Syneos Health (SYNH) 10-K 20 Feb 20 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 13, 2020	Jun. 28, 2019
Cover page.
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	001-36730
Entity Registrant Name	SYNEOS HEALTH, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	27-3403111
Entity Address, Address Line One	1030 Sync Street
Entity Address, City or Town	Morrisville
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	27560-5468
City Area Code	919
Local Phone Number	876-9300
Title of 12(b) Security	Class A Common Stock, par value $0.01 per share
Trading Symbol	SYNH
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 3,157,698,274
Entity Common Stock, Shares Outstanding		104,246,569
Documents Incorporated by Reference	Portions of the registrant’s Proxy Statement for its 2020 Annual Meeting of Stockholders are incorporated by reference into Part III hereof.
Entity Central Index Key	0001610950
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue	$ 4,675,815	$ 4,390,116	$ 2,672,064
Costs and operating expenses:
Selling, general, and administrative expenses	446,281	406,305	282,620
Restructuring and other costs	42,135	50,793	33,315
Transaction and integration-related expenses	61,275	64,841	123,815
Asset impairment charges	0	0	30,000
Depreciation	76,532	72,158	44,407
Amortization	165,933	201,527	135,529
Total operating expenses	4,438,061	4,229,934	2,700,930
Income (loss) from operations	237,754	160,182	(28,866)
Other expense, net:
Interest income	7,542	3,686	1,182
Interest expense	(129,820)	(130,701)	(63,725)
Gain (loss) on extinguishment of debt	10,395	(4,153)	(622)
Other (expense) income, net	(24,162)	28,244	(19,846)
Total other expense, net	(136,045)	(102,924)	(83,011)
Income (loss) before provision for income taxes	101,709	57,258	(111,877)
Income tax benefit (expense)	29,549	(32,974)	(26,592)
Net income (loss)	$ 131,258	$ 24,284	$ (138,469)
Earnings (loss) per share:
Basic (in USD per share)	$ 1.27	$ 0.23	$ (1.85)
Diluted (in USD per share)	$ 1.25	$ 0.23	$ (1.85)
Weighted average common shares outstanding:
Basic (in shares)	103,618	103,414	74,913
Diluted (in shares)	105,005	104,701	74,913
Revenue
Revenue	$ 4,675,815	$ 4,390,116	$ 1,852,843
Costs and operating expenses:
Direct costs (exclusive of depreciation and amortization) and Reimbursable out-of-pocket expenses	3,645,905	3,434,310	1,232,023
Reimbursable out-of-pocket expenses
Revenue	0	0	819,221
Costs and operating expenses:
Direct costs (exclusive of depreciation and amortization) and Reimbursable out-of-pocket expenses	$ 0	$ 0	$ 819,221

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 131,258	$ 24,284	$ (138,469)
Unrealized (loss) gain on derivative instruments, net of income tax benefit of $2,122, $782, and $10, respectively	(7,596)	(8,625)	23
Foreign currency translation adjustments, net of income tax expense of $0, $0, and $(9,005), respectively	24,198	(61,035)	19,842
Comprehensive income (loss)	$ 147,860	$ (45,376)	$ (118,604)

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive (Loss) Income (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Unrealized (loss) gain on derivative instruments, income tax (expense) benefit	$ 2,122,000
Unrealized (loss) gain on derivative instruments, income tax (expense) benefit		$ 782,000	$ 10,000
Foreign currency translation adjustments, income tax benefit (expense)	$ 0	$ 0	$ (9,005,000)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash, cash equivalents, and restricted cash	$ 163,689	$ 155,932
Accounts receivable and unbilled services, net	1,303,641	1,256,731
Prepaid expenses and other current assets	94,834	79,299
Total current assets	1,562,164	1,491,962
Property and equipment, net	203,926	183,486
Operating lease right-of-use assets	218,531
Goodwill	4,350,380	4,333,159
Intangible assets, net	973,081	1,133,612
Deferred income tax assets	37,012	9,317
Other long-term assets	108,701	103,373
Total assets	7,453,795	7,254,909
Current liabilities:
Accounts payable	136,686	98,624
Accrued expenses	568,911	563,527
Deferred revenue	696,907	777,141
Current portion of operating lease obligations	38,055
Current portion of fiance lease obligations	17,777
Current portion of finance lease obligations		13,806
Current portion of long-term debt	58,125	50,100
Total current liabilities	1,516,461	1,503,198
Long-term debt	2,550,395	2,737,019
Operating lease long-term obligations	218,343
Finance lease long-term obligations	36,914
Finance lease long-term obligations		26,759
Deferred income tax liabilities	11,101	25,120
Other long-term liabilities	90,927	106,669
Total liabilities	4,424,141	4,398,765
Commitments and contingencies (Note 17)
Shareholders' equity:
Preferred stock, $0.01 par value; 30,000 shares authorized, 0 shares issued and outstanding at December 31, 2019 and 2018	0	0
Common stock, $0.01 par value; 600,000 shares authorized, 103,866 and 103,372 shares issued and outstanding at December 31, 2019 and 2018, respectively	1,039	1,034
Additional paid-in capital	3,441,471	3,402,638
Accumulated other comprehensive loss, net of tax	(71,593)	(88,195)
Accumulated deficit	(341,263)	(459,333)
Total shareholders' equity	3,029,654	2,856,144
Total liabilities and shareholders' equity	$ 7,453,795	$ 7,254,909

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Preferred stock, par value (in USD per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	30,000,000	30,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	600,000,000	600,000,000
Common stock, shares issued (in shares)	103,865,770	103,372,000
Common stock, shares outstanding (in shares)	103,865,770	103,372,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income (loss)	$ 131,258	$ 24,284	$ (138,469)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	242,465	273,685	179,936
Share-based compensation	55,193	34,323	59,696
Provision for (recovery of) doubtful accounts	1,897	(4,587)	4,167
(Benefit from) provision for deferred income taxes	(40,069)	240	14,431
Foreign currency transaction adjustments	11,166	(16,165)	7,912
Asset impairment charges	0	0	30,000
Fair value adjustment of contingent obligations	17,260	(11,590)	(12,276)
Gain (loss) on extinguishment of debt	10,395	(4,153)	(622)
Other non-cash items	2,766	2,849	5,212
Changes in operating assets and liabilities, net of effect of business combinations:
Accounts receivable, unbilled services, and deferred revenue	(120,389)	(97,621)	60,623
Accounts payable and accrued expenses	28,316	60,024	(16,982)
Other assets and liabilities	(987)	33,853	3,386
Net cash provided by operating activities	318,481	303,448	198,258
Cash flows from investing activities:
Payments associated with business combinations, net of cash acquired	(712)	(90,890)	(1,678,381)
Purchases of property and equipment	(63,973)	(54,595)	(43,896)
Investments in unconsolidated affiliates	16,976	0	0
Other, net	0	0	(567)
Net cash used in investing activities	(81,661)	(145,485)	(1,722,844)
Cash flows from financing activities:
Proceeds from issuance of long-term debt, net of discount	582,000	0	2,598,000
Payments of debt financing costs	(2,636)	(3,062)	(25,476)
Repayments of long-term debt	(437,936)	(390,646)	(525,097)
Proceeds from accounts receivable financing agreement	127,815	187,700	0
Repayments of accounts receivable financing agreement	(22,400)	(18,300)	0
Proceeds from revolving line of credit	0	0	15,000
Repayments of revolving line of credit	0	0	(40,000)
Redemption of Senior Notes and associated breakage fees	(418,112)	0	(292,425)
Payments of contingent consideration related to business combinations	(178)	(23,102)	0
Payments of finance leases		(15,423)	(8,145)
Payments of finance leases	(14,493)
Payments for repurchases of common stock	(56,716)	(74,985)	0
Proceeds from exercises of stock options	40,322	21,821	19,335
Payments related to tax withholdings for share-based compensation	(13,135)	(3,359)	(6,824)
Net cash (used in) provided by financing activities	(215,469)	(319,356)	1,734,368
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(13,594)	(4,651)	9,116
Net change in cash, cash equivalents, and restricted cash	7,757	(166,044)	218,898
Cash, cash equivalents, and restricted cash - beginning of period	155,932	321,976	103,078
Cash, cash equivalents, and restricted cash - end of period	$ 163,689	$ 155,932	$ 321,976

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjusted beginning balance				$ (42,250)
Balance at beginning of period at Dec. 31, 2016	$ 301,473	$ 538	$ 573,176	(42,250)	$ (229,991)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Unrealized (loss) gain on derivatives instruments, net of taxes				23
Foreign currency translation adjustment, net of taxes	19,842			19,842
Business combinations		493	2,768,978
Stock repurchase		0	0		0
RSU distributions net of shares for tax withholding		2
RSU distributions net of shares for tax withholding			(6,826)
Stock option exercises		11	19,365
Share-based compensation			59,696
Net income (loss)	(138,469)
Balance at end of period at Dec. 31, 2017	3,022,579	1,044	3,414,389	(22,385)	(370,469)
Balance at end of period (Accounting Standards Update 2014-09) at Dec. 31, 2017	0
Balance at end of period (Accounting Standards Update 2016-16) at Dec. 31, 2017	(2,009)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjusted beginning balance	299,464			(18,535)
Unrealized (loss) gain on derivatives instruments, net of taxes				(8,625)
Foreign currency translation adjustment, net of taxes	(61,035)			(61,035)
Business combinations		0	0
Stock repurchase		(19)	(64,482)		(10,483)
RSU distributions net of shares for tax withholding		1
RSU distributions net of shares for tax withholding			(3,364)
Stock option exercises		8	21,772
Share-based compensation			34,323
Net income (loss)	24,284
Balance at end of period at Dec. 31, 2018	2,856,144	1,034	3,402,638	(88,195)	(459,333)
Balance at end of period (Accounting Standards Update 2014-09) at Dec. 31, 2018	(98,815)
Balance at end of period (Accounting Standards Update 2016-16) at Dec. 31, 2018	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjusted beginning balance	2,923,764			(88,195)
Unrealized (loss) gain on derivatives instruments, net of taxes				(7,596)
Foreign currency translation adjustment, net of taxes	24,198			24,198
Business combinations		0	0
Stock repurchase		(13)	(43,515)		(13,188)
RSU distributions net of shares for tax withholding		4
RSU distributions net of shares for tax withholding			(13,152)
Stock option exercises		14	40,307
Share-based compensation			55,193
Net income (loss)	131,258
Balance at end of period at Dec. 31, 2019	3,029,654	$ 1,039	$ 3,441,471	$ (71,593)	$ (341,263)
Balance at end of period (Accounting Standards Update 2014-09) at Dec. 31, 2019	0
Balance at end of period (Accounting Standards Update 2016-16) at Dec. 31, 2019	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjusted beginning balance	$ 2,856,144

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies Principal Business Syneos Health, Inc. (the “Company”) is a global end-to-end outsourcing biopharmaceutical solutions organization. The Company operates under two reportable segments, Clinical Solutions and Commercial Solutions, and derives its revenue through a suite of services designed to enhance its customers’ ability to successfully develop, launch, and market their products. The Company offers its solutions on both a standalone and integrated basis with biopharmaceutical development and commercialization services ranging from Phase I-IV clinical trial services to services associated with the commercialization of biopharmaceutical products. The Company’s customers include small, mid-sized, and large companies in the pharmaceutical, biotechnology, and medical device industries. Organization On August 1, 2017, the Company completed the merger (the “Merger”) with Double Eagle Parent, Inc. (“inVentiv”), the parent company of inVentiv Health, Inc. Upon closing, inVentiv was merged with and into the Company, with the Company continuing as the surviving corporation. Following the Merger, the Company amended and restated its certificate of incorporation to change its name from INC Research Holdings, Inc. to Syneos Health, Inc. effective as of January 4, 2018. Beginning August 1, 2017, inVentiv’s results of operations are included in the accompanying consolidated financial statements. For additional information related to the Merger, see "Note 3 - Business Combinations." Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP"), and include the accounts and results of operations of the Company and its controlled subsidiaries. All intercompany balances and transactions have been eliminated. Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities and the disclosures of contingent assets and liabilities as of the date of the financial statements, and the reported amounts of revenue and expenses for the periods presented in the financial statements. Examples of estimates and assumptions include, but are not limited to, determining the fair value of goodwill and intangible assets and their potential impairment, useful lives of tangible and intangible assets, useful lives of assets subject to leases, allowances for doubtful accounts, potential future outcomes of events for which income tax consequences have been recognized in the Company’s consolidated financial statements or tax returns, valuation allowances for deferred tax assets, fair value of share-based compensation and its recognition period, claims and insurance and self-insurance accruals, loss contingencies, fair value of derivative instruments and related hedge effectiveness, fair value of contingent tax sharing obligations, and judgments related to revenue recognition, among others. In addition, estimates and assumptions are used in the accounting for the Merger and other business combinations, including the fair value and useful lives of acquired tangible and intangible assets and the fair value of assumed liabilities. The Company evaluates its estimates and assumptions on an ongoing basis and bases its estimates on historical experience, current and expected future conditions, third-party evaluations, and various other assumptions that management believes are reasonable under the circumstances based on the information available to management at the time these estimates and assumptions are made. Actual results and outcomes may differ significantly from these estimates and assumptions. Business Combinations The Company accounts for business combinations in accordance with ASC Topic 805, Business Combinations , using the acquisition method of accounting. The purchase price, or total consideration transferred, is determined as the fair value of assets exchanged, equity instruments issued, and liabilities assumed at the acquisition date. The acquisition method of accounting requires that the identifiable assets acquired, the liabilities assumed, and any non-controlling interest in the acquiree are measured and recorded at their fair values on the date of a business combination. Goodwill represents the excess of the purchase price over the estimated fair value of the net assets acquired, including the amount assigned to identifiable intangible assets. Acquisition-related costs are expensed as incurred. The consolidated financial statements reflect the results of operations of the acquiree from the date of the acquisition. For additional information, see "Note 3 - Business Combinations." Foreign Currency Translation and Transactions For subsidiaries outside of the U.S. that operate in a local currency environment, revenue and expenses are translated to U.S. dollars at the monthly average rates of exchange prevailing during the period, assets and liabilities are translated at period-end exchange rates and equity accounts are translated at historical exchange rates. The net effect of foreign currency translation adjustments is included in shareholder's equity as a component of accumulated other comprehensive loss in the accompanying consolidated balance sheets. Foreign currency transaction gains and losses are the result of exchange rate changes during the period of time between the consummation and cash settlement of transactions denominated in currencies other than the functional currency. Foreign currency transaction gains and losses are recognized in earnings as incurred and are included in other expense, net in the accompanying consolidated statements of operations. Comprehensive Income (Loss) The Company has elected to present comprehensive income (loss) and its components as a separate financial statement. Other comprehensive income (loss) refers to revenue, expenses, gains, and losses that, under U.S. GAAP, are recorded as an element of shareholders' equity but are excluded from net income (loss). The Company's other comprehensive income (loss) consists of foreign currency translation adjustments, net of applicable taxes, resulting from the translation of foreign subsidiaries with functional currencies other than the U.S. dollar and the effective portions of the unrealized gains or losses associated with derivative instruments designated and accounted for as hedging instruments. Cash and Cash Equivalents Cash and cash equivalents consist of demand deposits with banks and other financial institutions and highly liquid investments with an original maturity of three months or less at the date of purchase. Cash and cash equivalents are carried at cost, which approximates their fair value. Certain of our subsidiaries participate in a notional cash pooling arrangement to manage global liquidity requirements. The parties to the arrangement combine their cash balances in pooling accounts with the ability to offset bank overdrafts of one subsidiary against positive cash account balances maintained in another subsidiary’s bank account at the same financial institution. The net cash balance related to this pooling arrangement is included in cash, cash equivalents, and restricted cash in the accompanying consolidated balance sheet. The Company’s net cash pool position consisted of the following as of December 31 (in thousands): 2019 2018 Gross cash position $ 326,002 $ 206,715 Less: cash borrowings (307,647) (199,784) Net cash position $ 18,355 $ 6,931 Restricted Cash Restricted cash represents cash and deposits held as security over bank deposits, lease guarantees, and insurance obligations that are restricted as to withdrawal or use. Restricted cash is classified as a current or long-term asset based on the timing and nature of when and how the cash is expected to be used or when the restrictions are expected to lapse. As of December 31, 2019 and 2018, restricted cash balances were $0.5 million and $2.1 million, respectively. Fair Value The Company records certain assets and liabilities at fair value in accordance with ASC Topic 820, Fair Value Measurement (see "Note 7 - Fair Value Measurements"). Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. This guidance also specifies a fair value hierarchy that distinguishes between valuation assumptions developed based on market data obtained from independent external sources and the reporting entity's own assumptions. In accordance with this guidance, fair value measurements are classified under the following hierarchy: Level 1 — Unadjusted quoted prices in active markets for identical instruments; Level 2 — Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs or significant value-drivers are observable in active markets; and Level 3 — Model-derived valuations in which one or more significant inputs or significant value-drivers are unobservable. Fair value measurements are classified according to the lowest level input or value-driver that is significant to the valuation. When available, the Company uses quoted market prices to determine fair value and classifies such instruments within the Level 1 category. In cases where market prices are not available, the Company estimates fair value using observable market inputs, in which case the measurements are classified within Level 2. If quoted or observable market prices are not available, fair value estimates are based upon valuation techniques in which one or more significant inputs are unobservable, including internally developed models. These measurements are classified within the Level 3 category. Derivative Financial Instruments The Company uses interest rate swaps designated as cash flow hedges to manage exposure to variable interest rates on its debt obligations. The Company designates its interest rate swaps as cash flow hedges because they are executed to hedge the Company's exposure to the variability in expected future cash flows that are attributable to changes in interest rates. Derivative financial instruments are measured at fair value and recognized in the accompanying consolidated balance sheets in prepaid expenses and other current assets, other long-term assets, accrued expenses, and other long-term liabilities, as disclosed in "Note 6 - Derivatives." The fair value of interest rate swaps is determined using the market standard methodology of discounted future variable cash receipts. The variable cash receipts are determined by discounting the future expected cash receipts that would occur if variable interest rates rise above the fixed rate of the swaps. The variable interest rates used in the calculation of projected receipts on the swap are based on an expectation of future interest rates derived from observable market interest rate curves and volatilities. Changes in the fair value of derivative instruments designated as hedging instruments are recorded each period according to the determination of the derivative's effectiveness. The effective portion of changes in the fair value of derivatives designated as cash flow hedges is recorded in accumulated other comprehensive loss and subsequently reclassified into earnings in the period during which the hedged transaction is recognized in earnings. The ineffective portion of the change in fair value of the derivatives is recognized as non-operating income or expense immediately when incurred and included in interest expense in the accompanying consolidated statements of operations. Allowance for Doubtful Accounts The Company maintains a credit approval process and makes judgments in connection with assessing its customers' ability to pay throughout the contractual obligation period. Generally, the Company has the ability to limit credit exposure by discontinuing services in the event of non-payment. The Company has certain customers that may depend on the ability to continue to raise capital in order to complete the development or commercialization of their products. The Company monitors its customers' credit worthiness and applies judgment in establishing a provision for estimated credit losses based on historical experience, current receivables aging, and customer-specific circumstances that would affect the customers' ability to meet their obligation. Property and Equipment Property and equipment primarily consists of furniture, vehicles, software, office equipment, computer equipment, and lab equipment. Purchased and constructed property and equipment is initially recorded at historical cost plus the estimated value of any associated legally or contractually required retirement obligations. Property and equipment acquired in a business combination are recorded based on the estimated fair value as of the acquisition date. The Company leases vehicles for certain sales representatives in the Commercial Solutions segment. These leases are classified and accounted for as leases in accordance with ASC Topic 842, Leases ("ASC 842"). For further information about lease arrangements, see "Note 5 - Leases." Property and equipment assets are depreciated using the straight-line method over the respective estimated useful lives as follows: Useful Life Buildings 39 years Furniture and fixtures 7 years Equipment 5 to 10 years Computer equipment and software 3 years Vehicles Lesser of lease term or the estimated economic life of the leased asset Leasehold improvements Lesser of remaining life of lease or the useful life of the asset Expenditures for repairs and maintenance are expensed as incurred and expenditures for major improvements that increase the functionality or extend the useful life of the asset are capitalized and depreciated over the estimated useful life of the asset. The Company capitalizes costs of computer software obtained for internal use and amortizes these costs on a straight-line basis over the estimated useful life of the product, not to exceed three The Company reviews property and equipment for impairment whenever facts and circumstances indicate that the carrying amounts of these assets might not be recoverable. For assessment purposes, property and equipment are grouped with other assets and liabilities at the lowest level that identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Recoverability of the carrying amount of the asset group to be held is assessed by comparing the carrying amount of the asset group to the estimated undiscounted future cash flows expected to be generated by this asset group. If the carrying value of the asset group exceeds its fair value, an impairment charge is recognized for the amount by which the carrying amount of the asset group exceeds its fair value. Leases On January 1, 2019, the Company adopted ASC 842 using the revised modified retrospective approach. The revised modified retrospective approach recognizes the effects of initially applying the new leases standard as a cumulative effect adjustment to retained earnings as of the adoption date. Under this election, the provisions of ASC 840 apply to the accounting and disclosures for lease arrangements in the comparative periods in an entity’s financial statements. In addition, the Company elected the package of practical expedients permitted under the transition guidance within ASC 842, in which the Company need not reassess (i) the historical lease classification, (ii) whether any expired or existing contract is or contains a lease, or (iii) the initial direct costs for any existing leases. At inception, a contract contains a lease if the contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. In evaluating whether it has the right to control the use of an identified asset, the Company assesses whether they have the right to direct the use of the identified asset and to obtain substantially all of the economic benefit from the use of the identified asset. Right-of-use ("ROU") assets represent the Company's right to use an underlying asset during the lease term and lease liabilities represent the Company's obligation to make lease payments arising from the lease. Assets and liabilities are recognized based on the present value of lease payments over the lease term. Most leases include one or more options to renew. The exercise of the renewal option is at the Company's sole discretion and the Company includes these options in determining the lease term used to establish its right-of-use assets and lease liabilities when it is reasonably certain the Company will exercise its option. Because most of the Company's leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the lease commencement date in determining the present value of lease payments. The Company uses the implicit rate when readily determinable. Operating lease expense is generally recognized on a straight-line basis over the lease term. The Company has agreements with lease and non-lease components, which are accounted for as a single lease component. Leases with a lease term of 12 months or less are not recorded on the balance sheet. The Company recognizes lease expense for these leases on a straight-line basis over the lease term. Variable lease payment amounts that cannot be determined at the commencement of the lease, such as increases in lease payments based on changes in index rates, are not included in the right-of-use assets or liabilities. These variable lease payments are expensed as incurred. Goodwill and Intangible Assets Goodwill represents the excess of purchase price over the estimated fair value of net assets acquired, including the amount assigned to identifiable intangible assets, in business combinations. In accordance with ASC Topic 350, Intangibles - Goodwill and Other , goodwill is not subject to amortization but must be tested for impairment annually or more frequently if events or changes in circumstances indicate that goodwill might be impaired. Goodwill is tested for impairment at the reporting unit level, which is one level below the operating segment level. This test requires the Company to determine if the implied fair value of the reporting unit's goodwill is less than its carrying amount. The Company has assigned goodwill to five reporting units. The Company's goodwill is principally related to the Merger completed in August 2017. The Company completed an annual impairment test as of October 1, 2019 for all of its reporting units, and concluded that there were no impairments. Intangible assets consist primarily of backlog, customer relationships, and trademarks. The Company amortizes intangible assets related to customer relationships and trademarks on a straight-line basis over the estimated useful life of the asset. Backlog is amortized based on the Company’s expectations of when the resulting revenue is expected to be earned. The Company reviews intangible assets at the end of each reporting period to determine if facts and circumstances indicate that the useful life is shorter than originally estimated or that the carrying amount of the assets might not be recoverable. If such facts and circumstances exist, the Company assesses the recoverability of identified assets by comparing the projected undiscounted cash flows associated with the related asset or group of assets over their remaining lives to their respective carrying amounts. Impairments, if any, are based on the excess of the carrying amount over the fair value of those assets and occur in the period in which the impairment determination is made. The weighted average estimated useful lives of the Company's intangible assets were as follows as of December 31: 2019 2018 Customer relationships 9.9 years 9.9 years Acquired backlog 2.2 years 2.2 years Trademarks 4.2 years 4.2 years No intangible asset impairment charges were recorded for the years ended December 31, 2019 or 2018. In connection with the Merger, the Company relaunched its operations under a new brand name in January 2018. As a result, the Company determined that the useful life of the intangible asset related to the INC Research trademark that had a carrying value of $35.0 million was no longer indefinite as of August 1, 2017. Based on this change in circumstances, the Company tested the asset for impairment and recorded a $30.0 million impairment charge during the third quarter of 2017, with the remaining value fully amortized over five months. In addition, the Company assigned a value of $8.8 million to the inVentiv Health trade name in connection with the Merger, which was amortized over the same five Contingencies In the normal course of business, the Company periodically becomes involved in various proceedings and claims, including investigations, disputes, litigations, and regulatory matters that are incidental to its business. The Company evaluates the likelihood of an unfavorable outcome of all legal and regulatory matters and records accruals for loss contingencies when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Gain contingencies are not recognized until realized. Legal fees are expensed as incurred. Because these matters are inherently unpredictable, and unfavorable developments or resolutions can occur, assessing contingencies is highly subjective and requires judgments about future events. These judgments and estimates are based, among other factors, on the status of the proceedings, the merits of the Company’s defenses, and the consultation with in-house and external counsel. The Company regularly reviews contingencies to determine whether its accruals and related disclosures are adequate. Although the Company believes that it has substantial defenses in these matters, the amount of losses incurred as a result of actual outcomes may differ significantly from the Company’s estimates. Revenue Recognition The Company adopted ASC Topic 606, Revenue from Contracts with Customers and all related amendments (“new revenue standard” or “ASC 606”) on January 1, 2018 using the modified retrospective method for all contracts not completed as of the date of adoption. The reported results for the years ended December 31, 2019 and 2018 reflect the application of ASC 606, while the reported results for the year ended December 31, 2017 were prepared under ASC Topic 605, Revenue Recognition ("ASC 605") and other authoritative guidance in effect for that period. Revenue Recognition under ASC 606 In accordance with ASC 606, revenue is recognized when, or as, a customer obtains control of promised services. The amount of revenue recognized reflects the consideration to which the Company expects to be entitled to receive in exchange for these services. A performance obligation is a promise (or a combination of promises) in a contract to transfer distinct goods or services to a customer and is the unit of accounting under ASC 606 for the purposes of revenue recognition. A contract’s transaction price is allocated to each separate performance obligation based upon the standalone selling price and is recognized as revenue, when, or as, the performance obligation is satisfied. The majority of the Company’s Clinical Solutions segment contracts have a single performance obligation because the promise to transfer individual services is not separately identifiable from other promises in the contracts, and therefore, is not distinct. For contracts with multiple performance obligations, the contract’s transaction price is allocated to each performance obligation using the best estimate of the standalone selling price of each distinct good or service in the contract. The majority of the Company's revenue arrangements are service contracts that range in duration from a few months to several years. Substantially all of the Company’s performance obligations, and associated revenue, are transferred to the customer over time. The Company generally receives compensation based on measuring progress toward completion using anticipated project budgets for direct labor and prices for each service offering. The Company is also reimbursed for certain third party pass-through and out-of-pocket costs. In addition, in certain instances a customer contract may include forms of variable consideration such as incentive fees, volume rebates or other provisions that can increase or decrease the transaction price. This variable consideration is generally awarded upon achievement of certain performance metrics, program milestones or cost targets. For the purposes of revenue recognition, variable consideration is assessed on a contract-by-contract basis and the amount included in the transaction price is estimated based on the Company’s anticipated performance and consideration of all information that is reasonably available. Variable consideration is recognized as revenue if and when it is deemed probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved in the future. Most of the Company's contracts can be terminated by the customer without cause with a 30-day notice. In the event of termination, the Company's contracts generally provide that the customer pay the Company for: (i) fees earned through the termination date; (ii) fees and expenses for winding down the project, which include both fees incurred and actual expenses; (iii) non-cancellable expenditures; and (iv) in some cases, a fee to cover a portion of the remaining professional fees on the project. Changes in the scope of work are common, especially under long-term contracts, and generally result in a change in the total contract transaction price. If the customer does not agree to a contract modification, the Company could bear the risk of cost overruns. Most of the Company’s contract modifications are for services that are not distinct from the services under the existing contract due to the significant integration service provided in the context of the contract and therefore result in a cumulative catch-up adjustment to revenue at the date of contract modification. Capitalized Costs The Company capitalizes certain costs associated with commissions and bonuses paid to its employees in the Clinical Solutions segment because these costs are incurred in obtaining contracts that have a term greater than one year. Capitalized costs are included in prepaid expenses and other current assets and other long-term assets in the accompanying consolidated balance sheets. The Company amortizes these costs in a manner that is consistent with the pattern of revenue recognition described below. The Company expenses costs to obtain contracts that have a term of one year or less. Clinical Solutions The Company’s Clinical Solutions segment provides solutions to address the clinical development needs of customers. The Company provides total biopharmaceutical program development through the full service platform, while also providing discrete services for any part of a clinical trial, primarily through functional service provider, Early Stage, and Real World and Late Phase (“RWLP”) services. The services provided via the full service platform and RWLP platforms generally span several years and a significant benefit to the customer is provided by integrating those services provided by the Company’s employees as well as those performed by third parties. Because the Company's full service platform provides a significant integration service to the customer, these contracts contain a single performance obligation. Revenue is recognized over time using an input measure of progress. The input measure reflects costs (including investigator payments and pass-through costs) incurred to date relative to total estimated costs to complete (“cost-to-cost measure of progress”). Under the cost-to-cost measure of progress methodology, revenue is recorded proportionally to costs incurred. Contract costs principally include direct labor, investigator payments, and pass-through costs. The estimate of total revenue and costs at completion requires significant judgment. Contract estimates are based on various assumptions to project future outcomes of events that often span several years. These estimates are reviewed periodically and any adjustments are recognized on a cumulative catch-up basis in the period they become known. The remaining service offerings within the Clinical Solutions segment are generally short-term, month-to-month contracts, time and materials basis contracts, or provide a series of distinct services that are substantially the same and have the same pattern of transfer to the customer (“series”). As such, revenue for these service offerings is generally recognized as services are performed for the amount the Company estimates it is entitled to for the period, similar to the pattern of recognition under ASC 605. Unsatisfied Performance Obligations As of December 31, 2019, the total aggregate transaction price allocated to the unsatisfied performance obligations under contracts with a contract term greater than one year and which are not accounted for as a series pursuant to ASC 606 was $5.40 billion. This amount includes revenue associated with reimbursable out-of-pocket expenses. The Company expects to recognize revenue over the remaining contract term of the individual projects, with contract terms generally ranging from one to five years. The amount of unsatisfied performance obligations is presented net of any constraints and, as a result, is lower than the potential contractual revenue. The contracts excluded due to constraints include contracts that do not commence within a certain period of time or require the Company to undertake numerous activities to fulfill these performance obligations, including various activities that are outside of the Company’s control. Accordingly, such contracts have been excluded from the unsatisfied performance obligations balance presented above. Commercial Solutions Services The Company’s Commercial Solutions segment provides a broad suite of complementary commercialization services including Deployment Solutions, communications (advertising and public relations), and consulting services. Deployment Solutions contracts offer outsourced services to promote and sell commercial products on behalf of a customer. The remaining Commercial Solutions contracts are generally short-term, month-to-month contracts or time and materials contracts. As such, Commercial Solutions revenue is generally recognized as services are performed for the amount of consideration the Company estimates it is entitled to for the period, similar to the pattern of recognition under ASC 605. For contracts billed on a fixed price basis, revenue is recognized over time based on the proportion of labor costs expended to total labor costs expected to complete the contract. The Commercial Solutions segment does not have significant unsatisfied performance obligations that are required to be disclosed under ASC 606 because the contracts are short-term in nature or represent a series. Revenue Recognition prior to adoption of ASC 606 Prior to the Company's adoption of ASC 606 on January 1, 2018, the Company recognized revenue when all of the following conditions were satisfied: (i) there was persuasive evidence of an arrangement; (ii) the service offering had been delivered to the customer; (iii) the collection of the fees was reasonably assured; and (iv) the arrangement consideration was fixed or determinable. The Company recorded revenue net of any tax assessments by governmental authorities, such as value added taxes, that were imposed on and concurrent with specific revenue generating transactions. In some cases, contracts provided for consideration that was contingent upon the occurrence of uncertain future events. The Company recognized contingent revenue when the contingency had been resolved and all other criteria for revenue recognition had been met. The Company recognized revenue from its service contracts eithe

