 Accrued executive supplemental life insurance retirement plan and deferred compensation plan 32,880 30,188 Other 36,375 24,270 Other long-term liabilities $ 159,239 $ 89,062

VENTURE CAPITAL INVESTMENTS A29

VENTURE CAPITAL INVESTMENTS AND MARKETABLE SECURITIES (Tables)	12 Months Ended
	Dec. 31, 2016
Marketable Securities and Equity-Method Affiliates [Abstract]
Summary of Marketable Securities	The following is a summary of the Company’s marketable securities, all of which are classified as available-for-sale, as of December 26, 2015 : Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Mutual fund $ 4,650 $ — $ (141 ) $ 4,509 Total $ 4,650 $ — $ (141 ) $ 4,509

FAIR VALUE (Tables)

FAIR VALUE (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets, Liabilities and Redeemable Noncontrolling Interest Measured on Recurring Basis	Assets, liabilities, and redeemable noncontrolling interest measured at fair value on a recurring basis are summarized below: December 31, 2016 Level 1 Level 2 Level 3 Total (in thousands) Cash equivalents $ — $ 21 $ — $ 21 Other assets: Life insurance policies — 22,121 — 22,121 Total assets measured at fair value $ — $ 22,142 $ — $ 22,142 Other current liabilities: Contingent consideration $ — $ — $ 3,621 $ 3,621 Total liabilities measured at fair value $ — $ — $ 3,621 $ 3,621 December 26, 2015 Level 1 Level 2 Level 3 Total (in thousands) Cash equivalents $ — $ 190 $ — $ 190 Other current assets: Marketable securities 4,509 — — 4,509 Foreign currency forward contracts — 15 — 15 Other assets: Life insurance policies — 20,364 — 20,364 Total assets measured at fair value $ 4,509 $ 20,569 $ — $ 25,078 Other current liabilities: Contingent consideration $ — $ — $ 1,172 $ 1,172 Other long-term liabilities: Contingent consideration — — 198 198 Redeemable noncontrolling interest — — 28,008 28,008 Total liabilities and redeemable noncontrolling interest measured at fair value $ — $ — $ 29,378 $ 29,378
Rollforward of Contingent Consideration	Contingent Consideration The following table provides a rollforward of the contingent consideration related to previous business acquisitions. See Note 2, “Business Acquisitions.” Fiscal Year 2016 2015 (in thousands) Beginning balance $ 1,370 $ 2,828 Additions 3,600 973 Payments (872 ) (600 ) Total gains or losses (realized/unrealized): Reversal of previously recorded contingent liability and change in fair value (477 ) (1,831 ) Ending balance $ 3,621 $ 1,370
Rollforward of the Fair Value of Redeemable Noncontrolling Interest	The following table provides a rollforward of the fair value of the Company’s redeemable noncontrolling interest for fiscal year 2015 : Redeemable Noncontrolling Interest (in thousands) December 27, 2014 $ 28,419 Total gains or losses (realized/unrealized): Net income attributable to noncontrolling interest 838 Foreign currency translation (1,066 ) Change in fair value, included in additional paid-in capital (183 ) December 26, 2015 28,008 Total gains or losses (realized/unrealized): Net income attributable to noncontrolling interest 320 Foreign currency translation (653 ) Change in fair value, included in additional paid-in capital (1,690 ) July 7, 2016 $ 25,985

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Rollforward of Goodwill	The following table provides a rollforward of the Company’s goodwill: Adjustments to Goodwill Adjustments to Goodwill December 27, 2014 Acquisitions Foreign Exchange December 26, 2015 Acquisitions Transfers Foreign Exchange December 31, 2016 (in thousands) RMS $ 59,196 $ — $ (1,029 ) $ 58,167 $ — $ (342 ) $ (1,428 ) $ 56,397 DSA 1,234,302 22,146 (4,398 ) 1,252,050 337,872 — (21,446 ) 1,568,476 Manufacturing 32,579 105,567 (4,534 ) 133,612 46,859 342 (13,169 ) 167,644 Gross carrying amount 1,326,077 1,443,829 1,792,517 Accumulated impairment loss - DSA (1,005,000 ) — — (1,005,000 ) — — — (1,005,000 ) Goodwill $ 321,077 $ 438,829 $ 787,517
Schedule of Intangible Assets, Net by Class	The following table displays intangible assets, net by major class: December 31, 2016 December 26, 2015 Gross Accumulated Net Gross Accumulated Net (in thousands) Backlog $ 8,370 $ (6,390 ) $ 1,980 $ 50,568 $ (50,554 ) $ 14 Technology 71,425 (14,314 ) 57,111 60,350 (5,911 ) 54,439 Trademarks and trade names 8,177 (4,124 ) 4,053 11,495 (5,944 ) 5,551 Other 16,775 (5,628 ) 11,147 14,711 (7,285 ) 7,426 Other intangible assets 104,747 (30,456 ) 74,291 137,124 (69,694 ) 67,430 Client relationships 519,123 (198,966 ) 320,157 396,537 (183,163 ) 213,374 Intangible assets $ 623,870 $ (229,422 ) $ 394,448 $ 533,661 $ (252,857 ) $ 280,804
Schedule of Estimated Amortization Expense	Estimated amortization expense for intangible assets for each of the next five fiscal years is expected to be as follows: Fiscal Year Amortization Expense (in thousands) 2017 $ 42,525 2018 40,731 2019 34,995 2020 34,382 2021 32,994

LONG-TERM DEBT AND CAPITAL LE32

LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Schedule of Long-term Debt, Net	Long-term debt, net consists of the following: December 31, 2016 December 26, 2015 (in thousands) Term loans $ 633,750 $ 390,000 Revolving credit facility 578,759 446,041 Other long-term debt 185 193 Total debt 1,212,694 836,234 Less: Current portion of long-term debt (24,560 ) (15,193 ) Long-term debt 1,188,134 821,041 Debt discount and debt issuance costs (7,633 ) (6,805 ) Long-term debt, net $ 1,180,501 $ 814,236
Schedule of Principal Maturities of Existing Debt	Principal maturities of existing debt for the periods set forth in the table below, are as follows: Principal (in thousands) 2017 $ 24,560 2018 36,563 2019 52,813 2020 81,250 2021 1,017,508 Total $ 1,212,694
Schedule of Future Minimum Lease Payments for Capital Leases	As of December 31, 2016 , the minimum lease payments under capital leases for each of the next five years and total thereafter were as follows: Minimum Lease Payments (in thousands) 2017 $ 4,097 2018 3,503 2019 3,005 2020 2,385 2021 2,250 Thereafter 27,974 Total $ 43,214

EQUITY AND REDEEMABLE NONCONT33

EQUITY AND REDEEMABLE NONCONTROLLING INTEREST (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Reconciliation of the Numerator and Denominator in the Computations of the Basic and Diluted Earnings per Share	The following table reconciles the numerator and denominator in the computations of basic and diluted earnings per share: Fiscal Year 2016 2015 2014 (in thousands) Numerator: Income from continuing operations, net of income taxes $ 156,086 $ 152,037 $ 129,924 Income (loss) from discontinued operations, net of income taxes 280 (950 ) (1,726 ) Less: Net income attributable to noncontrolling interests 1,601 1,774 1,500 Net income attributable to common shareholders $ 154,765 $ 149,313 $ 126,698 Denominator: Weighted-average shares outstanding—Basic 47,014 46,496 46,627 Effect of dilutive securities: Stock options, restricted stock units, performance share units and restricted stock 944 1,138 931 Weighted-average shares outstanding—Diluted 47,958 47,634 47,558
Changes to Each Component of Accumulated Other Comprehensive Income (LOss), Net of Income Taxes	Changes to each component of accumulated other comprehensive income (loss), net of income taxes, are as follows: Foreign Currency Translation and Other (3) Pension and Other Post-Retirement Benefit Plans Total (in thousands) December 27, 2014 $ (19,891 ) $ (54,356 ) $ (74,247 ) Other comprehensive loss before reclassifications (1) (60,745 ) (302 ) (61,047 ) Amounts reclassified from accumulated other comprehensive income (loss) (2,341 ) 2,617 276 Net current period other comprehensive income (loss) (63,086 ) 2,315 (60,771 ) Income tax expense — 530 530 December 26, 2015 (82,977 ) (52,571 ) (135,548 ) Other comprehensive loss before reclassifications (2) (71,618 ) (60,678 ) (132,296 ) Amounts reclassified from accumulated other comprehensive income (loss) — 1,711 1,711 Net current period other comprehensive income (loss) (71,618 ) (58,967 ) (130,585 ) Income tax expense (benefit) — (12,369 ) (12,369 ) December 31, 2016 $ (154,595 ) $ (99,169 ) $ (253,764 ) (1) The impact of the foreign currency translation adjustment to other comprehensive income (loss) before reclassifications for fiscal year 2015 was primarily due to the effect of changes in foreign currency exchange rates of the Euro and Canadian Dollar and to a lesser extent due to the impact of changes in the British Pound. (2) The impact of the foreign currency translation adjustment to other comprehensive income (loss) before reclassifications for fiscal year 2016 was primarily due to the effect of changes in foreign currency exchange rates of the Euro, British Pound, and Canadian Dollar and to a lesser extent due to the impact of changes in the Chinese Yuan Renminbi and Japanese Yen. (3) Foreign currency translation and other includes a non-significant amount of unrealized gains (losses) on available-for-sale marketable securities.
Rollforward of Redeemable Noncontrolling Interest	The following table provides a rollforward of the Company’s redeemable noncontrolling interest subsequent to the acquisition of the additional 12% equity interest on July 7, 2016: Redeemable Noncontrolling Interest (in thousands) July 7, 2016 $ 25,985 Purchase of 12% equity interest (12,360 ) Total gains or losses (realized/unrealized): Net income attributable to noncontrolling interest 357 Foreign currency translation (818 ) Modification of 13% purchase option 1,495 December 31, 2016 $ 14,659

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Components of Income from Continuing Operations Before Income Taxes and the Related Provision for Income Taxes	The components of income from continuing operations before income taxes and the related provision for income taxes are presented below: Fiscal Year 2016 2015 2014 (in thousands) Income from continuing operations before income taxes: U.S. $ 59,255 $ 76,157 $ 71,002 Non-U.S. 163,666 119,271 106,593 $ 222,921 $ 195,428 $ 177,595 Income tax provision: Current: Federal $ 18,592 $ 23,687 $ 13,733 Foreign 39,829 8,572 20,364 State 5,263 6,819 4,746 Total current 63,684 39,078 38,843 Deferred: Federal 7,206 1,790 12,982 Foreign (4,024 ) 3,064 (4,672 ) State (31 ) (541 ) 518 Total deferred 3,151 4,313 8,828 $ 66,835 $ 43,391 $ 47,671
Components of Deferred Tax Assets and Liabilities	The components of deferred tax assets and liabilities are as follows: December 31, 2016 December 26, 2015 (in thousands) Deferred tax assets: Compensation $ 70,863 $ 55,259 Accruals and reserves 8,103 8,941 Inventory reserves and valuations 3,447 2,022 Financing related — 902 Net operating loss and credit carryforwards 58,081 35,233 Other 2,921 2,593 Valuation allowance (10,101 ) (6,112 ) Total deferred tax assets 133,314 98,838 Deferred tax liabilities: Goodwill and other intangibles (121,256 ) (73,208 ) Financing related (854 ) — Depreciation related (32,271 ) (23,664 ) Venture capital investments (5,084 ) (3,570 ) Foreign withholding taxes (821 ) (6,590 ) Total deferred tax liabilities (160,286 ) (107,032 ) Net deferred taxes $ (26,972 ) $ (8,194 )
Reconciliations of the Statutory U.S. Federal Income Tax Rate to Effective Tax Rates	Reconciliations of the statutory U.S. Federal income tax rate to effective tax rates are as follows: Fiscal Year 2016 2015 2014 U.S. statutory income tax rate 35.0 % 35.0 % 35.0 % Foreign tax rate differences (10.3 )% (8.6 )% (9.4 )% State income taxes, net of Federal tax benefit 1.6 % 1.9 % 1.9 % Research tax credits and enhanced deductions (3.5 )% (2.6 )% (4.1 )% Enacted tax rate changes (0.8 )% (1.5 )% — % Impact of tax uncertainties 0.2 % (5.2 )% (0.7 )% Foreign withholding taxes 2.0 % 3.4 % — % Impact of acquisitions and restructuring 1.8 % (2.0 )% 1.6 % Other 4.0 % 1.8 % 2.5 % Effective income tax rate 30.0 % 22.2 % 26.8 %
Reconciliation of the Company's Beginning and Ending Unrecognized Income Tax Benefits	A reconciliation of the Company’s beginning and ending unrecognized income tax benefits is as follows: Fiscal Year 2016 2015 2014 (in thousands) Beginning balance $ 23,338 $ 34,627 $ 18,475 Additions to tax positions for current year 2,194 2,362 1,700 Additions to tax positions for prior years 2,035 3,028 18,502 Reductions to tax positions for current year — — — Reductions to tax positions for prior years (1,866 ) (3,991 ) (3,722 ) Settlements (918 ) (1,946 ) (308 ) Expiration of statute of limitations (597 ) (10,742 ) (20 ) Ending balance $ 24,186 $ 23,338 $ 34,627

