Number of individual customers accounting for more than ten percent of accounts receivable.

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Number of individual customers accounting for more than ten percent of net product sales.

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Carrying value as of the balance sheet date of obligations incurred through that date and payable for contractual rent under lease arrangements. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying value as of the balance sheet date of obligations incurred through that date and payable for contractual rent under lease arrangements.

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Carrying value as of the balance sheet date of obligations incurred through that date and due after one year (or beyond the operating cycle if longer) for contractual rent under lease arrangements.

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Amount of unrealized gain before deducting unrealized loss on investments in debt and equity securities classified as available-for-sale securities.

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Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale securities.

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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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No definition available.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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- Definition

The current portion of prepayments received from customers for goods or services to be provided in the future.

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Amount of revenue recognized that was previously reported as deferred or unearned revenue.

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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Amount before tax of foreign currency transaction realized and unrealized gain recognized in the income statement.

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Amount before tax of foreign currency transaction realized and unrealized loss recognized in the income statement.

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- Definition

Balance held at close of period in number of shares.

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Amount of investments in debt and equity securities, including, but not limited to, held-to-maturity, trading and available-for-sale expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer.

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Long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets.

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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.

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No definition available.

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Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts.

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Significant Accounting Policies (Details)	3 Months Ended		5 Months Ended	9 Months Ended		48 Months Ended
Significant Accounting Policies (Details)	Sep. 30, 2016 USD ($) customer shares	Sep. 30, 2015 USD ($) customer	May 31, 2016 USD ($)	Sep. 30, 2016 USD ($) customer segment shares	Sep. 30, 2015 USD ($) customer	Dec. 31, 2015 USD ($)
Concentration Risk [Line Items]
Total of realized and unrealized transaction losses	$ 34,000			$ 900,000
Total of realized and unrealized transaction gains		$ 200,000			$ 800,000
Marketable securities	9,627,000			9,627,000		$ 11,407,000
Carrying value of equity method investments	0			0
Accrued rent	3,600,000			3,600,000		5,400,000
Product revenue, net	34,300,000	$ 27,543,000		133,260,000	$ 79,262,000
Advanced payments from customers	4,532,000			$ 4,532,000		23,545,000
Number of operating segments \| segment				1
Geographic concentration risk
Concentration Risk [Line Items]
Long-lived assets	$ 0			$ 0		1,400,000
Net product revenue \| Customer concentration risk
Concentration Risk [Line Items]
Number of customers accounting for more than ten percent of net revenue \| customer	2	1		1	1
Concentration risk, percentage		70.00%		61.00%	74.00%
Net product revenue \| Customer concentration risk \| Customer One
Concentration Risk [Line Items]
Concentration risk, percentage	73.00%
Net product revenue \| Customer concentration risk \| Customer Two
Concentration Risk [Line Items]
Concentration risk, percentage	17.00%
Net product revenue \| Geographic concentration risk
Concentration Risk [Line Items]
Concentration risk, percentage	27.00%	30.00%		39.00%	26.00%
Accounts receivable \| Customer concentration risk
Concentration Risk [Line Items]
Concentration risk, percentage					61.00%
Number of customers accounting for more than ten percent of accounts receivable \| customer				2	1
Accounts receivable \| Customer concentration risk \| Customer One
Concentration Risk [Line Items]
Concentration risk, percentage				60.00%
Accounts receivable \| Customer concentration risk \| Customer Two
Concentration Risk [Line Items]
Concentration risk, percentage				39.00%
FRANCE
Concentration Risk [Line Items]
Product revenue, net				$ 25,500,000
Deferred revenue recognized			$ 3,000,000			22,500,000
Advanced payments from customers	$ 4,500,000			$ 4,500,000
FRANCE \| Net product revenue \| Geographic concentration risk
Concentration Risk [Line Items]
Concentration risk, percentage				17.00%
Other long-term liabilities
Concentration Risk [Line Items]
Accrued rent, noncurrent						4,800,000
Other current liabilities
Concentration Risk [Line Items]
Accrued rent, current	$ 3,600,000			$ 3,600,000		$ 600,000
REGENXBIO, Inc. \| Common Stock
Concentration Risk [Line Items]
Marketable securities (in shares) \| shares	687,139			687,139
REGENXBIO, Inc. \| Common Stock \| Level 1
Concentration Risk [Line Items]
Marketable securities	$ 9,600,000			$ 9,600,000
Marketable securities, unrealized gain	$ 4,100,000
Marketable securities, unrealized loss				$ 1,800,000