Financial Statement Details

Financial Statement Details	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Financial Statement Details	Financial Statement Details Accounts Receivable and Unbilled Services, net Accounts receivable and unbilled services, net of allowance for doubtful accounts, consisted of the following as of December 31 (in thousands): 2019 2018 Accounts receivable billed $ 787,652 $ 733,142 Less: Allowance for doubtful accounts (5,381) (4,587) Accounts receivable billed, net 782,271 728,555 Accounts receivable unbilled 372,109 422,860 Contract assets 149,261 105,316 Accounts receivable and unbilled services, net $ 1,303,641 $ 1,256,731 The following table summarizes the changes in the allowance for doubtful accounts (in thousands): Year Ended December 31, 2019 2018 2017 Balance at the beginning of the period $ (4,587) $ (9,076) $ (5,884) Current year (provision) recovery (1,897) 4,589 (4,167) Write-offs, net of recoveries and the effects of foreign currency exchange 1,103 (100) 975 Balance at the end of the period $ (5,381) $ (4,587) $ (9,076) Accounts Receivable Factoring Arrangement In May 2017, the Company entered into an accounts receivable factoring agreement to sell certain eligible unsecured trade accounts receivable, without recourse, to an unrelated third-party financial institution for cash. For the year ended December 31, 2019, the Company factored $210.5 million of trade accounts receivable on a non-recourse basis and received $209.0 million in cash proceeds from the sale. For the year ended December 31, 2018, the Company factored $251.9 million of trade accounts receivable on a non-recourse basis and received $250.4 million in cash proceeds from the sale. The fees associated with these transactions were insignificant. Property and Equipment, net Property and equipment, net of accumulated depreciation, consisted of the following as of December 31 (in thousands): 2019 2018 Software $ 99,500 $ 91,040 Vehicles 70,440 55,293 Computer equipment 95,228 82,280 Leasehold improvements 86,327 69,632 Office furniture, fixtures, and equipment 33,388 24,006 Buildings and land 4,256 4,348 Assets not yet placed in service 20,262 11,011 Property and equipment, gross 409,401 337,610 Less: Accumulated depreciation (205,475) (154,124) Property and equipment, net $ 203,926 $ 183,486 As of December 31, 2019 and 2018, the gross book value of vehicles under finance leases was $70.4 million and $55.3 million, respectively, and accumulated depreciation was $20.6 million and $17.6 million, respectively. For the years ended December 31, 2019 and 2018, amortization charges related to these assets, net of rebates, were $16.8 million and $14.5 million, respectively, and are included in depreciation on the accompanying consolidated statements of operations. Goodwill and Intangible Assets The changes in carrying amount of goodwill were as follows (in thousands): Clinical Commercial Total Balance as of December 31, 2017 $ 2,800,833 $ 1,491,738 $ 4,292,571 Business combinations (a) (5,692) 71,000 65,308 Impact of foreign currency translation and other (22,338) (2,382) (24,720) Balance as of December 31, 2018 2,772,803 1,560,356 4,333,159 Business combinations (b) 1,092 (204) 888 Impact of foreign currency translation 11,057 5,276 16,333 Balance as of December 31, 2019 $ 2,784,952 $ 1,565,428 $ 4,350,380 (a) Amounts represent measurement period adjustments in connection with the Merger and goodwill recognized in connection with the 2018 acquisition of Kinapse Topco Limited (“Kinapse”). (b) Amounts represent goodwill recognized in connection with an insignificant acquisition within the Clinical Solutions segment and measurement period adjustments in connection with the 2018 acquisition of Kinapse. Accumulated impairment losses of $8.1 million associated with the Clinical Solutions segment were recorded prior to 2016 and related to the former Phase I Services segment, now a component of the Clinical Solutions segment. No impairment of goodwill was recorded for the years ended December 31, 2019, 2018, or 2017. Accumulated impairment losses of $8.0 million associated with the Commercial Solutions segment were recorded prior to 2015 and related to the former Global Consulting segment, now a component of the Commercial Solutions segment. No impairment of goodwill was recorded for the years ended December 31, 2019, 2018, or 2017. Intangible assets, net consisted of the following (in thousands): December 31, 2019 December 31, 2018 Gross Accumulated Amortization Net Gross Accumulated Amortization Net Customer relationships $ 1,491,071 $ (546,835) $ 944,236 $ 1,484,704 $ (403,854) $ 1,080,850 Acquired backlog 136,972 (121,679) 15,293 136,428 (100,838) 35,590 Trademarks 31,326 (17,774) 13,552 31,159 (13,987) 17,172 Intangible assets, net $ 1,659,369 $ (686,288) $ 973,081 $ 1,652,291 $ (518,679) $ 1,133,612 Intangible assets are amortized over their estimated useful lives. The future estimated amortization expense for intangible assets is expected to be as follows (in thousands): Fiscal Year Ending: 2020 $ 149,739 2021 132,388 2022 126,989 2023 124,464 2024 120,312 2025 and thereafter 319,189 Total $ 973,081 Accrued Expenses Accrued expenses consisted of the following as of December 31 (in thousands): 2019 2018 Compensation, including bonuses, fringe benefits, and payroll taxes $ 195,604 $ 193,641 Professional fees, investigator fees, and pass-through costs 252,151 230,397 Rebates to customers 25,064 23,391 Contingent tax-sharing obligations assumed through business combinations, current portion 26,557 11,907 Income and other taxes 17,295 30,761 Restructuring and other costs, current portion 5,750 10,592 Interest expense 787 8,278 Facility-related obligations 433 9,288 Other liabilities 45,270 45,272 Total accrued expenses $ 568,911 $ 563,527 Accumulated other comprehensive loss, net of taxes Accumulated other comprehensive loss, net of taxes, consisted of the following (in thousands): Year Ended December 31, 2019 2018 Beginning balance $ (88,195) $ (22,385) Foreign Currency Translation: Beginning balance (80,955) (23,514) Impact from adoption of ASU 2018-02 — 3,594 Adjusted beginning balance (80,955) (19,920) Other comprehensive income (loss) before reclassifications 24,198 (61,035) Reclassification adjustments — — Ending balance (56,757) (80,955) Derivative Instruments: Beginning balance (7,240) 1,129 Impact from adoption of ASU 2018-02 — 256 Adjusted beginning balance (7,240) 1,385 Other comprehensive loss before reclassifications (11,529) (7,807) Reclassification adjustments 3,933 (818) Ending balance (14,836) (7,240) Accumulated other comprehensive loss, net of taxes $ (71,593) $ (88,195) Changes in accumulated other comprehensive loss consisted of the following (in thousands): Year Ended December 31, 2019 2018 2017 Foreign currency translation adjustments: Foreign currency translation adjustments, before tax $ 24,198 $ (61,035) $ 28,847 Income tax expense — — (9,005) Foreign currency translation adjustments, net of tax 24,198 (61,035) 19,842 Unrealized (loss) gain on derivative instruments: Unrealized (loss) gain during period, before tax (14,306) (8,577) 694 Income tax benefit (expense) 2,777 770 (251) Unrealized (loss) gain during period, net of tax (11,529) (7,807) 443 Reclassification adjustment, before tax 4,588 (830) (681) Income tax (expense) benefit (655) 12 261 Reclassification adjustment, net of tax 3,933 (818) (420) Total unrealized (loss) gain on derivative instruments, net of tax (7,596) (8,625) 23 Total other comprehensive income (loss), net of tax $ 16,602 $ (69,660) $ 19,865 Transaction and Integration-Related Expenses Transaction and integration-related expenses consisted of the following (in thousands): Year Ended December 31, 2019 2018 2017 Professional fees $ 34,538 $ 56,207 $ 68,967 Share-based compensation expense — — 31,327 Debt modification and related expenses 5,396 1,726 5,255 Integration and personnel retention-related costs 4,081 18,475 28,616 Fair value adjustments to contingent obligations 17,260 (11,590) (12,276) Other — 23 1,926 Total transaction and integration-related expenses $ 61,275 $ 64,841 $ 123,815 Other (Expense) Income, Net Other (expense) income, net consisted of the following (in thousands): Year Ended December 31, 2019 2018 2017 Net realized foreign currency (loss) gain $ (11,853) $ 10,452 $ (10,833) Net unrealized foreign currency (loss) gain (11,166) 16,165 (7,912) Other, net (1,143) 1,627 (1,101) Total other (expense) income, net $ (24,162) $ 28,244 $ (19,846) Supplemental disclosure of cash flow information The following table provides details of supplemental cash flow information (in thousands): Year Ended December 31, 2019 2018 2017 Cash paid for income taxes, net of refunds $ 12,200 $ 2,042 $ 13,300 Cash paid for interest 129,756 131,827 64,949 Supplemental disclosure of noncash investing and financing activities Fair value of shares issued and share-based awards assumed in business combinations $ — $ — $ 2,769,471 Fair value of contingent consideration related to business combinations — 4,353 — Purchases of property and equipment included in liabilities 20,052 14,075 14,801 Vehicles acquired through finance lease agreements 37,701 30,374 8,730

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Business Combinations	Business Combinations inVentiv Health Merger On August 1, 2017 (the “Merger Date”), the Company completed the Merger with inVentiv with the Company surviving as the accounting and legal entity acquirer. The Merger was accounted for as a business combination using the acquisition method of accounting in accordance with ASC Topic 805, Business Combinations . The purchase price has been allocated to the tangible assets and identifiable intangible assets acquired and liabilities assumed based upon their fair values. The excess of the purchase price over the tangible and intangible assets acquired and liabilities assumed has been recorded as goodwill. The goodwill in connection with the Merger is primarily attributable to the assembled workforce of inVentiv and the synergies of the Merger. In connection with the Merger, the Company assumed certain contingent tax-sharing obligations of inVentiv. The fair value of the contingent tax-sharing liability is remeasured at the end of each reporting period, with changes in the estimated fair value reflected in earnings until the liability is fully settled. The estimated fair value of the contingent tax-sharing obligations liability was $32.7 million and $15.7 million as of December 31, 2019 and 2018, respectively. The liability is included in accrued expenses and other long-term liabilities on the accompanying consolidated balance sheets. The results of inVentiv’s operations are included in the Company’s consolidated statements of operations beginning on the Merger Date. Computing a separate measure of inVentiv’s stand-alone profitability for the period after the Merger Date is impracticable. Fair Value of Consideration Transferred The Merger Date fair value of the consideration transferred consisted of the following (in thousands, except for share and per share amounts): Fair value of common stock issued to acquiree stockholders (a) $ 2,753,239 Fair value of replacement share-based awards issued to acquiree employees (b) 16,232 Repayment of term loan obligations and accrued interest (c) 1,736,152 Total consideration transferred $ 4,505,623 (a) Represents the fair value of 49,297,022 shares of the Company’s common stock at $55.85 per share, the closing price per share on the Merger closing date of August 1, 2017. (b) Represents the fair value of replacement share-based awards attributable to pre-combination services. For further information about the valuation of share-based awards, see "Note 18 - Share-Based Compensation." (c) Represents repayment of inVentiv’s term loan obligations and related accrued interest as part of the Merger consideration on the Merger Date. For further information, see "Note 4 - Long-Term Debt Obligations." Allocation of Consideration Transferred The following table summarizes the allocation of the consideration transferred based on management’s estimates of the Merger Date fair values of assets acquired and liabilities assumed, with the excess of the purchase price over the estimated fair values of the identifiable net assets acquired recorded as goodwill (in thousands): Assets acquired: Cash and cash equivalents $ 57,338 Restricted cash 433 Accounts receivable 367,595 Unbilled accounts receivable 262,944 Other current assets 97,922 Property and equipment 114,041 Intangible assets 1,334,200 Other assets 50,052 Total assets acquired 2,284,525 Liabilities assumed: Accounts payable 38,072 Accrued expenses 304,341 Deferred revenue 247,474 Capital leases 40,928 Long-term debt, current and non-current 737,872 Deferred income taxes, net 14,751 Other liabilities 119,480 Total liabilities assumed 1,502,918 Total identifiable assets acquired, net 781,607 Goodwill $ 3,724,016 The goodwill recognized in connection with the Merger was $3.72 billion, of which $2.23 billion was assigned to the Clinical Solutions segment and $1.49 billion to the Commercial Solutions segment. Goodwill generated in the Merger is not deductible for income tax purposes. The following table summarizes the fair value of identified intangible assets and their respective useful lives as of the Merger Date (dollars in thousands): Estimated Fair Value Estimated Useful Life Customer relationships $ 1,169,700 6 years - 11 years Backlog 137,100 5 months - 2 years Trademarks subject to amortization 27,400 5 months - 6 years Total intangible assets $ 1,334,200

Long-Term Debt Obligations

Long-Term Debt Obligations	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Long-Term Debt Obligations	Long-Term Debt Obligations The Company’s debt obligations consisted of the following as of December 31 (in thousands): 2019 2018 Secured Debt Term Loan A due March 2024 $ 1,550,000 $ 975,000 Term Loan B due August 2024 795,564 1,221,000 Accounts receivable financing agreement due September 2021 275,000 169,400 Total secured debt 2,620,564 2,365,400 Unsecured Debt 7.5% Senior Unsecured Notes due 2024 (the "Senior Notes") — 403,000 Total debt obligations 2,620,564 2,768,400 Add: Unamortized Senior Notes premium, net of term loan original issuance discount (4,928) 32,303 Less: Unamortized deferred issuance costs (7,116) (13,584) Less: Current portion of debt (58,125) (50,100) Total debt obligations, non-current portion $ 2,550,395 $ 2,737,019 Credit Agreement Concurrent with the completion of the Merger on August 1, 2017, the Company entered into a Credit agreement (the "Credit Agreement") for: (i) a $1.0 billion Term Loan A facility that matures on August 1, 2022 (“Term Loan A”); (ii) a $1.6 billion Term Loan B facility that matures on August 1, 2024 (“Term Loan B”); and (iii) a five On May 4, 2018, the Company entered into Amendment No.1 to the Credit Agreement, which, among other things, modified the terms of the Credit Agreement to reduce by 0.25% overall the applicable margins for Alternate Base Rate (as defined in the Credit Agreement) loans and Adjusted Eurocurrency Rate (as defined in the Credit Agreement) loans with respect to both Term Loan A and Term Loan B facilities. Amendment No. 2 to the Credit Agreement On March 26, 2019, the Company entered into Amendment No. 2 to the Credit Agreement (the "Second Amendment”). The Second Amendment, among other things, modified the terms of the Credit Agreement to refinance the existing Term Loan A facility and the Revolver as follows: (a) increased the existing Term Loan A facility by $587.5 million to $1.55 billion. $187.5 million of such increase was applied at closing to repay a portion of the Company’s existing Term Loan B facility and the fees and expenses incurred in connection with the Second Amendment. The remaining $400.0 million was drawn on October 2, 2019. The Company used the proceeds and cash on hand to redeem all of the Senior Notes for $403.0 million and pay a $15.1 million premium related to the early redemption; (b) increased the existing Revolver commitments available by $100.0 million to $600.0 million; and (c) extended the maturity of the Term Loan A facility and the Revolver to March 26, 2024. The funded amount of the Term Loan A facility was issued net of a discount and debt issuance costs totaling $2.8 million. These costs are being accreted as a component of interest expense using the effective interest rate method over the term of this facility. All obligations under the Credit Agreement are guaranteed by the Company and certain of the Company's direct and indirect wholly-owned domestic subsidiaries. The obligations under the Credit Agreement are secured by substantially all of the assets of the Company and the guarantors, including 65% of the capital stock of certain controlled foreign subsidiaries. Beginning on April 30, 2019 through January 31, 2024, the Term Loan A has no scheduled quarterly principal payments of the initial principal borrowed in year 1; 1.25%, or $19.4 million per quarter in year 2; 1.875%, or $29.1 million per quarter in year 3; and 2.50%, or $38.8 million per quarter thereafter; with the remaining outstanding principal due on March 26, 2024. During the years ended December 31, 2019 and 2018, the Company made mandatory principal repayments of $12.5 million and $25.0 million, respectively, towards its Term Loan A and settled $36.6 million of debt upon the closing of an acquisition in 2018. Under the Credit Agreement, the Company is required to make quarterly principal payments of the initial principal borrowed under the Term Loan B of 0.25%, or $4.0 million per quarter; with the remaining outstanding principal due on August 1, 2024. During the years ended December 31, 2019 and 2018, the Company made voluntary prepayments of $246.8 million and $329.0 million, respectively, on the Term Loan B. As a result of these and previous voluntary prepayments, the Company is not required to make a mandatory principal payment against the Term Loan B principal balance until maturity in August 2024. The term loans and the Revolver bear interest at a rate per annum equal to the Adjusted Eurocurrency Rate (“Eurocurrency Rate”) plus an applicable margin or an Alternate Base Rate plus an applicable margin. The Company may select among the Adjusted Eurocurrency Rate or the Alternate Base Rate, whichever is lower, except in circumstances where the Company requests a loan with less than a three-day notice. In such cases, the Company must use the Alternate Base Rate. The Adjusted Eurocurrency Rate is equal to LIBOR, subject to adjustment for reserve requirements. The Alternate Base Rate is equal to the highest of: (i) the federal funds rate plus 0.50%; (ii) the Adjusted Eurocurrency Rate for an interest period of one month plus 1.00%; (iii) the rate of interest per annum quoted by The Wall Street Journal as the prime rate; and (iv) 0.00%. Adjusted Eurocurrency Rate term loans are one, two, three, or six-month loans (or, with permission, twelve-month loans) and interest is due on the last day of each three-month period of the loans. Alternate Base Rate term loans have interest due the last day of each three-month period beginning in January 2018. In advance of the last day of the then-current type of loan, the Company may select a new type of loan, so long as it does not extend beyond the term loan’s maturity date. The applicable margins with respect to Alternate Base Rate and Adjusted Eurocurrency Rate borrowings are determined depending on the “First Lien Leverage Ratio” or the "Secured Net Leverage Ratio" (as defined in the Credit Agreement) and range as follows: Alternate Base Rate Adjusted Eurocurrency Rate Term Loan A 0.25 % - 0.50% 1.25 % - 1.50% Term Loan B 0.75 % - 1.00% 1.75 % - 2.00% Revolver 0.25 % - 0.50% 1.25 % - 1.50% The Company also pays a quarterly commitment fee between 0.25% and 0.375% on the average daily unused balance of the Revolver depending on the “First Lien Leverage Ratio” at the adjustment date. As of December 31, 2019, the interest rate on the Term Loan A and the Revolver was 3.299% and the interest rate on the Term Loan B was 3.799%. Letters of Credit The Revolver includes letters of credit ("LOCs") with a sublimit of $150.0 million. Fees are charged on all outstanding LOCs at an annual rate equal to the margin in effect on Eurocurrency Rate revolving loans plus fronting fees. The fee is payable quarterly in arrears on the last day of the calendar quarter after the issuance date until the underlying LOC expires. As of December 31, 2019, there were no outstanding Revolver borrowings and $18.8 million of LOCs outstanding, leaving $581.2 million in available borrowings under the Revolver. Additionally, the lease for the corporate headquarters in Morrisville, North Carolina includes a provision that may require the Company to issue a letter of credit in certain amounts to the landlord based on the debt rating of the Company issued by Moody’s Investors Service (or other nationally-recognized debt rating agency). From June 14, 2017 through June 14, 2020, if the debt rating of the Company is Ba3 or better, no LOC is required, or if the debt rating of the Company is B1 or lower, a LOC equal to 25% of the remaining minimum annual rent and estimated operating expenses (approximately $22.5 million as of December 31, 2019) is required to be issued to the landlord. This LOC would remain in effect until the Company’s debt rating was increased to Ba3 and maintained for a twelve twelve As of December 31, 2019 (and through the date of this filing), the Company’s debt rating was such that no LOC is currently required. Any LOC issued in accordance with the aforementioned requirements could be issued under the Company’s Revolver, and, if issued under the Revolver, would reduce its available borrowing capacity by the same amount accordingly. Debt Covenants The Credit Agreement contains usual and customary restrictive covenants that, among other things, place limitations on the Company's ability to pay dividends or make other restricted payments; prepay, redeem or purchase debt; incur liens; make loans and investments; incur additional indebtedness; amend or otherwise alter debt and other material arrangements; make acquisitions and dispose of assets; transact with affiliates; and engage in transactions that are not related to the Company's existing business. Each of the restrictive covenants is subject to important exceptions and qualifications that would allow the Company to engage in these activities under certain conditions, including the Company’s ability to: (i) pay dividends each year in an amount up to the greater of (a) 6% of the net cash proceeds received by the Company from any public offering and (b) 5% of the Company’s market capitalization; and (ii) pay unlimited dividends if the Company’s Secured Leverage Ratio (as defined in the Credit Agreement) is no greater than 3.0 to 1.0. In addition, with respect to the Term Loan A and Revolver, the Credit Agreement requires the Company to maintain a maximum First Lien Leverage Ratio (as defined in the Credit Agreement) of no more than 5.0 to 1.0 as of the last day of each fiscal quarter ending on or before December 31, 2019 (beginning with the first full fiscal quarter ending after the closing date of the Credit Agreement), and 4.5 to 1.0 from and after March 31, 2020. As of December 31, 2019, the Company was in compliance with all applicable debt covenants. Accounts Receivable Financing Agreement On June 29, 2018, the Company entered into an accounts receivable financing agreement ( as amended) with a termination date of June 29, 2020, unless terminated earlier pursuant to its terms. Under this agreement, certain of the Company’s consolidated subsidiaries will sell accounts receivable and unbilled services (including contract assets) balances to a wholly-owned, bankruptcy-remote special purpose entity (“SPE”). On September 30, 2019, the Company entered into an amendment that increased the amount the SPE can borrow from a third-party lender from $250.0 million to $275.0 million, secured by liens on certain receivables and other assets of the SPE. The Company has guaranteed the performance of the obligations of existing and future subsidiaries that sell and service the accounts receivable under this agreement. The available borrowing capacity varies monthly according to the levels of the Company’s eligible accounts receivable and unbilled receivables. Loans under this agreement will accrue interest at a reserve-adjusted LIBOR rate or a base rate equal to the higher of (i) the applicable lender’s prime rate, and (ii) the federal funds rate plus 0.50%. The Company may prepay loans upon one business day prior notice and may terminate or reduce the facility limit of the accounts receivable financing agreement with 15 days’ prior notice. The aforementioned amendment entered into on September 30, 2019 also extended the termination date as stated above from June 29, 2020 to September 30, 2021. As of December 31, 2019, the Company had $275.0 million of outstanding borrowings under the accounts receivable financing agreement, which are recorded in long-term debt on the accompanying consolidated balance sheet. As of December 31, 2019, there was no remaining borrowing capacity available. As of December 31, 2019, the interest rate on the outstanding borrowings under the accounts receivable financing agreement was 2.805%. 7.5% Senior Unsecured Notes due 2024 As a result of the Merger, the Company assumed $675.0 million of Senior Notes. Upon closing of the Merger, the Company immediately redeemed $270.0 million of the principal balance of Senior Notes and paid $20.3 million of the applicable early redemption penalty. In December 2017, the Company acquired $2.0 million of principal amount of the Senior Notes through an open market purchase for a cash payment of $2.2 million and immediately retired the principal amount. On October 2, 2019, the Company drew down the$400.0 million Term Loan A balance and used the proceeds and cash on hand to redeem all of the Senior Notes for $403.0 million and pay a $15.1 million premium related to the early redemption. For additional information regarding the accounting for these debt extinguishment costs and redemption penalties, see "Debt Extinguishment Costs and Senior Notes Redemption Penalty" below. Maturities of Debt Obligations As of December 31, 2019, the contractual maturities of the Company’s debt obligations (excluding finance leases that are presented in "Note 5 - Leases") were as follows (in thousands): 2020 $ 58,125 2021 381,563 2022 145,313 2023 155,000 2024 1,880,563 2025 and thereafter — Less: deferred issuance costs (7,116) Unamortized Senior Notes premium, net of term loan original issuance discount (4,928) Total $ 2,608,520 Debt Extinguishment Costs and Senior Notes Redemption Penalty In August 2017, the Company paid a contractual early redemption penalty of $20.3 million to redeem 40% of the Senior Notes that were assumed in the Merger. In accordance with ASC Topic 805, Business Combinations , the carrying value of the Senior Notes assumed in the Merger was adjusted to estimated fair value, which resulted in an increase of the amount of the Company’s consolidated debt and recognition of a premium on the Senior Notes, of which $20.3 million was allocated to the redeemed portion of the Senior Notes. This portion of the premium offset the early redemption penalty, resulting in no gain or loss on the extinguishment of the Senior Notes. The remaining balance of the premium associated with the fair value adjustment was being amortized as a component of interest expense using the effective interest rate method over the term of the remaining Senior Notes. On October 2, 2019, the Company fully redeemed all of the remaining Senior Notes and the remaining unamortized premium of $31.4 million related to the Senior Notes was written off and recorded as a gain on extinguishment of debt. This gain was partially offset by a $15.1 million early redemption premium paid by the Company, resulting in a net gain on extinguishment of debt of $16.3 million. Also during the year ended December 31, 2019, in connection with the Second Amendment and Term Loan B prepayments, the Company recorded a $5.9 million loss on extinguishment of debt, mainly due to the write-off of the deferred issuance costs and debt discount. During the year ended December 31, 2018, in conjunction with the Repricing Amendment and Term Loan B prepayments, as discussed above, the Company recognized a loss on extinguishment of debt of $4.2 million. During the year ended December 31, 2017, the Company made voluntary prepayments of $50.0 million against the principal balance of the Term Loan B and as a result recognized a loss on extinguishment of debt of $0.6 million. Debt Issuance Costs and Debt Discounts On September 30, 2019, the Company entered into an amendment to its account receivable financing agreement. The Company recorded debt issuance costs related to the amendment of approximately $0.2 million. The entire balance of debt issuance costs and fees of $0.5 million related to the accounts receivable financing agreement are being amortized over the term of this agreement. The Company recorded debt issuance costs and related fees in connection with the Revolver and the unfunded amount of the Term Loan A facility of approximately $3.5 million as of December 31, 2019, which are included in other long-term assets in the consolidated balance sheet. These costs are amortized as a component of interest expense on a straight-line basis over the related terms. The Company recorded debt issuance costs related to its term loans of approximately $13.6 million and $20.7 million as of December 31, 2018 and 2017, respectively. These costs were recorded as a reduction of the principal balance of the associated debt and are being amortized as a component of interest expense using the effective interest method over the term of the term loans. The Company recorded total debt issuance costs related to its revolving lines of credit of approximately $4.7 million and $5.2 million as of December 31, 2018 and 2017, respectively. Debt issuance costs associated with the revolving line of credit are included in other assets in the consolidated balance sheets. The debt issuance costs are amortized as a component of interest expense using the effective interest method over the term of the Revolver. Term Loan B borrowings under the Credit Agreement were issued net of a discount. The Company recorded an additional discount against the Term Loan A borrowings in connection with the Repricing Amendment during 2018. As of December 31, 2018 and 2017, the balances associated with these discounts were $3.0 million and $1.9 million, respectively, which are being accreted as a component of interest expense using the effective interest rate method over the term of the associated borrowings.

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	Leases The Company’s operating leases are primarily related to its office facilities. The Company’s finance leases are related to vehicles that the Company leases for certain sales representatives in its Commercial Solutions segment. The Company's leases have remaining lease terms of less than one year to 13 years, some of which include options to extend the term or terminate the lease. These options to extend or terminate a lease are included in the lease terms when it is reasonably certain that the Company will exercise that option. ROU assets and lease liabilities are recognized based on the present value of the fixed lease payments over the lease term at the commencement date. The ROU assets also include any initial direct costs incurred and lease payments made at or before the commencement date, and are reduced by lease incentives. The Company uses its incremental borrowing rate as the discount rate to determine the present value of the lease payments for leases that do not have a readily determinable implicit discount rate. The Company’s incremental borrowing rate is the rate of interest that it would have to borrow on a collateralized basis over a similar term and amount in a similar economic environment. The Company determines the incremental borrowing rates for its leases by adjusting the local risk free interest rate with a credit risk premium corresponding to the Company’s credit rating. The Company records rent expense for its operating leases on a straight-line basis from the lease commencement date until the end of the lease term. The Company records finance lease cost as a combination of the amortization expense for the ROU assets and interest expense for the outstanding lease liabilities using the discount rate discussed above. Variable lease payments for operating leases are related to office facilities and include but are not limited to common area maintenance, parking, electricity, and management fees. The variable lease payments for finance leases are related to maintenance programs for leased vehicles. Variable lease payments are based on occurrence or based on usage; therefore, they are not included as part of the initial calculations of the ROU assets and liabilities. The components of lease cost were as follows for the year ended December 31, 2019 (in thousands): Operating leases: Fixed lease costs Direct costs, selling, general, and administrative expenses and restructuring and other costs $ 63,215 Short-term lease costs Direct costs and selling, general, and administrative expenses 1,531 Variable lease costs Direct costs, selling, general, and administrative expenses and restructuring and other costs 34,803 Total operating lease costs $ 99,549 Finance leases: Amortization of right-of-use assets Depreciation $ 16,810 Interest on lease liabilities Interest expense 1,778 Variable lease costs Direct costs 7,795 Total finance lease costs $ 26,383 Supplemental balance sheet information related to finance leases was as follows as of December 31, 2019 (in thousands): Property and equipment, gross $ 70,440 Accumulated depreciation (20,594) Property and equipment, net $ 49,846 Current portion of finance lease obligations $ 17,777 Finance lease long-term obligations 36,914 Total finance lease liabilities $ 54,691 Supplemental cash flow information related to leases was as follows for the year ended December 31, 2019 (in thousands): Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ (50,792) Operating cash flows for finance leases (1,778) Financing cash flows for finance leases (14,493) Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 55,376 Finance leases 38,144 Lease obligations closed out in exchange for right-of-use assets: Operating leases $ (1,214) Weighted average remaining lease term as of December 31, 2019: Operating leases 7 years Finance leases 3 years Weighted average discount rate as of December 31, 2019: Operating leases 5.0 % Finance leases 2.9 % As of December 31, 2019, maturities of lease liabilities were as follows (in thousands): Operating Leases Finance Leases Total 2020 $ 49,538 $ 19,428 $ 68,966 2021 49,429 18,358 67,787 2022 42,981 14,462 57,443 2023 36,997 5,908 42,905 2024 30,708 16 30,724 2025 and thereafter 101,509 — 101,509 Total lease payments 311,162 58,172 $ 369,334 Less: management fee — (775) Less: imputed interest (54,764) (2,706) Total lease liabilities $ 256,398 $ 54,691 Under ASC Topic 840, Leases
Leases	Leases The Company’s operating leases are primarily related to its office facilities. The Company’s finance leases are related to vehicles that the Company leases for certain sales representatives in its Commercial Solutions segment. The Company's leases have remaining lease terms of less than one year to 13 years, some of which include options to extend the term or terminate the lease. These options to extend or terminate a lease are included in the lease terms when it is reasonably certain that the Company will exercise that option. ROU assets and lease liabilities are recognized based on the present value of the fixed lease payments over the lease term at the commencement date. The ROU assets also include any initial direct costs incurred and lease payments made at or before the commencement date, and are reduced by lease incentives. The Company uses its incremental borrowing rate as the discount rate to determine the present value of the lease payments for leases that do not have a readily determinable implicit discount rate. The Company’s incremental borrowing rate is the rate of interest that it would have to borrow on a collateralized basis over a similar term and amount in a similar economic environment. The Company determines the incremental borrowing rates for its leases by adjusting the local risk free interest rate with a credit risk premium corresponding to the Company’s credit rating. The Company records rent expense for its operating leases on a straight-line basis from the lease commencement date until the end of the lease term. The Company records finance lease cost as a combination of the amortization expense for the ROU assets and interest expense for the outstanding lease liabilities using the discount rate discussed above. Variable lease payments for operating leases are related to office facilities and include but are not limited to common area maintenance, parking, electricity, and management fees. The variable lease payments for finance leases are related to maintenance programs for leased vehicles. Variable lease payments are based on occurrence or based on usage; therefore, they are not included as part of the initial calculations of the ROU assets and liabilities. The components of lease cost were as follows for the year ended December 31, 2019 (in thousands): Operating leases: Fixed lease costs Direct costs, selling, general, and administrative expenses and restructuring and other costs $ 63,215 Short-term lease costs Direct costs and selling, general, and administrative expenses 1,531 Variable lease costs Direct costs, selling, general, and administrative expenses and restructuring and other costs 34,803 Total operating lease costs $ 99,549 Finance leases: Amortization of right-of-use assets Depreciation $ 16,810 Interest on lease liabilities Interest expense 1,778 Variable lease costs Direct costs 7,795 Total finance lease costs $ 26,383 Supplemental balance sheet information related to finance leases was as follows as of December 31, 2019 (in thousands): Property and equipment, gross $ 70,440 Accumulated depreciation (20,594) Property and equipment, net $ 49,846 Current portion of finance lease obligations $ 17,777 Finance lease long-term obligations 36,914 Total finance lease liabilities $ 54,691 Supplemental cash flow information related to leases was as follows for the year ended December 31, 2019 (in thousands): Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ (50,792) Operating cash flows for finance leases (1,778) Financing cash flows for finance leases (14,493) Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 55,376 Finance leases 38,144 Lease obligations closed out in exchange for right-of-use assets: Operating leases $ (1,214) Weighted average remaining lease term as of December 31, 2019: Operating leases 7 years Finance leases 3 years Weighted average discount rate as of December 31, 2019: Operating leases 5.0 % Finance leases 2.9 % As of December 31, 2019, maturities of lease liabilities were as follows (in thousands): Operating Leases Finance Leases Total 2020 $ 49,538 $ 19,428 $ 68,966 2021 49,429 18,358 67,787 2022 42,981 14,462 57,443 2023 36,997 5,908 42,905 2024 30,708 16 30,724 2025 and thereafter 101,509 — 101,509 Total lease payments 311,162 58,172 $ 369,334 Less: management fee — (775) Less: imputed interest (54,764) (2,706) Total lease liabilities $ 256,398 $ 54,691 Under ASC Topic 840, Leases