EMPLOYEE BENEFIT PLANS (Tables)

EMPLOYEE BENEFIT PLANS (Tables)	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Reconciliation of Benefit Obligations and Plans Assets of the Company's Pension Plans	The following table provides a reconciliation of benefit obligations and plan assets of the Company’s pension, DCP and ESLIRP plans: December 31, 2016 December 26, 2015 (in thousands) Change in projected benefit obligations: Benefit obligation at beginning of year $ 345,220 $ 359,130 Service cost 2,453 4,293 Interest cost 12,046 12,974 Benefit payments (13,383 ) (8,191 ) Curtailment (279 ) — Settlements (5,499 ) — Plan amendments 188 — Transfer in from acquisition 5,271 — Actuarial loss (gain) 71,006 (10,362 ) Administrative expenses paid (605 ) (411 ) Effect of foreign exchange (36,476 ) (12,213 ) Benefit obligation at end of year $ 379,942 $ 345,220 Change in fair value of plan assets: Fair value of plan assets at beginning of year $ 275,480 $ 281,290 Actual return on plan assets 23,388 6,263 Employer contributions 10,551 6,762 Settlements (5,499 ) — Transfer in from acquisition 508 — Benefit payments (13,383 ) (8,191 ) Administrative expenses paid (605 ) (411 ) Effect of foreign exchange (33,537 ) (10,233 ) Fair value of plan assets at end of year $ 256,903 $ 275,480 Net balance sheet liability $ 123,039 $ 69,740 Amounts recognized in balance sheet: Noncurrent assets $ — $ 261 Current liabilities 1,120 6,133 Noncurrent liabilities 121,919 63,868
Amounts Recognized in Accumulated Other Comprehensive Loss Related to the Company's Pensions Plans	Amounts recognized in accumulated other comprehensive loss related to the Company’s pension, DCP and ESLIRP plans are as follows: Fiscal Year 2016 2015 (in thousands) Net actuarial loss $ 123,743 $ 73,412 Net prior service cost (credit) (3,300 ) (4,584 ) Net amount recognized $ 120,443 $ 68,828
Accumulated Benefit Obligation and Fair of Plan Assets	The accumulated benefit obligation and fair value of plan assets for the Company’s pension, DCP and ESLIRP plans with accumulated benefit obligations in excess of plan assets are as follows: December 31, 2016 December 26, 2015 (in thousands) Accumulated benefit obligation $ 346,122 $ 306,433 Fair value of plan assets 242,172 253,225
Projected Benefit Obligation and Fair Value of Plan Assets	The projected benefit obligation and fair value of plan assets for the Company’s pension, DCP and ESLIRP plans with projected benefit obligations in excess of plan assets are as follows: December 31, 2016 December 26, 2015 (in thousands) Projected benefit obligation $ 379,942 $ 336,155 Fair value of plan assets 256,903 266,154
Amounts in Accumulated Other Comprehensive Income Expected to Be Recognized as Components of Net Periodic Benefit Cost Over the Next Fiscal Year	The amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit cost over the next fiscal year are as follows: December 31, 2016 (in thousands) Amortization of net actuarial loss $ 3,867 Amortization of net prior service credit (475 )
Components of Net Periodic Benefit Costs for the Company's Pension Plans	Components of net periodic benefit cost for the Company’s pension, DCP and ESLIRP plans are as follows: Fiscal Year 2016 2015 2014 (in thousands) Service cost $ 2,453 $ 4,293 $ 4,155 Interest cost 12,046 12,974 13,831 Expected return on plan assets (14,164 ) (16,987 ) (17,444 ) Amortization of prior service cost (credit) (292 ) (581 ) 1,211 Amortization of net loss (gain) 2,003 3,198 23 Curtailment (279 ) — — Settlements 788 — — Net periodic cost (benefit) $ 2,555 $ 2,897 $ 1,776
Weighted-average Assumptions	Weighted-average assumptions used to determine projected benefit obligations are as follows: December 31, 2016 December 26, 2015 Discount rate 3.01 % 3.89 % Rate of compensation increase 3.25 % 3.17 % Weighted-average assumptions used to determine net periodic benefit cost are as follows: December 31, 2016 December 26, 2015 December 27, 2014 Discount rate 3.89 % 3.75 % 4.44 % Expected long-term return on plan assets 5.83 % 6.24 % 6.41 % Rate of compensation increase 3.17 % 3.18 % 3.36 %
Fair Value of the Company's Pension Plan Assets by Asset Category	The fair value of the Company’s pension plan assets by asset category are as follows: December 31, 2016 December 26, 2015 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (in thousands) Cash $ 108 $ — $ — $ 108 $ 92 $ — $ — $ 92 Equity securities (1) 63,348 6,252 — 69,600 65,890 5,941 — 71,831 Debt securities (2) 59,294 3,269 — 62,563 68,489 2,822 — 71,311 Mutual funds (3) 64,698 56,596 — 121,294 63,689 65,725 — 129,414 Other 1,318 586 1,434 3,338 1,021 49 1,762 2,832 Total $ 188,766 $ 66,703 $ 1,434 $ 256,903 $ 199,181 $ 74,537 $ 1,762 $ 275,480 (1) This category comprises equity securities held by non-U.S. pension plans valued at the quoted closing price, and translated into U.S. dollars using a foreign currency exchange rate at year end. (2) This category comprises debt securities held by non-U.S. pension plans valued at the quoted closing price, and translated into U.S. dollars using a foreign currency exchange rate at year end. (3) This category comprises mutual funds valued at the net asset value of shares held at year end.
Estimated Future Benefit Payments Over the Next Five Years	Estimated future benefit payments during the next five years and in the aggregate for fiscal years thereafter, are as follows: Fiscal Year Pension Plans (in thousands) 2017 $ 8,610 2018 8,818 2019 9,682 2020 10,014 2021 30,717 Thereafter 57,705

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Financial Statement Line Items in Which Stock-based Compensation is Reflected	The following table provides the financial statement line items in which stock-based compensation is reflected: Fiscal Year 2016 2015 2014 (in thousands) Cost of revenue (excluding amortization of intangible assets) $ 6,508 $ 6,511 $ 5,382 Selling, general and administrative 37,134 33,611 25,653 Stock-based compensation expense, before income taxes 43,642 40,122 31,035 Provision for income taxes (15,548 ) (14,225 ) (11,006 ) Stock-based compensation, net of income taxes $ 28,094 $ 25,897 $ 20,029
Summary of Stock Option Activity	The following table summarizes stock option activities under the Company’s stock-based compensation plans: Number of shares Weighted Average Weighted Average Aggregate (in thousands, except per share amounts) Options outstanding as of December 26, 2015 2,066 $ 50.62 Options granted 588 $ 74.13 Options exercised (601 ) $ 38.52 Options canceled (83 ) $ 62.66 Options outstanding as of December 31, 2016 1,970 $ 60.82 3.4 $ 30,638 Options exercisable as of December 31, 2016 746 $ 48.34 2.6 $ 20,817 Options expected to vest as of December 31, 2016 1,202 $ 68.40 3.8 $ 9,690
Weighted-average Assumptions	The fair value of stock options granted was estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions: Fiscal Year 2016 2015 2014 Expected life (in years) 3.6 3.6 4.2 Expected volatility 25 % 28 % 30 % Risk-free interest rate 1.2 % 1.1 % 1.5 % Expected dividend yield 0 % 0 % 0 %
Summary of Restricted Stock and Restricted Stock Unit Activity	The following table summarizes the restricted stock and restricted stock units activity for fiscal year 2016 : Restricted Stock and Restricted Stock Units Weighted (in thousands) December 26, 2015 607 $ 55.52 Granted 236 $ 75.10 Vested (296 ) $ 49.29 Canceled (32 ) $ 63.36 December 31, 2016 515 $ 67.62
Information about PSUs and Related Weighted-Average Assumptions	The Company utilizes a Monte Carlo simulation valuation model to value these awards. Information pertaining to the Company’s PSUs and the related estimated weighted-average assumptions used to calculate their fair value were as follows: Fiscal Year 2016 2015 2014 PSUs granted 190,628 148,900 214,823 Weighted average per share fair value $ 80.38 $ 88.62 $ 67.82 Key Assumptions: Expected volatility 24 % 23 % 29 % Risk-free interest rate 0.91 % 0.96 % 0.63 % Expected dividend yield — % — % — % 20 trading day average stock price on grant date (4.8 )% 20.6 % 13.1 %

FOREIGN CURRENCY CONTRACTS (Tab

FOREIGN CURRENCY CONTRACTS (Tables)	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Notational Value and Fair Value of Foreign Currency Contracts	The Company did not have any foreign currency contracts open as of December 31, 2016 . The notional amount and fair value of the Company’s foreign currency forward contracts as of December 26, 2015 were as follows: Notional Amount Fair Value Balance Sheet Location (in thousands) $ 88,483 $ 15 Other current assets
Summary of Gains (Losses) Recognized on Foreign Exchange Forward Contracts	The following table summarizes gains (losses) recognized on foreign exchange forward contracts related to intercompany loans denominated in British Pounds and Euros on the Company’s consolidated statement of income: Fiscal Year Location of Gain (Loss) 2016 2015 (in thousands) Other income (expense), net $ 3,373 $ (4,917 )

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Payments Under Noncancellable Operating Leases	As of December 31, 2016 , minimum rental commitments under non-cancellable leases, net of income from subleases, for each of the next five years and total thereafter were as follows: Minimum Lease Payments (in thousands) 2017 $ 23,410 2018 20,273 2019 17,119 2020 13,254 2021 8,104 Thereafter 19,116 Total $ 101,276

RESTRUCTURING AND ASSET IMPAI39

RESTRUCTURING AND ASSET IMPAIRMENTS (Tables)	12 Months Ended
	Dec. 31, 2016
Restructuring and Related Activities [Abstract]
Rollforward of Company's Severance and Retention Costs Liability	The Company periodically implements workforce reductions to improve operating efficiency at various sites. The following table provides a rollforward of the Company’s severance and retention costs liability: December 31, 2016 December 26, 2015 December 27, 2014 (in thousands) Balance, beginning of period $ 2,969 $ 2,666 $ 2,782 Expense 8,454 6,173 7,792 Payments / utilization (7,473 ) (5,820 ) (7,900 ) Foreign currency adjustments (270 ) (50 ) (8 ) Balance, end of period $ 3,680 $ 2,969 $ 2,666
Schedule of Severance and Retention Costs	The following table presents severance and retention costs by classification on the consolidated statements of income: Fiscal Year 2016 2015 2014 (in thousands) Cost of services provided and products sold (excluding amortization of intangible assets) $ 4,717 $ 735 $ 3,342 Selling, general and administrative 3,737 5,438 4,450 Total severance and retention costs $ 8,454 $ 6,173 $ 7,792 The following presents severance and retention costs by reportable segment: Fiscal Year 2016 2015 2014 (in thousands) RMS $ 759 $ 1,338 $ 4,593 DSA 7,689 1,068 2,912 Manufacturing 6 1,639 166 Unallocated corporate — 2,128 121 Total severance and retention costs $ 8,454 $ 6,173 $ 7,792

