Fair Value - Summary of the Company's Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair value
Debt securities	$ 347,010
Contingent consideration	45,063	$ 32,400
Recurring Basis
Fair value
Cash equivalents	1,764	8,064
Contingent consideration	45,063	32,400
Assets, Total	393,837	447,474
Recurring Basis \| Level 1
Fair value
Cash equivalents	1,764	8,064
Assets, Total	65,433	81,859
Recurring Basis \| Level 2
Fair value
Assets, Total	281,388	331,262
Recurring Basis \| Level 3
Fair value
Contingent consideration	45,063	32,400
Assets, Total	47,016	34,353
U.S. government and agency debt securities \| Recurring Basis
Fair value
Debt securities	99,514	117,376
U.S. government and agency debt securities \| Recurring Basis \| Level 1
Fair value
Debt securities	63,669	73,795
U.S. government and agency debt securities \| Recurring Basis \| Level 2
Fair value
Debt securities	35,845	43,581
Corporate debt securities \| Recurring Basis
Fair value
Debt securities	168,968	195,855
Corporate debt securities \| Recurring Basis \| Level 2
Fair value
Debt securities	167,015	193,902
Corporate debt securities \| Recurring Basis \| Level 3
Fair value
Debt securities	1,953	1,953
International government agency debt securities \| Recurring Basis
Fair value
Debt securities	78,528	93,779
International government agency debt securities \| Recurring Basis \| Level 2
Fair value
Debt securities	$ 78,528	$ 93,779

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of asset recognized arising from contingent consideration in a business combination, expected to be realized beyond one year or the normal operating cycle, if longer.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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