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	DerivativesThe Company has entered into various interest rate swaps in an effort to limit its exposure to variable interest rates on its term loans. In May 2016, the Company entered into an interest rate swap that had an initial notional value of $300.0 million and became effective on June 30, 2016. A portion of the interest rate swaps expired on June 30, 2018, with the remainder expiring on May 14, 2020. As of December 31, 2019, the remaining notional value of these interest rate swaps was $100.0 million. In June 2018, the Company entered into two interest rate swaps with multiple counterparties. The first interest rate swap had an aggregate notional value of $1.22 billion, began accruing interest on June 29, 2018, and expired on December 31, 2018. The second interest rate swap had an initial aggregate notional value of $1.01 billion, an effective date of December 31, 2018, and will expire on June 30, 2021. As of December 31, 2019, the remaining notional value of this interest rate swap was $851.9 million. The significant terms of these derivatives are substantially the same as those contained within the Credit Agreement, including monthly settlements with the swap counterparties. Interest rate swaps are designated as hedging instruments. The amounts of hedge ineffectiveness recorded in net income (loss) during the years ended December 31, 2019, 2018, and 2017 were insignificant. As a result of an acquisition, the Company became a party to certain foreign currency exchange rate forward contracts that have expiration dates through April 2019 and were not designated as hedging instruments. During the year ended December 31, 2019, the amount of loss recognized in other (expense) income, net with respect to these contracts was insignificant. The fair values of the Company’s derivative financial instruments as of December 31 and the line items on the accompanying consolidated balance sheets to which they were recorded were as follows (in thousands): Balance Sheet Classification 2019 2018 Interest rate swaps - current Prepaid expenses and other current assets 155 1,355 Interest rate swaps - non-current Other long-term assets — 441 Foreign currency exchange rate swaps - current Accrued expenses — (138) Interest rate swaps - current Accrued expenses (11,358) (3,031) Interest rate swaps - non-current Other long-term liabilities (6,095) (6,201)

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Assets and Liabilities Carried at Fair Value As of December 31, 2019 and 2018, the Company’s financial assets and liabilities carried at fair value included cash and cash equivalents, trading securities, billed and unbilled accounts receivable (including contract assets), accounts payable, accrued expenses, deferred revenue, assumed contingent obligations, finance leases, liabilities under the accounts receivable financing agreement, and derivative instruments. The fair value of cash and cash equivalents, billed and unbilled accounts receivable (including contract assets), accounts payable, accrued expenses, deferred revenue, and the liabilities under the accounts receivable financing agreement approximates their respective carrying amounts because of the liquidity and short-term nature of these financial instruments. Financial Instruments Subject to Recurring Fair Value Measurements As of December 31, 2019, the fair values of the major classes of the Company’s assets and liabilities measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 Investments Measured Total Assets: Trading securities (a) $ 21,552 $ — $ — $ — $ 21,552 Partnership interest (b) — — — 7,226 7,226 Derivative instruments (c) — 155 — — 155 Total assets $ 21,552 $ 155 $ — $ 7,226 $ 28,933 Liabilities: Derivative instruments (c) $ — $ 17,453 $ — $ — $ 17,453 Contingent obligations related to business combinations (d) — — 37,324 — 37,324 Total liabilities $ — $ 17,453 $ 37,324 $ — $ 54,777 As of December 31, 2018, the fair value of the major classes of the Company’s assets and liabilities measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 Total Assets: Trading securities (a) $ 14,945 $ — $ — $ 14,945 Derivative instruments (e) — 1,796 — 1,796 Total assets $ 14,945 $ 1,796 $ — $ 16,741 Liabilities: Derivative instruments (e) $ — $ 9,370 $ — $ 9,370 Contingent obligations related to business combinations (d) — — 20,127 20,127 Total liabilities $ — $ 9,370 $ 20,127 $ 29,497 (a) Represents fair value of investments in mutual funds based on quoted market prices that are used to fund the liability associated with the deferred compensation plan. (b) The Company has committed to invest $21.5 million as a limited partner in two private equity funds. The private equity funds invest in opportunities in the healthcare and life sciences industry. As of December 31, 2019, the Company’s remaining unfunded commitment in the private equity funds was $14.6 million. The Company holds minor ownership interests (less than 3%) in each of the private equity funds and has determined that it does not exercise significant influence over the private equity funds' operating and finance activities. As the private equity funds do not have readily determinable fair values, the Company has estimated the fair values using each fund’s Net Asset Value, the amount by which the value of all assets exceeds all debt and liabilities, in accordance with ASC Topic 946 , Financial Services – Investment Companies. (c) Represents fair value of interest rate swap arrangements (see "Note 6 - Derivatives" for further information). (d) Represents fair value of contingent consideration obligations related to business combinations (see "Note 3 - Business Combinations" for further information). The fair value of these liabilities are determined based on the Company’s best estimate of the probable timing and amount of settlement. (e) Represents fair value of interest rate swap and foreign currency exchange rate forward contract arrangements (see "Note 6 - Derivatives" for further information). The following table presents a reconciliation of changes in the carrying amount of contingent obligations classified as Level 3 for the years ended December 31, 2019 and 2018 (in thousands): Balance at December 31, 2017 $ 50,480 Additions 4,353 Changes in fair value recognized in earnings (a) (11,604) Payments (23,102) Balance at December 31, 2018 20,127 Additions — Changes in fair value recognized in earnings (b) 17,375 Payments (178) Balance at December 31, 2019 $ 37,324 (a) The change in fair value recognized in earnings for the year ended December 31, 2018 is primarily due to a reduction in the estimate of the transaction tax deduction benefit associated with Double Eagle's acquisition of inVentiv in 2016. (b) The change in fair value recognized in earnings for the year ended December 31, 2019 is primarily due to an increase in the estimate of the transaction tax deduction benefit associated with Double Eagle's acquisition of inVentiv in 2016. During the years ended December 31, 2019 and 2018, there were no transfers of assets or liabilities between Level 1, Level 2, or Level 3 fair value measurements. Financial Instruments Subject to Non-Recurring Fair Value Measurements Certain assets, including goodwill and identifiable intangible assets, are carried on the accompanying consolidated balance sheets at cost and, subsequent to initial recognition, are measured at fair value on a non-recurring basis when certain identified events or changes in circumstances that may have a significant adverse effect on the carrying values of these assets occur. These assets are classified as Level 3 fair value measurements within the fair value hierarchy. Goodwill is tested for impairment annually or more frequently if events or changes in circumstances indicate a triggering event has occurred. Intangible assets are tested for impairment upon the occurrence of certain triggering events. During 2017, the Company recognized approximately $30.0 million of impairment related to intangible assets, as discussed in "Note 1 - Basis of Presentation and Summary of Significant Accounting Policies." As of December 31, 2019 and 2018, assets carried on the consolidated balance sheets and not remeasured to fair value on a recurring basis totaled $5.32 billion and $5.47 billion, respectively. Fair Value Disclosures for Financial Instruments Not Carried at Fair Value The estimated fair value of the term loans and the Senior Notes is determined based on the price that the Company would have to pay to settle the liabilities. As these liabilities are not actively traded, they are classified as Level 2 fair value measurements. The estimated fair values of the Company’s term loans and Senior Notes were as follows (in thousands): December 31, 2019 December 31, 2018 Carrying Value (a) Estimated Fair Value Carrying Value (a) Estimated Fair Value Term Loan A due August 2022 $ 1,545,721 $ 1,550,000 $ 973,218 $ 975,000 Term Loan B due August 2024 794,915 795,564 1,219,755 1,221,000 7.5% Senior Unsecured Notes due 2024 — — 438,330 423,150 (a) The carrying value of the term loan debt is shown net of original issue discounts. The carrying value of the Senior Notes is inclusive of unamortized premiums.

Restructuring and Other Costs

Restructuring and Other Costs	12 Months Ended
	Dec. 31, 2019
Restructuring and Related Activities [Abstract]
Restructuring and Other Costs	Restructuring and Other Costs Merger-Related Restructuring During 2017, in connection with the Merger, the Company established a restructuring plan to eliminate redundant positions and reduce its facility footprint worldwide. The Company expects to continue the ongoing evaluations of its workforce and facilities infrastructure needs in an effort to optimize its resources. Restructuring and other costs related to the Merger consisted of the following (in thousands): Year Ended December 31, 2019 2018 2017 Employee severance and benefit costs $ 12,029 $ 18,021 $ 11,274 Facility and lease termination costs 12,940 24,090 2,213 Other merger-related costs — 560 2,047 Total merger-related restructuring and other costs $ 24,969 $ 42,671 $ 15,534 The Company expects to continue to incur costs related to the restructuring of its operations in order to achieve the targeted synergies as a result of the Merger. However, the timing and the amount of these costs depends on various factors, including, but not limited to, identifying and realizing synergy opportunities and executing the integration of its combined operations. Non Merger-Related Restructuring and Other Costs During the years ended December 31, 2019, 2018, and 2017, the Company incurred employee severance costs and facility closure and lease termination costs related to the Company’s non Merger-related restructuring activities. The Company also assumed certain liabilities related to employee severance and facility closure costs as a result of actions taken by inVentiv prior to the Merger. In addition, the Company incurred consulting and other professional fees during the years ended December 31, 2019 and 2018 related to the continued consolidation of its legal entities and process changes to meet the requirements of new accounting standards. Restructuring and other costs related to these actions consisted of the following (in thousands): Year Ended December 31, 2019 2018 2017 Employee severance and benefit costs $ 13,214 $ 1,922 $ 8,641 CEO transition and retention costs — — 753 Facility and lease termination costs 3,262 1,567 1,331 Consulting fees — 3,488 4,975 Other costs 690 1,145 2,081 Total non-Merger related restructuring and other costs: $ 17,166 $ 8,122 $ 17,781 Accrued Restructuring Liabilities The following table summarizes the activity related to the liabilities associated with restructuring and other costs (in thousands): Employee Facility Closure and Lease Termination Costs Other Costs Total Balance at December 31, 2017 $ 8,858 $ 7,411 $ 524 $ 16,793 Expenses incurred (b) 19,853 22,276 4,615 46,744 Payments (21,237) (12,926) (5,087) (39,250) Balance at December 31, 2018 7,474 16,761 52 24,287 Adoption of ASC 842 (a) — (16,761) — (16,761) Expenses incurred (b) 25,243 — 690 25,933 Payments (26,989) — (720) (27,709) Balance at December 31, 2019 $ 5,728 $ — $ 22 $ 5,750 (a) As a result of the adoption of ASC 842, accrued expenses related to facility closure and lease termination costs are now reflected within the current portion of operating lease obligations and operating lease long-term obligations on the consolidated balance sheets as of December 31, 2019. These facility costs will be paid over the remaining terms of exited facilities, which range from 2020 through 2027. (b) The amount of expenses incurred excludes $6.7 million, $4.0 million, and $8.9 million of non-cash restructuring and other expenses incurred for the years ended December 31, 2019, 2018, and 2017, respectively, because these expenses were not subject to accrual prior to the period in which they were incurred. Expenses incurred for the year ended December 31, 2019 also exclude $9.5 million of facility lease closure and lease termination costs that are reflected as a reduction of operating lease right-of-use assets on the consolidated balance sheet under ASC 842. The Company expects the employee severance costs accrued as of December 31, 2019

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Shareholders' Equity	Shareholders' Equity Shares Outstanding Shares of common stock outstanding were as follows (in thousands): Year Ended December 31, 2019 2018 2017 Common stock shares, beginning balance 103,372 104,436 53,763 Common stock issuances related to business combinations — — 49,297 Stock repurchases (1,323) (1,973) — Stock option exercises 1,381 767 1,178 RSU distributions net of shares for tax withholding 436 142 198 Common stock shares, ending balance 103,866 103,372 104,436 Merger On August 1, 2017, the Company completed its Merger with inVentiv. The Company issued 49,297,022 fully diluted shares of the Company’s common stock in exchange for all outstanding inVentiv shares of common stock. Stock Repurchase Program On February 26, 2018, the Company's Board of Directors (the "Board") authorized the repurchase of up to an aggregate of $250.0 million of the Company's common stock to be executed from time to time in open market transactions effected through a broker at prevailing market prices, in block trades or through privately negotiated transactions through December 31, 2019 (the "stock repurchase program"). On December 5, 2019, the Board increased the dollar amount authorized under the stock repurchase program to up to an aggregate of $300.0 million and extended the term of the stock repurchase program to December 31, 2020. The Company intends to use cash on hand and future operating cash flow to fund the stock repurchase program. The stock repurchase program does not obligate the Company to repurchase any particular amount of the Company’s common stock and may be modified, extended, suspended, or discontinued at any time. The timing and amount of repurchases will be determined by the Company’s management based on a variety of factors such as the market price of the Company’s common stock, the Company’s corporate requirements for cash, and overall market conditions. The stock repurchase program will be subject to applicable legal requirements, including federal and state securities laws and applicable Nasdaq exchange rules. The Company may also repurchase shares of its common stock pursuant to a trading plan meeting the requirements of Rule 10b5-1 under the Securities Exchange Act of 1934, as amended, which would permit shares of the Company’s common stock to be repurchased when the Company might otherwise be precluded from doing so by law. The following table sets forth repurchase activity under the stock repurchase program from inception through December 31, 2019: Total number of shares purchased Average price Approximate March 2018 948,100 $ 39.55 $ 37,493 April 2018 1,024,400 $ 36.60 37,492 January 2019 552,100 $ 39.16 21,623 February 2019 120,600 $ 41.40 4,993 June 2019 509,100 $ 45.29 23,055 August 2019 141,100 $ 49.93 7,045 Total 3,295,400 $ 131,701 The Company immediately retired all of the repurchased common stock and charged the par value of the shares to common stock. The excess of the repurchase price over the par value was applied on a pro rata basis against additional paid-in capital, with the remainder applied to accumulated deficit. As of December 31, 2019, the Company has remaining authorization to repurchase up to approximately $168.3 million of its common stock under the stock repurchase program. The following is a summary of the Company's authorized, issued and outstanding shares at December 31: 2019 2018 Shares Authorized: Class A common stock 300,000,000 300,000,000 Class B common stock 300,000,000 300,000,000 Preferred stock 30,000,000 30,000,000 Total shares authorized 630,000,000 630,000,000 Shares Issued and Outstanding: Class A common stock 103,865,770 103,372,097 Class B common stock — — Preferred stock — — Total shares issued and outstanding 103,865,770 103,372,097 Voting Rights and Conversion Rights of Common Stock Each share of Class A common stock is entitled to one vote on all matters to be voted on by the shareholders of the Company, including the election of directors. Each share of Class B common stock is entitled to one vote on all matters to be voted on by the shareholders of the Company, except for the right to vote in the election of directors. Additionally, each share of Class B common stock is convertible (on a one-for-one basis) into Class A common stock at any time at the election of the holder. Dividend Rights and Preferences of Common Stock The holders of Class A and Class B common stock are entitled to dividends on a pro rata basis at such time and in such amounts as declared by the Board. There were no dividends paid during the years ended December 31, 2019, 2018, or 2017. Liquidation Rights and Preferences of Common Stock The holders of Class A and Class B common stock are entitled to participate on a pro rata basis in all distributions made in connection with a voluntary or involuntary liquidation, dissolution, or winding up of the affairs of the Company.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table provides a reconciliation of the numerators and denominators of the basic and diluted earnings (loss) per share computations (in thousands, except per share data): Year Ended December 31, 2019 2018 2017 Numerator: Net income (loss) $ 131,258 $ 24,284 $ (138,469) Denominator: Basic weighted average common shares outstanding 103,618 103,414 74,913 Effect of dilutive securities: Stock options and other awards under share-based compensation programs 1,387 1,287 — Diluted weighted average common shares outstanding 105,005 104,701 74,913 Earnings (loss) per share: Basic $ 1.27 $ 0.23 $ (1.85) Diluted $ 1.25 $ 0.23 $ (1.85) Potential common shares outstanding that are considered anti-dilutive are excluded from the computation of diluted earnings (loss) per share. Potential common shares related to stock options and other awards under share-based compensation programs may be determined to be anti-dilutive based on the application of the treasury stock method. Potential common shares are also anti-dilutive in periods when the Company incurred a net loss. The number of potential shares outstanding that were anti-dilutive and therefore excluded from the computation of diluted earnings (loss) per share, weighted for the portion of the period they were outstanding, are as follows (in thousands): Year Ended December 31, 2019 2018 2017 Anti-dilutive stock options and other awards 277 744 531 Anti-dilutive stock options and other awards under share-based compensation programs excluded based on reporting a net loss for the period — — 1,255 Total common stock equivalents excluded from diluted earnings (loss) per share 277 744 1,786

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The components of income (loss) before provision for income taxes were as follows (in thousands): Year Ended December 31, 2019 2018 2017 Domestic $ (17,066) $ (26,263) $ (204,352) Foreign 118,775 83,521 92,475 Income (loss) before provision for income taxes $ 101,709 $ 57,258 $ (111,877) The components of income tax expense were as follows (in thousands): Year Ended December 31, 2019 2018 2017 Federal income taxes: Current $ 13,952 $ (19,949) $ 6,299 Deferred 11,693 3,081 (18,731) Foreign income taxes: Current (21,452) (10,398) (18,030) Deferred 2,206 2,382 312 State income taxes: Current (2,850) (2,387) (430) Deferred 26,000 (5,703) 3,988 Income tax benefit (expense) $ 29,549 $ (32,974) $ (26,592) Tax Cuts and Jobs Act of 2017 On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act makes broad and complex changes to the U.S. tax code, including requiring companies to pay a one-time transition tax on certain undistributed earnings of foreign subsidiaries. The deemed repatriation transition tax ("Transition Tax") is a tax on previously untaxed accumulated and current earnings and profits ("E&P") of the Company's foreign subsidiaries. The Company was able to reasonably estimate the Transition Tax and recorded a provisional income tax expense of $63.1 million for the year ended December 31, 2017. The Tax Act created a new requirement related to global intangible low taxed income ("GILTI"). In particular, GILTI earned by controlled foreign corporations ("CFCs") must be included currently in the gross income of the CFC’s U.S. parent. Under GAAP, the Company can make an accounting policy election to either treat taxes due on the GILTI inclusion as a current period expense or factor such amounts into measurement of deferred taxes. The Company has elected to record GILTI impacts as a current period expense. The Company has approximately $745.2 million of undistributed foreign earnings, of which approximately $341.8 million will remain indefinitely reinvested in the foreign jurisdictions. These earnings are expected to be used to support the growth and working capital needs of the Company’s foreign subsidiaries. It is impracticable to determine the total amount of unrecognized deferred taxes with respect to these indefinitely reinvested earnings. The remaining $403.4 million of undistributed foreign earnings are not considered indefinitely reinvested, and the Company has provided a $3.4 million deferred tax liability, primarily related to state taxes, for the estimated tax liability that would be due upon repatriation. The Tax Act also introduced a new tax on U.S. corporations that derive tax benefits from deductible payments to non-US affiliates called the base erosion and anti-abuse tax ("BEAT"). BEAT applies when base eroding payments are in excess of three percent of the Company’s total deductible payments and where BEAT exceeds regular U.S. tax due, similar to a minimum tax. Final regulations related to BEAT were released in December 2019 and the Company has considered this guidance as part of the BEAT computation. The Company's base eroding payments do not exceed the three percent threshold of its deductible payments in 2019; therefore, the Company has not recorded any BEAT liability for the year ended December 31, 2019. Additionally, during 2019, the Company finalized its review of base erosion payments related to 2018 and concluded these payments were below the three percent threshold of its total deductible payments for 2018. As such, the Company has recognized a tax benefit representing the reversal of the 2018 BEAT liability previously recorded. Actual income tax expense differed from the amount computed by applying the U.S. federal tax rate of 21% during 2019 and 2018, and 35.0% during 2017 to pre-tax income (loss) as a result of the following (in thousands): Year Ended December 31, 2019 2018 2017 Expected income tax (expense) benefit at statutory rate $ (21,359) $ (12,024) $ 39,157 Change in income tax expense resulting from: Foreign income inclusion (39,557) (20,916) (780) Foreign earnings reinvestment assertion reversal — 3,823 112,087 Foreign earnings reinvestment assertion accrual — — (53,421) Changes in income tax valuation allowance (all jurisdictions) 68,537 15,228 (52,563) Change in fair value of contingent obligations (3,625) 2,434 4,344 Share-based compensation (1,094) (2,677) 8,901 Research and general business tax credits 1,871 10,937 5,718 State and local taxes, net of federal benefit 9,085 (7,715) 1,330 Capitalized transaction costs — (481) (6,486) Foreign rate differential 3,595 4,071 16,778 Changes in reserve for uncertain tax positions including interest (5,393) 1,190 947 Provision to tax return and other deferred tax adjustments 6,950 (12,251) (536) Base erosion and anti-abuse tax 15,054 (15,054) — Federal rate change — 1,226 (37,468) Transition tax — — (63,050) Nondeductible executive compensation (1,802) (159) (1,792) Other, net (2,713) (606) 242 Income tax benefit (expense) $ 29,549 $ (32,974) $ (26,592) The changes in the valuation allowance for deferred tax assets were as follows (in thousands): Year Ended December 31, 2019 2018 2017 Balance at the beginning of the period $ 150,316 $ 159,646 $ 5,238 Deferred tax assets assumed through business combinations — — 101,527 (Credited) charged to income tax expense (68,537) (15,228) 52,563 (Credited) charged to equity 42 11,848 — Foreign currency exchange 2,338 (5,950) — Other adjustments — — 318 Balance at the end of the period $ 84,159 $ 150,316 $ 159,646 As of December 31, 2019, the valuation allowance decreased by $66.2 million, resulting primarily from a net decrease of $68.5 million primarily due to the release of the valuation allowance on U.S. deferred tax assets and an increase of $2.3 million for changes related to foreign currency exchange. The Company assessed both positive and negative evidence in evaluating whether it could support the recognition of its U.S. net deferred tax asset position or if a valuation allowance would be required. Additionally, the Company elected to use the tax law ordering approach to determine the realizability of its deferred tax assets. A significant piece of objective positive evidence that the Company considered was the three year cumulative income, which includes adjustments for certain permanent items, for periods ending December 31, 2019, 2018, and 2017. This objective positive evidence was weighed against any subjective negative evidence available to the Company and it was determined that the substantial objective positive evidence was sufficient to overcome the substantial negative evidence. As a result of this positive evidence, the Company released its entire valuation allowance for the U.S. federal deferred tax assets and a large portion of its valuation allowance related to state deferred tax assets. The Company recorded a benefit of $68.5 million, a benefit of $15.2 million and an expense of $52.6 million for the net change in valuation allowance for the years ended December 31, 2019, 2018, and 2017, respectively. The income tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities are as follows at December 31 (in thousands): 2019 2018 Deferred tax assets: Net operating losses $ 199,002 $ 262,047 Tax credits 51,273 57,306 Deferred revenue 13,598 13,817 Employee compensation and other benefits 27,287 27,128 Allowance for doubtful accounts 1,091 963 Deferred rent — 2,564 Lease obligations 64,114 — Accrued expenses 8,508 11,445 Prepaid royalty 6,525 — Interest limitation carryforwards 15,624 12,831 Other 10,154 5,433 Total deferred tax assets 397,176 393,534 Less: valuation allowance (84,159) (150,316) Net deferred tax assets 313,017 243,218 Deferred tax liabilities: Undistributed foreign earnings (3,366) (3,818) Right of use asset (57,055) — Foreign branch operations — (1,733) Depreciation and amortization (226,252) (250,090) Other (433) (3,380) Total deferred tax liabilities (287,106) (259,021) Net deferred tax assets (liabilities) $ 25,911 $ (15,803) As of December 31, 2019 and 2018, the Company had U.S. federal NOL carryforwards of approximately $569.5 million and $846.5 million, respectively. As of December 31, 2019 and 2018, the Company had state NOL carryforwards of approximately $1.04 billion and $1.03 billion, respectively, a portion of which expires annually. The Company also had foreign NOL carryforwards of $85.8 million and $118.2 million as of December 31, 2019 and 2018, respectively. A valuation allowance has been established for jurisdictions where the future benefit of the NOL carryforwards is not more likely than not to be realized. As of December 31, 2019 and 2018, the Company had Canadian research and development credit carry forwards of $48.5 million and $51.8 million, respectively. For the years ended December 31, 2019 and 2018, a valuation allowance of $48.5 million and $48.2 million, respectively, has been established against these tax credits where the future benefit of the credits is not more likely than not to be realized. The Company had gross unrecognized tax benefits, exclusive of associated interest and penalties, of approximately $23.2 million and $19.2 million as of December 31, 2019 and 2018, respectively. The Company recognizes accrued interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 2019 and 2018, the Company had accrued interest and penalties related to uncertain tax positions of $6.4 million and $4.4 million, respectively. For the years ended December 31, 2019 and 2018, the Company recorded tax expense in the accompanying consolidated statements of operations related to interest and penalties associated with uncertain tax positions of $2.1 million, $0.5 million, respectively. The Company anticipates that during the next 12 months, the unrecognized tax benefits will decrease by approximately $15.1 million. A reconciliation of the beginning and ending balances of unrecognized tax benefits, excluding accrued interest and penalties, is as follows (in thousands): Unrecognized tax benefits balance at December 31, 2016 $ 15,738 Lapse of statute of limitations 191 Increases for tax positions of prior years 27,974 Decreases for tax positions of prior years (226) Impact of foreign currency translation 1 Unrecognized tax benefits balance at December 31, 2017 43,678 Increases for tax positions in the current year 673 Increases for tax positions of prior years 344 Decreases for tax positions in prior year (25,309) Impact of foreign currency translation (141) Unrecognized tax benefits balance at December 31, 2018 19,245 Increases for tax positions in the current year 2,222 Increases for tax positions of prior years 2,255 Decreases for tax positions in prior year (440) Impact of foreign currency translation (44) Unrecognized tax benefits balance at December 31, 2019 $ 23,238 Due to the geographic breadth of the Company's operations, numerous tax audits may be ongoing throughout the world at any point in time. Income tax liabilities are recorded based on estimates of additional income taxes which will be due upon the conclusion of these audits. Estimates of these income tax liabilities are made based upon prior experience and are updated in light of changes in facts and circumstances. However, due to the uncertain and complex application of tax regulations, it is possible that the ultimate resolution of audits may result in liabilities which could be materially different from these estimates. In such an event, the Company will record additional income tax expense or benefit in the period in which such resolution occurs. The Company remains subject to audit by the IRS and various state taxing jurisdictions with the earliest open period of 1999, due to NOL carryforwards. The Company's tax filings are open to investigation from 2015 forward in the United Kingdom, which is the jurisdiction of the Company's largest foreign operation. In addition, income tax returns for various tax years are currently under examination by the respective tax authorities in the U.S, the United Kingdom, Germany, Russia, and India. The Company believes that its reserve for uncertain tax positions is adequate to cover existing risks or exposures related to all open tax years.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customers	Revenue from Contracts with Customers Unsatisfied Performance Obligations As of December 31, 2019, the total aggregate transaction price allocated to the unsatisfied performance obligations under contracts with contract terms greater than one year and that are not accounted for as a series pursuant to ASC 606 was $5.40 billion. This amount includes revenue associated with reimbursable out-of-pocket expenses. The Company expects to recognize revenue over the remaining contract term of the individual projects, with contract terms generally ranging from one Timing of Billing and Performance

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment Information	Segment Information The Company is managed through two reportable segments: Clinical Solutions and Commercial Solutions. Each reportable segment consists of multiple service offerings that, when combined, create a fully integrated biopharmaceutical services organization . Clinical Solutions offers a variety of services spanning Phase I to Phase IV of clinical development , including full service global studies, as well as individual service offerings such as clinical monitoring, investigator recruitment, patient recruitment, data management, and study startup to assist customers with their drug development process. Commercial Solutions provides commercialization services to the pharmaceutical, biotechnology, and healthcare industries, which include Deployment Solutions, communications solutions (public relations and advertising), and consulting related services. The Company’s Chief Operating Decision Maker (the "CODM") reviews segment performance and allocates resources based upon segment revenue and income from operations. Inter-segment revenue is eliminated from the segment reporting provided to the CODM and is not included in the segment revenue presented in the table below. Certain costs are not allocated to the Company’s reportable segments and are reported as general corporate expenses. These costs primarily consist of share-based compensation and general operational expenses associated with the Company’s senior leadership, finance, Board, investor relations, and internal audit functions. Prior to the adoption of ASC 606, revenue and costs for reimbursed out-of-pocket expenses were not allocated to the Company’s segments. The Company does not allocate depreciation, amortization, asset impairment charges, restructuring, or transaction and integration-related expenses to its segments. Additionally, the CODM reviews the Company’s assets on a consolidated basis and does not allocate assets to its reportable segments for purposes of assessing segment performance or allocating resources. Information about reportable segment operating results was as follows (in thousands): Year Ended December 31, 2019 2018 2017 (a) Revenue: Clinical Solutions $ 3,421,596 $ 3,211,202 $ 1,459,968 Commercial Solutions 1,254,219 1,178,914 392,875 Total revenue 4,675,815 4,390,116 1,852,843 Reimbursable out-of-pocket expenses not allocated to segments — — 819,221 Total consolidated revenue 4,675,815 4,390,116 2,672,064 Segment direct costs: Clinical Solutions 2,616,249 2,477,920 930,176 Commercial Solutions 1,000,645 937,060 291,310 Total segment direct costs 3,616,894 3,414,980 1,221,486 Segment selling, general, and administrative expenses: Clinical Solutions 275,645 266,381 203,206 Commercial Solutions 92,287 86,333 40,236 Total segment selling, general, and administrative expenses 367,932 352,714 243,442 Segment operating income: Clinical Solutions 529,702 466,901 326,586 Commercial Solutions 161,287 155,521 61,329 Total segment operating income 690,989 622,422 387,915 Direct costs and operating expenses not allocated to segments: Reimbursable out-of-pocket expenses — — 819,221 Share-based compensation included in direct costs 29,011 19,330 10,537 Share-based compensation included in selling, general, and administrative expenses 26,182 14,902 14,041 Corporate selling, general, and administrative expenses 52,167 38,689 25,137 Restructuring and other costs 42,135 50,793 33,315 Transaction and integration-related expenses 61,275 64,841 123,815 Asset impairment charges — — 30,000 Depreciation and amortization 242,465 273,685 179,936 Total consolidated income from operations $ 237,754 $ 160,182 $ (28,866) (a) Following the Merger, beginning August 1, 2017, the Company’s consolidated results of operations include results of operations of inVentiv.

Operations by Geographic Locati

Operations by Geographic Location	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Operations by Geographic Location	Operations by Geographic Location The Company conducts its global operations through wholly-owned subsidiaries and representative sales offices. The Company attributes revenue to geographical locations based upon the location where the work is performed. The following table summarizes total revenue by geographic area (in thousands, all intercompany transactions have been eliminated): Year Ended December 31, 2019 2018 2017 Revenue: North America (a) $ 3,079,608 $ 2,974,330 $ 1,174,462 Europe, Middle East and Africa 1,055,007 955,882 458,264 Asia-Pacific 444,819 375,351 174,345 Latin America 96,381 84,553 45,772 Revenue (b) 4,675,815 4,390,116 1,852,843 Reimbursable out-of-pocket expenses (b) — — 819,221 Total revenue $ 4,675,815 $ 4,390,116 $ 2,672,064 (a) Revenue for the North America region includes revenue attributable to the U.S. of $2.93 billion and $2.82 billion, or 62.7% and 64.3% of total revenue, for the years ended December 31, 2019 and 2018, respectively. For the year ended December 31, 2017, revenue for the North America region includes revenue attributable to the U.S. of $1.13 billion, or 60.9% of revenue excluding reimbursable out-of-pocket expenses. No other countries represented more than 10% of total revenue for any year. (b) The Company adopted ASC 606 on January 1, 2018 using the modified retrospective method for all contracts not completed as of the date of adoption. The following table summarizes long-lived assets by geographic area as of December 31 (in thousands, all intercompany transactions have been eliminated): 2019 2018 Property and equipment, net: North America (a) $ 159,709 $ 133,593 Europe, Middle East and Africa 28,514 33,053 Asia-Pacific 12,742 13,328 Latin America 2,961 3,512 Total property and equipment, net $ 203,926 $ 183,486 (a) Long-lived assets for the North America region include property and equipment, net attributable to the U.S. of $153.1 million and $128.3 million as of December 31, 2019 and 2018, respectively.