Business Segment and Geographic

Business Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Revenue and Other Financial Information by Reportable Segment	The following table presents revenue and other financial information by reportable segment: Fiscal Year 2016 2015 2014 (in thousands) RMS Revenue $ 494,037 $ 470,411 $ 503,656 Operating income 136,365 120,973 120,736 Depreciation and amortization 20,853 22,526 27,309 Capital expenditures 11,642 17,398 18,669 DSA Revenue $ 836,593 $ 612,173 $ 538,218 Operating income 138,157 121,981 69,749 Depreciation and amortization 71,816 46,812 47,138 Capital expenditures 27,493 30,333 19,759 Manufacturing Revenue $ 350,802 $ 280,718 $ 255,788 Operating income 104,543 74,675 79,260 Depreciation and amortization 25,566 18,129 14,295 Capital expenditures 12,247 9,814 15,621
Reconciliation of Segment Operating Income and Capital Expenditures to Respective Consolidated Amounts	For fiscal years ended 2016 , 2015 and 2014 , reconciliations of segment operating income and capital expenditures to the respective consolidated amounts are as follows: Operating Income Capital Expenditures Fiscal Year Fiscal Year 2016 2015 2014 2016 2015 2014 (in thousands) Total reportable segments $ 379,065 $ 317,629 $ 269,745 $ 51,382 $ 57,545 $ 54,049 Unallocated corporate (141,646 ) (111,180 ) (92,075 ) 3,906 5,707 2,876 Total consolidated $ 237,419 $ 206,449 $ 177,670 $ 55,288 $ 63,252 $ 56,925
Revenue for Each Significant Product or Service Offering	Revenue for each significant product or service offering is as follows : Fiscal Year 2016 2015 2014 (in thousands) RMS $ 494,037 $ 470,411 $ 503,656 DSA 836,593 612,173 538,218 Manufacturing 350,802 280,718 255,788 Total revenue $ 1,681,432 $ 1,363,302 $ 1,297,662
Summary of Unallocated Corporate Overhead	A summary of unallocated corporate overhead consists of the following : Fiscal Year 2016 2015 2014 (in thousands) Stock-based compensation expense $ 27,272 $ 25,751 $ 18,474 Salary, bonus, and fringe 39,189 33,026 30,838 Consulting, audit, and professional services 23,421 15,418 13,431 IT related expenses 13,233 8,400 6,528 Depreciation expense 8,423 7,414 7,703 Acquisition related adjustments 15,608 11,644 6,285 Other general unallocated corporate expenses 14,500 9,527 8,816 Total unallocated corporate overhead costs $ 141,646 $ 111,180 $ 92,075
Revenue and Long-Lived Assets by Geographic Area	Revenue and long-lived assets by geographic area are as follows: U.S. Europe Canada Japan Other Non-U.S. Consolidated (in thousands) 2016 Revenue $ 850,422 $ 520,937 $ 194,210 $ 46,829 $ 69,034 $ 1,681,432 Long-lived assets 462,330 177,423 78,866 20,941 16,267 755,827 2015 Revenue $ 659,466 $ 435,491 $ 172,349 $ 40,520 $ 55,476 $ 1,363,302 Long-lived assets 402,238 159,445 77,535 22,348 16,393 677,959 2014 Revenue $ 588,531 $ 446,263 $ 163,490 $ 49,921 $ 49,457 $ 1,297,662 Long-lived assets 386,624 153,203 95,272 23,896 17,802 676,797

SELECTED QUARTERLY FINANCIAL 41

SELECTED QUARTERLY FINANCIAL DATA (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data	The following table contains quarterly financial information for fiscal years 2016 and 2015 . The operating results for any quarter are not necessarily indicative of future period results. First Quarter Second Quarter Third Quarter Fourth Quarter Fiscal Year 2016 (in thousands, except per share amounts) Total revenue $ 354,868 $ 434,055 $ 425,720 $ 466,789 Gross profit (1) 140,768 169,747 156,270 179,881 Operating income 51,472 58,061 58,795 69,091 Net income attributable to common shareholders 37,143 35,207 37,735 44,680 Earnings (loss) per common share Basic: Continuing operations attributable to common shareholders $ 0.80 $ 0.75 $ 0.79 $ 0.95 Discontinued operations $ — $ — $ 0.01 $ — Net income attributable to common shareholders $ 0.80 $ 0.75 $ 0.80 $ 0.95 Diluted: Continuing operations attributable to common shareholders $ 0.78 $ 0.73 $ 0.78 $ 0.93 Discontinued operations $ — $ — $ 0.01 $ — Net income attributable to common shareholders $ 0.78 $ 0.73 $ 0.79 $ 0.93 Fiscal Year 2015 Total revenue $ 320,414 $ 339,573 $ 349,465 $ 353,850 Gross profit (1) 119,660 132,783 138,075 140,574 Operating income 43,005 55,735 55,440 52,269 Net income attributable to common shareholders 31,541 48,509 37,379 31,884 Earnings (loss) per common share Basic: Continuing operations attributable to common shareholders $ 0.67 $ 1.04 $ 0.81 $ 0.71 Discontinued operations $ — $ — $ — $ (0.02 ) Net income attributable to common shareholders $ 0.67 $ 1.04 $ 0.81 $ 0.69 Diluted: Continuing operations attributable to common shareholders $ 0.66 $ 1.02 $ 0.79 $ 0.69 Discontinued operations $ — $ — $ — $ (0.02 ) Net income attributable to common shareholders $ 0.66 $ 1.02 $ 0.79 $ 0.67 (1) Gross profit is calculated as total revenues minus cost of revenue (excluding amortization of intangible assets).

SUBSEQUENT EVENTS (Tables)

SUBSEQUENT EVENTS (Tables)	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Carrying Amounts of the Major Classes of Assets and Liabilities Associated with Thunder	As of December 31, 2016 , the carrying amounts of the major classes of assets and liabilities associated with the CDMO business were as follows: December 31, 2016 (in thousands) Assets Current assets $ 4,270 Property, plant and equipment, net 11,313 Goodwill 35,857 Long-term assets 17,332 Total assets $ 68,772 Liabilities Current liabilities $ 5,840 Long-term liabilities 7,856 Total liabilities $ 13,696

DESCRIPTION OF BUSINESS AND S43

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Segment Reporting (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016USD ($)	Sep. 24, 2016USD ($)	Jun. 25, 2016USD ($)	Mar. 26, 2016USD ($)	Dec. 26, 2015USD ($)	Sep. 26, 2015USD ($)	Jun. 27, 2015USD ($)	Mar. 28, 2015USD ($)	Dec. 31, 2016USD ($)segments	Dec. 26, 2015USD ($)	Dec. 27, 2014USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments | segments									3
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue	$ 466,789	$ 425,720	$ 434,055	$ 354,868	$ 353,850	$ 349,465	$ 339,573	$ 320,414	$ 1,681,432	$ 1,363,302	$ 1,297,662
Operating income	$ 69,091	$ 58,795	$ 58,061	$ 51,472	$ 52,269	$ 55,440	$ 55,735	$ 43,005	237,419	206,449	177,670
Manufacturing
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue									350,802	280,718	255,788
Operating income									104,543	74,675	79,260
RMS
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue									494,037	470,411	503,656
Operating income									136,365	120,973	120,736
Operating Segments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Operating income									$ 379,065	317,629	269,745
Operating Segments | Reclassified Between Segments | Manufacturing
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue										2,800	3,700
Operating income										500	600
Operating Segments | Reclassified Between Segments | RMS
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Total revenue										(2,800)	(3,700)
Operating income										$ (500)	$ (600)

DESCRIPTION OF BUSINESS AND S44

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentrations of Credit Risk (Details) - Client Concentration Risk - client	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Composition of trade receivables
Number of clients accounting for more than 5% of revenue or trade receivables	0	0
Percentage of revenue or trade receivables	5.00%

DESCRIPTION OF BUSINESS AND S45

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Property, Plant and Equipment, Net (Details)	12 Months Ended
	Dec. 31, 2016
Minimum | Buildings
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	20 years
Minimum | Machinery and equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	3 years
Minimum | Furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	5 years
Minimum | Computer hardware and software
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	3 years
Minimum | Vehicles
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	3 years
Maximum | Buildings
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	40 years
Maximum | Machinery and equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	20 years
Maximum | Furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	10 years
Maximum | Computer hardware and software
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	8 years
Maximum | Vehicles
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	5 years

DESCRIPTION OF BUSINESS AND S46

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Venture Capital Investments (Details)	Dec. 31, 2016
Minimum
Schedule of Equity Method Investments [Line Items]
Company's ownership percentage	0.70%
Maximum
Schedule of Equity Method Investments [Line Items]
Company's ownership percentage	12.00%

DESCRIPTION OF BUSINESS AND S47

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Life Insurance Contracts (Details) $ in Millions	Dec. 31, 2016USD ($)contract	Dec. 26, 2015USD ($)contract
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of life insurance contracts | contract	43	42
Face value of life insurance contracts | $	$ 61.4	$ 60.5

DESCRIPTION OF BUSINESS AND S48

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Revenue Recognition (Details)	Dec. 31, 2016milestone
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenue recognition, number of milestones achieved	0

DESCRIPTION OF BUSINESS AND S49

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Advertising Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Advertising costs	$ 1.4	$ 1.2	$ 1.3

DESCRIPTION OF BUSINESS AND S50

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Pension and Other Post-Retirement Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Decrease in company's benefit obligations from new mortality improvement scales	$ 1.3	$ 3.3

DESCRIPTION OF BUSINESS AND S51

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Newly Adopted Accounting Pronouncements (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
New Accounting Pronouncement, Early Adoption [Line Items]
Increase to inventories		$ 4,021,000	$ (3,364,000)	$ 2,956,000
Accounting Standards Update 2015-11
New Accounting Pronouncement, Early Adoption [Line Items]
Increase to inventories	$ 0

BUSINESS ACQUISITIONS - Agilux

BUSINESS ACQUISITIONS - Agilux, Additional Information (Details) - Agilux - USD ($) $ in Thousands	Sep. 28, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
Purchase price	$ 64,900
Purchase price allocation	62,025
Cash acquired	$ 2,900
Transaction and integration costs		$ 1,700

BUSINESS ACQUISITIONS - Agil53

BUSINESS ACQUISITIONS - Agilux, Purchase Price Allocation (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Sep. 28, 2016	Dec. 26, 2015	Dec. 27, 2014
Business Acquisition [Line Items]
Goodwill	$ 787,517		$ 438,829	$ 321,077
Agilux
Business Acquisition [Line Items]
Acquired receivables, contractual amount		$ 4,799
Trade receivables		4,799
Other current assets (excluding cash)		1,509
Property, plant and equipment		3,907
Other long-term assets		11
Definite-lived intangible assets		21,900
Goodwill		43,899
Current liabilities		(3,987)
Long-term liabilities		(10,013)
Total purchase price allocation		$ 62,025

BUSINESS ACQUISITIONS - Agil54

BUSINESS ACQUISITIONS - Agilux, Definite Lived Intangible Assets (Details) - Agilux $ in Thousands	Sep. 28, 2016USD ($)
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 21,900
Weighted Average Amortization Life	14 years
Client relationships
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 16,700
Weighted Average Amortization Life	17 years
Other intangible assets
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 5,200
Weighted Average Amortization Life	4 years

BUSINESS ACQUISITIONS - Blue St

BUSINESS ACQUISITIONS - Blue Stream Laboratories, Additional Information (Details) - Blue Stream - USD ($) $ in Thousands	Jun. 27, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
Transaction and integration costs		$ 600
Purchase price	$ 11,700
Contingent consideration	3,000
Purchase price allocation	$ 11,749

BUSINESS ACQUISITIONS - Blue 56

BUSINESS ACQUISITIONS - Blue Stream Laboratories, Allocation of Purchase Price (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Jun. 27, 2016	Dec. 26, 2015	Dec. 27, 2014
Business Acquisition [Line Items]
Goodwill	$ 787,517		$ 438,829	$ 321,077
Blue Stream
Business Acquisition [Line Items]
Acquired receivables, contractual amount		$ 1,104
Trade receivables		1,104
Other current assets (excluding cash)		15
Property, plant and equipment		912
Other long-term assets		187
Definite-lived intangible assets		1,230
Goodwill		10,477
Current liabilities		(1,132)
Long-term liabilities		(1,044)
Total purchase price allocation		$ 11,749

BUSINESS ACQUISITIONS - Blue 57

BUSINESS ACQUISITIONS - Blue Stream Laboratories, Definite Lived Intangible Assets (Details) - Blue Stream $ in Thousands	Jun. 27, 2016USD ($)
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 1,230
Weighted Average Amortization Life	7 years
Client relationships, net
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 650
Weighted Average Amortization Life	10 years
Other intangible assets
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 580
Weighted Average Amortization Life	5 years

