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Significant Accounting Policies - Additional Information (Detail) $ in Millions | 6 Months Ended
--- | ---
Jun. 30, 2021 USD ($) Customer Segment | Jun. 30, 2020 USD ($)
Significant Accounting Policies [Line Items] |  |
Trade receivables, credit period | 30 days |
Maturities period | 24 months |
Unrealized gain (loss) on held-to-maturity securities | $ | $ 0.1 | $ 1.3
Number of operating segments | Segment | 1 |
Change in accounting principle, accounting standards update, adopted [true false] | true |
Change in accounting principle, accounting standards update, adoption date | Jan. 01, 2021 |
Change in accounting principle, accounting standards update, immaterial effect [true false] | true |
Accounting Standards Update [Extensible List] | us-gaap:AccountingStandardsUpdate201912Member |
Short Term Investments |  |
Significant Accounting Policies [Line Items] |  |
Maturities period | 12 months |
Long Term Investments |  |
Significant Accounting Policies [Line Items] |  |
Maturities period | 12 months |
Money Market Instruments |  |
Significant Accounting Policies [Line Items] |  |
Maturities period | 90 days |
Gross Product Sales | Customer Concentration Risk |  |
Significant Accounting Policies [Line Items] |  |
Number of customers | Customer | 3 |
Customer A | Gross Product Sales | Customer Concentration Risk |  |
Significant Accounting Policies [Line Items] |  |
Concentration risk percentage | 27.00% | 25.00%
Customer A | Accounts Receivable | Customer Concentration Risk |  |
Significant Accounting Policies [Line Items] |  |
Concentration risk percentage | 40.00% | 32.00%
Customer B | Gross Product Sales | Customer Concentration Risk |  |
Significant Accounting Policies [Line Items] |  |
Concentration risk percentage | 36.00% | 37.00%
Customer B | Accounts Receivable | Customer Concentration Risk |  |
Significant Accounting Policies [Line Items] |  |
Concentration risk percentage | 34.00% | 38.00%
Customer C | Gross Product Sales | Customer Concentration Risk |  |
Significant Accounting Policies [Line Items] |  |
Concentration risk percentage | 30.00% | 29.00%
Customer C | Accounts Receivable | Customer Concentration Risk |  |
Significant Accounting Policies [Line Items] |  |
Concentration risk percentage | 21.00% | 23.00%
Internal Revenue Service (IRS) |  |
Significant Accounting Policies [Line Items] |  |
Open tax year | 2018 |
Earliest Tax Year | New Jersey Department of Treasury |  |
Significant Accounting Policies [Line Items] |  |
Open tax year | 2012 |
Latest Tax Year | New Jersey Department of Treasury |  |
Significant Accounting Policies [Line Items] |  |
Open tax year | 2015 |

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- Definition Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8672-108599 + Details
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