Concentration of Credit Risk

Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2019
Risks and Uncertainties [Abstract]
Concentration of Credit Risk	Concentration of Credit Risk Financial assets that subject the Company to credit risk primarily consist of cash and cash equivalents and billed and unbilled accounts receivable. The Company's cash and cash equivalents consist principally of cash and are maintained at several financial institutions with reputable credit ratings. The Company maintains cash depository accounts with several financial institutions worldwide and is exposed to credit risk related to the potential inability to access liquidity in financial institutions where its cash and cash equivalents are concentrated. The Company has not historically incurred any losses with respect to these balances and believes that they bear minimal credit risk. As of December 31, 2019, substantially all of the Company’s cash and cash equivalents were held within the United States. As of December 31, 2018, the amount of cash and cash equivalents held outside the United States by the Company’s foreign subsidiaries was $43.6 million, or 28% of the total consolidated cash and cash equivalents balance. Substantially all of the Company's revenue is earned by performing services under contracts with pharmaceutical and biotechnology companies. The concentration of credit risk is equal to the outstanding billed accounts receivable, unbilled accounts receivable, and contract assets less deferred revenue. No single customer accounted for greater than 10% of the Company’s revenue for the years ended December 31, 2019 or 2017. During the year ended December 31, 2018, one customer accounted for approximately 11% of the Company’s revenue, which was primarily earned in the Clinical Solutions segment.

Related-Party Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Related-Party Transactions	Related-Party Transactions For the year ended December 31, 2019, the Company had revenue of $0.4 million from a customer whose board of directors included a member who was also a member of the Company’s Board. This customer became a related party of the Company during the fourth quarter of 2019. For the year ended December 31, 2018, the Company had revenue of $0.4 million from two customers each of whose respective boards of directors included a member who was also a member of the Company’s Board. No material related party revenue was recorded for the year ended December 31, 2017. For the year ended December 31, 2019, the Company incurred reimbursable out-of-pocket expenses of $1.1 million for professional services obtained from a provider whose board of directors included a member who was also a member of the Company's Board. These expenses are included within direct costs on the consolidated statements of operations. This provider ceased to be a related-party as of December 31, 2019. For the year ended December 31, 2018, the Company incurred reimbursable out-of-pocket expenses of $3.5 million for professional services obtained from two related-party providers. One provider had a member of its board of directors who was also a member of the Company’s Board and the other provider had a significant shareholder who was also a significant shareholder of the Company. At December 31, 2018, the Company had liabilities of $1.2 million included in accounts payable and accrued expenses on the consolidated balance sheet associated with obligations to these related parties. For the year ended December 31, 2017, the Company incurred reimbursable out-of-pocket expenses of $0.4 million for professional services obtained from a provider whose significant shareholder was also a significant shareholder of the Company.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Contingencies The Company is involved in various claims and legal actions arising in the ordinary course of business. The Company accrues a liability when a loss is considered probable and the amount can be reasonably estimated. When a material loss contingency is reasonably possible but not probable, the Company does not record a liability, but instead discloses the nature and the amount of the claim, and an estimate of the loss or range of loss, if such an estimate can be made. Legal fees are expensed as incurred. In the opinion of management, the outcome of any existing claims and legal or regulatory proceedings, other than the specific matters described below, if decided adversely, is not expected to have a material adverse effect on the Company's business, financial condition, results of operations, or cash flows. On December 1, 2017, the first of two virtually identical actions alleging federal securities law claims was filed against the Company and certain of its officers on behalf of a putative class of its shareholders. The first action, captioned Bermudez v. INC Research, Inc., et al, No. 17-09457 (S.D.N.Y.) in the Southern District of New York, names as defendants the Company, Michael Bell, Alistair MacDonald, Michael Gilbertini, and Gregory S. Rush (the "Bermudez action"), and the second action, Vaitkuvienë v. Syneos Health, Inc., et al, No. 18-0029 (E.D.N.C.) in the Eastern District of North Carolina, filed on January 25, 2018 (the “Vaitkuvienë action"), names as defendants the Company, Alistair MacDonald, and Gregory S. Rush (the "Initial Defendants"). Both complaints allege similar claims under Section 10(b) and Section 20(a) of the Securities Exchange Act of 1934 on behalf of a putative class of purchasers of the Company's common stock between May 10, 2017 and November 8, 2017 and November 9, 2017. The complaints allege that the Company published inaccurate or incomplete information regarding, among other things, the financial performance and business outlook for inVentiv’s business prior to the Merger and with respect to the combined company following the Merger. On January 30, 2018, two alleged shareholders separately filed motions seeking to be appointed lead plaintiff and approving the selection of lead counsel. On March 30, 2018, Plaintiff Bermudez filed a notice of voluntary dismissal of the Bermudez action, without prejudice, and as to all defendants. On May 29, 2018, the Court in the Vaitkuvienë action appointed the San Antonio Fire & Police Pension Fund and El Paso Firemen & Policemen’s Pension Fund as Lead Plaintiffs and, on June 7, 2018, the Court entered a schedule providing for, among other things, Lead Plaintiffs to file an amended complaint by July 23, 2018 (later extended to July 30, 2018). Lead Plaintiffs filed their amended complaint on July 30, 2018, which also includes a claim against the Initial Defendants, as well as each member of the board of directors at the time of the INC Research - inVentiv Health merger vote in July 2017 (the “Defendants”), contending that the inVentiv merger proxy was misleading under Section 14(a) of the Act. Lead Plaintiffs seek, among other things, orders (i) declaring that the lawsuit is a proper class action and (ii) awarding compensatory damages in an amount to be proven at trial, including interest thereon, and reasonable costs and expenses incurred in this action, including attorneys’ fees and experts' fees, to Lead Plaintiffs and other class members. Defendants filed a Motion to Dismiss Plaintiffs’ Amended Complaint on September 20, 2018. Lead Plaintiffs filed a Response in Opposition to such motion on November 21, 2018, and Defendants filed a Reply to such response on December 5, 2018. On May 23, 2019, Lead Plaintiffs filed a Notice of Filings in Related Case regarding the New Jersey shareholder action filed on March 1, 2019 described below, and Defendants filed their response on May 31, 2019. On September 26, 2019, the Court ordered, among other things, that this action is stayed in light of the litigation filed on March 1, 2019 and described below, pending before the United States District Court for the District of New Jersey. The Company and the other defendants deny the allegations in these complaints and intend to defend vigorously against these claims. In the Company's opinion, the ultimate outcome of this matter is not expected to have a material adverse effect on the Company's financial position, results of operations, or cash flows. On September 24, 2018, the Court unsealed a civil complaint in the Western District of Washington captioned United States, et. al vs. AstraZeneca PLC, et. al, No. 2:17-cv-01328-RSL (W.D. Wa.) against inVentiv Health, Inc. and other co-defendants. The complaint alleges that the Company and co-defendants violated the Federal False Claims Act (and various state analogues) and Anti-Kickback Statute through the provision of clinical education services. On December 17, 2018, the United States moved to dismiss this lawsuit, as well as other similar lawsuits supported by the relator in this action. On November 5, 2019, the Court granted such motion and dismissed this action with prejudice as to the relator and without prejudice as to the United States. The Company denies the allegations in the complaint and intends to defend vigorously against these claims. In the Company’s opinion, the ultimate outcome of this matter is not expected to have a material adverse effect on the Company’s financial position, results of operations, or cash flows. On February 21, 2019, the SEC notified the Company that it had commenced an investigation into the Company’s revenue accounting policies, internal controls and related matters. On August 26, 2019, the SEC notified the Company that it had concluded its investigation and does not intend to recommend an enforcement action against the Company at that time. On March 1, 2019, a complaint was filed in the United States District Co urt for the District of New Jersey on behalf of a putative class of shareholders who purchased the Company's common stock during the period between May 10, 2017 and February 27, 2019. The action, captioned Murakami v. Syneos Health, Inc. et al, No. 19-7377 (D.N.J.), names the Company and certain of its executive officers as defendants and alleges violations of the Securities Exchange Act of 1934, as amended, based on allegedly false or misleading statements about its business, operations, and prospects. The plaintiffs seek awards of compensatory damages, among other relief, and their costs and attorneys’ and experts’ fees. On March 28, 2019, Lead Plaintiffs in the Vaitkuvienë action filed a motion to intervene and to transfer this action to the Eastern District of North Carolina, and the Company filed its response on April 22, 2019. On April 30, 2019, a shareholder filed a motion seeking to be appointed lead plaintiff and approving the selection of lead counsel. On October 16, 2019, the Court ordered that Plaintiff, by November 8, 2019, file proof of service of the Complaint in Compliance with Rule 4, or otherwise show cause why the action should not be dismissed for failure to properly serve Defendants (the "Order to Show Cause"). The Court further ordered that the action is stayed and that both motions are administratively terminated pending the Court's resolution of the Order to Show Cause. Plaintiff filed a response to the Order to Show Cause on November 8, 2019, and the Company and the other defendants filed a response on November 20, 2019. The parties are awaiting a ruling on the Order to Show Cause. The Company and the other defendants deny the allegations in the complaint and intend to defend vigorously against these claims. In the Company's opinion, the ultimate outcome of this matter is not expected to have a material adverse effect on the Company's financial position, results of operations, or cash flows. The Company is presently unable to predict the duration, scope, or result of the foregoing putative class actions, or any other related lawsuit. As such, the Company is presently unable to develop a reasonable estimate of a possible loss or range of losses, if any, related to these matters. While the Company intends to defend the putative class action litigation vigorously, the outcome of such litigation or any other litigation is necessarily uncertain. The Company could be forced to expend significant resources in the defense of these lawsuits or future ones, and it may not prevail. As such, these matters could have a material adverse effect on the Company's business, annual, or interim results of operations, cash flows, or its financial condition. Assumed Contingent Tax-Sharing Obligation As a result of the Merger, the Company assumed contingent tax-sharing obligations arising from inVentiv’s 2016 merger with Double Eagle Parent, Inc. As of December 31, 2019 and 2018, the estimated fair value of the assumed contingent tax-sharing obligations was $32.7 million and $15.7 million, respectively. For additional information, refer to "Note 3 - Business Combinations." Contingent Earn-out Liability In connection with the Kinapse acquisition, the Company recorded a contingent earn-out liability to be paid based on Kinapse meeting revenue targets through March 31, 2021. The fair value of the earn out liability is remeasured at the end of each reporting period, with changes in the estimated fair value reflected in earnings until the liability is settled. The estimated fair value of the contingent earn out liability was $4.6 million and $4.4 million as of December 31, 2019 and 2018, respectively, and is included in other long-term liabilities on the accompanying consolidated balance sheets. For additional information, refer to “Note 3 - Business Combinations.”

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Share-Based Compensation	Share-Based Compensation Overview of Employee Share-Based Compensation Plans The Company has two equity-based compensation plans, the Syneos Health, Inc. 2018 Equity Incentive Plan (“2018 Plan”) and the Syneos Health, Inc. 2016 Employee Stock Purchase Plan, as amended and restated ("ESPP"). In addition, the Company had the INC Research Holdings, Inc. 2014 Equity Incentive Plan ("2014 Plan") and the INC Research Holdings, Inc. 2010 Equity Incentive Plan ("2010 Plan") that were terminated effective May 24, 2018 and October 30, 2014, respectively, except as to outstanding awards. No further awards can be issued under the 2014 or 2010 Plans. The 2018 Plan was effective on May 24, 2018, and permits granting of stock options, stock appreciation rights, restricted stock awards, restricted stock units ("RSUs"), or stock awards to employees, as well as non-employee directors, consultants, or other personal service providers. The terms of equity-based instruments granted are determined at the time of grant and are typically subject to such conditions as continued employment, passage of time, and/or satisfaction of performance criteria. The Company has granted stock options and RSUs, which typically vest ratably over three four ten On August 1, 2017, in connection with the Merger, the Company filed a Form S-8 Registration Statement for the Double Eagle Parent, Inc. 2016 Omnibus Equity Incentive Plan ("Double Eagle Plan" and together with the 2018 Plan, 2014 Plan, and 2010 Plan, the “Plans”). The number of shares registered in that filing was 1,500,000. Under this plan, the Company issued replacement awards consisting of stock options and RSUs. No further awards can be issued under the Double Eagle Plan. As of December 31, 2019, the Company had equity grants outstanding under the 2010 Plan, 2014 Plan, 2018 Plan, and the Double Eagle Plan. The maximum number of shares reserved for issuance under the Plans was 15,167,325, of which 5,008,943 shares were available for future grants as of December 31, 2019. In addition, under the 2018 Plan, any shares of the Company’s common stock that are retained by or returned to the Company under any outstanding awards that are canceled, expired, forfeited, surrendered, settled in cash, or otherwise terminated without delivery of the shares, in each case, will prior to vesting or exercise become available for future grants. Employee Stock Purchase Plan In March 2016, the Board approved the ESPP, which was also approved by the Company’s shareholders in May 2016. The ESPP was subsequently amended and restated and approved by the Board in March 2018, and also approved by the Company’s shareholders in May 2018. The ESPP allows eligible employees to authorize payroll deductions of up to 10% of their annual base salary or wages to be applied toward the purchase of full shares of the Company’s common stock on the last trading day of the offering period. Participating employees can purchase shares of the Company's common stock at a 15% discount to the lesser of the closing price of the Company's common stock as quoted on the Nasdaq Stock Exchange on (i) the first trading day of the offering period or (ii) the last trading day of the offering period. Offering periods under the ESPP are six Share-Based Awards Exchanged in Business Combination As a result of the Merger, the Company assumed the equity incentive plans formerly related to inVentiv. In connection with the Merger, the vesting conditions of certain outstanding time-based and performance-based stock option awards and RSUs of inVentiv were modified at the discretion of its board of directors. These changes were treated as modifications of share-based awards and accounted for according to the provisions of ASC Topic 718, Compensation - Stock Compensation . Each vested option to purchase shares of inVentiv common stock outstanding immediately prior to the effective date of the Merger was automatically converted into a vested option to acquire shares of the Company’s common stock, on substantially the same terms and conditions, adjusted by the 3.4928 exchange ratio; and each restricted stock unit of inVentiv outstanding immediately prior to the effective date of the Merger was automatically converted into shares of the Company’s common stock at an exchange ratio of 3.4928. The fair value of these awards was allocated to the purchase consideration in the amount of $16.2 million and post-combination expense in the amount of $27.1 million, based on the portion of the vesting period completed prior to the date of the Merger. Similarly, at the discretion of the Company’s Board, upon the Merger certain share-based awards of the Company outstanding immediately prior to the effective date of the Merger vested, and certain performance-based RSUs were converted into RSUs at 100% of the target. The outstanding awards of approximately 50 employees were impacted. The aggregate incremental fair value of these awards was approximately $2.7 million, of which approximately $0.5 million, $0.1 million, and $1.5 million was recognized as share-based compensation expense during the years ended December 31, 2019, 2018, and 2017, respectively. There is no remaining incremental fair value to be recognized. Stock Option Awards The following table sets forth the summary of stock option activity under the Plans for the year ended December 31, 2019: Number of Weighted Weighted Average Aggregate Intrinsic Value Outstanding at December 31, 2018 1,910,577 $ 27.92 Exercised (872,474) 27.29 Forfeited (15,479) 43.07 Expired (38,447) 33.75 Outstanding at December 31, 2019 984,177 28.01 5.24 $ 30,965 Vested and expected to vest at December 31, 2019 984,177 28.01 5.24 $ 30,965 Exercisable at December 31, 2019 925,001 $ 27.06 5.20 $ 29,983 (a) Represents the total pre-tax intrinsic value (i.e., the aggregate difference between the closing price of the Company’s common stock on December 31, 2019 of $59.47 and the exercise price for in-the-money options) that would have been received by the holders if all instruments had been exercised on December 31, 2019. As of December 31, 2019, there was $0.1 million of unrecognized compensation expense related to non-vested stock options, which is expected to be recognized over a weighted average period of 0.6 years. Other information pertaining to the Company's stock option awards was as follows (in thousands, except per share data): Year Ended December 31, 2019 2018 2017 Weighted average grant date fair value of options granted $ — $ — $ 13.88 Total intrinsic value of options exercised 20,288 9,156 37,928 Fair Value Assumptions The fair values of stock option awards and ESPP offerings were determined using the Black-Scholes valuation model and the following assumptions: Year Ended December 31, 2019 2018 2017 Expected volatility: Stock options —% —% 24.5% - 24.6% ESPP 39.1% - 51.9% 32.3% - 69.3% 36.0% - 46.5% Risk-free interest rate: Stock options —% —% 1.80% ESPP 1.88% - 2.52% 1.85% - 2.28% 0.79% - 1.08% Expected term (in years): Stock options — — 4.75 - 5.0 ESPP 0.5 0.5 0.5 Restricted Stock Units Awards The following table sets forth a summary of RSUs outstanding under the 2014 and 2018 Plans as of December 31, 2019 and changes during the year then ended: Number of Shares Weighted Average Non-vested at December 31, 2018 2,203,966 $ 41.02 Granted 1,521,614 45.41 Vested (732,786) 41.35 Forfeited (441,418) 42.36 Non-vested at December 31, 2019 2,551,376 $ 43.48 At December 31, 2019, there was $65.7 million of unrecognized compensation expense related to unvested RSUs, which is expected to be recognized over a weighted average period of 1.8 years. Performance-Based Awards During the years ended December 31, 2019, 2018, and 2017, the Board and Compensation Committee granted certain executive officers performance-based RSUs (“PRSUs”). The PRSUs are subject to the Company's achieving certain performance targets including revenue growth, adjusted diluted EPS growth, and return on invested capital. These awards are included in the RSU table above. Compensation expense related to PRSUs is recorded based on the estimated quantity of awards that are expected to vest. At each reporting period, management re-assesses the probability that the performance conditions will be achieved and adjusts compensation expense to reflect any changes in the estimated probability of vesting until the actual level of achievement of the performance targets is known. Share-Based Compensation Expense Total share-based compensation expense recognized was as follows (in thousands): Year Ended December 31, 2019 2018 2017 Direct costs $ 29,011 $ 19,330 $ 10,537 Selling, general, and administrative expenses 26,182 14,902 14,041 Restructuring and other costs — 91 3,791 Transaction and integration-related expenses — — 31,327 Total share-based compensation expense $ 55,193 $ 34,323 $ 59,696 The total income tax benefit recognized in the consolidated statements of operations for share-based compensation arrangements was approximately $10.8 million, $1.7 million, and $1.6 million for the years ended December 31, 2019, 2018, and 2017, respectively.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans Defined Contribution Retirement Plans In the U.S., the Company offers defined contribution retirement benefit plans that comply with Section 401(a) of the Internal Revenue Code under which it matches employee deferrals at varying percentages and at specified limits of the employee’s salary. The Company’s contributions related to these defined contribution retirement plans were as follows (in thousands): Year Ended December 31, 2019 2018 2017 Defined contribution retirement plan contributions $ 29,834 $ 24,801 $ 15,429 The Company also has defined contribution retirement plans outside of the U.S. The Company's contributions related to these plans were approximately $10.0 million during the year ended December 31, 2019. The Company's contributions associated with all of its defined contribution retirement plans are recorded in direct costs and selling, general, and administrative expenses on the accompanying consolidated statements of operations. Deferred Compensation Plan The Company offers a nonqualified Deferred Compensation Plan for certain employees pursuant to Section 409a of the Internal Revenue Code (“NQDC Plan”). Under this plan, participants can defer, on a pre-tax basis, from 1.0% up to a maximum of 80.0% of salary and from 1.0% up to a maximum of 100.0% of commissions and performance and non-performance based bonuses. The Company does not make matching contributions into the NQDC Plan. Distributions will be made to participants upon termination of employment or death in a lump sum, unless installments are selected.