BUSINESS ACQUISITIONS - WIL Res

BUSINESS ACQUISITIONS - WIL Research, Additional Information (Details) - WIL Research - USD ($) $ in Thousands	Apr. 04, 2016	Dec. 31, 2016	Dec. 31, 2016	Dec. 26, 2015
Business Acquisition [Line Items]
Purchase price	$ 604,800
Assumed liabilities	400
Purchase price allocation	577,391
Cash acquired	27,400
Goodwill resulting from transaction	$ 19,000
Transaction and integration costs			$ 15,500	$ 3,200
Revenue		$ 176,100
Operating income (loss)		$ 12,500
Additional amortization of intangible assets and depreciation of fixed assets			400	13,600
Reversal of interest expense on borrowings			$ 2,600	10,500
Acquisition-related transaction costs				$ 11,500

BUSINESS ACQUISITIONS - WIL R59

BUSINESS ACQUISITIONS - WIL Research, Allocation of Purchase Price (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Apr. 04, 2016	Dec. 26, 2015	Dec. 27, 2014
Business Acquisition [Line Items]
Goodwill	$ 787,517		$ 438,829	$ 321,077
WIL Research
Business Acquisition [Line Items]
Acquired receivables, contractual amount		$ 48,625
Trade receivables		48,157
Inventories		2,296
Other current assets (excluding cash)		3,814
Property, plant and equipment		129,066
Other long-term assets		1,060
Definite-lived intangible assets		164,800
Goodwill		330,602
Deferred revenue		(39,103)
Current liabilities		(27,386)
Long-term liabilities		(35,915)
Total purchase price allocation		$ 577,391

BUSINESS ACQUISITIONS - WIL R60

BUSINESS ACQUISITIONS - WIL Research, Definite Lived Intangible Assets (Details) - WIL Research $ in Thousands	Apr. 04, 2016USD ($)
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 164,800
Weighted Average Amortization Life	13 years
Client relationships, net
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 137,500
Weighted Average Amortization Life	15 years
Developed technology
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 20,700
Weighted Average Amortization Life	3 years
Backlog
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 6,600
Weighted Average Amortization Life	1 year

BUSINESS ACQUISITIONS - WIL La

BUSINESS ACQUISITIONS - WIL Laboratories, Pro Forma Financial Information (Details) - WIL Research - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Business Acquisition [Line Items]
Revenue	$ 1,741,964	$ 1,578,133
Net income attributable to common shareholders	$ 175,779	$ 153,974
Earnings (loss) per common share
Basic (in dollars per share)	$ 3.74	$ 3.31
Diluted (in dollars per share)	$ 3.67	$ 3.23

BUSINESS ACQUISITIONS - Oncote

BUSINESS ACQUISITIONS - Oncotest, Additional Information (Details) - Oncotest $ in Thousands, € in Millions	Nov. 18, 2015USD ($)	Dec. 31, 2016USD ($)	Dec. 26, 2015USD ($)	Dec. 31, 2016EUR (€)	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Purchase price	$ 36,000
Contingent consideration	300
Gain on contingent consideration liability		$ 300
Maximum contingent consideration				€ 2	$ 2,100
Purchase price allocation	35,431
Cash acquired	$ 600
Transaction and integration costs			$ 2,100

BUSINESS ACQUISITIONS - Onco63

BUSINESS ACQUISITIONS - Oncotest, Purchase Price Allocation (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015	Nov. 18, 2015	Dec. 27, 2014
Business Acquisition [Line Items]
Goodwill	$ 787,517	$ 438,829		$ 321,077
Oncotest
Business Acquisition [Line Items]
Acquired receivables, contractual amount			$ 3,546
Trade receivables			3,520
Inventories			129
Other current assets (excluding cash)			706
Property, plant and equipment			2,528
Definite-lived intangible assets			13,330
Goodwill			22,894
Other long-term assets			250
Current liabilities			(3,456)
Long-term liabilities			(4,470)
Total purchase price allocation			$ 35,431

BUSINESS ACQUISITIONS - Onco64

BUSINESS ACQUISITIONS - Oncotest, Definite-Lived Intangible Assets (Details) - Oncotest $ in Thousands	Nov. 18, 2015USD ($)
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 13,330
Weighted Average Amortization Life	19 years
Client relationships, net
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 7,146
Weighted Average Amortization Life	19 years
Developed technology
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 5,960
Weighted Average Amortization Life	19 years
Other intangible assets
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 224
Weighted Average Amortization Life	3 years

BUSINESS ACQUISITIONS - Celsis

BUSINESS ACQUISITIONS - Celsis, Additional Information (Details) - Celsis - USD ($) $ in Thousands	Jul. 24, 2015	Dec. 26, 2015	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Business Acquisition [Line Items]
Purchase price	$ 214,500
Assumed liabilities	10,300
Purchase price allocation	212,236
Cash acquired	$ 2,300
Transaction and integration costs			$ 1,000	$ 8,800
Revenue		$ 11,100
Operating income (loss)		$ (6,100)
Nonrecurring costs and other adjustments				$ (600)	$ 13,100

BUSINESS ACQUISITIONS - Cels66

BUSINESS ACQUISITIONS - Celsis, Purchase Price Allocation (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015	Jul. 24, 2015	Dec. 27, 2014
Business Acquisition [Line Items]
Goodwill	$ 787,517	$ 438,829		$ 321,077
Celsis
Business Acquisition [Line Items]
Acquired receivables, contractual amount			$ 5,410
Trade receivables			5,288
Inventories			10,103
Other current assets (excluding cash)			13,269
Property, plant and equipment			4,639
Definite-lived intangible assets			118,140
Goodwill			105,550
Other long-term assets			537
Current debt			(9,766)
Current liabilities			(7,136)
Long-term liabilities			(28,388)
Total purchase price allocation			$ 212,236

BUSINESS ACQUISITIONS - Cels67

BUSINESS ACQUISITIONS - Celsis, Definite-Lived Intangible Assets (Details) - Celsis $ in Thousands	Jul. 24, 2015USD ($)
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 118,140
Weighted Average Amortization Life	15 years
Client relationships
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 71,000
Weighted Average Amortization Life	16 years
Developed technology
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 39,140
Weighted Average Amortization Life	14 years
Trademark and trade names
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 5,200
Weighted Average Amortization Life	14 years
Non-compete
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 2,800
Weighted Average Amortization Life	5 years

BUSINESS ACQUISITIONS - Cels68

BUSINESS ACQUISITIONS - Celsis, Pro Forma Financial Information (Details) - Celsis - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 26, 2015	Dec. 27, 2014
Business Acquisition [Line Items]
Revenue	$ 1,380,493	$ 1,329,025
Net income attributable to common shareholders	$ 162,672	$ 110,387
Earnings (loss) per common share
Basic (in dollars per share)	$ 3.50	$ 2.37
Diluted (in dollars per share)	$ 3.42	$ 2.32

BUSINESS ACQUISITIONS - Sunris

BUSINESS ACQUISITIONS - Sunrise, Additional Information (Details) - USD ($) $ in Thousands	May 05, 2015	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Business Acquisition [Line Items]
Bargain purchase gain		$ 16	$ (9,837)	$ 0
Sunrise
Business Acquisition [Line Items]
Purchase price	$ 9,558
Bargain purchase gain	(9,821)
Cash acquired	$ 100
Transaction and integration costs			$ 1,500
Sunrise | Client relationships
Business Acquisition [Line Items]
Weighted average useful life		15 years

BUSINESS ACQUISITIONS - Sunr70

BUSINESS ACQUISITIONS - Sunrise, Purchase Price Allocation (Details) - USD ($) $ in Thousands	May 05, 2015	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Business Acquisition [Line Items]
Bargain purchase gain		$ 16	$ (9,837)	$ 0
Sunrise
Business Acquisition [Line Items]
Acquired receivables, contractual amount	$ 995
Trade receivables	965
Inventories	1,518
Other current assets (excluding cash)	973
Property, plant and equipment	13,698
Definite-lived intangible assets	3,400
Current liabilities	(925)
Long-term liabilities	(250)
Fair value of net assets acquired	19,379
Bargain purchase gain	(9,821)
Total purchase price allocation	$ 9,558

BUSINESS ACQUISITIONS - ChanTe

BUSINESS ACQUISITIONS - ChanTest, Additional Information (Details) - ChanTest - USD ($) $ in Thousands	Oct. 29, 2014	Dec. 26, 2015	Dec. 27, 2014
Business Acquisition [Line Items]
Purchase price	$ 59,200
Contingent consideration	300	$ 2,000
Gain on contingent consideration liability		$ 300
Purchase price allocation	52,029
Cash acquired	$ 7,200
Transaction and integration costs			$ 1,100

BUSINESS ACQUISITIONS - Chan72

BUSINESS ACQUISITIONS - ChanTest Preliminary Purchase Price (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014	Oct. 29, 2014
Business Acquisition [Line Items]
Goodwill	$ 787,517	$ 438,829	$ 321,077
ChanTest
Business Acquisition [Line Items]
Current assets (excluding cash)				$ 4,669
Property, plant and equipment				1,637
Definite-lived intangible assets				23,920
Goodwill				34,775
Current liabilities				(3,486)
Long-term debt, net and capital leases				(9,486)
Total purchase price allocation				$ 52,029

BUSINESS ACQUISITIONS - Chan73

BUSINESS ACQUISITIONS - ChanTest, Indefinite Lived Intangible Assets (Details) - ChanTest $ in Thousands	Oct. 29, 2014USD ($)
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 23,920
Weighted Average Amortization Life	12 years
Client relationships
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 19,000
Weighted Average Amortization Life	13 years
Other intangible assets
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 4,920
Weighted Average Amortization Life	9 years

BUSINESS ACQUISITIONS - VivoPa

BUSINESS ACQUISITIONS - VivoPath, Additional Information (Details) - VivoPath - USD ($) $ in Millions	Jun. 16, 2014	Dec. 31, 2016	Dec. 26, 2015
Business Acquisition [Line Items]
Purchase price	$ 2.3
Contingent consideration	$ 1.6	$ 0.2
Maximum contingent consideration		$ 2.4
Contingent consideration, payment period		3 years
Contingent consideration, payment		$ 0.2	$ 0.6
Gain on contingent consideration liability			$ 0.8

BUSINESS ACQUISITIONS - Argent

BUSINESS ACQUISITIONS - Argenta and BioFocus, Additional Information (Details) - Agrenta and BioFocus $ in Thousands, € in Millions	Apr. 01, 2015USD ($)	Apr. 01, 2014USD ($)	Dec. 27, 2014USD ($)	Dec. 31, 2016EUR (€)	Jun. 27, 2015EUR (€)
Business Acquisition [Line Items]
Percentage of voting interests acquired		100.00%
Total purchase price allocation		$ 191,800
Contingent consideration		900
Gain on contingent consideration liability	$ 800
Maximum contingent consideration | €				€ 5.3	€ 5
Purchase price allocation		183,594
Cash acquired		8,200
Transaction and integration costs			$ 5,300
Revenue			71,400
Operating income (loss)			$ 1,800
Adjustments, including amortization of intangible assets and depreciation of fixed assets		$ 3,700

BUSINESS ACQUISITIONS - Arge76

BUSINESS ACQUISITIONS - Argenta and BioFocus, Purchase Price Allocation (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014	Apr. 01, 2014
Business Acquisition [Line Items]
Goodwill	$ 787,517	$ 438,829	$ 321,077
Agrenta and BioFocus
Business Acquisition [Line Items]
Current assets (excluding cash)				$ 31,682
Property, plant and equipment				21,008
Other long-term assets				11,140
Definite-lived intangible assets				104,470
Goodwill				65,235
Current liabilities				(13,139)
Long-term debt, net and capital leases				(36,802)
Total purchase price allocation				$ 183,594

BUSINESS ACQUISITIONS - Arge77

BUSINESS ACQUISITIONS - Argenta and BioFocus, Definite Lived Intangible Assets (Details) - Agrenta and BioFocus $ in Thousands	Apr. 01, 2014USD ($)
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 104,470
Weighted Average Amortization Life	17 years
Client relationships
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 94,000
Weighted Average Amortization Life	18 years
Backlog
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 5,900
Weighted Average Amortization Life	1 year
Trademark and trade names
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 1,170
Weighted Average Amortization Life	3 years
Leasehold interests
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 1,000
Weighted Average Amortization Life	13 years
Other intangible assets
Business Acquisition [Line Items]
Definite-Lived Intangible Assets	$ 2,400
Weighted Average Amortization Life	19 years

