Fair Value Measurements	9 Months Ended
Fair Value Measurements	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The fair value hierarchy is based on inputs to valuation techniques that are used to measure fair value that are either observable or unobservable. Observable inputs reflect assumptions market participants would use in pricing an asset or liability based on market data obtained from independent sources while unobservable inputs reflect a reporting entity’s pricing based upon its own market assumptions. The fair value hierarchy consists of the following three levels: •Level 1 – Inputs are quoted prices in active markets for identical assets or liabilities. •Level 2 – Inputs are quoted prices for similar assets or liabilities in an active market, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable and market-corroborated inputs which are derived principally from or corroborated by observable market data. •Level 3 – Inputs are derived from valuation techniques in which one or more significant inputs or value drivers are unobservable. All highly liquid investments with maturities at date of purchase of three months or less are considered to be cash equivalents. Based on their short-term nature, the carrying value of cash equivalents approximate their fair value. As of September 30, 2021 and December 31, 2020, $42.6 million and $66.0 million, respectively, of the Company’s cash and cash equivalents balance related to money-market fund investments. These short-term money-market funds are considered Level 1 investments. The Company has a deferred compensation plan, which is funded through company-owned life insurance (“COLI”) policies. The COLI asset is carried at fair value derived from quoted market prices of investments within the COLI policies, which are considered Level 2 inputs. The fair value of the COLI asset was $9.8 million and $7.4 million as of September 30, 2021 and December 31, 2020, respectively. The Company estimates the fair value of each foreign exchange forward contract by using the present value of expected cash flows. The estimate takes into account the difference between the current market forward price and contracted forward price for each foreign exchange contract and applies the difference in the rates to each outstanding contract. Valuations for all derivatives fall within Level 2 of the GAAP valuation hierarchy. The fair values of the Company’s derivative instruments outstanding as of September 30, 2021 and December 31, 2020 were immaterial. The Company has contingent consideration liabilities related to acquisitions which are measured on a recurring basis and recorded at fair value, determined using the discounted cash flow method. The inputs used to calculate the fair value of the contingent consideration liabilities are considered to be Level 3 inputs due to the lack of relevant market activity and significant management judgment. An increase in future cash flows may result in a higher estimated fair value while a decrease in future cash flows may result in a lower estimated fair value of the contingent consideration liabilities. Remeasurements to fair value are recorded in adjustment to fair value of contingent consideration in the Unaudited Condensed Consolidated Statements of Operations. Refer to Note 7, Balance Sheet Components, for the estimated fair value of the contingent consideration liabilities as of September 30, 2021 and December 31, 2020. The fair value of the Notes is measured using quoted price inputs. The Notes are not actively traded, and thus the price inputs represent a Level 2 measurement. As the quoted price inputs are highly variable from day to day, the fair value estimates could significantly increase or decrease. The Notes are carried at their principal amount less unamortized debt discount and issuance costs, and are not carried at fair value at each period end. The original debt discount was calculated at a market interest rate for nonconvertible debt at the time of issuance, which represented a Level 3 fair value measurement. The approximate fair value of the 2025 Notes as of September 30, 2021 and December 31, 2020 was $522.1 million and $263.4 million, respectively. As of September 30, 2021, the 2023 Notes have been fully repurchased. The approximate fair value of the 2023 Notes as of December 31, 2020 was $7.1 million. The fair values were estimated on the basis of inputs that are observable in the market and are considered Level 2 fair value measurements.

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.