Quarterly Results of Operations

Quarterly Results of Operations - Unaudited	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations - Unaudited	Quarterly Results of Operations — Unaudited The following was a summary of the Company's consolidated quarterly results of operations for each of the fiscal years ended December 31, 2019 and 2018 (in thousands, except per share data): 2019 First Quarter Second Quarter Third Quarter Fourth Quarter Revenue $ 1,119,006 $ 1,166,827 $ 1,177,028 $ 1,212,954 Income from operations (a) (b) 26,816 58,134 69,443 83,361 Net (loss) income (c) (d) (30,004) 11,292 58,920 91,050 Basic (loss) earnings per share $ (0.29) $ 0.11 $ 0.57 $ 0.88 Diluted (loss) earnings per share $ (0.29) $ 0.11 $ 0.56 $ 0.86 2018 First Quarter Second Quarter Third Quarter Fourth Quarter Revenue $ 1,057,196 $ 1,072,530 $ 1,114,918 $ 1,145,472 Income from operations (a) (b) 10,175 30,722 39,817 79,468 Net (loss) income (c) (d) (24,552) 13,560 (10,394) 45,670 Basic (loss) earnings per share $ (0.24) $ 0.13 $ (0.10) $ 0.44 Diluted (loss) earnings per share $ (0.24) $ 0.13 $ (0.10) $ 0.44 (a) Transaction and integration-related expenses for the three months ended March 31, 2019, June 30, 2019, September 30, 2019, and December 31, 2019 were $16.7 million, $7.7 million, $10.5 million, and $26.4 million respectively. Transaction and integration-related expenses for the three months ended March 31, 2018, June 30, 2018, September 30, 2018, and December 31, 2018 were $25.2 million, $18.0 million, $18.6 million, and $3.0 million, respectively. See "Note 2 - Financial Statement Details" for additional information. (b) Restructuring and other costs for the three months ended March 31, 2019, June 30, 2019, September 30, 2019, and December 31, 2019 were $14.4 million, $11.9 million, $13.5 million, and $2.3 million, respectively. Restructuring and other costs for the three months ended March 31, 2018, June 30, 2018, September 30, 2018, and December 31, 2018 were $13.7 million, $8.6 million, $19.3 million, and $9.2 million, respectively. (c) During the three months ended December 31, 2019, the Company recorded a net gain on extinguishment of debt of $14.8 million related to the redemption of the Senior Notes and subsequent write-off of the associated unamortized premium. During the three months ended March 31, 2019, the Company recorded a loss on extinguishment of debt of $4.4 million associated with the repricing of the Credit Agreement and voluntary prepayments. During the three months ended March 31, 2018, June 30, 2018, September 30, 2018, and December 31, 2018, the Company recorded a loss on extinguishment of debt of $0.2 million, $1.9 million, $1.8 million, and $0.3 million, respectively, associated with the repricing of the Credit Agreement and voluntary prepayments. (d) The Company's income tax benefit for the year ended December 31, 2019 included BEAT tax provisions (benefits) for the three months ended March 31, 2019, June 30, 2019, September 30, 2019, and December 31, 2019 in the amounts of $7.5 million, $2.0 million, $(2.1) million and ($22.5 million), respectively. Additionally, during the three months ended December 31, 2019, the Company's income tax benefit included a $68.5 million benefit from the release of its entire valuation allowance on U.S. deferred tax assets and a large portion of its valuation allowance related to state deferred tax assets. During the three months ended December 2018, the Company's income tax expense included a BEAT tax provision in the amount of $15.1 million and a benefit of $15.3 million as a result of partial releases of its domestic and foreign valuation allowances. See "Note 11 - Income Taxes" for additional information.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Principles of Consolidation	Principles of ConsolidationThe accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP"), and include the accounts and results of operations of the Company and its controlled subsidiaries. All intercompany balances and transactions have been eliminated.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities and the disclosures of contingent assets and liabilities as of the date of the financial statements, and the reported amounts of revenue and expenses for the periods presented in the financial statements. Examples of estimates and assumptions include, but are not limited to, determining the fair value of goodwill and intangible assets and their potential impairment, useful lives of tangible and intangible assets, useful lives of assets subject to leases, allowances for doubtful accounts, potential future outcomes of events for which income tax consequences have been recognized in the Company’s consolidated financial statements or tax returns, valuation allowances for deferred tax assets, fair value of share-based compensation and its recognition period, claims and insurance and self-insurance accruals, loss contingencies, fair value of derivative instruments and related hedge effectiveness, fair value of contingent tax sharing obligations, and judgments related to revenue recognition, among others. In addition, estimates and assumptions are used in the accounting for the Merger and other business combinations, including the fair value and useful lives of acquired tangible and intangible assets and the fair value of assumed liabilities. The Company evaluates its estimates and assumptions on an ongoing basis and bases its estimates on historical experience, current and expected future conditions, third-party evaluations, and various other assumptions that management believes are reasonable under the circumstances based on the information available to management at the time these estimates and assumptions are made. Actual results and outcomes may differ significantly from these estimates and assumptions.
Business Combinations	Business Combinations The Company accounts for business combinations in accordance with ASC Topic 805, Business Combinations
Foreign Currency Translation and Transactions	Foreign Currency Translation and Transactions For subsidiaries outside of the U.S. that operate in a local currency environment, revenue and expenses are translated to U.S. dollars at the monthly average rates of exchange prevailing during the period, assets and liabilities are translated at period-end exchange rates and equity accounts are translated at historical exchange rates. The net effect of foreign currency translation adjustments is included in shareholder's equity as a component of accumulated other comprehensive loss in the accompanying consolidated balance sheets. Foreign currency transaction gains and losses are the result of exchange rate changes during the period of time between the consummation and cash settlement of transactions denominated in currencies other than the functional currency. Foreign currency transaction gains and losses are recognized in earnings as incurred and are included in other expense, net in the accompanying consolidated statements of operations.
Comprehensive Income (Loss)	Comprehensive Income (Loss) The Company has elected to present comprehensive income (loss) and its components as a separate financial statement. Other comprehensive income (loss) refers to revenue, expenses, gains, and losses that, under U.S. GAAP, are recorded as an element of shareholders' equity but are excluded from net income (loss). The Company's other comprehensive income (loss) consists of foreign currency translation adjustments, net of applicable taxes, resulting from the translation of foreign subsidiaries with functional currencies other than the U.S. dollar and the effective portions of the unrealized gains or losses associated with derivative instruments designated and accounted for as hedging instruments.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consist of demand deposits with banks and other financial institutions and highly liquid investments with an original maturity of three months or less at the date of purchase. Cash and cash equivalents are carried at cost, which approximates their fair value.
Restricted Cash	Restricted CashRestricted cash represents cash and deposits held as security over bank deposits, lease guarantees, and insurance obligations that are restricted as to withdrawal or use. Restricted cash is classified as a current or long-term asset based on the timing and nature of when and how the cash is expected to be used or when the restrictions are expected to lapse.
Fair Value	Fair Value The Company records certain assets and liabilities at fair value in accordance with ASC Topic 820, Fair Value Measurement (see "Note 7 - Fair Value Measurements"). Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. This guidance also specifies a fair value hierarchy that distinguishes between valuation assumptions developed based on market data obtained from independent external sources and the reporting entity's own assumptions. In accordance with this guidance, fair value measurements are classified under the following hierarchy: Level 1 — Unadjusted quoted prices in active markets for identical instruments; Level 2 — Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs or significant value-drivers are observable in active markets; and Level 3 — Model-derived valuations in which one or more significant inputs or significant value-drivers are unobservable. Fair value measurements are classified according to the lowest level input or value-driver that is significant to the valuation. When available, the Company uses quoted market prices to determine fair value and classifies such instruments within the Level 1 category. In cases where market prices are not available, the Company estimates fair value using observable market inputs, in which case the measurements are classified within Level 2. If quoted or observable market prices are not available, fair value estimates are based upon valuation techniques in which one or more significant inputs are unobservable, including internally developed models. These measurements are classified within the Level 3 category.
Derivative Financial Instruments	Derivative Financial Instruments The Company uses interest rate swaps designated as cash flow hedges to manage exposure to variable interest rates on its debt obligations. The Company designates its interest rate swaps as cash flow hedges because they are executed to hedge the Company's exposure to the variability in expected future cash flows that are attributable to changes in interest rates. Derivative financial instruments are measured at fair value and recognized in the accompanying consolidated balance sheets in prepaid expenses and other current assets, other long-term assets, accrued expenses, and other long-term liabilities, as disclosed in "Note 6 - Derivatives." The fair value of interest rate swaps is determined using the market standard methodology of discounted future variable cash receipts. The variable cash receipts are determined by discounting the future expected cash receipts that would occur if variable interest rates rise above the fixed rate of the swaps. The variable interest rates used in the calculation of
Allowance for Doubtful Accounts	Allowance for Doubtful AccountsThe Company maintains a credit approval process and makes judgments in connection with assessing its customers' ability to pay throughout the contractual obligation period. Generally, the Company has the ability to limit credit exposure by discontinuing services in the event of non-payment. The Company has certain customers that may depend on the ability to continue to raise capital in order to complete the development or commercialization of their products. The Company monitors its customers' credit worthiness and applies judgment in establishing a provision for estimated credit losses based on historical experience, current receivables aging, and customer-specific circumstances that would affect the customers' ability to meet their obligation.
Property and Equipment	Property and Equipment Property and equipment primarily consists of furniture, vehicles, software, office equipment, computer equipment, and lab equipment. Purchased and constructed property and equipment is initially recorded at historical cost plus the estimated value of any associated legally or contractually required retirement obligations. Property and equipment acquired in a business combination are recorded based on the estimated fair value as of the acquisition date. The Company leases vehicles for certain sales representatives in the Commercial Solutions segment. These leases are classified and accounted for as leases in accordance with ASC Topic 842, Leases ("ASC 842"). For further information about lease arrangements, see "Note 5 - Leases." Property and equipment assets are depreciated using the straight-line method over the respective estimated useful lives as follows: Useful Life Buildings 39 years Furniture and fixtures 7 years Equipment 5 to 10 years Computer equipment and software 3 years Vehicles Lesser of lease term or the estimated economic life of the leased asset Leasehold improvements Lesser of remaining life of lease or the useful life of the asset Expenditures for repairs and maintenance are expensed as incurred and expenditures for major improvements that increase the functionality or extend the useful life of the asset are capitalized and depreciated over the estimated useful life of the asset. The Company capitalizes costs of computer software obtained for internal use and amortizes these costs on a straight-line basis over the estimated useful life of the product, not to exceed three The Company reviews property and equipment for impairment whenever facts and circumstances indicate that the carrying amounts of these assets might not be recoverable. For assessment purposes, property and equipment are grouped with other assets and liabilities at the lowest level that identifiable cash flows are
Leases	Leases On January 1, 2019, the Company adopted ASC 842 using the revised modified retrospective approach. The revised modified retrospective approach recognizes the effects of initially applying the new leases standard as a cumulative effect adjustment to retained earnings as of the adoption date. Under this election, the provisions of ASC 840 apply to the accounting and disclosures for lease arrangements in the comparative periods in an entity’s financial statements. In addition, the Company elected the package of practical expedients permitted under the transition guidance within ASC 842, in which the Company need not reassess (i) the historical lease classification, (ii) whether any expired or existing contract is or contains a lease, or (iii) the initial direct costs for any existing leases. At inception, a contract contains a lease if the contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. In evaluating whether it has the right to control the use of an identified asset, the Company assesses whether they have the right to direct the use of the identified asset and to obtain substantially all of the economic benefit from the use of the identified asset. Right-of-use ("ROU") assets represent the Company's right to use an underlying asset during the lease term and lease liabilities represent the Company's obligation to make lease payments arising from the lease. Assets and liabilities are recognized based on the present value of lease payments over the lease term. Most leases include one or more options to renew. The exercise of the renewal option is at the Company's sole discretion and the Company includes these options in determining the lease term used to establish its right-of-use assets and lease liabilities when it is reasonably certain the Company will exercise its option. Because most of the Company's leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the lease commencement date in determining the present value of lease payments. The Company uses the implicit rate when readily determinable. Operating lease expense is generally recognized on a straight-line basis over the lease term. The Company has agreements with lease and non-lease components, which are accounted for as a single lease component. Leases with a lease term of 12 months or less are not recorded on the balance sheet. The Company recognizes lease expense for these leases on a straight-line basis over the lease term. Variable lease payment amounts that cannot be determined at the commencement of the lease, such as increases in lease payments based on changes in index rates, are not included in the right-of-use assets or liabilities. These variable lease payments are expensed as incurred.
Goodwill	Goodwill and Intangible Assets Goodwill represents the excess of purchase price over the estimated fair value of net assets acquired, including the amount assigned to identifiable intangible assets, in business combinations. In accordance with ASC Topic 350, Intangibles - Goodwill and Other , goodwill is not subject to amortization but must be tested for impairment annually or more frequently if events or changes in circumstances indicate that goodwill might be impaired. Goodwill is tested for impairment at the reporting unit level, which is one level below the operating segment level. This test requires the Company to determine if the implied fair value of the reporting unit's goodwill is less than its carrying amount. The Company has assigned goodwill to five reporting units. The Company's goodwill is principally related to the Merger completed in August 2017. The Company completed an annual impairment test as of October 1, 2019 for all of its reporting units, and concluded that there were no impairments.
Intangible Assets	Intangible assets consist primarily of backlog, customer relationships, and trademarks. The Company amortizes intangible assets related to customer relationships and trademarks on a straight-line basis over the estimated useful life of the asset. Backlog is amortized based on the Company’s expectations of when the resulting revenue is expected to be earned. The Company reviews intangible assets at the end of each reporting period to determine if facts and circumstances indicate that the useful life is shorter than originally estimated or that the carrying amount of the assets might not be recoverable. If such facts and circumstances exist, the Company assesses the recoverability of identified assets by comparing the projected undiscounted cash flows associated with the related asset or group of assets over their remaining lives to their respective carrying amounts. Impairments, if any, are based on the excess of the carrying amount over the fair value of those assets and occur in the period in which the impairment determination is made.
Contingencies	Contingencies In the normal course of business, the Company periodically becomes involved in various proceedings and claims, including investigations, disputes, litigations, and regulatory matters that are incidental to its business. The Company evaluates the likelihood of an unfavorable outcome of all legal and regulatory matters and records accruals for loss contingencies when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Gain contingencies are not recognized until realized. Legal fees are expensed as incurred. Because these matters are inherently unpredictable, and unfavorable developments or resolutions can occur, assessing contingencies is highly subjective and requires judgments about future events. These judgments and estimates are based, among other factors, on the status of the proceedings, the merits of the Company’s defenses, and the consultation with in-house and external counsel. The Company regularly reviews contingencies to determine whether its accruals and related disclosures are adequate. Although the Company believes that it has substantial defenses in these matters, the amount of losses incurred as a result of actual outcomes may differ significantly from the Company’s estimates.
Revenue Recognition	Revenue Recognition The Company adopted ASC Topic 606, Revenue from Contracts with Customers and all related amendments (“new revenue standard” or “ASC 606”) on January 1, 2018 using the modified retrospective method for all contracts not completed as of the date of adoption. The reported results for the years ended December 31, 2019 and 2018 reflect the application of ASC 606, while the reported results for the year ended December 31, 2017 were prepared under ASC Topic 605, Revenue Recognition ("ASC 605") and other authoritative guidance in effect for that period. Revenue Recognition under ASC 606 In accordance with ASC 606, revenue is recognized when, or as, a customer obtains control of promised services. The amount of revenue recognized reflects the consideration to which the Company expects to be entitled to receive in exchange for these services. A performance obligation is a promise (or a combination of promises) in a contract to transfer distinct goods or services to a customer and is the unit of accounting under ASC 606 for the purposes of revenue recognition. A contract’s transaction price is allocated to each separate performance obligation based upon the standalone selling price and is recognized as revenue, when, or as, the performance obligation is satisfied. The majority of the Company’s Clinical Solutions segment contracts have a single performance obligation because the promise to transfer individual services is not separately identifiable from other promises in the contracts, and therefore, is not distinct. For contracts with multiple performance obligations, the contract’s transaction price is allocated to each performance obligation using the best estimate of the standalone selling price of each distinct good or service in the contract. The majority of the Company's revenue arrangements are service contracts that range in duration from a few months to several years. Substantially all of the Company’s performance obligations, and associated revenue, are transferred to the customer over time. The Company generally receives compensation based on measuring progress toward completion using anticipated project budgets for direct labor and prices for each service offering. The Company is also reimbursed for certain third party pass-through and out-of-pocket costs. In addition, in certain instances a customer contract may include forms of variable consideration such as incentive fees, volume rebates or other provisions that can increase or decrease the transaction price. This variable consideration is generally awarded upon achievement of certain performance metrics, program milestones or cost targets. For the purposes of revenue recognition, variable consideration is assessed on a contract-by-contract basis and the amount included in the transaction price is estimated based on the Company’s anticipated performance and consideration of all information that is reasonably available. Variable consideration is recognized as revenue if and when it is deemed probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved in the future. Most of the Company's contracts can be terminated by the customer without cause with a 30-day notice. In the event of termination, the Company's contracts generally provide that the customer pay the Company for: (i) fees earned through the termination date; (ii) fees and expenses for winding down the project, which include both fees incurred and actual expenses; (iii) non-cancellable expenditures; and (iv) in some cases, a fee to cover a portion of the remaining professional fees on the project. Changes in the scope of work are common, especially under long-term contracts, and generally result in a change in the total contract transaction price. If the customer does not agree to a contract modification, the Company could bear the risk of cost overruns. Most of the Company’s contract modifications are for services that are not distinct from the services under the existing contract due to the significant integration service provided in the context of the contract and therefore result in a cumulative catch-up adjustment to revenue at the date of contract modification. Capitalized Costs The Company capitalizes certain costs associated with commissions and bonuses paid to its employees in the Clinical Solutions segment because these costs are incurred in obtaining contracts that have a term greater than one year. Capitalized costs are included in prepaid expenses and other current assets and other long-term assets in the accompanying consolidated balance sheets. The Company amortizes these costs in a manner that is consistent with the pattern of revenue recognition described below. The Company expenses costs to obtain contracts that have a term of one year or less. Clinical Solutions The Company’s Clinical Solutions segment provides solutions to address the clinical development needs of customers. The Company provides total biopharmaceutical program development through the full service platform, while also providing discrete services for any part of a clinical trial, primarily through functional service provider, Early Stage, and Real World and Late Phase (“RWLP”) services. The services provided via the full service platform and RWLP platforms generally span several years and a significant benefit to the customer is provided by integrating those services provided by the Company’s employees as well as those performed by third parties. Because the Company's full service platform provides a significant integration service to the customer, these contracts contain a single performance obligation. Revenue is recognized over time using an input measure of progress. The input measure reflects costs (including investigator payments and pass-through costs) incurred to date relative to total estimated costs to complete (“cost-to-cost measure of progress”). Under the cost-to-cost measure of progress methodology, revenue is recorded proportionally to costs incurred. Contract costs principally include direct labor, investigator payments, and pass-through costs. The estimate of total revenue and costs at completion requires significant judgment. Contract estimates are based on various assumptions to project future outcomes of events that often span several years. These estimates are reviewed periodically and any adjustments are recognized on a cumulative catch-up basis in the period they become known. The remaining service offerings within the Clinical Solutions segment are generally short-term, month-to-month contracts, time and materials basis contracts, or provide a series of distinct services that are substantially the same and have the same pattern of transfer to the customer (“series”). As such, revenue for these service offerings is generally recognized as services are performed for the amount the Company estimates it is entitled to for the period, similar to the pattern of recognition under ASC 605. Unsatisfied Performance Obligations As of December 31, 2019, the total aggregate transaction price allocated to the unsatisfied performance obligations under contracts with a contract term greater than one year and which are not accounted for as a series pursuant to ASC 606 was $5.40 billion. This amount includes revenue associated with reimbursable out-of-pocket expenses. The Company expects to recognize revenue over the remaining contract term of the individual projects, with contract terms generally ranging from one to five years. The amount of unsatisfied performance obligations is presented net of any constraints and, as a result, is lower than the potential contractual revenue. The contracts excluded due to constraints include contracts that do not commence within a certain period of time or require the Company to undertake numerous activities to fulfill these performance obligations, including various activities that are outside of the Company’s control. Accordingly, such contracts have been excluded from the unsatisfied performance obligations balance presented above. Commercial Solutions Services The Company’s Commercial Solutions segment provides a broad suite of complementary commercialization services including Deployment Solutions, communications (advertising and public relations), and consulting services. Deployment Solutions contracts offer outsourced services to promote and sell commercial products on behalf of a customer. The remaining Commercial Solutions contracts are generally short-term, month-to-month contracts or time and materials contracts. As such, Commercial Solutions revenue is generally recognized as services are performed for the amount of consideration the Company estimates it is entitled to for the period, similar to the pattern of recognition under ASC 605. For contracts billed on a fixed price basis, revenue is recognized over time based on the proportion of labor costs expended to total labor costs expected to complete the contract. The Commercial Solutions segment does not have significant unsatisfied performance obligations that are required to be disclosed under ASC 606 because the contracts are short-term in nature or represent a series. Revenue Recognition prior to adoption of ASC 606 Prior to the Company's adoption of ASC 606 on January 1, 2018, the Company recognized revenue when all of the following conditions were satisfied: (i) there was persuasive evidence of an arrangement; (ii) the service offering had been delivered to the customer; (iii) the collection of the fees was reasonably assured; and (iv) the arrangement consideration was fixed or determinable. The Company recorded revenue net of any tax assessments by governmental authorities, such as value added taxes, that were imposed on and concurrent with specific revenue generating transactions. In some cases, contracts provided for consideration that was contingent upon the occurrence of uncertain future events. The Company recognized contingent revenue when the contingency had been resolved and all other criteria for revenue recognition had been met. The Company recognized revenue from its service contracts either using a fee-for-service method or proportional performance method. The majority of the Company’s service contracts represented a single unit of accounting. For fee-for-service contracts, the Company recorded revenue as contractual items (i.e., “units”) were delivered to the customer, or, in the event the contract was time and materials based, when labor hours were incurred. The Company used the proportional performance method when its fees for a service obligation were fixed pursuant to the contractual terms. Revenue was recognized as services were performed and measured on a proportional performance basis, generally using output measures specific to the services provided. The Company believed the best indicator of effort expended to complete its performance requirement related to its contractual obligation were the actual units delivered to the customer or the incurrence of labor hours when no other pattern of performance existed. In the event the Company used labor hours as the basis for determining proportional performance, the Company estimated the number of hours remaining to complete its service obligation. Actual hours incurred to complete the service requirement may have differed from the Company’s estimate, and any differences were accounted for prospectively. Examples of output measures used by the Company were site or investigator recruitment, patient enrollment, data management, or other deliverables common to its Clinical Solutions segment. The Company entered into multiple element arrangements in which the Company was engaged to provide multiple services under one agreement. In such arrangements, the Company recorded revenue as each separate service, or element, was delivered to the customer. Such arrangements resided predominantly within the Company’s Commercial Solutions segment where the Company was engaged to provide recruiting, deployment, and detailing services. These services may have been sold individually or in combination with contractual fees based on fixed fees for each element, variable fees for each element, or a combination of both. For the arrangements that included multiple elements, arrangement consideration was allocated at inception to units of accounting based on the relative selling price. The best evidence of selling price of a unit of accounting was vendor-specific objective evidence (“VSOE”), which is the price the Company charges when the deliverable is sold separately. When VSOE is not available to determine selling price, the Company uses relevant third-party evidence (“TPE”) of selling price, if available. When neither VSOE nor TPE of selling price existed, the Company used its best estimate of selling price, which generally consisted of an expected margin on the cost of services. Accounts Receivable, Unbilled Services, and Deferred Revenue Accounts receivable are recorded at net realizable value. Unbilled accounts receivable arise when services have been rendered for which revenue has been recognized but the customers have not been billed. Contractual provisions and payment schedules may or may not correspond to the timing of the performance of services under the contract. Unbilled services include contract assets, under which the right to bill the customer is subject to factors other than the passage of time. These amounts may not exceed their net realizable value. Contract assets are generally classified as current. Deferred revenue is a contract liability that consists of customer payments received in advance of performance and billings in excess of revenue recognized, net of revenue recognized from the balance at the beginning of the period. Timing of Billing and Performance
Reimbursable Out-of-Pocket Expenses	Reimbursable Out-of-Pocket ExpensesThe Company incurs and is reimbursed by its customers for certain costs, including fees paid to principal investigators and for other out-of-pocket costs (such as travel expenses for the Company's clinical monitors and sales representatives). The Company includes these costs in total operating expenses, and the related reimbursements in revenue, as the Company is the principal in the applicable arrangements and is responsible for fulfilling the promise to provide the specified services.
Share-Based Compensation	Share-Based Compensation The Company measures and recognizes compensation expense related to all share-based awards based on the estimated fair value of the awards. The fair value of restricted stock and stock unit awards is measured on the grant date based on the fair market value of the Company's common stock. The fair value of stock option awards and Employee Stock Purchase Plan awards is estimated on the grant date using the Black-Scholes option-pricing model and is affected by the Company's stock price and a number of highly complex and subjective assumptions. These assumptions include, but are not limited to, the following: Expected Term - Given the Company's limited history with employee share-based awards, the Company does not have sufficient Company-specific information related to the life of the awards. The Company estimates expected term using the average of the time-to-vest and the contractual life of the options. Expected Volatility - Expected volatility of the Company's stock price is estimated based on (i) the historical volatility of the Company's stock for periods in which the Company has sufficient information, or (ii) the simple average of the historical stock volatility of several comparable publicly traded companies for periods for which the Company does not have sufficient information. Risk-Free Interest Rate - The risk-free interest rate is based on the yield in effect at the time of grant for United States Treasury zero-coupon notes with maturities approximating each grant's expected term. Expected Dividend Yield - The Company has not paid and does not anticipate paying cash dividends on its common stock; therefore, the expected dividend yield is assumed to be zero.
Income Taxes	Income Taxes The Company and its United States (U.S.) subsidiaries file a consolidated U.S. federal income tax return. Other subsidiaries of the Company file tax returns in their local jurisdictions. The Company estimates its tax liability based on current tax laws in the statutory jurisdictions in which it operates. Accordingly, the impact of changes in income tax laws on deferred tax assets and deferred tax liabilities is recognized in earnings in the period during which such changes are enacted. The Company records deferred tax assets and liabilities based on temporary differences between the financial reporting basis and tax basis of the Company's assets and liabilities at enacted tax rates expected to be in effect when the differences are realized or settled. Deferred income tax assets represent amounts available to reduce income taxes payable on taxable income in future years. Such assets arise because of temporary differences between the financial reporting and tax bases of assets and liabilities, as well as from net operating loss and tax credit carryforwards. The Company evaluates recoverability of these future tax deductions. The Company established a valuation allowance against a portion of deferred income tax assets that the Company believes it is more likely than not will not be realized. The Company evaluates the recoverability of these future tax deductions by assessing future expected taxable income. In estimating future taxable income, the Company has considered both positive and negative evidence, such as historical and forecasted results of operations, and implementation of prudent and feasible tax planning strategies. If the objectively verifiable negative evidence outweighs any available positive evidence (or the only available positive is subjective and cannot be verified), then a valuation allowance will likely be deemed necessary. If a valuation allowance is deemed to be unnecessary, such allowance is released and any related benefit is recognized in the period of the change. The Company recognizes a tax benefit from any uncertain tax positions only if they are more likely than not to be sustained upon examination based on the technical merits of the position. The amount of the accrual for which an exposure exists is measured as the largest amount of benefit determined on a cumulative probability basis that the Company believes is more likely than not to be realized upon ultimate settlement of the position. Components of the reserve for uncertain tax positions are classified as either a current or a long-term liability in the accompanying consolidated balance sheets based on when the Company expects each of the items to be settled. Judgment is required in determining what constitutes an uncertain tax position, as well as assessing the outcome of each tax position. The Company considers many factors when evaluating and estimating tax positions and tax benefits. In addition, the calculation of tax liabilities involves dealing with uncertainties in the application of complex tax regulations in domestic and foreign jurisdictions. If the calculation of the liability related to uncertain tax positions proves to be more or less than the ultimate assessment, a tax expense or tax benefit, respectively, would result. Unrecognized tax benefits are presented as either a reduction to a deferred tax asset for a net operating loss ("NOL") carryforward, a similar tax loss, or a tax credit carryforward or as a liability.
Advertising Costs	Advertising CostsAdvertising costs include costs incurred to promote the Company's business and are expensed as incurred.
Restructuring and Other Costs	Restructuring and Other Costs Restructuring and other costs primarily consist of one-time employee termination benefits, contract termination costs, and other costs associated with an exit or disposal activity. The Company accounts for restructuring costs in accordance with the authoritative guidance in ASC Topic 420, Exit or Disposal Cost Obligations . This guidance requires that a liability for a cost associated with an exit or disposal activity be recognized in the period in which the liability is incurred, as opposed to the period in which management commits to a plan of action for termination. The guidance also requires that the liabilities associated with an exit or disposal activity be measured at the fair value in the period in which the liability is incurred, except for: (i) liabilities related to one-time employee termination benefits, which shall be measured and recognized at the date the entity notifies employees of termination, unless employees are required to render services beyond a minimum retention period, in which case the liability is recognized ratably over the future service period; and (ii) liabilities related to an operating lease, which shall be measured and recognized when the contract does not have any future economic benefit to the entity (i.e., the entity ceases to utilize the rights conveyed by the contract). Restructuring liabilities are included in accrued expenses and other long-term liabilities in the accompanying consolidated balance sheets.
Earnings Per Share	Earnings Per Share The Company determines earnings per share in accordance with the authoritative guidance in ASC Topic 260, Earnings Per Share . The Company has one class of common stock for purposes of the earnings per share calculation and therefore computes basic earnings per share by dividing net income (loss) by the weighted average number of common shares outstanding for the applicable period. Diluted earnings per share are computed in the same manner as basic earnings per share, except that the number of shares is increased to assume exercise of potentially dilutive equity awards using the treasury stock method, unless the effect of such increase would be anti-dilutive. Under the treasury stock method, the amount the employee must pay for exercising equity awards and the amount of compensation cost for future service that the Company has not yet recognized are assumed to be used to repurchase shares.
Subsequent Events	Subsequent Events The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The Company evaluated all events and transactions through the date that these financial statements were issued.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In June 2016, the Financial Accounting Standards Board issued ASU No. 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The provisions of ASU 2016-13 modify the impairment model to utilize an expected loss methodology in place of the currently used incurred loss methodology and require consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The standard will be effective for the Company on January 1, 2020. The adoption of ASU 2016-13 is not expected to have a material impact on the Company’s consolidated financial statements.

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Schedule of Cash Pool Position	The Company’s net cash pool position consisted of the following as of December 31 (in thousands): 2019 2018 Gross cash position $ 326,002 $ 206,715 Less: cash borrowings (307,647) (199,784) Net cash position $ 18,355 $ 6,931
Estimated Useful Lives of Property and Equipment	Property and equipment assets are depreciated using the straight-line method over the respective estimated useful lives as follows: Useful Life Buildings 39 years Furniture and fixtures 7 years Equipment 5 to 10 years Computer equipment and software 3 years Vehicles Lesser of lease term or the estimated economic life of the leased asset Leasehold improvements Lesser of remaining life of lease or the useful life of the asset Property and equipment, net of accumulated depreciation, consisted of the following as of December 31 (in thousands): 2019 2018 Software $ 99,500 $ 91,040 Vehicles 70,440 55,293 Computer equipment 95,228 82,280 Leasehold improvements 86,327 69,632 Office furniture, fixtures, and equipment 33,388 24,006 Buildings and land 4,256 4,348 Assets not yet placed in service 20,262 11,011 Property and equipment, gross 409,401 337,610 Less: Accumulated depreciation (205,475) (154,124) Property and equipment, net $ 203,926 $ 183,486
Estimated Useful Lives of Intangible Assets	The weighted average estimated useful lives of the Company's intangible assets were as follows as of December 31: 2019 2018 Customer relationships 9.9 years 9.9 years Acquired backlog 2.2 years 2.2 years Trademarks 4.2 years 4.2 years

Financial Statement Details (Ta

Financial Statement Details (Tables)	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Accounts Receivable, Net and Changes in the Allowance for Doubtful Accounts	Accounts receivable and unbilled services, net of allowance for doubtful accounts, consisted of the following as of December 31 (in thousands): 2019 2018 Accounts receivable billed $ 787,652 $ 733,142 Less: Allowance for doubtful accounts (5,381) (4,587) Accounts receivable billed, net 782,271 728,555 Accounts receivable unbilled 372,109 422,860 Contract assets 149,261 105,316 Accounts receivable and unbilled services, net $ 1,303,641 $ 1,256,731
Schedule of Changes in the Allowance for Doubtful Accounts	The following table summarizes the changes in the allowance for doubtful accounts (in thousands): Year Ended December 31, 2019 2018 2017 Balance at the beginning of the period $ (4,587) $ (9,076) $ (5,884) Current year (provision) recovery (1,897) 4,589 (4,167) Write-offs, net of recoveries and the effects of foreign currency exchange 1,103 (100) 975 Balance at the end of the period $ (5,381) $ (4,587) $ (9,076)
Estimated Useful Lives of Property and Equipment	Property and equipment assets are depreciated using the straight-line method over the respective estimated useful lives as follows: Useful Life Buildings 39 years Furniture and fixtures 7 years Equipment 5 to 10 years Computer equipment and software 3 years Vehicles Lesser of lease term or the estimated economic life of the leased asset Leasehold improvements Lesser of remaining life of lease or the useful life of the asset Property and equipment, net of accumulated depreciation, consisted of the following as of December 31 (in thousands): 2019 2018 Software $ 99,500 $ 91,040 Vehicles 70,440 55,293 Computer equipment 95,228 82,280 Leasehold improvements 86,327 69,632 Office furniture, fixtures, and equipment 33,388 24,006 Buildings and land 4,256 4,348 Assets not yet placed in service 20,262 11,011 Property and equipment, gross 409,401 337,610 Less: Accumulated depreciation (205,475) (154,124) Property and equipment, net $ 203,926 $ 183,486
Change in Carrying Amount of Goodwill	The changes in carrying amount of goodwill were as follows (in thousands): Clinical Commercial Total Balance as of December 31, 2017 $ 2,800,833 $ 1,491,738 $ 4,292,571 Business combinations (a) (5,692) 71,000 65,308 Impact of foreign currency translation and other (22,338) (2,382) (24,720) Balance as of December 31, 2018 2,772,803 1,560,356 4,333,159 Business combinations (b) 1,092 (204) 888 Impact of foreign currency translation 11,057 5,276 16,333 Balance as of December 31, 2019 $ 2,784,952 $ 1,565,428 $ 4,350,380 (a) Amounts represent measurement period adjustments in connection with the Merger and goodwill recognized in connection with the 2018 acquisition of Kinapse Topco Limited (“Kinapse”). (b) Amounts represent goodwill recognized in connection with an insignificant acquisition within the Clinical Solutions segment and measurement period adjustments in connection with the 2018 acquisition of Kinapse.
Schedule of Finite Lived Intangible Assets	Intangible assets, net consisted of the following (in thousands): December 31, 2019 December 31, 2018 Gross Accumulated Amortization Net Gross Accumulated Amortization Net Customer relationships $ 1,491,071 $ (546,835) $ 944,236 $ 1,484,704 $ (403,854) $ 1,080,850 Acquired backlog 136,972 (121,679) 15,293 136,428 (100,838) 35,590 Trademarks 31,326 (17,774) 13,552 31,159 (13,987) 17,172 Intangible assets, net $ 1,659,369 $ (686,288) $ 973,081 $ 1,652,291 $ (518,679) $ 1,133,612
Schedule of Indefinite Lived Intangible Assets	Intangible assets, net consisted of the following (in thousands): December 31, 2019 December 31, 2018 Gross Accumulated Amortization Net Gross Accumulated Amortization Net Customer relationships $ 1,491,071 $ (546,835) $ 944,236 $ 1,484,704 $ (403,854) $ 1,080,850 Acquired backlog 136,972 (121,679) 15,293 136,428 (100,838) 35,590 Trademarks 31,326 (17,774) 13,552 31,159 (13,987) 17,172 Intangible assets, net $ 1,659,369 $ (686,288) $ 973,081 $ 1,652,291 $ (518,679) $ 1,133,612
Schedule of Future Amortization Expense	The future estimated amortization expense for intangible assets is expected to be as follows (in thousands): Fiscal Year Ending: 2020 $ 149,739 2021 132,388 2022 126,989 2023 124,464 2024 120,312 2025 and thereafter 319,189 Total $ 973,081
Schedule of Accrued Expenses	Accrued expenses consisted of the following as of December 31 (in thousands): 2019 2018 Compensation, including bonuses, fringe benefits, and payroll taxes $ 195,604 $ 193,641 Professional fees, investigator fees, and pass-through costs 252,151 230,397 Rebates to customers 25,064 23,391 Contingent tax-sharing obligations assumed through business combinations, current portion 26,557 11,907 Income and other taxes 17,295 30,761 Restructuring and other costs, current portion 5,750 10,592 Interest expense 787 8,278 Facility-related obligations 433 9,288 Other liabilities 45,270 45,272 Total accrued expenses $ 568,911 $ 563,527
Schedule of Accumulated Other Comprehensive Loss, Net of Taxes	Accumulated other comprehensive loss, net of taxes, consisted of the following (in thousands): Year Ended December 31, 2019 2018 Beginning balance $ (88,195) $ (22,385) Foreign Currency Translation: Beginning balance (80,955) (23,514) Impact from adoption of ASU 2018-02 — 3,594 Adjusted beginning balance (80,955) (19,920) Other comprehensive income (loss) before reclassifications 24,198 (61,035) Reclassification adjustments — — Ending balance (56,757) (80,955) Derivative Instruments: Beginning balance (7,240) 1,129 Impact from adoption of ASU 2018-02 — 256 Adjusted beginning balance (7,240) 1,385 Other comprehensive loss before reclassifications (11,529) (7,807) Reclassification adjustments 3,933 (818) Ending balance (14,836) (7,240) Accumulated other comprehensive loss, net of taxes $ (71,593) $ (88,195)
Reclassification out of Accumulated Other Comprehensive Loss	Changes in accumulated other comprehensive loss consisted of the following (in thousands): Year Ended December 31, 2019 2018 2017 Foreign currency translation adjustments: Foreign currency translation adjustments, before tax $ 24,198 $ (61,035) $ 28,847 Income tax expense — — (9,005) Foreign currency translation adjustments, net of tax 24,198 (61,035) 19,842 Unrealized (loss) gain on derivative instruments: Unrealized (loss) gain during period, before tax (14,306) (8,577) 694 Income tax benefit (expense) 2,777 770 (251) Unrealized (loss) gain during period, net of tax (11,529) (7,807) 443 Reclassification adjustment, before tax 4,588 (830) (681) Income tax (expense) benefit (655) 12 261 Reclassification adjustment, net of tax 3,933 (818) (420) Total unrealized (loss) gain on derivative instruments, net of tax (7,596) (8,625) 23 Total other comprehensive income (loss), net of tax $ 16,602 $ (69,660) $ 19,865
Transaction and Integration-Related Expenses	Transaction and integration-related expenses consisted of the following (in thousands): Year Ended December 31, 2019 2018 2017 Professional fees $ 34,538 $ 56,207 $ 68,967 Share-based compensation expense — — 31,327 Debt modification and related expenses 5,396 1,726 5,255 Integration and personnel retention-related costs 4,081 18,475 28,616 Fair value adjustments to contingent obligations 17,260 (11,590) (12,276) Other — 23 1,926 Total transaction and integration-related expenses $ 61,275 $ 64,841 $ 123,815
Schedule of Other (Expense) Income, Net	Other (expense) income, net consisted of the following (in thousands): Year Ended December 31, 2019 2018 2017 Net realized foreign currency (loss) gain $ (11,853) $ 10,452 $ (10,833) Net unrealized foreign currency (loss) gain (11,166) 16,165 (7,912) Other, net (1,143) 1,627 (1,101) Total other (expense) income, net $ (24,162) $ 28,244 $ (19,846)
Supplemental Disclosure of Cash Flow Information	The following table provides details of supplemental cash flow information (in thousands): Year Ended December 31, 2019 2018 2017 Cash paid for income taxes, net of refunds $ 12,200 $ 2,042 $ 13,300 Cash paid for interest 129,756 131,827 64,949 Supplemental disclosure of noncash investing and financing activities Fair value of shares issued and share-based awards assumed in business combinations $ — $ — $ 2,769,471 Fair value of contingent consideration related to business combinations — 4,353 — Purchases of property and equipment included in liabilities 20,052 14,075 14,801 Vehicles acquired through finance lease agreements 37,701 30,374 8,730

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Fair Value of Consideration Transferred	The Merger Date fair value of the consideration transferred consisted of the following (in thousands, except for share and per share amounts): Fair value of common stock issued to acquiree stockholders (a) $ 2,753,239 Fair value of replacement share-based awards issued to acquiree employees (b) 16,232 Repayment of term loan obligations and accrued interest (c) 1,736,152 Total consideration transferred $ 4,505,623 (a) Represents the fair value of 49,297,022 shares of the Company’s common stock at $55.85 per share, the closing price per share on the Merger closing date of August 1, 2017. (b) Represents the fair value of replacement share-based awards attributable to pre-combination services. For further information about the valuation of share-based awards, see "Note 18 - Share-Based Compensation." (c)
Allocation of Consideration Transferred	The following table summarizes the allocation of the consideration transferred based on management’s estimates of the Merger Date fair values of assets acquired and liabilities assumed, with the excess of the purchase price over the estimated fair values of the identifiable net assets acquired recorded as goodwill (in thousands): Assets acquired: Cash and cash equivalents $ 57,338 Restricted cash 433 Accounts receivable 367,595 Unbilled accounts receivable 262,944 Other current assets 97,922 Property and equipment 114,041 Intangible assets 1,334,200 Other assets 50,052 Total assets acquired 2,284,525 Liabilities assumed: Accounts payable 38,072 Accrued expenses 304,341 Deferred revenue 247,474 Capital leases 40,928 Long-term debt, current and non-current 737,872 Deferred income taxes, net 14,751 Other liabilities 119,480 Total liabilities assumed 1,502,918 Total identifiable assets acquired, net 781,607 Goodwill $ 3,724,016
Preliminary Estimates of Fair Value of Intangible Assets and Estimated Useful Lives	The following table summarizes the fair value of identified intangible assets and their respective useful lives as of the Merger Date (dollars in thousands): Estimated Fair Value Estimated Useful Life Customer relationships $ 1,169,700 6 years - 11 years Backlog 137,100 5 months - 2 years Trademarks subject to amortization 27,400 5 months - 6 years Total intangible assets $ 1,334,200

Long-Term Debt Obligations (Tab

Long-Term Debt Obligations (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Debt Obligations	The Company’s debt obligations consisted of the following as of December 31 (in thousands): 2019 2018 Secured Debt Term Loan A due March 2024 $ 1,550,000 $ 975,000 Term Loan B due August 2024 795,564 1,221,000 Accounts receivable financing agreement due September 2021 275,000 169,400 Total secured debt 2,620,564 2,365,400 Unsecured Debt 7.5% Senior Unsecured Notes due 2024 (the "Senior Notes") — 403,000 Total debt obligations 2,620,564 2,768,400 Add: Unamortized Senior Notes premium, net of term loan original issuance discount (4,928) 32,303 Less: Unamortized deferred issuance costs (7,116) (13,584) Less: Current portion of debt (58,125) (50,100) Total debt obligations, non-current portion $ 2,550,395 $ 2,737,019 The applicable margins with respect to Alternate Base Rate and Adjusted Eurocurrency Rate borrowings are determined depending on the “First Lien Leverage Ratio” or the "Secured Net Leverage Ratio" (as defined in the Credit Agreement) and range as follows: Alternate Base Rate Adjusted Eurocurrency Rate Term Loan A 0.25 % - 0.50% 1.25 % - 1.50% Term Loan B 0.75 % - 1.00% 1.75 % - 2.00% Revolver 0.25 % - 0.50% 1.25 % - 1.50%
Schedule of Maturities of Debt Obligations	As of December 31, 2019, the contractual maturities of the Company’s debt obligations (excluding finance leases that are presented in "Note 5 - Leases") were as follows (in thousands): 2020 $ 58,125 2021 381,563 2022 145,313 2023 155,000 2024 1,880,563 2025 and thereafter — Less: deferred issuance costs (7,116) Unamortized Senior Notes premium, net of term loan original issuance discount (4,928) Total $ 2,608,520