BUSINESS ACQUISITIONS - Arge78

BUSINESS ACQUISITIONS - Argenta and BioFocus, Pro Forma Information (Details) - Agrenta and BioFocus $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 27, 2014USD ($)$ / shares
Business Acquisition [Line Items]
Revenue | $	$ 1,322,771
Net income attributable to common shareholders | $	$ 128,195
Earnings (loss) per common share
Basic (in dollars per share) | $ / shares	$ 2.75
Diluted (in dollars per share) | $ / shares	$ 2.70

SUPPLEMENTAL BALANCE SHEET IN79

SUPPLEMENTAL BALANCE SHEET INFORMATION (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Recoveries to the allowance for doubtful accounts	$ 0.5
Allowance for doubtful accounts		$ 1.8	$ 0.5
Depreciation expense	$ 85	$ 70.7	$ 70.5

SUPPLEMENTAL BALANCE SHEET IN80

SUPPLEMENTAL BALANCE SHEET INFORMATION - Composition of Trade Receivables, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Supplemental Balance Sheet Information [Abstract]
Client receivables	$ 283,997	$ 230,010
Unbilled revenue	82,203	45,996
Total	366,200	276,006
Less: Allowance for doubtful accounts	(2,150)	(5,938)
Trade receivables, net	$ 364,050	$ 270,068

SUPPLEMENTAL BALANCE SHEET IN81

SUPPLEMENTAL BALANCE SHEET INFORMATION - Composition of Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Supplemental Balance Sheet Information [Abstract]
Raw materials and supplies	$ 18,893	$ 15,998
Work in process	13,681	12,101
Finished products	63,259	65,636
Inventories	$ 95,833	$ 93,735

SUPPLEMENTAL BALANCE SHEET IN82

SUPPLEMENTAL BALANCE SHEET INFORMATION - Composition of Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Supplemental Balance Sheet Information [Abstract]
Investments	$ 3,771	$ 20,516
Prepaid income tax	40,705	26,350
Restricted cash	532	271
Other	0	149
Other current assets	$ 45,008	$ 47,286

SUPPLEMENTAL BALANCE SHEET IN83

SUPPLEMENTAL BALANCE SHEET INFORMATION - Composition of Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,461,967	$ 1,322,772
Less: Accumulated depreciation	(706,140)	(644,813)
Property, plant and equipment, net	755,827	677,959
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	47,392	39,846
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	784,129	713,841
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	403,123	362,695
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	47,071	41,477
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	24,148	21,783
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	127,283	113,466
Vehicles
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,118	3,819
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 24,703	$ 25,845

SUPPLEMENTAL BALANCE SHEET IN84

SUPPLEMENTAL BALANCE SHEET INFORMATION - Composition of Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Supplemental Balance Sheet Information [Abstract]
Life insurance policies	$ 29,456	$ 27,554
Venture capital investments	45,331	32,730
Restricted cash	1,736	1,745
Other	11,907	9,614
Other assets	$ 88,430	$ 71,643

SUPPLEMENTAL BALANCE SHEET IN85

SUPPLEMENTAL BALANCE SHEET INFORMATION - Composition of Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Supplemental Balance Sheet Information [Abstract]
Accrued income taxes	$ 25,621	$ 12,168
Other	879	376
Other current liabilities	$ 26,500	$ 12,544

SUPPLEMENTAL BALANCE SHEET IN86

SUPPLEMENTAL BALANCE SHEET INFORMATION Composition of Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Supplemental Balance Sheet Information [Abstract]
Long-term pension liability	$ 89,984	$ 34,604
Accrued executive supplemental life insurance retirement plan and deferred compensation plan	32,880	30,188
Other	36,375	24,270
Other long-term liabilities	$ 159,239	$ 89,062

VENTURE CAPITAL INVESTMENTS A87

VENTURE CAPITAL INVESTMENTS AND MARKETABLE SECURITIES (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Marketable Securities and Equity-Method Affiliates [Abstract]
Gains related to venture capital investments	$ 10,284,000	$ 3,823,000	$ 9,301,000
Total commitment	84,800,000
Venture capital investments	38,200,000
Dividends received	7,100,000	7,300,000	$ 7,400,000
Consolidated retained earnings (accumulated deficit)	4,400,000	2,400,000
Sales of available for sale securities	4,600,000	0
Marketable securities	$ 0	$ 4,509,000

VENTURE CAPITAL INVESTMENTS A88

VENTURE CAPITAL INVESTMENTS AND MARKETABLE SECURITIES - Summary of Marketable Securities (Details) - USD ($)	Dec. 31, 2016	Dec. 26, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		$ 4,650,000
Gross Unrealized Gains		0
Gross Unrealized Losses		(141,000)
Fair Value	$ 0	4,509,000
Mutual fund
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		4,650,000
Gross Unrealized Gains		0
Gross Unrealized Losses		(141,000)
Fair Value		$ 4,509,000

FAIR VALUE - Assets, Liabilitie

FAIR VALUE - Assets, Liabilities, and Redeemable Noncontrolling Interest Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 21	$ 190
Other current assets:
Marketable securities		4,509
Foreign currency forward contracts		15
Other assets:
Life insurance policies	22,121	20,364
Total assets measured at fair value	22,142	25,078
Other current liabilities:
Contingent consideration	3,621	1,172
Other long-term liabilities:
Contingent consideration		198
Redeemable noncontrolling interest		28,008
Total liabilities and redeemable noncontrolling interest measured at fair value	3,621	29,378
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Other current assets:
Marketable securities		4,509
Foreign currency forward contracts		0
Other assets:
Life insurance policies	0	0
Total assets measured at fair value	0	4,509
Other current liabilities:
Contingent consideration	0	0
Other long-term liabilities:
Contingent consideration		0
Redeemable noncontrolling interest		0
Total liabilities and redeemable noncontrolling interest measured at fair value	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	21	190
Other current assets:
Marketable securities		0
Foreign currency forward contracts		15
Other assets:
Life insurance policies	22,121	20,364
Total assets measured at fair value	22,142	20,569
Other current liabilities:
Contingent consideration	0	0
Other long-term liabilities:
Contingent consideration		0
Redeemable noncontrolling interest		0
Total liabilities and redeemable noncontrolling interest measured at fair value	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Other current assets:
Marketable securities		0
Foreign currency forward contracts		0
Other assets:
Life insurance policies	0	0
Total assets measured at fair value	0	0
Other current liabilities:
Contingent consideration	3,621	1,172
Other long-term liabilities:
Contingent consideration		198
Redeemable noncontrolling interest		28,008
Total liabilities and redeemable noncontrolling interest measured at fair value	$ 3,621	$ 29,378

FAIR VALUE (Details)

FAIR VALUE (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Fair Value Disclosures [Abstract]
Transfers between fair value levels	$ 0	$ 0

FAIR VALUE - Rollforward of Co

FAIR VALUE - Rollforward of Contingent Consideration (Details) - Contingent Consideration - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 1,370	$ 2,828
Additions	3,600	973
Payments	(872)	(600)
Total gains or losses (realized/unrealized):
Reversal of previously recorded contingent liability and change in fair value	(477)	(1,831)
Ending balance	$ 3,621	$ 1,370

FAIR VALUE - Rollforward of the

FAIR VALUE - Rollforward of the Fair Value of Redeemable Noncontrolling Interest (Details) - Redeemable Noncontrolling Interest - Level 3 - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jul. 07, 2016	Dec. 26, 2015
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance		$ 28,419
Total gains or losses (realized/unrealized):
Net income attributable to noncontrolling interest	$ 320	838
Foreign currency translation	(653)	(1,066)
Change in fair value, included in additional paid-in capital	(1,690)	(183)
Ending balance	$ 25,985	$ 28,008

GOODWILL AND INTANGIBLE ASSET93

GOODWILL AND INTANGIBLE ASSETS - Rollforward of Company's Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Goodwill [Roll Forward]
Gross carrying amount, beginning balance	$ 1,443,829	$ 1,326,077
Adjustments to Goodwill, Acquisitions
Adjustments to Goodwill, Foreign Exchange
Adjustments to Goodwill, Transfers
Gross carrying amount, ending balance	1,792,517	1,443,829
Goodwill	787,517	438,829	$ 321,077
RMS
Goodwill [Roll Forward]
Gross carrying amount, beginning balance	58,167	59,196
Adjustments to Goodwill, Acquisitions	0	0
Adjustments to Goodwill, Foreign Exchange	(1,428)	(1,029)
Adjustments to Goodwill, Transfers	(342)
Gross carrying amount, ending balance	56,397	58,167
DSA
Goodwill [Roll Forward]
Gross carrying amount, beginning balance	1,252,050	1,234,302
Adjustments to Goodwill, Acquisitions	337,872	22,146
Adjustments to Goodwill, Foreign Exchange	(21,446)	(4,398)
Adjustments to Goodwill, Transfers	0
Gross carrying amount, ending balance	1,568,476	1,252,050
Accumulated impairment loss - DSA	(1,005,000)	(1,005,000)	$ (1,005,000)
Manufacturing
Goodwill [Roll Forward]
Gross carrying amount, beginning balance	133,612	32,579
Adjustments to Goodwill, Acquisitions	46,859	105,567
Adjustments to Goodwill, Foreign Exchange	(13,169)	(4,534)
Adjustments to Goodwill, Transfers	342
Gross carrying amount, ending balance	$ 167,644	$ 133,612

GOODWILL AND INTANGIBLE ASSET94

GOODWILL AND INTANGIBLE ASSETS - Intangible Assets, Net by Major Class (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Finite-lived intangible assets
Gross	$ 623,870	$ 533,661
Accumulated Amortization	(229,422)	(252,857)
Net	394,448	280,804
Backlog
Finite-lived intangible assets
Gross	8,370	50,568
Accumulated Amortization	(6,390)	(50,554)
Net	1,980	14
Technology
Finite-lived intangible assets
Gross	71,425	60,350
Accumulated Amortization	(14,314)	(5,911)
Net	57,111	54,439
Trademark and trade names
Finite-lived intangible assets
Gross	8,177	11,495
Accumulated Amortization	(4,124)	(5,944)
Net	4,053	5,551
Other
Finite-lived intangible assets
Gross	16,775	14,711
Accumulated Amortization	(5,628)	(7,285)
Net	11,147	7,426
Other intangible assets
Finite-lived intangible assets
Gross	104,747	137,124
Accumulated Amortization	(30,456)	(69,694)
Net	74,291	67,430
Client relationships
Finite-lived intangible assets
Gross	519,123	396,537
Accumulated Amortization	(198,966)	(183,163)
Net	$ 320,157	$ 213,374

GOODWILL AND INTANGIBLE ASSET95

GOODWILL AND INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Impairment charge	$ 1,900
Amortization of intangible assets	$ 41,699	$ 24,229	$ 25,957

GOODWILL AND INTANGIBLE ASSET96

GOODWILL AND INTANGIBLE ASSETS - Estimated Amortization Expense for Intangible Assets for Next Five Fiscal Years (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 41,699	$ 24,229	$ 25,957
Estimated amortization expense for each of the next five fiscal years
2,017	42,525
2,018	40,731
2,019	34,995
2,020	34,382
2,021	$ 32,994

LONG-TERM DEBT AND CAPITAL LE97

LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS - Long-term Debt, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Debt Instrument [Line Items]
Total debt	$ 1,212,694	$ 836,234
Less: Current portion of long-term debt	(24,560)	(15,193)
Long-term debt	1,188,134	821,041
Debt discount and debt issuance costs	(7,633)	(6,805)
Long-term debt, net	1,180,501	814,236
Term loans
Debt Instrument [Line Items]
Total debt	633,750	390,000
Revolving credit facility
Debt Instrument [Line Items]
Total debt	578,759	446,041
Other long-term debt
Debt Instrument [Line Items]
Total debt	$ 185	$ 193

LONG-TERM DEBT AND CAPITAL LE98

LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS (Details)	Mar. 30, 2016USD ($)payment	Apr. 30, 2015USD ($)	Dec. 31, 2016USD ($)	Mar. 29, 2016USD ($)	Dec. 26, 2015USD ($)	Jun. 27, 2015USD ($)	Mar. 31, 2015USD ($)
Debt Instrument [Line Items]
Weighted average interest rate			1.89%		1.33%
Credit facility	$ 1,650,000,000	$ 1,300,000,000		$ 1,300,000,000			$ 970,000,000
Capitalized debt issuance costs	3,300,000
Expensed debt issuance costs	1,400,000
Maximum increase to the term loan and/or revolving line of credit	$ 500,000,000
Letter of Credit
Debt Instrument [Line Items]
Amount outstanding under letters of credit			$ 4,900,000		$ 4,900,000
Credit facility
Debt Instrument [Line Items]
Minimum EBITDA less capital expenditures to consolidated cash interest expense	3.50
Maximum consolidated indebtedness to consolidated EBITDA	4.25
Maximum consolidated indebtedness to consolidated EBITDA, with step downs	3.50
Capital Lease Obligation | Argenta and BioFocus UK
Debt Instrument [Line Items]
Capital lease obligations						$ 35,800,000
Federal Funds Rate
Debt Instrument [Line Items]
Interest rate	0.50%	0.50%
LIBOR
Debt Instrument [Line Items]
Interest rate	1.00%	1.00%
Term Loan Facility
Debt Instrument [Line Items]
Credit facility	$ 650,000,000	$ 400,000,000
Number of quarterly installment payments | payment	19
Multi-currency Revolving Facility
Debt Instrument [Line Items]
Credit facility	$ 1,000,000,000	$ 900,000,000

LONG-TERM DEBT AND CAPITAL LE99

LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS - Principal Maturities of Long Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Debt Disclosure [Abstract]
2,017	$ 24,560
2,018	36,563
2,019	52,813
2,020	81,250
2,021	1,017,508
Total debt	$ 1,212,694	$ 836,234

LONG-TERM DEBT AND CAPITAL L100

LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS - Future Minimum Lease Payments Under Capital Lease Payments (Details) $ in Thousands	Dec. 31, 2016USD ($)
Debt Disclosure [Abstract]
2,017	$ 4,097
2,018	3,503
2,019	3,005
2,020	2,385
2,021	2,250
Thereafter	27,974
Total	$ 43,214

EQUITY AND REDEEMABLE NONCON101

EQUITY AND REDEEMABLE NONCONTROLLING INTEREST - Reconciliation of Numerator and Denominator in the Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Numerator:
Income from continuing operations, net of income taxes	$ 156,086	$ 152,037	$ 129,924
Income (loss) from discontinued operations, net of income taxes	280	(950)	(1,726)
Less: Net income attributable to noncontrolling interests	1,601	1,774	1,500
Net income attributable to common shareholders	$ 154,765	$ 149,313	$ 126,698
Denominator:
Weighted-average shares outstanding—Basic (in shares)	47,014	46,496	46,627
Effect of dilutive securities:
Stock options, restricted stock units, performance share units and restricted stock (in shares)	944	1,138	931
Weighted-average shares outstanding—Diluted (in shares)	47,958	47,634	47,558

EQUITY AND REDEEMABLE NONCON102

EQUITY AND REDEEMABLE NONCONTROLLING INTEREST - Earnings Per Share, Additional Information (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted-average shares outstanding—Diluted (in shares)	47,958	47,634	47,558
Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	800	500	600
Restricted Stock, Restricted Stock Units, and PSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted-average shares outstanding—Diluted (in shares)	1,100	1,100	1,200

EQUITY AND REDEEMABLE NONCON103

EQUITY AND REDEEMABLE NONCONTROLLING INTEREST - Treasury Shares, Additional Information (Details) - USD ($) shares in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2010	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014	Dec. 25, 2010
Treasury Shares and Accelerated Stock Repurchase Program (ASR)
Shares repurchased		$ 12,267,000	$ 117,478,000	$ 122,018,000
Shares acquired for individual minimum statutory tax withholding (in shares)		0.2	0.1	0.1
Shares acquired for individual minimum statutory tax withholding		$ 12,300,000	$ 8,700,000	$ 6,800,000
2010 Share Repurchase Program
Treasury Shares and Accelerated Stock Repurchase Program (ASR)
Authorized increases to share repurchase program	$ 500,000,000		$ 150,000,000	$ 250,000,000	$ 250,000,000
Aggregate authorization of share repurchase program		1,150,000,000
Number of shares repurchased (in shares)			1.5	2.1
Shares repurchased			$ 108,800,000	$ 110,600,000
Amount remaining on the authorized share repurchase program		$ 69,700,000

EQUITY AND REDEEMABLE NONCON104

EQUITY AND REDEEMABLE NONCONTROLLING INTEREST - Changes to Accumulated Other Comprehensive Income (Loss), Net of Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Increase (Decrease) in Stockholders' Equity
Beginning balance	$ 737,556	$ 675,927	$ 644,077
Other comprehensive loss before reclassifications	(132,296)	(61,047)
Amounts reclassified from accumulated other comprehensive income (loss)	1,711	276
Net current period other comprehensive income (loss)	(130,585)	(60,771)
Income tax expense (benefit)	(12,369)	530	(9,897)
Ending balance	839,125	737,556	675,927
Foreign Currency Translation and Other
Increase (Decrease) in Stockholders' Equity
Beginning balance	(82,977)	(19,891)
Other comprehensive loss before reclassifications	(71,618)	(60,745)
Amounts reclassified from accumulated other comprehensive income (loss)	0	(2,341)
Net current period other comprehensive income (loss)	(71,618)	(63,086)
Income tax expense (benefit)	0	0
Ending balance	(154,595)	(82,977)	(19,891)
Pension and Other Post-Retirement Benefit Plans
Increase (Decrease) in Stockholders' Equity
Beginning balance	(52,571)	(54,356)
Other comprehensive loss before reclassifications	(60,678)	(302)
Amounts reclassified from accumulated other comprehensive income (loss)	1,711	2,617
Net current period other comprehensive income (loss)	(58,967)	2,315
Income tax expense (benefit)	(12,369)	530
Ending balance	(99,169)	(52,571)	(54,356)
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity
Beginning balance	(135,548)	(74,247)	5,357
Ending balance	$ (253,764)	$ (135,548)	$ (74,247)

EQUITY AND REDEEMABLE NONCON105

EQUITY AND REDEEMABLE NONCONTROLLING INTEREST - Redeemable Noncontrolling Interest, Additional Information (Details) - USD ($) $ in Millions	Jul. 07, 2016	Jan. 31, 2013	Dec. 31, 2016	Jul. 08, 2016
Schedule of Investments [Line Items]
Redeemable noncontrolling interest, contractually defined redemption value			$ 14.1
Vital River
Schedule of Investments [Line Items]
Ownership interest	12.00%	75.00%	87.00%	12.00%
Remaining noncontrolling equity interest		25.00%	13.00%
Purchase price of additional equity interest	$ 10.8
Gain in equity equal to the excess fair value of additional equity interest purchased	1.6
Charge in other income (expense), net equal to the excess fair value of the hybrid equity instrument	$ 1.5
Vital River
Schedule of Investments [Line Items]
Purchase price		$ 24.2
Cash acquired		$ 2.7

EQUITY AND REDEEMABLE NONCON106

EQUITY AND REDEEMABLE NONCONTROLLING INTEREST - Rollforward of Redeemable Noncontrolling Interest (Details) - USD ($) $ in Thousands	6 Months Ended
	Dec. 31, 2016	Jul. 08, 2016	Jul. 07, 2016	Jan. 31, 2013
Increase (Decrease) in Temporary Equity [Roll Forward]
July 7, 2016	$ 25,985
Purchase of 12% equity interest	(12,360)
Foreign currency translation	(818)
December 31, 2016	14,659
Net Income Attributable to Noncontrolling Interest
Increase (Decrease) in Temporary Equity [Roll Forward]
Income (loss) attributable to noncontrolling interest	357
Other Income (Expense)
Increase (Decrease) in Temporary Equity [Roll Forward]
Income (loss) attributable to noncontrolling interest	$ 1,495
Vital River
Increase (Decrease) in Temporary Equity [Roll Forward]
Ownership interest	87.00%	12.00%	12.00%	75.00%
Remaining noncontrolling equity interest	13.00%			25.00%

INCOME TAXES Components of Inco

INCOME TAXES Components of Income from Continuing Operations Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Income from continuing operations before income taxes:
U.S.	$ 59,255	$ 76,157	$ 71,002
Non-U.S.	163,666	119,271	106,593
Income from continuing operations, before income taxes	222,921	195,428	177,595
Current:
Federal	18,592	23,687	13,733
Foreign	39,829	8,572	20,364
State	5,263	6,819	4,746
Total current	63,684	39,078	38,843
Deferred:
Federal	7,206	1,790	12,982
Foreign	(4,024)	3,064	(4,672)
State	(31)	(541)	518
Total deferred	3,151	4,313	8,828
Provision for income taxes	$ 66,835	$ 43,391	$ 47,671

INCOME TAXES Deferred Taxes (De

INCOME TAXES Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Deferred tax assets:
Compensation	$ 70,863	$ 55,259
Accruals and reserves	8,103	8,941
Inventory reserves and valuations	3,447	2,022
Financing related	0	902
Net operating loss and credit carryforwards	58,081	35,233
Other	2,921	2,593
Valuation allowance	(10,101)	(6,112)
Total deferred tax assets	133,314	98,838
Deferred tax liabilities:
Goodwill and other intangibles	(121,256)	(73,208)
Financing related	(854)	0
Depreciation related	(32,271)	(23,664)
Venture capital investments	(5,084)	(3,570)
Foreign withholding taxes	(821)	(6,590)
Total deferred tax liabilities	(160,286)	(107,032)
Net deferred taxes	$ (26,972)	$ (8,194)

INCOME TAXES Reconciliation of

INCOME TAXES Reconciliation of US Statutory Tax Rate and Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Income Tax Disclosure [Abstract]
U.S. statutory income tax rate	35.00%	35.00%	35.00%
Foreign tax rate differences	(10.30%)	(8.60%)	(9.40%)
State income taxes, net of Federal tax benefit	1.60%	1.90%	1.90%
Research tax credits and enhanced deductions	(3.50%)	(2.60%)	(4.10%)
Enacted tax rate changes	(0.80%)	(1.50%)	0.00%
Impact of tax uncertainties	0.20%	(5.20%)	(0.70%)
Foreign withholding taxes	2.00%	3.40%	0.00%
Impact of acquisitions and restructuring	1.80%	(2.00%)	1.60%
Other	4.00%	1.80%	2.50%
Effective income tax rate	30.00%	22.20%	26.80%

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Income Tax Contingency [Line Items]
Increase in valuation allowance	$ 4,000
Valuation allowance	10,101	$ 6,112
Increase in unrecognized income tax benefits	800
Unrecognized tax benefits that would impact effective tax rate	21,400	20,100
Increase in unrecognized income tax benefits that would impact tax rate	1,300
Decrease in unrecognized tax benefits that is reasonably possible	4,600
Accrued interest related to unrecognized income tax benefits	1,700	1,000
Accrued penalties related to unrecognized income tax benefits	200
Earnings of non-U.S. subsidiaries considered to be indefinitely reinvested	704,600
Foreign withholding taxes related to consolidated appropriations act	4,500
Foreign Tax Authority
Income Tax Contingency [Line Items]
Operating loss carryforwards	58,500	$ 34,600
Foreign Tax Authority | Tax Credit Carryforwards, Expiring in 2028 and Beyond
Income Tax Contingency [Line Items]
Tax credit carryforward	40,500
Foreign Tax Authority | Net Operating Loss Carryforward, Expiring after 2016
Income Tax Contingency [Line Items]
Operating loss carryforwards	5,200
Foreign Tax Authority | Net Operating Loss Carryforward, Carried Forward Indefinitely
Income Tax Contingency [Line Items]
Operating loss carryforwards	12,800
Canada | Tax Credit Carryforwards, Expiring in 2028 and Beyond
Income Tax Contingency [Line Items]
Tax credit carryforward	$ 16,800

INCOME TAXES Change in Tax Posi

INCOME TAXES Change in Tax Positions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Reconciliation of Unrecognized Tax Benefits
Beginning balance	$ 23,338	$ 34,627	$ 18,475
Additions to tax positions for current year	2,194	2,362	1,700
Additions to tax positions for prior years	2,035	3,028	18,502
Reductions to tax positions for current year	0	0	0
Reductions to tax positions for prior years	(1,866)	(3,991)	(3,722)
Settlements	(918)	(1,946)	(308)
Expiration of statute of limitations	(597)	(10,742)	(20)
Ending balance	$ 24,186	$ 23,338	$ 34,627