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Schedule of Lease, Cost	The components of lease cost were as follows for the year ended December 31, 2019 (in thousands): Operating leases: Fixed lease costs Direct costs, selling, general, and administrative expenses and restructuring and other costs $ 63,215 Short-term lease costs Direct costs and selling, general, and administrative expenses 1,531 Variable lease costs Direct costs, selling, general, and administrative expenses and restructuring and other costs 34,803 Total operating lease costs $ 99,549 Finance leases: Amortization of right-of-use assets Depreciation $ 16,810 Interest on lease liabilities Interest expense 1,778 Variable lease costs Direct costs 7,795 Total finance lease costs $ 26,383
Schedule of Assets And Liabilities	Supplemental balance sheet information related to finance leases was as follows as of December 31, 2019 (in thousands): Property and equipment, gross $ 70,440 Accumulated depreciation (20,594) Property and equipment, net $ 49,846 Current portion of finance lease obligations $ 17,777 Finance lease long-term obligations 36,914 Total finance lease liabilities $ 54,691
Supplemental Cash Flow Information	Supplemental cash flow information related to leases was as follows for the year ended December 31, 2019 (in thousands): Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ (50,792) Operating cash flows for finance leases (1,778) Financing cash flows for finance leases (14,493) Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 55,376 Finance leases 38,144 Lease obligations closed out in exchange for right-of-use assets: Operating leases $ (1,214) Weighted average remaining lease term as of December 31, 2019: Operating leases 7 years Finance leases 3 years Weighted average discount rate as of December 31, 2019: Operating leases 5.0 % Finance leases 2.9 %
Schedule of Finance Lease, Liability, Maturity	As of December 31, 2019, maturities of lease liabilities were as follows (in thousands): Operating Leases Finance Leases Total 2020 $ 49,538 $ 19,428 $ 68,966 2021 49,429 18,358 67,787 2022 42,981 14,462 57,443 2023 36,997 5,908 42,905 2024 30,708 16 30,724 2025 and thereafter 101,509 — 101,509 Total lease payments 311,162 58,172 $ 369,334 Less: management fee — (775) Less: imputed interest (54,764) (2,706) Total lease liabilities $ 256,398 $ 54,691
Schedule of Lessee, Operating Lease, Liability, Maturity	As of December 31, 2019, maturities of lease liabilities were as follows (in thousands): Operating Leases Finance Leases Total 2020 $ 49,538 $ 19,428 $ 68,966 2021 49,429 18,358 67,787 2022 42,981 14,462 57,443 2023 36,997 5,908 42,905 2024 30,708 16 30,724 2025 and thereafter 101,509 — 101,509 Total lease payments 311,162 58,172 $ 369,334 Less: management fee — (775) Less: imputed interest (54,764) (2,706) Total lease liabilities $ 256,398 $ 54,691

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Interest Rate Swaps Designated as Hedging Instruments on the Consolidated Balance Sheets	The fair values of the Company’s derivative financial instruments as of December 31 and the line items on the accompanying consolidated balance sheets to which they were recorded were as follows (in thousands): Balance Sheet Classification 2019 2018 Interest rate swaps - current Prepaid expenses and other current assets 155 1,355 Interest rate swaps - non-current Other long-term assets — 441 Foreign currency exchange rate swaps - current Accrued expenses — (138) Interest rate swaps - current Accrued expenses (11,358) (3,031) Interest rate swaps - non-current Other long-term liabilities (6,095) (6,201)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	As of December 31, 2019, the fair values of the major classes of the Company’s assets and liabilities measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 Investments Measured Total Assets: Trading securities (a) $ 21,552 $ — $ — $ — $ 21,552 Partnership interest (b) — — — 7,226 7,226 Derivative instruments (c) — 155 — — 155 Total assets $ 21,552 $ 155 $ — $ 7,226 $ 28,933 Liabilities: Derivative instruments (c) $ — $ 17,453 $ — $ — $ 17,453 Contingent obligations related to business combinations (d) — — 37,324 — 37,324 Total liabilities $ — $ 17,453 $ 37,324 $ — $ 54,777 As of December 31, 2018, the fair value of the major classes of the Company’s assets and liabilities measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 Total Assets: Trading securities (a) $ 14,945 $ — $ — $ 14,945 Derivative instruments (e) — 1,796 — 1,796 Total assets $ 14,945 $ 1,796 $ — $ 16,741 Liabilities: Derivative instruments (e) $ — $ 9,370 $ — $ 9,370 Contingent obligations related to business combinations (d) — — 20,127 20,127 Total liabilities $ — $ 9,370 $ 20,127 $ 29,497 (a) Represents fair value of investments in mutual funds based on quoted market prices that are used to fund the liability associated with the deferred compensation plan. (b) The Company has committed to invest $21.5 million as a limited partner in two private equity funds. The private equity funds invest in opportunities in the healthcare and life sciences industry. As of December 31, 2019, the Company’s remaining unfunded commitment in the private equity funds was $14.6 million. The Company holds minor ownership interests (less than 3%) in each of the private equity funds and has determined that it does not exercise significant influence over the private equity funds' operating and finance activities. As the private equity funds do not have readily determinable fair values, the Company has estimated the fair values using each fund’s Net Asset Value, the amount by which the value of all assets exceeds all debt and liabilities, in accordance with ASC Topic 946 , Financial Services – Investment Companies. (c) Represents fair value of interest rate swap arrangements (see "Note 6 - Derivatives" for further information). (d) Represents fair value of contingent consideration obligations related to business combinations (see "Note 3 - Business Combinations" for further information). The fair value of these liabilities are determined based on the Company’s best estimate of the probable timing and amount of settlement. (e) Represents fair value of interest rate swap and foreign currency exchange rate forward contract arrangements (see "Note 6 - Derivatives" for further information).
Schedule of Derivative Assets at Fair Value	As of December 31, 2018, the fair value of the major classes of the Company’s assets and liabilities measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 Total Assets: Trading securities (a) $ 14,945 $ — $ — $ 14,945 Derivative instruments (e) — 1,796 — 1,796 Total assets $ 14,945 $ 1,796 $ — $ 16,741 Liabilities: Derivative instruments (e) $ — $ 9,370 $ — $ 9,370 Contingent obligations related to business combinations (d) — — 20,127 20,127 Total liabilities $ — $ 9,370 $ 20,127 $ 29,497 (a) Represents fair value of investments in mutual funds based on quoted market prices that are used to fund the liability associated with the deferred compensation plan. (b) The Company has committed to invest $21.5 million as a limited partner in two private equity funds. The private equity funds invest in opportunities in the healthcare and life sciences industry. As of December 31, 2019, the Company’s remaining unfunded commitment in the private equity funds was $14.6 million. The Company holds minor ownership interests (less than 3%) in each of the private equity funds and has determined that it does not exercise significant influence over the private equity funds' operating and finance activities. As the private equity funds do not have readily determinable fair values, the Company has estimated the fair values using each fund’s Net Asset Value, the amount by which the value of all assets exceeds all debt and liabilities, in accordance with ASC Topic 946 , Financial Services – Investment Companies. (c) Represents fair value of interest rate swap arrangements (see "Note 6 - Derivatives" for further information). (d) Represents fair value of contingent consideration obligations related to business combinations (see "Note 3 - Business Combinations" for further information). The fair value of these liabilities are determined based on the Company’s best estimate of the probable timing and amount of settlement. (e) Represents fair value of interest rate swap and foreign currency exchange rate forward contract arrangements (see "Note 6 - Derivatives" for further information).
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	The following table presents a reconciliation of changes in the carrying amount of contingent obligations classified as Level 3 for the years ended December 31, 2019 and 2018 (in thousands): Balance at December 31, 2017 $ 50,480 Additions 4,353 Changes in fair value recognized in earnings (a) (11,604) Payments (23,102) Balance at December 31, 2018 20,127 Additions — Changes in fair value recognized in earnings (b) 17,375 Payments (178) Balance at December 31, 2019 $ 37,324 (a) The change in fair value recognized in earnings for the year ended December 31, 2018 is primarily due to a reduction in the estimate of the transaction tax deduction benefit associated with Double Eagle's acquisition of inVentiv in 2016. (b) The change in fair value recognized in earnings for the year ended December 31, 2019 is primarily due to an increase in the estimate of the transaction tax deduction benefit associated with Double Eagle's acquisition of inVentiv in 2016.
Schedule of Estimated Fair Value of Financial Instruments Not Recorded at Fair Value	December 31, 2019 December 31, 2018 Carrying Value (a) Estimated Fair Value Carrying Value (a) Estimated Fair Value Term Loan A due August 2022 $ 1,545,721 $ 1,550,000 $ 973,218 $ 975,000 Term Loan B due August 2024 794,915 795,564 1,219,755 1,221,000 7.5% Senior Unsecured Notes due 2024 — — 438,330 423,150 (a) The carrying value of the term loan debt is shown net of original issue discounts. The carrying value of the Senior Notes is inclusive of unamortized premiums.

Restructuring and Other Costs (

Restructuring and Other Costs (Tables)	12 Months Ended
	Dec. 31, 2019
Restructuring and Related Activities [Abstract]
Schedule of Restructuring and Related Costs	Restructuring and other costs related to the Merger consisted of the following (in thousands): Year Ended December 31, 2019 2018 2017 Employee severance and benefit costs $ 12,029 $ 18,021 $ 11,274 Facility and lease termination costs 12,940 24,090 2,213 Other merger-related costs — 560 2,047 Total merger-related restructuring and other costs $ 24,969 $ 42,671 $ 15,534 Restructuring and other costs related to these actions consisted of the following (in thousands): Year Ended December 31, 2019 2018 2017 Employee severance and benefit costs $ 13,214 $ 1,922 $ 8,641 CEO transition and retention costs — — 753 Facility and lease termination costs 3,262 1,567 1,331 Consulting fees — 3,488 4,975 Other costs 690 1,145 2,081 Total non-Merger related restructuring and other costs: $ 17,166 $ 8,122 $ 17,781 The following table summarizes the activity related to the liabilities associated with restructuring and other costs (in thousands): Employee Facility Closure and Lease Termination Costs Other Costs Total Balance at December 31, 2017 $ 8,858 $ 7,411 $ 524 $ 16,793 Expenses incurred (b) 19,853 22,276 4,615 46,744 Payments (21,237) (12,926) (5,087) (39,250) Balance at December 31, 2018 7,474 16,761 52 24,287 Adoption of ASC 842 (a) — (16,761) — (16,761) Expenses incurred (b) 25,243 — 690 25,933 Payments (26,989) — (720) (27,709) Balance at December 31, 2019 $ 5,728 $ — $ 22 $ 5,750 (a) As a result of the adoption of ASC 842, accrued expenses related to facility closure and lease termination costs are now reflected within the current portion of operating lease obligations and operating lease long-term obligations on the consolidated balance sheets as of December 31, 2019. These facility costs will be paid over the remaining terms of exited facilities, which range from 2020 through 2027. (b) The amount of expenses incurred excludes $6.7 million, $4.0 million, and $8.9 million of non-cash restructuring and other expenses incurred for the years ended December 31, 2019, 2018, and 2017, respectively, because these expenses were not subject to accrual prior to the period in which they were incurred. Expenses incurred for the year ended December 31, 2019 also exclude $9.5 million of facility lease closure and lease termination costs that are reflected as a reduction of operating lease right-of-use assets on the consolidated balance sheet under ASC 842.

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Schedule of common stock outstanding	Shares of common stock outstanding were as follows (in thousands): Year Ended December 31, 2019 2018 2017 Common stock shares, beginning balance 103,372 104,436 53,763 Common stock issuances related to business combinations — — 49,297 Stock repurchases (1,323) (1,973) — Stock option exercises 1,381 767 1,178 RSU distributions net of shares for tax withholding 436 142 198 Common stock shares, ending balance 103,866 103,372 104,436
Schedule of repurchase activity	The following table sets forth repurchase activity under the stock repurchase program from inception through December 31, 2019: Total number of shares purchased Average price Approximate March 2018 948,100 $ 39.55 $ 37,493 April 2018 1,024,400 $ 36.60 37,492 January 2019 552,100 $ 39.16 21,623 February 2019 120,600 $ 41.40 4,993 June 2019 509,100 $ 45.29 23,055 August 2019 141,100 $ 49.93 7,045 Total 3,295,400 $ 131,701
Schedule of stock by class	The following is a summary of the Company's authorized, issued and outstanding shares at December 31: 2019 2018 Shares Authorized: Class A common stock 300,000,000 300,000,000 Class B common stock 300,000,000 300,000,000 Preferred stock 30,000,000 30,000,000 Total shares authorized 630,000,000 630,000,000 Shares Issued and Outstanding: Class A common stock 103,865,770 103,372,097 Class B common stock — — Preferred stock — — Total shares issued and outstanding 103,865,770 103,372,097

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table provides a reconciliation of the numerators and denominators of the basic and diluted earnings (loss) per share computations (in thousands, except per share data): Year Ended December 31, 2019 2018 2017 Numerator: Net income (loss) $ 131,258 $ 24,284 $ (138,469) Denominator: Basic weighted average common shares outstanding 103,618 103,414 74,913 Effect of dilutive securities: Stock options and other awards under share-based compensation programs 1,387 1,287 — Diluted weighted average common shares outstanding 105,005 104,701 74,913 Earnings (loss) per share: Basic $ 1.27 $ 0.23 $ (1.85) Diluted $ 1.25 $ 0.23 $ (1.85)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The number of potential shares outstanding that were anti-dilutive and therefore excluded from the computation of diluted earnings (loss) per share, weighted for the portion of the period they were outstanding, are as follows (in thousands): Year Ended December 31, 2019 2018 2017 Anti-dilutive stock options and other awards 277 744 531 Anti-dilutive stock options and other awards under share-based compensation programs excluded based on reporting a net loss for the period — — 1,255 Total common stock equivalents excluded from diluted earnings (loss) per share 277 744 1,786

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Components of Income (Loss) before Provision for Income Taxes	The components of income (loss) before provision for income taxes were as follows (in thousands): Year Ended December 31, 2019 2018 2017 Domestic $ (17,066) $ (26,263) $ (204,352) Foreign 118,775 83,521 92,475 Income (loss) before provision for income taxes $ 101,709 $ 57,258 $ (111,877)
Schedule of Components of Income Tax (Expense) Benefit	The components of income tax expense were as follows (in thousands): Year Ended December 31, 2019 2018 2017 Federal income taxes: Current $ 13,952 $ (19,949) $ 6,299 Deferred 11,693 3,081 (18,731) Foreign income taxes: Current (21,452) (10,398) (18,030) Deferred 2,206 2,382 312 State income taxes: Current (2,850) (2,387) (430) Deferred 26,000 (5,703) 3,988 Income tax benefit (expense) $ 29,549 $ (32,974) $ (26,592)
Schedule of Effective Income Tax Rate Reconciliation	Actual income tax expense differed from the amount computed by applying the U.S. federal tax rate of 21% during 2019 and 2018, and 35.0% during 2017 to pre-tax income (loss) as a result of the following (in thousands): Year Ended December 31, 2019 2018 2017 Expected income tax (expense) benefit at statutory rate $ (21,359) $ (12,024) $ 39,157 Change in income tax expense resulting from: Foreign income inclusion (39,557) (20,916) (780) Foreign earnings reinvestment assertion reversal — 3,823 112,087 Foreign earnings reinvestment assertion accrual — — (53,421) Changes in income tax valuation allowance (all jurisdictions) 68,537 15,228 (52,563) Change in fair value of contingent obligations (3,625) 2,434 4,344 Share-based compensation (1,094) (2,677) 8,901 Research and general business tax credits 1,871 10,937 5,718 State and local taxes, net of federal benefit 9,085 (7,715) 1,330 Capitalized transaction costs — (481) (6,486) Foreign rate differential 3,595 4,071 16,778 Changes in reserve for uncertain tax positions including interest (5,393) 1,190 947 Provision to tax return and other deferred tax adjustments 6,950 (12,251) (536) Base erosion and anti-abuse tax 15,054 (15,054) — Federal rate change — 1,226 (37,468) Transition tax — — (63,050) Nondeductible executive compensation (1,802) (159) (1,792) Other, net (2,713) (606) 242 Income tax benefit (expense) $ 29,549 $ (32,974) $ (26,592)
Summary of Valuation Allowance	The changes in the valuation allowance for deferred tax assets were as follows (in thousands): Year Ended December 31, 2019 2018 2017 Balance at the beginning of the period $ 150,316 $ 159,646 $ 5,238 Deferred tax assets assumed through business combinations — — 101,527 (Credited) charged to income tax expense (68,537) (15,228) 52,563 (Credited) charged to equity 42 11,848 — Foreign currency exchange 2,338 (5,950) — Other adjustments — — 318 Balance at the end of the period $ 84,159 $ 150,316 $ 159,646
Schedule of Deferred Tax Assets and Liabilities	The income tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities are as follows at December 31 (in thousands): 2019 2018 Deferred tax assets: Net operating losses $ 199,002 $ 262,047 Tax credits 51,273 57,306 Deferred revenue 13,598 13,817 Employee compensation and other benefits 27,287 27,128 Allowance for doubtful accounts 1,091 963 Deferred rent — 2,564 Lease obligations 64,114 — Accrued expenses 8,508 11,445 Prepaid royalty 6,525 — Interest limitation carryforwards 15,624 12,831 Other 10,154 5,433 Total deferred tax assets 397,176 393,534 Less: valuation allowance (84,159) (150,316) Net deferred tax assets 313,017 243,218 Deferred tax liabilities: Undistributed foreign earnings (3,366) (3,818) Right of use asset (57,055) — Foreign branch operations — (1,733) Depreciation and amortization (226,252) (250,090) Other (433) (3,380) Total deferred tax liabilities (287,106) (259,021) Net deferred tax assets (liabilities) $ 25,911 $ (15,803)
Schedule Of Unrecognized Tax Benefits	A reconciliation of the beginning and ending balances of unrecognized tax benefits, excluding accrued interest and penalties, is as follows (in thousands): Unrecognized tax benefits balance at December 31, 2016 $ 15,738 Lapse of statute of limitations 191 Increases for tax positions of prior years 27,974 Decreases for tax positions of prior years (226) Impact of foreign currency translation 1 Unrecognized tax benefits balance at December 31, 2017 43,678 Increases for tax positions in the current year 673 Increases for tax positions of prior years 344 Decreases for tax positions in prior year (25,309) Impact of foreign currency translation (141) Unrecognized tax benefits balance at December 31, 2018 19,245 Increases for tax positions in the current year 2,222 Increases for tax positions of prior years 2,255 Decreases for tax positions in prior year (440) Impact of foreign currency translation (44) Unrecognized tax benefits balance at December 31, 2019 $ 23,238

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Schedule of Segment Information	Information about reportable segment operating results was as follows (in thousands): Year Ended December 31, 2019 2018 2017 (a) Revenue: Clinical Solutions $ 3,421,596 $ 3,211,202 $ 1,459,968 Commercial Solutions 1,254,219 1,178,914 392,875 Total revenue 4,675,815 4,390,116 1,852,843 Reimbursable out-of-pocket expenses not allocated to segments — — 819,221 Total consolidated revenue 4,675,815 4,390,116 2,672,064 Segment direct costs: Clinical Solutions 2,616,249 2,477,920 930,176 Commercial Solutions 1,000,645 937,060 291,310 Total segment direct costs 3,616,894 3,414,980 1,221,486 Segment selling, general, and administrative expenses: Clinical Solutions 275,645 266,381 203,206 Commercial Solutions 92,287 86,333 40,236 Total segment selling, general, and administrative expenses 367,932 352,714 243,442 Segment operating income: Clinical Solutions 529,702 466,901 326,586 Commercial Solutions 161,287 155,521 61,329 Total segment operating income 690,989 622,422 387,915 Direct costs and operating expenses not allocated to segments: Reimbursable out-of-pocket expenses — — 819,221 Share-based compensation included in direct costs 29,011 19,330 10,537 Share-based compensation included in selling, general, and administrative expenses 26,182 14,902 14,041 Corporate selling, general, and administrative expenses 52,167 38,689 25,137 Restructuring and other costs 42,135 50,793 33,315 Transaction and integration-related expenses 61,275 64,841 123,815 Asset impairment charges — — 30,000 Depreciation and amortization 242,465 273,685 179,936 Total consolidated income from operations $ 237,754 $ 160,182 $ (28,866) (a) Following the Merger, beginning August 1, 2017, the Company’s consolidated results of operations include results of operations of inVentiv.

Operations by Geographic Loca_2

Operations by Geographic Location (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Total Revenue by Geographic Area	The following table summarizes total revenue by geographic area (in thousands, all intercompany transactions have been eliminated): Year Ended December 31, 2019 2018 2017 Revenue: North America (a) $ 3,079,608 $ 2,974,330 $ 1,174,462 Europe, Middle East and Africa 1,055,007 955,882 458,264 Asia-Pacific 444,819 375,351 174,345 Latin America 96,381 84,553 45,772 Revenue (b) 4,675,815 4,390,116 1,852,843 Reimbursable out-of-pocket expenses (b) — — 819,221 Total revenue $ 4,675,815 $ 4,390,116 $ 2,672,064 (a) Revenue for the North America region includes revenue attributable to the U.S. of $2.93 billion and $2.82 billion, or 62.7% and 64.3% of total revenue, for the years ended December 31, 2019 and 2018, respectively. For the year ended December 31, 2017, revenue for the North America region includes revenue attributable to the U.S. of $1.13 billion, or 60.9% of revenue excluding reimbursable out-of-pocket expenses. No other countries represented more than 10% of total revenue for any year. (b) The Company adopted ASC 606 on January 1, 2018 using the modified retrospective method for all contracts not completed as of the date of adoption.
Long-Lived Assets by Geographic Area	The following table summarizes long-lived assets by geographic area as of December 31 (in thousands, all intercompany transactions have been eliminated): 2019 2018 Property and equipment, net: North America (a) $ 159,709 $ 133,593 Europe, Middle East and Africa 28,514 33,053 Asia-Pacific 12,742 13,328 Latin America 2,961 3,512 Total property and equipment, net $ 203,926 $ 183,486 (a) Long-lived assets for the North America region include property and equipment, net attributable to the U.S. of $153.1 million and $128.3 million as of December 31, 2019 and 2018, respectively.

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Summary of Stock Option Activity	The following table sets forth the summary of stock option activity under the Plans for the year ended December 31, 2019: Number of Weighted Weighted Average Aggregate Intrinsic Value Outstanding at December 31, 2018 1,910,577 $ 27.92 Exercised (872,474) 27.29 Forfeited (15,479) 43.07 Expired (38,447) 33.75 Outstanding at December 31, 2019 984,177 28.01 5.24 $ 30,965 Vested and expected to vest at December 31, 2019 984,177 28.01 5.24 $ 30,965 Exercisable at December 31, 2019 925,001 $ 27.06 5.20 $ 29,983
Summary of Other Information Pertaining to Stock Option Awards	Other information pertaining to the Company's stock option awards was as follows (in thousands, except per share data): Year Ended December 31, 2019 2018 2017 Weighted average grant date fair value of options granted $ — $ — $ 13.88 Total intrinsic value of options exercised 20,288 9,156 37,928
Stock Option Valuation Assumptions	The fair values of stock option awards and ESPP offerings were determined using the Black-Scholes valuation model and the following assumptions: Year Ended December 31, 2019 2018 2017 Expected volatility: Stock options —% —% 24.5% - 24.6% ESPP 39.1% - 51.9% 32.3% - 69.3% 36.0% - 46.5% Risk-free interest rate: Stock options —% —% 1.80% ESPP 1.88% - 2.52% 1.85% - 2.28% 0.79% - 1.08% Expected term (in years): Stock options — — 4.75 - 5.0 ESPP 0.5 0.5 0.5
Summary of Restricted Stock Unit Activity	The following table sets forth a summary of RSUs outstanding under the 2014 and 2018 Plans as of December 31, 2019 and changes during the year then ended: Number of Shares Weighted Average Non-vested at December 31, 2018 2,203,966 $ 41.02 Granted 1,521,614 45.41 Vested (732,786) 41.35 Forfeited (441,418) 42.36 Non-vested at December 31, 2019 2,551,376 $ 43.48
Summary of Share-Based Compensation Expense	Total share-based compensation expense recognized was as follows (in thousands): Year Ended December 31, 2019 2018 2017 Direct costs $ 29,011 $ 19,330 $ 10,537 Selling, general, and administrative expenses 26,182 14,902 14,041 Restructuring and other costs — 91 3,791 Transaction and integration-related expenses — — 31,327 Total share-based compensation expense $ 55,193 $ 34,323 $ 59,696

Employee Benefit Plan (Tables)

Employee Benefit Plan (Tables)	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Schedule of Contributions to Defined Contribution Plan	The Company’s contributions related to these defined contribution retirement plans were as follows (in thousands): Year Ended December 31, 2019 2018 2017 Defined contribution retirement plan contributions $ 29,834 $ 24,801 $ 15,429

Quarterly Results of Operatio_2

Quarterly Results of Operations - Unaudited (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following was a summary of the Company's consolidated quarterly results of operations for each of the fiscal years ended December 31, 2019 and 2018 (in thousands, except per share data): 2019 First Quarter Second Quarter Third Quarter Fourth Quarter Revenue $ 1,119,006 $ 1,166,827 $ 1,177,028 $ 1,212,954 Income from operations (a) (b) 26,816 58,134 69,443 83,361 Net (loss) income (c) (d) (30,004) 11,292 58,920 91,050 Basic (loss) earnings per share $ (0.29) $ 0.11 $ 0.57 $ 0.88 Diluted (loss) earnings per share $ (0.29) $ 0.11 $ 0.56 $ 0.86 2018 First Quarter Second Quarter Third Quarter Fourth Quarter Revenue $ 1,057,196 $ 1,072,530 $ 1,114,918 $ 1,145,472 Income from operations (a) (b) 10,175 30,722 39,817 79,468 Net (loss) income (c) (d) (24,552) 13,560 (10,394) 45,670 Basic (loss) earnings per share $ (0.24) $ 0.13 $ (0.10) $ 0.44 Diluted (loss) earnings per share $ (0.24) $ 0.13 $ (0.10) $ 0.44 (a) Transaction and integration-related expenses for the three months ended March 31, 2019, June 30, 2019, September 30, 2019, and December 31, 2019 were $16.7 million, $7.7 million, $10.5 million, and $26.4 million respectively. Transaction and integration-related expenses for the three months ended March 31, 2018, June 30, 2018, September 30, 2018, and December 31, 2018 were $25.2 million, $18.0 million, $18.6 million, and $3.0 million, respectively. See "Note 2 - Financial Statement Details" for additional information. (b) Restructuring and other costs for the three months ended March 31, 2019, June 30, 2019, September 30, 2019, and December 31, 2019 were $14.4 million, $11.9 million, $13.5 million, and $2.3 million, respectively. Restructuring and other costs for the three months ended March 31, 2018, June 30, 2018, September 30, 2018, and December 31, 2018 were $13.7 million, $8.6 million, $19.3 million, and $9.2 million, respectively. (c) During the three months ended December 31, 2019, the Company recorded a net gain on extinguishment of debt of $14.8 million related to the redemption of the Senior Notes and subsequent write-off of the associated unamortized premium. During the three months ended March 31, 2019, the Company recorded a loss on extinguishment of debt of $4.4 million associated with the repricing of the Credit Agreement and voluntary prepayments. During the three months ended March 31, 2018, June 30, 2018, September 30, 2018, and December 31, 2018, the Company recorded a loss on extinguishment of debt of $0.2 million, $1.9 million, $1.8 million, and $0.3 million, respectively, associated with the repricing of the Credit Agreement and voluntary prepayments. (d) The Company's income tax benefit for the year ended December 31, 2019 included BEAT tax provisions (benefits) for the three months ended March 31, 2019, June 30, 2019, September 30, 2019, and December 31, 2019 in the amounts of $7.5 million, $2.0 million, $(2.1) million and ($22.5 million), respectively. Additionally, during the three months ended December 31, 2019, the Company's income tax benefit included a $68.5 million benefit from the release of its entire valuation allowance on U.S. deferred tax assets and a large portion of its valuation allowance related to state deferred tax assets. During the three months ended December 2018, the Company's income tax expense included a BEAT tax provision in the amount of $15.1 million and a benefit of $15.3 million as a result of partial releases of its domestic and foreign valuation allowances. See "Note 11 - Income Taxes" for additional information.

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details)	Aug. 01, 2017USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2019USD ($)reporting_unitsegment	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of reportable segments | segment			2
Restricted cash			$ 500,000	$ 2,100,000		$ 500,000
Number of reporting units with goodwill assigned | reporting_unit			5
Impairment of goodwill						0
Carrying value			$ 973,081,000	1,133,612,000		973,081,000
Unsatisfied performance obligations under contracts with a contract term greater than one year			5,400,000,000			5,400,000,000
Revenue recognized, included in contract liabilities balance at beginning of period			568,000,000
Increase (decrease) in revenue recognized, allocated to performance obligation partially satisfied in previous periods			$ 66,800,000
Expected dividend yield assumed			0.00%
Advertising costs			$ 9,500,000	12,300,000	$ 6,500,000
InVentiv Merger
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impairment charge			0	0
Trade Names | InVentiv Health
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Useful life	5 months
Carrying value	$ 8,800,000
Trademarks
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Carrying value			$ 13,552,000	$ 17,172,000		$ 13,552,000
Parent Company | Trademarks
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Useful life	5 months
Trademarks | Parent Company
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impairment charge		$ 30,000,000
Indefinite-lived intangible assets	$ 35,000,000
Computer equipment and software
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property and equipment, estimated useful life			3 years

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies - Net Cash Pool Position (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Gross cash position	$ 326,002	$ 206,715
Less: cash borrowings	(307,647)	(199,784)
Net cash position	$ 18,355	$ 6,931

Basis of Presentation and Sum_6

Basis of Presentation and Summary of Significant Accounting Policies - Estimated Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2019
Buildings
Property, Plant and Equipment
Property and equipment, estimated useful life	39 years
Furniture and fixtures
Property, Plant and Equipment
Property and equipment, estimated useful life	7 years
Computer equipment and software
Property, Plant and Equipment
Property and equipment, estimated useful life	3 years
Minimum | Equipment
Property, Plant and Equipment
Property and equipment, estimated useful life	5 years
Maximum | Equipment
Property, Plant and Equipment
Property and equipment, estimated useful life	10 years
Maximum | Computer equipment and software
Property, Plant and Equipment
Property and equipment, estimated useful life	3 years

Basis of Presentation and Sum_7

Basis of Presentation and Summary of Significant Accounting Policies - Estimated Useful Lives of Intangible Assets (Details) - Weighted average	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	9 years 10 months 24 days	9 years 10 months 24 days
Backlog
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	2 years 2 months 12 days	2 years 2 months 12 days
Trademarks
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	4 years 2 months 12 days	4 years 2 months 12 days

Financial Statement Details - S

Financial Statement Details - Schedule of Accounts Receivable, Net and Changes in the Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounts receivable billed	$ 787,652	$ 733,142
Less: Allowance for doubtful accounts	(5,381)	(4,587)
Accounts receivable billed, net	782,271	728,555
Accounts receivable unbilled	372,109	422,860
Contract assets	149,261	105,316
Accounts receivable and unbilled services, net	1,303,641	1,256,731
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at the beginning of the period	(4,587)	(9,076)	$ (5,884)
Current year (provision) recovery	(1,897)	4,589	(4,167)
Write-offs, net of recoveries and the effects of foreign currency exchange	1,103	(100)	975
Balance at the end of the period	$ (5,381)	$ (4,587)	$ (9,076)

Financial Statement Details - N

Financial Statement Details - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment
Trade receivables sold	$ 210,500	$ 251,900
Proceeds from sale of trade receivables	209,000	250,400
Property and equipment, gross	70,440
Accumulated depreciation	20,594
Vehicles
Property, Plant and Equipment
Property and equipment, gross	70,400	55,300
Accumulated depreciation	20,600	17,600
Amortization charges, net of rebates	$ 16,800	$ 14,500

Financial Statement Details -_2

Financial Statement Details - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment
Property and equipment, gross	$ 409,401	$ 337,610
Less: Accumulated depreciation	(205,475)	(154,124)
Property and equipment, net	203,926	183,486
Software
Property, Plant and Equipment
Property and equipment, gross	99,500	91,040
Vehicles
Property, Plant and Equipment
Property and equipment, gross	70,440	55,293
Computer equipment
Property, Plant and Equipment
Property and equipment, gross	95,228	82,280
Leasehold improvements
Property, Plant and Equipment
Property and equipment, gross	86,327	69,632
Office furniture, fixtures, and equipment
Property, Plant and Equipment
Property and equipment, gross	33,388	24,006
Buildings and land
Property, Plant and Equipment
Property and equipment, gross	4,256	4,348
Assets not yet placed in service
Property, Plant and Equipment
Property and equipment, gross	$ 20,262	$ 11,011