EMPLOYEE BENEFIT PLANS (Details

EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Defined Benefit Plan Disclosure [Line Items]
Deferral period	3 years
Maximum annual contributions per employee, percent	10.00%
Period of highest consecutive years of compensation	5 years
Costs associated with deferred compensation plan and executive supplemental life insurance retirement plans	$ 2,200	$ 2,600	$ 3,300
Life insurance policies	$ 29,456	27,554
Sensitivity of expected rate of return on plan assets, percent change	0.50%
Sensitivity of change in expected rate of return, annual pension expense amount	$ 1,300
Employer contributions	4,000
Expected employer contributions in 2017	4,000
Accumulated benefit obligation	1,200	900
Costs associated with employee savings plan	$ 6,200	$ 5,300	$ 4,900
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Weighted average target plan asset allocations	45.00%
Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Weighted average target plan asset allocations	31.50%
Other Securities
Defined Benefit Plan Disclosure [Line Items]
Weighted average target plan asset allocations	23.50%

EMPLOYEE BENEFIT PLANS - Recon

EMPLOYEE BENEFIT PLANS - Reconciliation of Benefit Obligations and Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Change in fair value of plan assets:
Employer contributions	$ 4,000
Pension Plans
Change in projected benefit obligations:
Benefit obligation at beginning of year	345,220	$ 359,130
Service cost	2,453	4,293	$ 4,155
Interest cost	12,046	12,974	13,831
Benefit payments	(13,383)	(8,191)
Curtailment	(279)	0
Settlements	(5,499)	0
Plan amendments	188	0
Transfer in from acquisition	5,271	0
Actuarial loss (gain)	71,006	(10,362)
Administrative expenses paid	(605)	(411)
Effect of foreign exchange	(36,476)	(12,213)
Benefit obligation at end of year	379,942	345,220	359,130
Change in fair value of plan assets:
Fair value of plan assets at beginning of year	275,480	281,290
Actual return on plan assets	23,388	6,263
Employer contributions	10,551	6,762
Settlements	(5,499)	0
Transfer in from acquisition	508	0
Administrative expenses paid	(605)	(411)
Effect of foreign exchange	(33,537)	(10,233)
Fair value of plan assets at end of year	256,903	275,480	$ 281,290
Net balance sheet liability	123,039	69,740
Amounts recognized in balance sheet:
Noncurrent assets	0	261
Current liabilities	1,120	6,133
Noncurrent liabilities	$ 121,919	$ 63,868

EMPLOYEE BENEFIT PLANS - Amount

EMPLOYEE BENEFIT PLANS - Amounts Recognized in Accumulated Other Comprehensive Loss (Details) - Pension Plans - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Amounts recognized in accumulated other comprehensive income (loss)
Net actuarial loss	$ 123,743	$ 73,412
Net prior service cost (credit)	(3,300)	(4,584)
Net amount recognized	$ 120,443	$ 68,828

EMPLOYEE BENEFIT PLANS - Accum

EMPLOYEE BENEFIT PLANS - Accumulated Benefit Obligation and Fair Value of Plan Assets for Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets (Details) - Pension Plans - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Plans with Accumulated Benefit Obligations in Excess of Plan Assets
Accumulated benefit obligation	$ 346,122	$ 306,433
Fair value of plan assets	$ 242,172	$ 253,225

EMPLOYEE BENEFIT PLANS - Proje

EMPLOYEE BENEFIT PLANS - Projected Benefit Obligation and Fair Value of Plan Assets for Pension Plans with Projected Benefit Obligations in Excess of Plan Assets (Details) - Pension Plans - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 379,942	$ 336,155
Fair value of plan assets	$ 256,903	$ 266,154

EMPLOYEE BENEFIT PLANS - Amoun

EMPLOYEE BENEFIT PLANS - Amounts in Accumulated Other Comprehensive Income Expected to be Recognized as Components of Net Periodic Benefit Cost Over the Next Fiscal Year (Details) - Pension Plans $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Defined Benefit Plan Disclosure [Line Items]
Amortization of net actuarial loss	$ 3,867
Amortization of net prior service credit	$ (475)

EMPLOYEE BENEFIT PLANS - Compo

EMPLOYEE BENEFIT PLANS - Components of Net Period Benefit Cost (Details) - Pension Plans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2,453	$ 4,293	$ 4,155
Interest cost	12,046	12,974	13,831
Expected return on plan assets	(14,164)	(16,987)	(17,444)
Amortization of prior service cost (credit)	(292)	(581)	1,211
Amortization of net loss (gain)	2,003	3,198	23
Curtailment	(279)	0	0
Settlements	788	0	0
Net periodic cost (benefit)	$ 2,555	$ 2,897	$ 1,776

EMPLOYEE BENEFIT PLANS - Weigh

EMPLOYEE BENEFIT PLANS - Weighted-average Assumptions (Details) - Pension Plans	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Weighted-average assumptions used to determine projected benefit obligations
Discount rate	3.01%	3.89%
Rate of compensation increase	3.25%	3.17%
Weighted-average assumptions used to determine net periodic benefit cost
Discount rate	3.89%	3.75%	4.44%
Expected long-term return on plan assets	5.83%	6.24%	6.41%
Rate of compensation increase	3.17%	3.18%	3.36%

EMPLOYEE BENEFIT PLANS - Fair

EMPLOYEE BENEFIT PLANS - Fair Value of Company's Pension Plan Assets by Asset Category (Details) - Pension Plans - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 256,903	$ 275,480	$ 281,290
Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	108	92
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	69,600	71,831
Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	62,563	71,311
Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	121,294	129,414
Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,338	2,832
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	188,766	199,181
Level 1 | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	108	92
Level 1 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	63,348	65,890
Level 1 | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	59,294	68,489
Level 1 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	64,698	63,689
Level 1 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,318	1,021
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	66,703	74,537
Level 2 | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,252	5,941
Level 2 | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,269	2,822
Level 2 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	56,596	65,725
Level 2 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	586	49
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,434	1,762
Level 3 | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,434	$ 1,762

EMPLOYEE BENEFIT PLANS - Estim

EMPLOYEE BENEFIT PLANS - Estimated Future Benefit Payments (Details) - Pension Plans $ in Thousands	Dec. 31, 2016USD ($)
Defined Benefit Plan Disclosure [Line Items]
2,017	$ 8,610
2,018	8,818
2,019	9,682
2,020	10,014
2,021	30,717
Thereafter	$ 57,705

STOCK-BASED COMPENSATION (Detai

STOCK-BASED COMPENSATION (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares to be awarded (in shares)	7,300,000
Stock based awards plan modification, incremental compensation cost		$ 4,500,000
Capitalized stock-based compensation related costs	$ 0	0	$ 0
Pool of excess tax benefits	32,200,000	22,300,000	$ 10,800,000
Income tax benefit to additional paid-in capital related to the exercise of stock options and vesting of restricted shares and restricted stock units	$ 9,300,000	$ 10,600,000
Weighted-average grant date fair value of stock options granted (in dollars per share)	$ 15.12	$ 17.24	$ 15.19
Stock-based compensation related to PSUs	$ 43,642,000	$ 40,122,000	$ 31,035,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested stock options expected to vest	$ 10,800,000
Weighted average vesting period of unvested stock options expected to vest	2 years 2 months
Intrinsic value of options exercised	$ 23,000,000	$ 28,300,000	$ 30,500,000
Stock Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years	4 years	4 years
Stock options, expiration period	5 years	5 years	5 years
Stock Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, expiration period	7 years	7 years	7 years
Restricted Stock Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	2 years
Restricted Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average vesting period of unvested stock options expected to vest	1 year 2 months
Unrecognized compensation cost related to unvested restricted stock units expected to vest	$ 19,200,000
Fair value of awards vested	$ 14,600,000	$ 15,700,000	$ 13,900,000
Restricted Stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	2 years	2 years	2 years
Restricted Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years	4 years	4 years
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of awards vested	$ 18,000,000	$ 6,600,000
Maximum number of common shares to be issued upon vesting of PSUs (in shares)	300,000
Stock-based compensation related to PSUs	$ 19,700,000	$ 14,700,000	$ 8,500,000
PSUs | Performance Shares Grantee Group Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSUs granted (in shares)	18,000
Weighted average per share fair value (in dollars per share)	$ 73.70
PSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years	3 years	3 years
Number of shares employee is entitled to receive at no cost (in shares)	0	0	0
2007 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equivalent shares (in shares)	1
2007 Incentive Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares to be awarded (in shares)	18,700,000
2007 Incentive Plan | Restricted Stock, Restricted Stock Units, and PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equivalent shares (in shares)	2.3
2016 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equivalent shares (in shares)	1
2016 Incentive Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares to be awarded (in shares)	6,116,000
2016 Incentive Plan | Restricted Stock, Restricted Stock Units, and PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equivalent shares (in shares)	2.3

STOCK-BASED COMPENSATION - Fin

STOCK-BASED COMPENSATION - Financial Statement Line Items in Which Stock-Based Compensation is Located (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	$ 43,642	$ 40,122	$ 31,035
Provision for income taxes	(15,548)	(14,225)	(11,006)
Stock-based compensation, net of income taxes	28,094	25,897	20,029
Cost of revenue (excluding amortization of intangible assets)
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	6,508	6,511	5,382
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	$ 37,134	$ 33,611	$ 25,653

STOCK-BASED COMPENSATION - Sto

STOCK-BASED COMPENSATION - Stock Option Activities (Details) - 2007 Incentive Plan - Stock Options $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)$ / sharesshares
Number of shares
Options outstanding, balance at the beginning of the period (in shares) | shares	2,066
Options granted (in shares) | shares	588
Options exercised (in shares) | shares	(601)
Options canceled (in shares) | shares	(83)
Options outstanding, balance at the end of the period (in shares) | shares	1,970
Weighted Average Exercise Price
Options outstanding, balance at the beginning of the period (in dollars per share) | $ / shares	$ 50.62
Options granted (in dollars per share) | $ / shares	74.13
Options exercised (in dollars per share) | $ / shares	38.52
Options canceled (in dollars per share) | $ / shares	62.66
Options outstanding, balance at the end of the period (in dollars per share) | $ / shares	$ 60.82
Other Disclosures
Options outstanding weighted average remaining contractual life	3 years 5 months
Options outstanding, aggregate intrinsic value | $	$ 30,638
Options exercisable (in shares) | shares	746
Options exercisable (in dollars per share) | $ / shares	$ 48.34
Options exercisable, weighted average remaining contractual life	2 years 7 months
Options exercisable, aggregate intrinsic value | $	$ 20,817
Options expected to vest (in shares) | shares	1,202
Options expected to vest (in dollars per share) | $ / shares	$ 68.40
Options expected to vest, weighted average remaining contractual life	3 years 9 months
Options expected to vest, aggregate intrinsic value | $	$ 9,690

STOCK-BASED COMPENSATION - 125

STOCK-BASED COMPENSATION - Stock Options, Weighted Average Assumptions (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected life (in years)	3 years 7 months 12 days	3 years 7 months 12 days	4 years 2 months 12 days
Expected volatility	25.00%	28.00%	30.00%
Risk-free interest rate	1.20%	1.10%	1.50%
Expected dividend yield	0.00%	0.00%	0.00%

STOCK-BASED COMPENSATION - Res

STOCK-BASED COMPENSATION - Restricted Stock and Restricted Stock Units Activity (Details) - 2007 Incentive Plan - Restricted Stock and Restricted Stock Units shares in Thousands	12 Months Ended
	Dec. 31, 2016$ / sharesshares
Restricted Stock and Restricted Stock Units
Balance at the beginning of the period (in shares) | shares	607
Granted (in shares) | shares	236
Vested (in shares) | shares	(296)
Canceled (in shares) | shares	(32)
Balance at the end of the period (in shares) | shares	515
Weighted Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share) | $ / shares	$ 55.52
Granted (in dollars per share) | $ / shares	75.10
Vested (in dollars per share) | $ / shares	49.29
Canceled (in dollars per share) | $ / shares	63.36
Balance at the end of the period (in dollars per share) | $ / shares	$ 67.62

STOCK-BASED COMPENSATION - Per

STOCK-BASED COMPENSATION - Performance Based Stock Award Program (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Key Assumptions:
Expected volatility	25.00%	28.00%	30.00%
Risk-free interest rate	1.20%	1.10%	1.50%
Expected dividend yield	0.00%	0.00%	0.00%
Average trading days for stock price on grant date	20 days
PSU Grantee Group One | PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSUs granted (in shares)	190,628	148,900	214,823
Key Assumptions:
Expected volatility	24.00%	23.00%	29.00%
Risk-free interest rate	0.91%	0.96%	0.63%
Expected dividend yield	0.00%	0.00%	0.00%
20 trading day average stock price on grant date	(4.80%)	20.60%	13.10%
PSU Grantee Group One | 2007 Incentive Plan | PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average per share fair value (in dollars per share)	$ 80.38	$ 88.62	$ 67.82