Financial Statement Details - C

Financial Statement Details - Change in Carrying Amount of Goodwill (Details) - USD ($)	12 Months Ended			15 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Goodwill [Roll Forward]
Beginning balance, Goodwill	$ 4,333,159,000	$ 4,292,571,000
Business combinations	888,000	65,308,000
Impact of foreign currency translation and other		(24,720,000)
Impact of foreign currency translation	16,333,000
Ending balance,Goodwill	4,350,380,000	4,333,159,000	$ 4,292,571,000	$ 4,350,380,000
Impairment of goodwill				0
Clinical Solutions
Goodwill [Roll Forward]
Beginning balance, Goodwill	2,772,803,000	2,800,833,000
Business combinations	1,092,000	(5,692,000)
Impact of foreign currency translation and other		(22,338,000)
Impact of foreign currency translation	11,057,000
Ending balance,Goodwill	2,784,952,000	2,772,803,000	2,800,833,000	2,784,952,000
Accumulated impairment loss	8,100,000	8,100,000	8,100,000	8,100,000
Impairment of goodwill	0	0	0
Commercial Solutions
Goodwill [Roll Forward]
Beginning balance, Goodwill	1,560,356,000	1,491,738,000
Business combinations	(204,000)	71,000,000
Impact of foreign currency translation and other		(2,382,000)
Impact of foreign currency translation	5,276,000
Ending balance,Goodwill	1,565,428,000	1,560,356,000	1,491,738,000	1,565,428,000
Accumulated impairment loss	8,000,000	8,000,000	8,000,000	$ 8,000,000
Impairment of goodwill	$ 0	$ 0	$ 0

Financial Statement Details -_3

Financial Statement Details - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 1,659,369	$ 1,652,291
Accumulated amortization	(686,288)	(518,679)
Finite-lived intangible assets, net	973,081	1,133,612
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	1,491,071	1,484,704
Accumulated amortization	(546,835)	(403,854)
Finite-lived intangible assets, net	944,236	1,080,850
Backlog
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	136,972	136,428
Accumulated amortization	(121,679)	(100,838)
Finite-lived intangible assets, net	15,293	35,590
Trademarks subject to amortization
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	31,326	31,159
Accumulated amortization	(17,774)	(13,987)
Finite-lived intangible assets, net	$ 13,552	$ 17,172

Financial Statement Details -_4

Financial Statement Details - Schedule of Future Amortization Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2020	$ 149,739
2021	132,388
2022	126,989
2023	124,464
2024	120,312
2025 and thereafter	319,189
Finite-lived intangible assets, net	$ 973,081	$ 1,133,612

Financial Statement Details -_5

Financial Statement Details - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accrued Liabilities, Current
Compensation, including bonuses, fringe benefits, and payroll taxes	$ 195,604	$ 193,641
Professional fees, investigator fees, and pass-through costs	252,151	230,397
Rebates to customers	25,064	23,391
Contingent tax-sharing obligations assumed through business combinations, current portion	26,557	11,907
Income and other taxes	17,295	30,761
Restructuring and other costs, current portion	5,750	10,592
Interest expense	787	8,278
Facility-related obligations	433	9,288
Other liabilities	45,270	45,272
Total accrued expenses	$ 568,911	$ 563,527

Financial Statement Details -_6

Financial Statement Details - Summary of Changes in Accumulated Other Comprehensive Loss, Net of Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019	Jan. 01, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 2,856,144	$ 3,022,579	$ 301,473
Balance at end of period	3,029,654	2,856,144	3,022,579
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(88,195)	(22,385)	(42,250)
Balance at end of period	(71,593)	(88,195)	(22,385)
Foreign Currency Translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(80,955)	(23,514)
Impact from adoption of ASU 2018-02				$ 0	$ 3,594
Adjusted beginning balance				(80,955)	(19,920)
Other comprehensive gain (loss) before reclassifications	24,198	(61,035)
Reclassification adjustment	0	0
Balance at end of period	(56,757)	(80,955)	(23,514)
Derivative Insturments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(7,240)	1,129
Impact from adoption of ASU 2018-02				0	256
Adjusted beginning balance				$ (7,240)	$ 1,385
Other comprehensive gain (loss) before reclassifications	(11,529)	(7,807)	443
Reclassification adjustment	3,933	(818)	(420)
Balance at end of period	$ (14,836)	$ (7,240)	$ 1,129

Financial Statement Details - T

Financial Statement Details - Tax Effects Allocated to Each Component of OCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive (loss) income, net of tax	$ 16,602	$ (69,660)	$ 19,865
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Foreign currency translation adjustments, before tax	24,198	(61,035)	28,847
Income tax expense	0	0	(9,005)
Unrealized gain (loss) arising during period, net-of-tax	24,198	(61,035)
Reclassification adjustment, net of tax	0	0
Other comprehensive (loss) income, net of tax	24,198	(61,035)	19,842
Derivative instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized (loss) gain during period, before tax	(14,306)
Income tax benefit (expense)	2,777
Unrealized gain (loss) arising during period, net-of-tax	(11,529)
Reclassification adjustment, before tax	4,588
Income tax (expense) benefit	(655)
Reclassification adjustment, net of tax	3,933
Other comprehensive (loss) income, net of tax	(7,596)
Derivative Insturments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized (loss) gain during period, before tax		(8,577)	694
Income tax benefit (expense)		770	(251)
Unrealized gain (loss) arising during period, net-of-tax	(11,529)	(7,807)	443
Reclassification adjustment, before tax		(830)	(681)
Income tax (expense) benefit		12	261
Reclassification adjustment, net of tax	$ 3,933	(818)	(420)
Other comprehensive (loss) income, net of tax		$ (8,625)	$ 23

Financial Statement Details -_7

Financial Statement Details - Transaction and Integration-Related Expenses (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Professional fees									$ 34,538	$ 56,207	$ 68,967
Share-based compensation expense									0	0	31,327
Debt modification and related expenses									5,396	1,726	5,255
Integration and personnel retention-related costs									4,081	18,475	28,616
Fair value adjustments to contingent obligations									17,260	(11,590)	(12,276)
Other									0	23	1,926
Total transaction and integration-related expenses	$ 26,400	$ 10,500	$ 7,700	$ 16,700	$ 3,000	$ 18,600	$ 18,000	$ 25,200	$ 61,275	$ 64,841	$ 123,815

Financial Statement Details -_8

Financial Statement Details - Schedule of Other (Expense) Income, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net realized foreign currency (loss) gain	$ (11,853)	$ 10,452	$ (10,833)
Net unrealized foreign currency (loss) gain	(11,166)	16,165	(7,912)
Other, net	(1,143)	1,627	(1,101)
Total other (expense) income, net	$ (24,162)	$ 28,244	$ (19,846)

Financial Statement Details -_9

Financial Statement Details - Supplemental Cash Flow Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental disclosure of cash flow information
Cash paid for income taxes, net of refunds	$ 12,200,000	$ 2,042,000	$ 13,300,000
Cash paid for interest	129,756,000	131,827,000	64,949,000
Supplemental disclosure of noncash investing and financing activities
Fair value of shares issued and share-based awards assumed in business combinations	0		2,769,471,000
Fair value of contingent consideration related to business combinations	0	4,353,000	0
Purchases of property and equipment included in liabilities	20,052,000	14,075,000	14,801,000
Vehicles acquired through finance lease agreements	$ 37,701,000	$ 30,374,000	$ 8,730

Business Combinations - Narrati

Business Combinations - Narrative (Details) - USD ($) $ in Thousands	Aug. 01, 2017	Aug. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill			$ 4,350,380	$ 4,333,159	$ 4,292,571
Clinical Solutions
Business Acquisition [Line Items]
Goodwill			2,784,952	2,772,803	2,800,833
Commercial Solutions
Business Acquisition [Line Items]
Goodwill			1,565,428	1,560,356	$ 1,491,738
Recurring
Business Acquisition [Line Items]
Contingent obligations related to business combinations			37,324	20,127
InVentiv Merger
Business Acquisition [Line Items]
Goodwill	$ 3,724,016
Aggregate purchase price for the acquisition	4,505,623
InVentiv Merger | Clinical Solutions
Business Acquisition [Line Items]
Goodwill	2,230,000
InVentiv Merger | Commercial Solutions
Business Acquisition [Line Items]
Goodwill	$ 1,490,000
InVentiv Merger | Recurring
Business Acquisition [Line Items]
Contingent obligations related to business combinations			$ 32,700	15,700
Kinapse Topco Limited
Business Acquisition [Line Items]
Contingent obligations related to business combinations				$ 4,400
Goodwill		$ 74,600
Aggregate purchase price for the acquisition		100,100
Cash acquired		4,900
Intangible assets		$ 57,300

Business Combinations - Fair Va

Business Combinations - Fair Value of Consideration Transferred (Details) $ / shares in Units, $ in Thousands	Aug. 01, 2017USD ($)$ / sharesshares
Business Acquisition [Line Items]
Value of common stock issued (USD per share) | $ / shares	$ 55.85
InVentiv Merger
Business Acquisition [Line Items]
Repayment of term loan obligations and accrued interest	$ 1,736,152
Total consideration transferred	$ 4,505,623
Number of shares of common stock issued (in shares) | shares	49,297,022
InVentiv Merger | Acquiree Stockholders
Business Acquisition [Line Items]
Fair value of common stock/replacement share-based awards issued	$ 2,753,239
InVentiv Merger | Acquiree Employees
Business Acquisition [Line Items]
Fair value of common stock/replacement share-based awards issued	$ 16,232

Business Combinations - Allocat

Business Combinations - Allocation of Consideration Transferred (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Aug. 01, 2017
Liabilities assumed:
Goodwill	$ 4,350,380	$ 4,333,159	$ 4,292,571
InVentiv Merger
Assets acquired:
Cash and cash equivalents				$ 57,338
Restricted cash				433
Accounts receivable				367,595
Unbilled accounts receivable				262,944
Other current assets				97,922
Property and equipment				114,041
Intangible assets				1,334,200
Other assets				50,052
Total assets acquired				2,284,525
Liabilities assumed:
Accounts payable				38,072
Accrued expenses				304,341
Deferred revenue				247,474
Capital leases				40,928
Long-term debt, current and non-current				737,872
Deferred income taxes, net				14,751
Other liabilities				119,480
Total liabilities assumed				1,502,918
Total identifiable assets acquired, net				781,607
Goodwill				$ 3,724,016

Business Combinations - Prelimi

Business Combinations - Preliminary Estimates of Fair Value of Intangible Assets and Estimated Useful Lives (Details) - InVentiv Merger $ in Thousands	Aug. 01, 2017USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Fair Value	$ 1,334,200
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Fair Value	$ 1,169,700
Customer relationships | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	6 years
Customer relationships | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	11 years
Backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Fair Value	$ 137,100
Backlog | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	5 months
Backlog | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	2 years
Trademarks subject to amortization
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Fair Value	$ 27,400
Trademarks subject to amortization | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	5 months
Trademarks subject to amortization | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	6 years

Long-Term Debt Obligations - Sc

Long-Term Debt Obligations - Schedule of Debt Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018	Aug. 01, 2017
Debt Instrument
Total debt obligations	$ 2,620,564		$ 2,768,400
Add: Unamortized Senior Notes premium, net of term loan original issuance discount	(4,928)		32,303
Less: Unamortized deferred issuance costs	(7,116)		(13,584)
Less: Current portion of debt	(58,125)		(50,100)
Long-term debt	2,550,395		2,737,019
7.5% Senior Unsecured Notes due 2024 (inclusive of unamortized premium)
Debt Instrument
Add: Unamortized Senior Notes premium, net of term loan original issuance discount	(4,928)
Secured Debt
Debt Instrument
Total debt obligations	2,620,564		2,365,400
Secured Debt | 2017 Credit Agreement - Amendment No 2 - Term Loan A Due March 2024
Debt Instrument
Total debt obligations	1,550,000		975,000
Secured Debt | 2017 Credit Agreement - Amendment No 2 - Term Loan B Due August 2024
Debt Instrument
Total debt obligations	795,564		1,221,000
Unsecured Debt
Debt Instrument
Less: Unamortized deferred issuance costs	$ (3,500)
Unsecured Debt | 7.5% Senior Unsecured Notes due 2024 (inclusive of unamortized premium)
Debt Instrument
Interest rate	7.50%			7.50%
Total debt obligations	$ 0		403,000
Accounts Receivable Securitization | Secured Debt
Debt Instrument
Less: Unamortized deferred issuance costs	(500)	$ (200)
Accounts Receivable Securitization | Secured Debt | Accounts Receivable Financing Agreement Due June 2020
Debt Instrument
Total debt obligations	$ 275,000		$ 169,400

Long-Term Debt Obligations - De

Long-Term Debt Obligations - Debt Narrative (Details) - USD ($)	Oct. 02, 2019	Mar. 26, 2019	Jun. 29, 2018	May 04, 2018	Aug. 01, 2017	Dec. 31, 2017	Aug. 31, 2017	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Sep. 29, 2019
Debt Instrument
Repayments of debt														$ 437,936,000	$ 390,646,000	$ 525,097,000
Long-term debt								$ 2,608,520,000						2,608,520,000
Repayments of long term debt and breakage fees														418,112,000	0	292,425,000
Gain (loss) on extinguishment of debt								14,800,000	$ (4,400,000)	$ (300,000)	$ (1,800,000)	$ (1,900,000)	$ (200,000)	10,395,000	(4,153,000)	(622,000)
Debt issuance costs								7,116,000		13,584,000				$ 7,116,000	13,584,000
Secured Debt
Debt Instrument
Early repayment of senior debt	$ 403,000,000
Early redemption premium paid	15,100,000
2017 Credit Agreement
Debt Instrument
Potential annual dividend payments, percent of net cash proceeds received by Company from any public offering														6.00%
Potential annual dividend payments, percent of market capitalization														5.00%
Minimum secured leverage ratio to exceed in order not to pay unlimited dividends														3
Debt discount						$ 1,900,000				3,000,000					3,000,000	1,900,000
Long-term Debt Acquired
Debt Instrument
Repayments of debt														$ 36,600,000
2017 Credit Agreement, Term Loan A and Revolving Credit Facility | December 31, 2017 through December 31, 2018
Debt Instrument
Maximum first lien leverage ratio														5
2017 Credit Agreement, Term Loan A and Revolving Credit Facility | As of last day of each fiscal quarter ending from and after March 31, 2019
Debt Instrument
Maximum first lien leverage ratio														4.5
Secured Debt | Term Loan
Debt Instrument
Debt issuance costs						20,700,000		7,116,000		13,600,000				$ 7,116,000	13,600,000	20,700,000
Secured Debt | Accounts Receivable Securitization
Debt Instrument
Debt issuance costs								$ 500,000						500,000			$ 200,000
Secured Debt | 2017 Credit Agreement - Term Loan A
Debt Instrument
Repayments of debt														$ 12,500,000	25,000,000
Secured Debt | 2017 Credit Agreement - Term Loan A | Term Loan
Debt Instrument
Face amount					$ 1,000,000,000
Principal payment required in year two (percent of outstanding balance)														1.25%
Quarterly principal payment required in year two														$ 19,400,000
Principal payment required in year three (percent of outstanding balance)														1.875%
Quarterly principal payment required in year three														$ 29,100,000
Principal payment required thereafter (percent of outstanding balance)														2.50%
Quarterly payment required thereafter														$ 38,800,000
Interest rate								3.299%						3.299%
Secured Debt | 2017 Credit Agreement - Revolving Credit Facility | Revolver
Debt Instrument
Term					5 years
Maximum borrowing capacity					$ 500,000,000
Interest rate								3.299%						3.299%
Outstanding borrowings								$ 0						$ 0
Available borrowings								581,200,000						$ 581,200,000
Debt issuance costs						5,200,000				$ 4,700,000					4,700,000	5,200,000
Secured Debt | 2017 Credit Agreement - Revolving Credit Facility | Revolver | Minimum
Debt Instrument
Quarterly commitment fee on average daily unused balance					0.25%
Secured Debt | 2017 Credit Agreement - Revolving Credit Facility | Revolver | Maximum
Debt Instrument
Quarterly commitment fee on average daily unused balance					0.375%
Secured Debt | 2017 Credit Agreement - Revolving Credit Facility | Revolver | Eurodollar Rate | Minimum
Debt Instrument
Applicable margin on variable rate (percent)														1.25%
Secured Debt | 2017 Credit Agreement - Revolving Credit Facility | Revolver | Eurodollar Rate | Maximum
Debt Instrument
Applicable margin on variable rate (percent)														1.50%
Secured Debt | 2017 Credit Agreement - Revolving Credit Facility | Revolver | Base Rate | Minimum
Debt Instrument
Applicable margin on variable rate (percent)														0.25%
Secured Debt | 2017 Credit Agreement - Revolving Credit Facility | Revolver | Base Rate | Maximum
Debt Instrument
Applicable margin on variable rate (percent)														0.50%
Secured Debt | 2017 Credit Agreement - Revolving Credit Facility | Letter of credit
Debt Instrument
Maximum borrowing capacity					$ 150,000,000
Outstanding borrowings								$ 18,800,000						$ 18,800,000
Secured Debt | Term Loan A | Alternate Base Rate
Debt Instrument
Increase (decrease) to basis spread on variable rate				(0.25%)
Secured Debt | Term Loan A | Term Loan | Base Rate | Minimum
Debt Instrument
Applicable margin on variable rate (percent)														0.25%
Secured Debt | Term Loan A | Term Loan | Base Rate | Maximum
Debt Instrument
Applicable margin on variable rate (percent)														0.50%
Secured Debt | Term Loan A | Term Loan | Eurocurrency Rate | Minimum
Debt Instrument
Applicable margin on variable rate (percent)														1.25%
Secured Debt | Term Loan A | Term Loan | Eurocurrency Rate | Maximum
Debt Instrument
Applicable margin on variable rate (percent)														1.50%
Secured Debt | 2017 Credit Agreement - Amendment No 2 - Term Loan A Due March 2024 | Term Loan
Debt Instrument
Face amount		$ 1,550,000,000
Face amount, increase		587,500,000
Long-term debt	400,000,000
Secured Debt | 2017 Credit Agreement - Amendment No 2 - Term Loan A Due March 2024, Available Within Nine Months Of Closing | Term Loan
Debt Instrument
Face amount, increase	400,000,000
Early repayment of senior debt	403,000,000
Payment for debt extinguishment or debt prepayment cost	15,100,000
Secured Debt | 2017 Credit Agreement - Amendment No 2 - Term Loan B Due August 2024
Debt Instrument
Repayments of debt		187,500,000												$ 246,800,000	329,000,000	50,000,000
Secured Debt | 2017 Credit Agreement - Amendment No 2 - Term Loan B Due August 2024 | Term Loan
Debt Instrument
Face amount					$ 1,600,000,000
Principal payment required (percent of outstanding balance)														0.25%
Quarterly principal payment required														$ 4,000,000
Interest rate								3.799%						3.799%
Secured Debt | 2017 Credit Agreement - Amendment No 2 - Revolving Credit Facility Due March 2024 | Revolver
Debt Instrument
Maximum borrowing capacity		600,000,000
Maximum borrowing capacity, increase limit		$ 100,000,000
Secured Debt | 2017 Credit Agreement - Amendment No 2 - Term Loan A Due March 2024, Funded Amount | Term Loan
Debt Instrument
Debt instrument, unamortized discount (premium) and debt issuance costs, net								$ 2,800,000						$ 2,800,000
Secured Debt | 2017 Credit Agreement
Debt Instrument
Percent of capital stock of certain controlled foreign subsidiaries securing debt obligations					65.00%
Secured Debt | 2017 Credit Agreement | Federal Funds Effective Rate
Debt Instrument
Applicable margin on variable rate (percent)					0.50%
Secured Debt | 2017 Credit Agreement | Eurodollar Rate
Debt Instrument
Applicable margin on variable rate (percent)					1.00%
Secured Debt | 2017 Credit Agreement | Base Rate
Debt Instrument
Applicable margin on variable rate (percent)					0.00%
Secured Debt | Accounts Receivable Financing Agreement Due June 2020 | Accounts Receivable Securitization
Debt Instrument
Available borrowings								0						0
Long-term debt								$ 275,000,000						$ 275,000,000
Weighted average imputed interest rate								2.805%						2.805%
Secured Debt | Repricing Agreement and Term Loan B
Debt Instrument
Gain (loss) on extinguishment of debt, before write off of debt issuance cost															$ 4,200,000
Unsecured Debt
Debt Instrument
Early redemption premium paid	15,100,000
Gain (loss) on extinguishment of debt, before write off of debt issuance cost	16,300,000
Debt instrument, unamortized premium, remaining	$ 31,400,000
Debt issuance costs								$ 3,500,000						$ 3,500,000
Unsecured Debt | 2017 Credit Agreement - Amendment No 2 - Term Loan B Due August 2024
Debt Instrument
Gain (loss) on extinguishment of debt, before write off of debt issuance cost																$ 600,000
Unsecured Debt | 7.5% Senior Unsecured Notes due 2024 (inclusive of unamortized premium)
Debt Instrument
Interest rate					7.50%			7.50%						7.50%
Aggregate principal amount redeemed						2,000,000
Repayments of long term debt and breakage fees						$ 2,200,000
Unsecured Debt | 7.5% Senior Unsecured Notes due 2024 (inclusive of unamortized premium) | InVentiv Merger
Debt Instrument
Face amount					$ 675,000,000
Aggregate principal amount redeemed					270,000,000
Payment for debt extinguishment or debt prepayment cost							$ 20,300,000
Percentage redeemed							40.00%
Gain (loss) on extinguishment of debt, before write off of debt issuance cost					20,300,000
Gain (loss) on extinguishment of debt					$ 0
Morrisville, North Carolina | After June 14, 2020
Debt Instrument
Period increased credit rating must be maintained and after which letter of credit is no longer needed														12 years
Morrisville, North Carolina | Ba3 rating or Better | June 14, 2017 through June 14, 2020
Debt Instrument
Letter of credit issuance provision, amount of letter of credit required								$ 0						$ 0
Period increased credit rating must be maintained and after which letter of credit is no longer needed														12 months
Morrisville, North Carolina | B1 rating or Lower | June 14, 2017 through June 14, 2020
Debt Instrument
Letter of credit issuance provision, amount of letter of credit required								$ 22,500,000						$ 22,500,000
Percent of remaining minimum annual rent and estimated operating expenses								25.00%						25.00%
Morrisville, North Carolina | B1 rating or Lower | After June 14, 2020
Debt Instrument
Percent of remaining minimum annual rent and estimated operating expenses								100.00%						100.00%
Morrisville, North Carolina | Ba2 rating or Better | After June 14, 2020
Debt Instrument
Letter of credit issuance provision, amount of letter of credit required								$ 0						$ 0
Morrisville, North Carolina | Ba3 rating | After June 14, 2020
Debt Instrument
Percent of remaining minimum annual rent and estimated operating expenses								25.00%						25.00%
Subsidiaries | Secured Debt | Accounts Receivable Financing Agreement Due June 2020 | Accounts Receivable Securitization
Debt Instrument
Maximum borrowing capacity																	$ 275,000,000	$ 250,000,000
Subsidiaries | Secured Debt | Accounts Receivable Financing Agreement Due June 2020 | Accounts Receivable Securitization | Federal Funds Rate
Debt Instrument
Applicable margin on variable rate (percent)			0.50%

Long-Term Debt Obligations - _2

Long-Term Debt Obligations - Schedule of Variable Rate Margins (Details) - Secured Debt	12 Months Ended
	Dec. 31, 2019
Term Loan | Term Loan A | Base Rate | Minimum
Debt Instrument
Applicable margin on variable rate (percent)	0.25%
Term Loan | Term Loan A | Base Rate | Maximum
Debt Instrument
Applicable margin on variable rate (percent)	0.50%
Term Loan | Term Loan A | Eurocurrency Rate | Minimum
Debt Instrument
Applicable margin on variable rate (percent)	1.25%
Term Loan | Term Loan A | Eurocurrency Rate | Maximum
Debt Instrument
Applicable margin on variable rate (percent)	1.50%
Term Loan | Term Loan B | Base Rate | Minimum
Debt Instrument
Applicable margin on variable rate (percent)	0.75%
Term Loan | Term Loan B | Base Rate | Maximum
Debt Instrument
Applicable margin on variable rate (percent)	1.00%
Term Loan | Term Loan B | Eurodollar Rate | Minimum
Debt Instrument
Applicable margin on variable rate (percent)	1.75%
Term Loan | Term Loan B | Eurodollar Rate | Maximum
Debt Instrument
Applicable margin on variable rate (percent)	2.00%
Revolver | Revolver | Base Rate | Minimum
Debt Instrument
Applicable margin on variable rate (percent)	0.25%
Revolver | Revolver | Base Rate | Maximum
Debt Instrument
Applicable margin on variable rate (percent)	0.50%
Revolver | Revolver | Eurodollar Rate | Minimum
Debt Instrument
Applicable margin on variable rate (percent)	1.25%
Revolver | Revolver | Eurodollar Rate | Maximum
Debt Instrument
Applicable margin on variable rate (percent)	1.50%

Long-Term Debt Obligations - Ma

Long-Term Debt Obligations - Maturities of Debt Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Maturities of Long-term Debt [Abstract]
2020	$ 58,125
2021	381,563
2022	145,313
2023	155,000
2024	1,880,563
2025 and thereafter	0
Less: deferred issuance costs	(7,116)	$ (13,584)
Debt Instrument, Unamortized Discount (Premium), Net	4,928	(32,303)
Total	2,608,520
7.5% Senior Unsecured Notes due 2024 (inclusive of unamortized premium)
Maturities of Long-term Debt [Abstract]
Debt Instrument, Unamortized Discount (Premium), Net	4,928
Term Loan | Secured Debt
Maturities of Long-term Debt [Abstract]
Less: deferred issuance costs	$ (7,116)	$ (13,600)	$ (20,700)

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Capital lease obligation	$ 40.6
Rental expense	62.9
Vehicles
Lessee, Lease, Description [Line Items]
Gross book balue of vehicles under capital leases	55.3
Accumulated depreciation	$ 17.6
Minimum
Lessee, Lease, Description [Line Items]
Lease, remaining lease term		1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease, remaining lease term		13 years

Leases - Components of Lease Co

Leases - Components of Lease Cost (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2019USD ($)
Leases [Abstract]
Fixed lease costs	$ 63,215
Short-term lease costs	1,531
Variable lease costs	34,803
Total operating lease cost	99,549
Amortization of right-of-use asset	16,810
Interest on lease liabilities	1,778
Variable lease costs	7,795
Total finance lease costs	$ 26,383

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information Related to Leases (Details) $ in Thousands	Dec. 31, 2019USD ($)
Leases [Abstract]
Property and equipment, gross	$ 70,440
Accumulated depreciation	(20,594)
Property and equipment, net	49,846
Current portion of fiance lease obligations	17,777
Finance lease long-term obligations	36,914
Total finance lease liabilities	$ 54,691

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information Related to Leases (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Leases [Abstract]
Operating cash flows for operating leases	$ (50,792)
Operating cash flows for finance leases	(1,778)
Financing cash flows for finance leases	(14,493)
Right-of-use asset obtained in exchange for lease liability, Operating leases	55,376
Right-of-use asset obtained in exchange for lease liability, Finance leases	38,144
Lease obligations closed out in exchange for right-of-use asset, Operating leases	$ (1,214)
Weighted average remaining lease term, Operating lease	7 years
Weighted average remaining lease term, Finance lease	3 years
Weighted average discount rate, Operating leases	5.00%
Weighted average discount rate, Finance leases	2.90%

Leases - Maturities of Lease Li

Leases - Maturities of Lease Liabilities (Details) $ in Thousands	Dec. 31, 2019USD ($)
Operating Leases
2020	$ 49,538
2021	49,429
2022	42,981
2023	36,997
2024	30,708
2025 and thereafter	101,509
Total lease payments	311,162
Less: imputed interest	(54,764)
Total lease liabilites	256,398
Finance Leases
2020	19,428
2021	18,358
2022	14,462
2023	5,908
2024	16
2025 and thereafter	0
Total lease payments	58,172
Less: management fee	(775)
Less: imputed interest	(2,706)
Total lease liabilities	54,691
2020	68,966
2021	67,787
2022	57,443
2023	42,905
2024	30,724
2025 and thereafter	101,509
Total lease payments	$ 369,334

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) $ in Millions	Dec. 31, 2019USD ($)	Jun. 30, 2018USD ($)interest_rate_swap	May 31, 2016USD ($)
Derivative [Line Items]
Number of interest rate derivatives held | interest_rate_swap		2
Interest Rate Swap
Derivative [Line Items]
Interest rate swaps, notional amount	$ 851.9
Interest Rate Swap portion Expiring June 30, 2018 (remainder expiring on May 14, 2020)
Derivative [Line Items]
Interest rate swaps, notional amount	$ 100		$ 300
Interest Rate Swap Expiring December 31, 2018
Derivative [Line Items]
Interest rate swaps, notional amount		$ 1,220
Interest Rate Swap Expiring June 30, 2021
Derivative [Line Items]
Interest rate swaps, notional amount		$ 1,010

Derivatives - Interest Rate Swa

Derivatives - Interest Rate Swaps Designated as Hedging Instruments on Consolidated Balance Sheets (Details) - Cash Flow Hedging - Designated as Hedging Instrument - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Interest Rate Swap | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Interest rate swaps - current	$ 155	$ 1,355
Interest Rate Swap | Other long-term assets
Derivatives, Fair Value [Line Items]
Interest rate swaps - non-current	0	441
Interest Rate Swap | Accrued expenses
Derivatives, Fair Value [Line Items]
Interest rate swaps - current	(11,358)	(3,031)
Interest Rate Swap | Other long-term liabilities
Derivatives, Fair Value [Line Items]
Interest rate swaps - non-current	(6,095)	(6,201)
Foreign Currency Exchange Rate Swap | Accrued expenses
Derivatives, Fair Value [Line Items]
Interest rate swaps - current	$ 0	$ (138)

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Liabilities:
Contractual obligation	$ 21,500
Contractual obligation, not yet satisfied	14,600
Recurring
Assets:
Trading securities	21,552	$ 14,945
Derivative instruments	155	1,796
Total assets	28,933	16,741
Liabilities:
Derivative instruments	17,453	9,370
Contingent obligations related to business combinations	37,324	20,127
Total liabilities	54,777	29,497
Recurring | Partnership interest
Assets:
Partnership interest	7,226
Recurring | Level 1
Assets:
Trading securities	21,552	14,945
Derivative instruments	0	0
Total assets	21,552	14,945
Liabilities:
Derivative instruments	0	0
Contingent obligations related to business combinations	0	0
Total liabilities	0	0
Recurring | Level 1 | Partnership interest
Assets:
Partnership interest	0
Recurring | Level 2
Assets:
Trading securities	0	0
Derivative instruments	155	1,796
Total assets	155	1,796
Liabilities:
Derivative instruments	17,453	9,370
Contingent obligations related to business combinations	0	0
Total liabilities	17,453	9,370
Recurring | Level 2 | Partnership interest
Assets:
Partnership interest	0
Recurring | Level 3
Assets:
Trading securities	0	0
Derivative instruments	0	0
Total assets	0	0
Liabilities:
Derivative instruments	0	0
Contingent obligations related to business combinations	37,324	20,127
Total liabilities	37,324	$ 20,127
Recurring | Level 3 | Partnership interest
Assets:
Partnership interest	0
Recurring | Investments Measured at Net Asset Value
Assets:
Total assets	7,226
Recurring | Investments Measured at Net Asset Value | Partnership interest
Assets:
Partnership interest	$ 7,226

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Changes in the Carrying Amount of Contingent Tax Sharing Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of period	$ 20,127	$ 50,480
Additions	0	4,353
Changes in fair value recognized in earnings	17,375	(11,604)
Payments	(178)	(23,102)
Balance at End of period	$ 37,324	$ 20,127

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Asset impairment charges	$ 0	$ 0	$ 30,000
Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Intangible assets, carrying amount	$ 5,320,000	$ 5,470,000

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Estimated Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Aug. 01, 2017
7.5% Senior Unsecured Notes due 2024 (inclusive of unamortized premium) | Unsecured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate	7.50%		7.50%
Carrying Value | 2017 Credit Agreement - Amendment No 2 - Term Loan A Due March 2024 | Secured Debt | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	$ 1,545,721	$ 973,218
Carrying Value | 2017 Credit Agreement - Amendment No 2 - Term Loan B Due August 2024 | Secured Debt | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	794,915	1,219,755
Carrying Value | 7.5% Senior Unsecured Notes due 2024 (inclusive of unamortized premium) | Unsecured Debt | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying value	0	438,330
Estimated Fair Value | 2017 Credit Agreement - Amendment No 2 - Term Loan A Due March 2024 | Secured Debt | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	1,550,000	975,000
Estimated Fair Value | 2017 Credit Agreement - Amendment No 2 - Term Loan B Due August 2024 | Secured Debt | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	795,564	1,221,000
Estimated Fair Value | 7.5% Senior Unsecured Notes due 2024 (inclusive of unamortized premium) | Unsecured Debt | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	$ 0	$ 423,150

Restructuring and Other Costs -

Restructuring and Other Costs - Merger Related Restructuring (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Total merger-related restructuring and other costs	$ 17,166	$ 8,122	$ 17,781
Employee severance and benefit costs
Restructuring Cost and Reserve [Line Items]
Total merger-related restructuring and other costs	13,214	1,922	8,641
Facility and lease termination costs
Restructuring Cost and Reserve [Line Items]
Total merger-related restructuring and other costs	3,262	1,567	1,331
Other merger-related costs
Restructuring Cost and Reserve [Line Items]
Total merger-related restructuring and other costs	690	1,145	2,081
InVentiv Merger
Restructuring Cost and Reserve [Line Items]
Total merger-related restructuring and other costs	24,969	42,671	15,534
InVentiv Merger | Employee severance and benefit costs
Restructuring Cost and Reserve [Line Items]
Total merger-related restructuring and other costs	12,029	18,021	11,274
InVentiv Merger | Facility and lease termination costs
Restructuring Cost and Reserve [Line Items]
Total merger-related restructuring and other costs	12,940	24,090	2,213
InVentiv Merger | Other merger-related costs
Restructuring Cost and Reserve [Line Items]
Total merger-related restructuring and other costs	$ 0	$ 560	$ 2,047

Restructuring and Other Costs_2

Restructuring and Other Costs - Non-Merger Related Restructuring and Other Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Total non-Merger related restructuring and other costs:	$ 17,166	$ 8,122	$ 17,781
Employee severance and benefit costs
Restructuring Cost and Reserve [Line Items]
Total non-Merger related restructuring and other costs:	13,214	1,922	8,641
CEO transition and retention costs
Restructuring Cost and Reserve [Line Items]
Total non-Merger related restructuring and other costs:	0	0	753
Facility and lease termination costs
Restructuring Cost and Reserve [Line Items]
Total non-Merger related restructuring and other costs:	3,262	1,567	1,331
Consulting fees
Restructuring Cost and Reserve [Line Items]
Total non-Merger related restructuring and other costs:	0	3,488	4,975
Other costs
Restructuring Cost and Reserve [Line Items]
Total non-Merger related restructuring and other costs:	$ 690	$ 1,145	$ 2,081

Restructuring and Other Costs_3

Restructuring and Other Costs - Schedule of Restructuring and Related Costs (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Reserve
Balance at the beginning of the period				$ 4,587				$ 9,076	$ 4,587	$ 9,076	$ 5,884
Expenses incurred	$ 2,300	$ 13,500	$ 11,900	14,400	$ 9,200	$ 19,300	$ 8,600	13,700	42,135	50,793	33,315
Balance at the end of the period	5,381				4,587				5,381	4,587	9,076
Business exit costs and (gain) loss on termination of lease									9,500
Other Costs
Restructuring Reserve
Other restructuring expenses, non-cash									6,700	4,000	8,900
Business Restructuring Reserves
Restructuring Reserve
Balance at the beginning of the period				24,287				16,793	24,287	16,793
Expenses incurred									25,933	46,744
Adoption of ASC 842									(16,761)
Cash payments made									(27,709)	(39,250)
Balance at the end of the period	5,750				24,287				5,750	24,287	16,793
Business Restructuring Reserves | Employee Severance Costs
Restructuring Reserve
Balance at the beginning of the period				7,474				8,858	7,474	8,858
Expenses incurred									25,243	19,853
Adoption of ASC 842									0
Cash payments made									(26,989)	(21,237)
Balance at the end of the period	5,728				7,474				5,728	7,474	8,858
Business Restructuring Reserves | Facility Closure and Lease Termination Costs
Restructuring Reserve
Balance at the beginning of the period				16,761				7,411	16,761	7,411
Expenses incurred									0	22,276
Adoption of ASC 842									(16,761)
Cash payments made									0	(12,926)
Balance at the end of the period	0				16,761				0	16,761	7,411
Business Restructuring Reserves | Other Costs
Restructuring Reserve
Balance at the beginning of the period				$ 52				$ 524	52	524
Expenses incurred									690	4,615
Adoption of ASC 842									0
Cash payments made									(720)	(5,087)
Balance at the end of the period	$ 22				$ 52				$ 22	$ 52	$ 524

Shareholders' Equity - Schedule

Shareholders' Equity - Schedule of Common Stock Activity (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period (in shares)	103,372,000	104,436,000	53,763,000
Common stock issuances related to business combinations (in shares)	0	0	49,297,000
Stock repurchases (in shares)	(1,323,000)	(1,973,000)	0
Stock option exercises (in shares)	1,381,000	767,000	1,178,000
RSU distributions net of shares for tax withholding (in shares)	436,000	142,000	198,000
Balance at end of period (in shares)	103,865,770	103,372,000	104,436,000

Shareholders' Equity - Narrativ

Shareholders' Equity - Narrative (Details)	Aug. 01, 2017shares	Dec. 31, 2019USD ($)numberOfVote	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 05, 2019USD ($)	Feb. 26, 2018USD ($)
Class of Stock
Stock repurchase program, authorized amount					$ 300,000,000	$ 250,000,000
Class C common stock dividends		$ 0	$ 0	$ 0
Common Stock
Class of Stock
Remaining authorization to repurchase amount		$ 168,300,000
Class A common stock
Class of Stock
Number of votes | numberOfVote		1
Class B common stock, conversion ratio		1
Class B common stock
Class of Stock
Number of votes | numberOfVote		1
InVentiv Merger
Class of Stock
Number of shares of common stock issued (in shares) | shares	49,297,022
InVentiv Merger | Common Stock
Class of Stock
Number of shares of common stock issued (in shares) | shares	49,297,022

Shareholders' Equity - Schedu_2

Shareholders' Equity - Schedule of Repurchase Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended						12 Months Ended			22 Months Ended
	Aug. 31, 2019	Jun. 30, 2019	Feb. 28, 2019	Jan. 31, 2019	Apr. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Class of Stock
Stock repurchased (in shares)							1,323,000	1,973,000	0
Common Stock
Class of Stock
Stock repurchased (in shares)	141,100	509,100	120,600	552,100	1,024,400	948,100				3,295,400
Treasure stock acquired, average cost per share (in dollars per share)	$ 49.93	$ 45.29	$ 41.40	$ 39.16	$ 36.60	$ 39.55
Total value of stock repurchased, net of underwriting discounts, commissions and related expenses	$ 7,045	$ 23,055	$ 4,993	$ 21,623	$ 37,492	$ 37,493				$ 131,701

Shareholders' Equity - Schedu_3

Shareholders' Equity - Schedule of Stock by Class (Details) - shares	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shares Authorized:
Common stock, shares authorized (in shares)	600,000,000	600,000,000
Preferred stock, shares authorized (in shares)	30,000,000	30,000,000
Common and Preferred stock, shares authorized (in shares)	630,000,000	630,000,000
Shares Issued:
Common stock, shares issued (in shares)	103,865,770	103,372,000
Preferred stock, shares issued (in shares)	0	0
Common and Preferred stock, shares issued (in shares)	103,865,770	103,372,097
Shares Outstanding:
Common stock, shares outstanding (in shares)	103,865,770	103,372,000	104,436,000	53,763,000
Preferred stock, shares outstanding (in shares)	0	0
Total shares outstanding	103,865,770	103,372,097
Class A common stock
Shares Authorized:
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Shares Issued:
Common stock, shares issued (in shares)		103,372,097
Shares Outstanding:
Common stock, shares outstanding (in shares)		103,372,097
Class B common stock
Shares Authorized:
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Shares Issued:
Common stock, shares issued (in shares)	0	0
Shares Outstanding:
Common stock, shares outstanding (in shares)	0	0

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator
Net income (loss)	$ 91,050	$ 58,920	$ 11,292	$ (30,004)	$ 45,670	$ (10,394)	$ 13,560	$ (24,552)	$ 131,258	$ 24,284	$ (138,469)
Denominator
Basic net income per share (in shares)									103,618	103,414	74,913
Effect of dilutive securities (in shares)									1,387	1,287	0
Diluted net income per share (in shares)									105,005	104,701	74,913
Earnings loss per share
Basic (in USD per share)	$ 0.88	$ 0.57	$ 0.11	$ (0.29)	$ 0.44	$ (0.10)	$ 0.13	$ (0.24)	$ 1.27	$ 0.23	$ (1.85)
Diluted (in USD per share)	$ 0.86	$ 0.56	$ 0.11	$ (0.29)	$ 0.44	$ (0.10)	$ 0.13	$ (0.24)	$ 1.25	$ 0.23	$ (1.85)

Earnings Per Share - Schedule_2

Earnings Per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share
Total common stock equivalents excluded from diluted earnings (loss) per share	277	744	1,786
Stock Options and Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share
Total common stock equivalents excluded from diluted earnings (loss) per share	277	744	531
Stock Options and Restricted Stock Units | Antidilutive Securities Excluded Due to Reporting of Net Loss During the Period
Antidilutive Securities Excluded from Computation of Earnings Per Share
Total common stock equivalents excluded from diluted earnings (loss) per share	0	0	1,255

Income Taxes - Components of In

Income Taxes - Components of Income (Loss) before Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Domestic	$ (17,066)	$ (26,263)	$ (204,352)
Foreign	118,775	83,521	92,475
Income (loss) before provision for income taxes	$ 101,709	$ 57,258	$ (111,877)

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Federal income taxes:
Current	$ 13,952	$ (19,949)	$ 6,299
Deferred	11,693	3,081	(18,731)
Foreign income taxes:
Current	(21,452)	(10,398)	(18,030)
Deferred	2,206	2,382	312
State income taxes:
Current	(2,850)	(2,387)	(430)
Deferred	26,000	(5,703)	3,988
Income tax benefit (expense)	$ 29,549	$ (32,974)	$ (26,592)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Balance Sheet Statements, Captions
Tax cuts and jobs act, provisional Transition Tax expense			$ 63,100
Accumulated foreign earnings	$ 745,200
Foreign earnings previously taxed in the US, intended to be permanently reinvested	341,800
Foreign earnings previously taxed in the US, intended to be repatriated	403,400
Undistributed foreign earnings	$ 3,366	$ 3,818
Federal tax rate	21.00%	21.00%	35.00%
Valuation allowance increase (decrease)	$ (66,200)
Gross unrecognized tax benefits	23,238	$ 19,245	$ 43,678	$ 15,738
Accrued income tax interest and penalties	6,400	4,400
Amount of interest and penalties recognized in income tax expense (benefit) associated with unrecognized tax benefits	2,100	500
Decrease in unrecognized tax benefits	15,100
Research and Development Credit Carry Forwards | Canada Revenue Agency
Condensed Balance Sheet Statements, Captions
Canadian research and development credit carry forwards		48,500	51,800
Valuation allowance, Canadian research and development credit carry forwards		48,500	48,200
Domestic Tax Authority
Condensed Balance Sheet Statements, Captions
Operating loss carryforwards	569,500	846,500
State and Local Jurisdiction
Condensed Balance Sheet Statements, Captions
Operating loss carryforwards	1,040,000	1,030,000
Foreign Tax Authority
Condensed Balance Sheet Statements, Captions
Operating loss carryforwards	85,800	118,200
Valuation Allowance of Deferred Tax Assets
Condensed Balance Sheet Statements, Captions
Valuation allowance increase (decrease)	(68,500)	(15,200)	52,600
(Credited) charged to income tax expense	(68,537)	(15,228)	52,563
Foreign currency exchange	$ 2,338	$ (5,950)	$ 0

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended					12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Expected income tax (expense) benefit at statutory rate						$ (21,359)	$ (12,024)	$ 39,157
Change in income tax expense resulting from:
Foreign income inclusion						(39,557)	(20,916)	(780)
Foreign earnings reinvestment assertion reversal						0	3,823	112,087
Foreign earnings reinvestment assertion accrual						0	0	(53,421)
Changes in income tax valuation allowance (all jurisdictions)	$ 68,500				$ 15,300	68,537	15,228	(52,563)
Change in fair value of contingent obligations						(3,625)	2,434	4,344
Share-based compensation						(1,094)	(2,677)	8,901
Research and general business tax credits						1,871	10,937	5,718
State and local taxes, net of federal benefit						9,085	(7,715)	1,330
Capitalized transaction costs						0	(481)	(6,486)
Foreign rate differential						3,595	4,071	16,778
Changes in reserve for uncertain tax positions including interest						(5,393)	1,190	947
Provision to tax return and other deferred tax adjustments						6,950	(12,251)	(536)
Base erosion and anti-abuse tax	$ (22,500)	$ (2,100)	$ 2,000	$ 7,500	$ 15,100	(15,054)	15,054	0
Federal rate change						0	1,226	(37,468)
Transition tax						0	0	(63,050)
Nondeductible executive compensation						(1,802)	(159)	(1,792)
Other, net						(2,713)	(606)	242
Income tax benefit (expense)						$ 29,549	$ (32,974)	$ (26,592)

Income Taxes - Summary of Valua

Income Taxes - Summary of Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the beginning of the period	$ 4,587	$ 9,076	$ 5,884
Other adjustments	1,103	(100)	975
Balance at the end of the period	5,381	4,587	9,076
Valuation Allowance of Deferred Tax Assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the beginning of the period	150,316	159,646	5,238
Deferred tax assets assumed through business combinations	0	0	101,527
(Credited) charged to income tax expense	(68,537)	(15,228)	52,563
(Credited) charged to equity	42	11,848	0
Foreign currency exchange	2,338	(5,950)	0
Other adjustments	0	0	318
Balance at the end of the period	$ 84,159	$ 150,316	$ 159,646

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating losses	$ 199,002	$ 262,047
Tax credits	51,273	57,306
Deferred revenue	13,598	13,817
Employee compensation and other benefits	27,287	27,128
Allowance for doubtful accounts	1,091	963
Deferred rent	0	2,564
Lease obligations	64,114	0
Accrued expenses	8,508	11,445
Prepaid royalty	6,525	0
Interest limitation carryforwards	15,624	12,831
Other	10,154	5,433
Total deferred tax assets	397,176	393,534
Less: valuation allowance	(84,159)	(150,316)
Net deferred tax assets	313,017	243,218
Deferred tax liabilities:
Undistributed foreign earnings	(3,366)	(3,818)
Foreign branch operations	0	(1,733)
Right of use asset	(57,055)	0
Depreciation and amortization	(226,252)	(250,090)
Other	(433)	(3,380)
Total deferred tax liabilities	(287,106)	(259,021)
Net deferred tax assets (liabilities)		$ (15,803)
Net deferred tax assets (liabilities)	$ 25,911

Income Taxes - Schedule of Unre

Income Taxes - Schedule of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, balance at beginning of the period	$ 19,245	$ 43,678	$ 15,738
Lapse of statute of limitations			191
Increases for tax positions in the current year	2,222	673
Increases for tax positions of prior years	2,255	344	27,974
Decreases for tax positions of prior years	(440)	(25,309)	(226)
Impact of foreign currency translation			1
Impact of foreign currency translation	(44)	(141)
Unrecognized tax benefits, balance at end of the period	$ 23,238	$ 19,245	$ 43,678

Revenue from Contract with Cust

Revenue from Contract with Customer (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Disaggregation of Revenue [Line Items]
Unsatisfied performance obligations under contracts with a contract term greater than one year	$ 5,400
Revenue recognized, included in contract liabilities balance at beginning of period	568
Increase (decrease) in revenue recognized, allocated to performance obligation partially satisfied in previous periods	$ 66.8
Minimum
Disaggregation of Revenue [Line Items]
Contract term	1 year
Maximum
Disaggregation of Revenue [Line Items]
Contract term	5 years

Segment Information - Narrative

Segment Information - Narrative (Details)	12 Months Ended
	Dec. 31, 2019segment
Segment Reporting [Abstract]
Number of reportable segments	2

Segment Information - Summary o

Segment Information - Summary of Segment Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information
Revenue									$ 4,675,815	$ 4,390,116	$ 2,672,064
Selling, general, and administrative expenses									446,281	406,305	282,620
Income (loss) from operations	$ 83,361	$ 69,443	$ 58,134	$ 26,816	$ 79,468	$ 39,817	$ 30,722	$ 10,175	237,754	160,182	(28,866)
Total share-based compensation expense											59,696
Restructuring and other costs	2,300	13,500	11,900	14,400	9,200	19,300	8,600	13,700	42,135	50,793	33,315
Transaction and integration-related expenses	26,400	10,500	7,700	16,700	3,000	18,600	18,000	25,200	61,275	64,841	123,815
Asset impairment charges									0	0	30,000
Direct costs
Segment Reporting Information
Total share-based compensation expense									29,011	19,330	10,537
Selling, general, and administrative expenses
Segment Reporting Information
Total share-based compensation expense									26,182	14,902	14,041
Operating Segments
Segment Reporting Information
Selling, general, and administrative expenses									367,932	352,714	243,442
Income (loss) from operations									690,989	622,422	387,915
Corporate
Segment Reporting Information
Selling, general, and administrative expenses									52,167	38,689	25,137
Restructuring and other costs									42,135	50,793	33,315
Transaction and integration-related expenses									61,275	64,841	123,815
Asset impairment charges									0	0	30,000
Depreciation and amortization									242,465	273,685	179,936
Corporate | Direct costs
Segment Reporting Information
Total share-based compensation expense									29,011	19,330	10,537
Corporate | Selling, general, and administrative expenses
Segment Reporting Information
Total share-based compensation expense									26,182	14,902	14,041
Clinical Solutions | Operating Segments
Segment Reporting Information
Selling, general, and administrative expenses									275,645	266,381	203,206
Income (loss) from operations									529,702	466,901	326,586
Commercial Solutions | Operating Segments
Segment Reporting Information
Selling, general, and administrative expenses									92,287	86,333	40,236
Income (loss) from operations									161,287	155,521	61,329
Revenue
Segment Reporting Information
Revenue	$ 1,212,954	$ 1,177,028	$ 1,166,827	$ 1,119,006	$ 1,145,472	$ 1,114,918	$ 1,072,530	$ 1,057,196	4,675,815	4,390,116	1,852,843
Cost of Goods and Services Sold									3,645,905	3,434,310	1,232,023
Revenue | Operating Segments
Segment Reporting Information
Revenue									4,675,815	4,390,116	1,852,843
Cost of Goods and Services Sold									3,616,894	3,414,980	1,221,486
Revenue | Clinical Solutions | Operating Segments
Segment Reporting Information
Revenue									3,421,596	3,211,202	1,459,968
Cost of Goods and Services Sold									2,616,249	2,477,920	930,176
Revenue | Commercial Solutions | Operating Segments
Segment Reporting Information
Revenue									1,254,219	1,178,914	392,875
Cost of Goods and Services Sold									1,000,645	937,060	291,310
Reimbursable out-of-pocket expenses
Segment Reporting Information
Revenue									0	0	819,221
Cost of Goods and Services Sold									0	0	819,221
Reimbursable out-of-pocket expenses | Corporate
Segment Reporting Information
Revenue									0	0	819,221
Cost of Goods and Services Sold									$ 0	$ 0	$ 819,221

Operations by Geographic Loca_3

Operations by Geographic Location - Total Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers
Revenue									$ 4,675,815	$ 4,390,116	$ 2,672,064
United States
Revenues from External Customers
Revenue									$ 2,930,000	$ 2,820,000
Geographic Concentration Risk | Revenue | United States
Revenues from External Customers
Concentration risk percentage									62.70%	64.30%	60.90%
Revenue
Revenues from External Customers
Revenue	$ 1,212,954	$ 1,177,028	$ 1,166,827	$ 1,119,006	$ 1,145,472	$ 1,114,918	$ 1,072,530	$ 1,057,196	$ 4,675,815	$ 4,390,116	$ 1,852,843
Revenue | North America
Revenues from External Customers
Revenue									3,079,608	2,974,330	1,174,462
Revenue | United States
Revenues from External Customers
Revenue											1,130,000
Revenue | Europe, Middle East and Africa
Revenues from External Customers
Revenue									1,055,007	955,882	458,264
Revenue | Asia-Pacific
Revenues from External Customers
Revenue									444,819	375,351	174,345
Revenue | Latin America
Revenues from External Customers
Revenue									96,381	84,553	45,772
Reimbursable out-of-pocket expenses
Revenues from External Customers
Revenue									$ 0	$ 0	$ 819,221

Operations by Geographic Loca_4

Operations by Geographic Location - Long-Lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Long-Lived Assets
Property and equipment, net	$ 203,926	$ 183,486
North America
Long-Lived Assets
Property and equipment, net	159,709	133,593
United States
Long-Lived Assets
Property and equipment, net	153,100	128,300
Europe, Middle East and Africa
Long-Lived Assets
Property and equipment, net	28,514	33,053
Asia-Pacific
Long-Lived Assets
Property and equipment, net	12,742	13,328
Latin America
Long-Lived Assets
Property and equipment, net	$ 2,961	$ 3,512

Concentration of Credit Risk -

Concentration of Credit Risk - Concentration of Cash Balances (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Geographic Concentration Risk | Cash and Cash Equivalents | Non-US
Concentration Risk
Cash, cash equivalents, and restricted cash	$ 43.6
Concentration risk percentage	28.00%
Customer Concentration Risk | Revenue
Concentration Risk
Concentration risk percentage	11.00%
Customer Concentration Risk | Billed and Unbilled Trade Account Receivable
Concentration Risk
Concentration risk percentage	13.00%

Related-Party Transactions - Na

Related-Party Transactions - Narrative (Details) - Affiliated Entity $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)Counterparty	Dec. 31, 2018USD ($)customer	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Related Party Transaction
Revenue from related party	$ 400			$ 400
Number of counterparties		2	2
Incurred professional service costs, related party	$ 1,100			3,500	$ 400
Liabilities, related party		$ 1,200	$ 1,200	$ 1,200

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Thousands	Jan. 30, 2018plaintiff	Dec. 01, 2017action	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Recurring
Loss Contingencies [Line Items]
Contingent obligations related to business combinations			$ 37,324	$ 20,127
InVentiv Merger | Recurring
Loss Contingencies [Line Items]
Contingent obligations related to business combinations			$ 32,700	15,700
Kinapse Topco Limited
Loss Contingencies [Line Items]
Contingent obligations related to business combinations				$ 4,400
Pending Litigation | Bermudez and Vaitkuviene actions
Loss Contingencies [Line Items]
Number of actions taken by plaintiff | action		2
Number of plaintiffs | plaintiff	2

Share-Based Compensation - Narr

Share-Based Compensation - Narrative (Details) $ / shares in Units, $ in Thousands	Aug. 01, 2017USD ($)employeeshares	Mar. 31, 2016	Dec. 31, 2019USD ($)plan$ / sharesshares	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Share-based Compensation Arrangement by Share-based Payment Award
Number of plans | plan			2
Number of shares authorized | shares			15,167,325
Number of shares available for future grants | shares			5,008,943
Total share-based compensation expense					$ 59,696
Income tax benefit recognized for stock-based compensation arrangements			$ 10,800	$ 1,700	1,600
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award
Share price (in USD per share) | $ / shares			$ 59.47
Transaction and integration-related expenses
Share-based Compensation Arrangement by Share-based Payment Award
Total share-based compensation expense			$ 0	0	31,327
InVentiv Merger | Transaction and integration-related expenses
Share-based Compensation Arrangement by Share-based Payment Award
Total share-based compensation expense	$ 27,100
InVentiv Merger | Acquiree Employees
Share-based Compensation Arrangement by Share-based Payment Award
Fair value of awards allocated to purchase consideration	$ 16,232
InVentiv Merger | Conversion of Inventiv Shares Into INC Research Shares
Share-based Compensation Arrangement by Share-based Payment Award
Exchange ratio	3.4928
Stock options
Share-based Compensation Arrangement by Share-based Payment Award
Unrecognized compensation expense related to non-vested stock options			$ 100
Weighted average period of recognition (in years)			7 months 6 days
Performance-based Restricted Stock Units Converted Into Time-based Restricted Stock Units | InVentiv Merger
Share-based Compensation Arrangement by Share-based Payment Award
Percent of target for conversion of performance-based RSUs	100.00%
Number of current employees affected by plan modification | employee	50
Incremental compensation expense	$ 2,700
Performance-based Restricted Stock Units Converted Into Time-based Restricted Stock Units | InVentiv Merger | Transaction and integration-related expenses
Share-based Compensation Arrangement by Share-based Payment Award
Total share-based compensation expense			$ 500	100	1,500
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award
Weighted average period of recognition (in years)			1 year 9 months 18 days
Unrecognized compensation expense related to RSU's			$ 65,700
Granted (in shares) | shares			1,521,614
Double Eagle Plan
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares authorized | shares	1,500,000
Employee Stock Purchase Plan (ESPP)
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period			6 months
Payroll deductions as a percentage of employee base salary, maximum		10.00%
Discount from market price of common stock, offering date		15.00%
Total share-based compensation expense			$ 6,500	$ 5,700	$ 1,700
Shares issued (in shares) | shares			896,679
Shares available for future grants (in shares) | shares			2,603,321
Minimum | 2014 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period			3 years
Maximum | 2014 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period			4 years
Maximum | 2014 Equity Incentive Plan | Stock options
Share-based Compensation Arrangement by Share-based Payment Award
Expiration term			10 years

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Option Activity (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares
Common Stock
Aggregate Intrinsic Value (in thousands)(a)
Share price (in USD per share)	$ 59.47
Stock options
Number of Options
Outstanding at December 31, 2018 (in shares) | shares	1,910,577
Exercised (in shares) | shares	(872,474)
Forfeited (in shares) | shares	(15,479)
Expired (in shares) | shares	(38,447)
Outstanding at December 31, 2019 (in shares) | shares	984,177
Vested and expected to vest at December 31, 2019 (in shares) | shares	984,177
Exercisable at December 31, 2019 (in shares) | shares	925,001
Weighted Average Exercise Price
Outstanding at December 31, 2018 (in usd per share)	$ 27.92
Exercised (in usd per share)	27.29
Forfeited (in usd per share)	43.07
Expired (in usd per share)	33.75
Outstanding at December 31, 2019 (in usd per share)	28.01
Vested and expected to vest at December 31, 2019 (in usd per share)	28.01
Exercisable at December 31, 2019 (in usd per share)	$ 27.06
Weighted Average Remaining Contractual Life (in years)
Outstanding at December 31, 2019 (in years)	5 years 2 months 26 days
Vested and exercisable at December 31, 2019 (in years)	5 years 2 months 26 days
Exercisable at December 31, 2019 (in years)	5 years 2 months 12 days
Aggregate Intrinsic Value (in thousands)(a)
Outstanding at December 31, 2019 (in usd) | $	$ 30,965
Vested and expected to vest at December 31, 2019 (in usd) | $	30,965
Exercisable at December 31, 2019 (in usd) | $	$ 29,983

Share-Based Compensation - Su_2

Share-Based Compensation - Summary of Other Information Pertaining to Stock Option Awards (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Payment Arrangement [Abstract]
Weighted average grant date fair value of options granted (per share)	$ 0	$ 0	$ 13.88
Total intrinsic value of options exercised	$ 20,288	$ 9,156	$ 37,928

Share-Based Compensation - Stoc

Share-Based Compensation - Stock Option Valuation Assumptions (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock options
Share-based Compensation Arrangement by Share-based Payment Award
Expected volatility - Stock options	0.00%	0.00%
Expected volatility - Stock options- minimum			24.50%
Expected volatility - Stock options- maximum			24.60%
Risk-free interest rate - Stock options	0.00%	0.00%	1.80%
Expected term (in years)	0 years	0 years
Stock options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award
Expected term (in years)			4 years 9 months
Stock options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award
Expected term (in years)			5 years
ESPP
Share-based Compensation Arrangement by Share-based Payment Award
Expected volatility - Stock options- minimum	39.10%	32.30%	36.00%
Expected volatility - Stock options- maximum	51.90%	69.30%	46.50%
Risk-free interest rate - Stock options -minimum	1.88%	1.85%	0.79%
Risk-free interest rate - Stock options -maximum	2.52%	2.28%	1.08%
Expected term (in years)	6 months	6 months	6 months

Share-Based Compensation - Su_3

Share-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2019$ / sharesshares
Number of Shares
Non-vested at December 31, 2018 (in shares) | shares	2,203,966
Granted (in shares) | shares	1,521,614
Vested (in shares) | shares	(732,786)
Forfeited (in shares) | shares	(441,418)
Non-vested at December 31, 2019 (in shares) | shares	2,551,376
Weighted Average Grant Date Fair Value
Non-vested at December 31, 2018 (in usd per share) | $ / shares	$ 41.02
Granted (in usd per share) | $ / shares	45.41
Vested (in usd per share) | $ / shares	41.35
Forfeited (in usd per share) | $ / shares	42.36
Non-vested at December 31, 2019 (in usd per share) | $ / shares	$ 43.48

Share-Based Compensation - Su_4

Share-Based Compensation - Summary of Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost
Total share-based compensation expense			$ 59,696
Direct costs
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost
Total share-based compensation expense	$ 29,011	$ 19,330	10,537
Selling, general, and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost
Total share-based compensation expense	26,182	14,902	14,041
Restructuring and other costs
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost
Total share-based compensation expense	0	91	3,791
Transaction and integration-related expenses
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost
Total share-based compensation expense	$ 0	$ 0	$ 31,327

Employee Benefit Plans - Schedu

Employee Benefit Plans - Schedule of Contributions to Defined Contribution Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Total defined contribution retirement plan contributions	$ 29,834	$ 24,801	$ 15,429

Employee Benefit Plan - Narrati

Employee Benefit Plan - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Deferred Compensation Arrangement [Line Items]
Deferred compensation liabilities	$ 21,200	$ 14,600
Foreign Plan
Deferred Compensation Arrangement [Line Items]
Employer contribution amount	$ 10,000
Minimum
Deferred Compensation Arrangement [Line Items]
Allowable deferred amount, salary, percent	1.00%
Allowable deferred amount, commissions, percent	1.00%
Maximum
Deferred Compensation Arrangement [Line Items]
Allowable deferred amount, salary, percent	80.00%
Allowable deferred amount, commissions, percent	100.00%

Quarterly Results of Operatio_3

Quarterly Results of Operations - Unaudited - Summary of Consolidated Quarterly Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Income Statements, Captions [Line Items]
Revenue									$ 4,675,815	$ 4,390,116	$ 2,672,064
Income (loss) from operations	$ 83,361	$ 69,443	$ 58,134	$ 26,816	$ 79,468	$ 39,817	$ 30,722	$ 10,175	237,754	160,182	(28,866)
Net income (loss)	$ 91,050	$ 58,920	$ 11,292	$ (30,004)	$ 45,670	$ (10,394)	$ 13,560	$ (24,552)	$ 131,258	$ 24,284	$ (138,469)
Basic (loss) earnings per share (in USD per share)	$ 0.88	$ 0.57	$ 0.11	$ (0.29)	$ 0.44	$ (0.10)	$ 0.13	$ (0.24)	$ 1.27	$ 0.23	$ (1.85)
Diluted (loss) earnings per share (in USD per share)	$ 0.86	$ 0.56	$ 0.11	$ (0.29)	$ 0.44	$ (0.10)	$ 0.13	$ (0.24)	$ 1.25	$ 0.23	$ (1.85)
Transaction and integration-related expenses	$ 26,400	$ 10,500	$ 7,700	$ 16,700	$ 3,000	$ 18,600	$ 18,000	$ 25,200	$ 61,275	$ 64,841	$ 123,815
Restructuring and other costs	2,300	13,500	11,900	14,400	9,200	19,300	8,600	13,700	42,135	50,793	33,315
Gain (loss) on extinguishment of debt	14,800			(4,400)	(300)	(1,800)	(1,900)	(200)	10,395	(4,153)	(622)
Base erosion and anti-abuse tax	(22,500)	(2,100)	2,000	7,500	15,100				(15,054)	15,054	0
Changes in income tax valuation allowance	(68,500)				(15,300)				(68,537)	(15,228)	52,563
Revenue
Condensed Income Statements, Captions [Line Items]
Revenue	$ 1,212,954	$ 1,177,028	$ 1,166,827	$ 1,119,006	$ 1,145,472	$ 1,114,918	$ 1,072,530	$ 1,057,196	$ 4,675,815	$ 4,390,116	$ 1,852,843

Uncategorized Items - synh-2019

Label	Element	Value
Retained Earnings [Member]
Stockholders' Equity Attributable To Parent, Adjusted Balance	synh_StockholdersEquityAttributableToParentAdjustedBalance	$ (473,134,000)
Stockholders' Equity Attributable To Parent, Adjusted Balance	synh_StockholdersEquityAttributableToParentAdjustedBalance	(232,000,000)
Stockholders' Equity Attributable To Parent, Adjusted Balance	synh_StockholdersEquityAttributableToParentAdjustedBalance	(459,333,000)
Accounting Standards Update 2014-09 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(98,815,000)
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	0
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	0
Accounting Standards Update 2016-16 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	0
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(2,009,000)
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	0
Accounting Standards Update 2018-02 [Member] | AOCI Attributable to Parent [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	0
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	3,850,000
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	0
Accounting Standards Update 2018-02 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	0
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(3,850,000)
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 0