FOREIGN CURRENCY CONTRACTS - F

FOREIGN CURRENCY CONTRACTS - Fair Value and Notational Value of Foreign Currency Contracts (Details) - Foreign Exchange Contract $ in Thousands	Dec. 26, 2015USD ($)
Derivative [Line Items]
Notional Amount	$ 88,483
Other Current Assets
Derivative [Line Items]
Fair Value	$ 15

FOREIGN CURRENCY CONTRACTS - G

FOREIGN CURRENCY CONTRACTS - Gains (Losses) Recognized on Foreign Exchange Forward Contracts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Derivatives, Fair Value [Line Items]
Duration of forward contracts outstanding		3 months
Other income (expense), net | Foreign Exchange Contract
Derivatives, Fair Value [Line Items]
Gain (loss) recognized	$ 3,373	$ (4,917)

COMMITMENTS AND CONTINGENCIE130

COMMITMENTS AND CONTINGENCIES (Details) $ in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2015patent	Dec. 31, 2016USD ($)	Dec. 26, 2015USD ($)	Dec. 27, 2014USD ($)
Commitments and Contingencies Disclosure [Abstract]
Rent expense from operating leases		$ 21.8	$ 23.4	$ 14.2
Maximum insurance deductibles		5
Litigation [Line Items]
Unconditional purchase obligations		86.2
Government Billing
Litigation [Line Items]
Liability for excess amounts billed on contracts		1.8	$ 1.5
Additional charge for excess amounts billed on contracts		$ 0.3
Pending Litigation | Idexx
Litigation [Line Items]
Patents allegedly infringed, number | patent	3

COMMITMENTS AND CONTINGENCIES M

COMMITMENTS AND CONTINGENCIES Minimum Rental Commitments Under Non-Cancelable Leases (Details) $ in Thousands	Dec. 31, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,017	$ 23,410
2,018	20,273
2,019	17,119
2,020	13,254
2,021	8,104
Thereafter	19,116
Total	$ 101,276

RESTRUCTURING AND ASSET IMPA132

RESTRUCTURING AND ASSET IMPAIRMENTS - Rollforward of Severance and Retention Costs Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Restructuring Reserve [Roll Forward]
Balance, beginning of period	$ 2,969	$ 2,666	$ 2,782
Expense	8,454	6,173	7,792
Payments / utilization	(7,473)	(5,820)	(7,900)
Foreign currency adjustments	(270)	(50)	(8)
Balance, end of period	$ 3,680	$ 2,969	$ 2,666

RESTRUCTURING AND ASSET IMPA133

RESTRUCTURING AND ASSET IMPAIRMENTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Restructuring Cost and Reserve [Line Items]
Severance and retention costs liability	$ 3,680	$ 2,969	$ 2,666	$ 2,782
Consolidation of Safety Assessment Facilities in Ireland
Restructuring Cost and Reserve [Line Items]
Asset impairments	9,400
Consolidation of Research Model Operations in U.S., Japan and Europe
Restructuring Cost and Reserve [Line Items]
Asset impairments		1,800	2,200
Accelerated depreciation			4,300
Gain on disposition of European facility			$ 1,000
Accrued Compensation
Restructuring Cost and Reserve [Line Items]
Severance and retention costs liability	3,600	2,600
Other long-term liabilities
Restructuring Cost and Reserve [Line Items]
Severance and retention costs liability	$ 100	$ 300

RESTRUCTURING AND ASSET IMPA134

RESTRUCTURING AND ASSET IMPAIRMENTS - Severance and Retention Costs By Classification on the Consolidated Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Restructuring Cost and Reserve [Line Items]
Total severance and retention costs	$ 8,454	$ 6,173	$ 7,792
Cost of revenue (excluding amortization of intangible assets)
Restructuring Cost and Reserve [Line Items]
Total severance and retention costs	4,717	735	3,342
Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Total severance and retention costs	$ 3,737	$ 5,438	$ 4,450

RESTRUCTURING AND ASSET IMPA135

RESTRUCTURING AND ASSET IMPAIRMENTS - Severance and Retention Costs by Reportable Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Segment Reporting Information [Line Items]
Total severance and retention costs	$ 8,454	$ 6,173	$ 7,792
Operating Segments | RMS
Segment Reporting Information [Line Items]
Total severance and retention costs	759	1,338	4,593
Operating Segments | DSA
Segment Reporting Information [Line Items]
Total severance and retention costs	7,689	1,068	2,912
Operating Segments | Manufacturing
Segment Reporting Information [Line Items]
Total severance and retention costs	6	1,639	166
Unallocated corporate
Segment Reporting Information [Line Items]
Total severance and retention costs	$ 0	$ 2,128	$ 121

SEGMENT AND GEOGRAPHIC INFOR136

SEGMENT AND GEOGRAPHIC INFORMATION Financial Information by Reportable Business Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 26, 2015	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Segment Reporting Information [Line Items]
Revenue	$ 466,789	$ 425,720	$ 434,055	$ 354,868	$ 353,850	$ 349,465	$ 339,573	$ 320,414	$ 1,681,432	$ 1,363,302	$ 1,297,662
Operating income	$ 69,091	$ 58,795	$ 58,061	$ 51,472	$ 52,269	$ 55,440	$ 55,735	$ 43,005	237,419	206,449	177,670
Depreciation and amortization									126,658	94,881	96,445
Capital expenditures									55,288	63,252	56,925
RMS
Segment Reporting Information [Line Items]
Revenue									494,037	470,411	503,656
Operating income									136,365	120,973	120,736
Depreciation and amortization									20,853	22,526	27,309
Capital expenditures									11,642	17,398	18,669
DSA
Segment Reporting Information [Line Items]
Revenue									836,593	612,173	538,218
Operating income									138,157	121,981	69,749
Depreciation and amortization									71,816	46,812	47,138
Capital expenditures									27,493	30,333	19,759
Manufacturing
Segment Reporting Information [Line Items]
Revenue									350,802	280,718	255,788
Operating income									104,543	74,675	79,260
Depreciation and amortization									25,566	18,129	14,295
Capital expenditures									$ 12,247	$ 9,814	$ 15,621

SEGMENT AND GEOGRAPHIC INFOR137

SEGMENT AND GEOGRAPHIC INFORMATION Reconciliation of Segment Operating Income and Capital Expenditures (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 26, 2015	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Segment Reporting Information [Line Items]
Operating Income	$ 69,091	$ 58,795	$ 58,061	$ 51,472	$ 52,269	$ 55,440	$ 55,735	$ 43,005	$ 237,419	$ 206,449	$ 177,670
Capital expenditures									55,288	63,252	56,925
Total reportable segments
Segment Reporting Information [Line Items]
Operating Income									379,065	317,629	269,745
Capital expenditures									51,382	57,545	54,049
Unallocated corporate
Segment Reporting Information [Line Items]
Operating Income									(141,646)	(111,180)	(92,075)
Capital expenditures									$ 3,906	$ 5,707	$ 2,876

SEGMENT AND GEOGRAPHIC INFOR138

SEGMENT AND GEOGRAPHIC INFORMATION Revenue by Product and Service Offering (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 26, 2015	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Segment Reporting Information [Line Items]
Total revenue	$ 466,789	$ 425,720	$ 434,055	$ 354,868	$ 353,850	$ 349,465	$ 339,573	$ 320,414	$ 1,681,432	$ 1,363,302	$ 1,297,662
RMS
Segment Reporting Information [Line Items]
Total revenue									494,037	470,411	503,656
DSA
Segment Reporting Information [Line Items]
Total revenue									836,593	612,173	538,218
Manufacturing
Segment Reporting Information [Line Items]
Total revenue									$ 350,802	$ 280,718	$ 255,788

SEGMENT AND GEOGRAPHIC INFOR139

SEGMENT AND GEOGRAPHIC INFORMATION Unallocated Corporate Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Segment Reporting Information [Line Items]
Stock-based compensation	$ 43,642	$ 40,122	$ 31,035
Depreciation expense	85,000	70,700	70,500
Unallocated corporate
Segment Reporting Information [Line Items]
Stock-based compensation	27,272	25,751	18,474
Salary, bonus, and fringe	39,189	33,026	30,838
Consulting, audit, and professional services	23,421	15,418	13,431
IT related expenses	13,233	8,400	6,528
Depreciation expense	8,423	7,414	7,703
Acquisition related adjustments	15,608	11,644	6,285
Other general unallocated corporate expenses	14,500	9,527	8,816
Total unallocated corporate overhead costs	$ 141,646	$ 111,180	$ 92,075

SEGMENT AND GEOGRAPHIC INFOR140

SEGMENT AND GEOGRAPHIC INFORMATION Revenue and Capital Assets by Geographic Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Segment Reporting Information [Line Items]
Revenue	$ 1,681,432	$ 1,363,302	$ 1,297,662
Long-lived assets	755,827	677,959	676,797
U.S.
Segment Reporting Information [Line Items]
Revenue	850,422	659,466	588,531
Long-lived assets	462,330	402,238	386,624
Europe
Segment Reporting Information [Line Items]
Revenue	520,937	435,491	446,263
Long-lived assets	177,423	159,445	153,203
Canada
Segment Reporting Information [Line Items]
Revenue	194,210	172,349	163,490
Long-lived assets	78,866	77,535	95,272
Japan
Segment Reporting Information [Line Items]
Revenue	46,829	40,520	49,921
Long-lived assets	20,941	22,348	23,896
Other Non-U.S.
Segment Reporting Information [Line Items]
Revenue	69,034	55,476	49,457
Long-lived assets	$ 16,267	$ 16,393	$ 17,802

SELECTED QUARTERLY FINANCIAL141

SELECTED QUARTERLY FINANCIAL DATA (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 26, 2015	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$ 466,789	$ 425,720	$ 434,055	$ 354,868	$ 353,850	$ 349,465	$ 339,573	$ 320,414	$ 1,681,432	$ 1,363,302	$ 1,297,662
Gross profit	179,881	156,270	169,747	140,768	140,574	138,075	132,783	119,660
Operating income	69,091	58,795	58,061	51,472	52,269	55,440	55,735	43,005	$ 237,419	$ 206,449	$ 177,670
Net income attributable to common shareholders	$ 44,680	$ 37,735	$ 35,207	$ 37,143	$ 31,884	$ 37,379	$ 48,509	$ 31,541
Basic:
Continuing operations attributable to common shareholders (in dollars per share)	$ 0.95	$ 0.79	$ 0.75	$ 0.80	$ 0.71	$ 0.81	$ 1.04	$ 0.67	$ 3.28	$ 3.23	$ 2.76
Discontinued operations (in dollars per share)	0	0.01	0	0	(0.02)	0	0	0	0.01	(0.02)	(0.04)
Net income attributable to common shareowners (in dollars per share)	0.95	0.80	0.75	0.80	0.69	0.81	1.04	0.67	3.29	3.21	2.72
Diluted:
Continuing operations attributable to common shareowners (in dollars per share)	0.93	0.78	0.73	0.78	0.69	0.79	1.02	0.66	3.22	3.15	2.70
Discontinued operations (in dollars per share)	0	0.01	0	0	(0.02)	0	0	0	0.01	(0.02)	(0.04)
Net income attributable to common shareowners (in dollars per share)	$ 0.93	$ 0.79	$ 0.73	$ 0.78	$ 0.67	$ 0.79	$ 1.02	$ 0.66	$ 3.23	$ 3.13	$ 2.66

SUBSEQUENT EVENTS - Narrative

SUBSEQUENT EVENTS - Narrative (Details) - Subsequent Event - Disposal Group, Held-for-sale, Not Discontinued Operations - CDMO Business	Feb. 10, 2017USD ($)
Subsequent Event [Line Items]
Cash received from disposal	$ 75,000,000
Percentage of revenue from business disposed	1.00%

SUBSEQUENT EVENTS - Carrying Am

SUBSEQUENT EVENTS - Carrying Amounts of the Major Classes of Assets and Liabilities Associated with Thunder Disposal (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Liabilities
Current liabilities	$ 1,623	$ 1,840
Long-term liabilities	5,771	$ 7,890
CDMO Business | Disposal Group, Held-for-sale, Not Discontinued Operations
Assets
Current assets	4,270
Property, plant and equipment, net	11,313
Goodwill	35,857
Long-term assets	17,332
Total assets	68,772
Liabilities
Current liabilities	5,840
Long-term liabilities	7,856
Total liabilities	$ 13,696