Hyperion Therapeutics (HPTX) 10-Q 8 Aug 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014	Aug. 05, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Jun-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Trading Symbol	'HPTX	'
Entity Registrant Name	'HYPERION THERAPEUTICS INC	'
Entity Central Index Key	'0001386858	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	20,597,919

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets	'	'
Cash and cash equivalents	$80,637	$74,232
Short-term investments	42,278	28,045
Accounts receivable, net	19,437	4,419
Inventories	2,907	3,513
Prepaid expenses and other current assets	971	1,403
Total current assets	146,230	111,612
Long-term investments	2,632	15,780
Property and equipment, net	1,056	936
Intangible assets, net	147,126	13,442
Goodwill	3,789	'
Other non-current assets	1,343	749
Total assets	302,176	142,519
Current liabilities	'	'
Accounts payable	6,821	2,292
Accrued liabilities and other	31,335	12,187
Notes payable, current portion	5,086	5,652
Total current liabilities	43,242	20,131
Notes payable, net of current portion	685	2,621
Deferred rent	361	81
Acquisition-related contingent consideration (Note 4)	69,456	'
Acquisition-related contingent liability (Note 4)	34,497	'
Deferred tax liability, net	3,167	'
Total liabilities	151,408	22,833
Commitments and contingencies (Note 13)	'	'
Stockholders' equity	'	'
Preferred stock, par value $0.0001 - 10,000,000 shares authorized; none issued and outstanding	'	'
Common stock, par value $0.0001 - 100,000,000 shares authorized at June 30, 2014 and December 31, 2013; 20,597,919 and 20,137,145 shares issued and outstanding at June 30, 2014 and December 31, 2013, respectively	2	2
Additional paid-in capital	254,403	242,109
Accumulated other comprehensive loss	-2	-55
Accumulated deficit	-103,635	-122,370
Total stockholders' equity	150,768	119,686
Total liabilities and stockholders' equity	$302,176	$142,519

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013
Statement Of Financial Position [Abstract]	'	'
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	20,597,919	20,137,145
Common stock, shares outstanding	20,597,919	20,137,145

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]	'	'	'	'
Net product revenue	$37,095	$7,305	$56,577	$8,088
Costs and expenses:	'	'	'	'
Cost of sales	4,473	875	6,856	943
Research and development	4,046	2,562	7,264	4,401
Selling, general and administrative	11,365	9,220	22,536	17,164
Amortization of intangible asset	1,014	329	2,028	329
Change in acquisition-related contingencies (Notes 4 and 6)	704	'	704	'
Total costs and expenses	21,602	12,986	39,388	22,837
Income (loss) from operations	15,493	-5,681	17,189	-14,749
Interest income	140	11	278	12
Interest expense	-269	-387	-569	-795
Gain from settlement of retention option (Note 3)	'	31,079	'	31,079
Other income (expense), net	-4	'	-194	500
Income before income taxes	15,360	25,022	16,704	16,047
Income tax benefit	-2,119	'	-2,031	'
Net income	$17,479	$25,022	$18,735	$16,047
Net income per share	'	'	'	'
Basic	$0.86	$1.25	$0.92	$0.86
Diluted	$0.81	$1.17	$0.87	$0.80
Weighted average number of shares used to compute net income per share of common stock:	'	'	'	'
Basic	20,335,618	20,050,987	20,263,803	18,716,332
Diluted	21,613,996	21,358,275	21,572,716	19,978,089

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]	'	'	'	'
Net income	$17,479	$25,022	$18,735	$16,047
Other comprehensive income:	'	'	'	'
Unrealized gain on investments arising during the period	8	'	53	'
Other comprehensive income	8	'	53	'
Comprehensive income	$17,487	$25,022	$18,788	$16,047

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities	'	'
Net income	$18,735	$16,047
Adjustments to reconcile net income to net cash provided by (used in) operating activities	'	'
Depreciation	193	51
Amortization of debt discount and debt issuance cost	278	278
Stock-based compensation expense	3,220	1,756
Amortization of intangible asset	2,028	329
Gain from foreign currency translation adjustment	-17	'
Provision for inventory obsolescence	145	'
Amortization of discount on available-for-sale investments	208	'
Excess tax benefit from stock-based compensation	-47	'
Gain from settlement of retention option (Note 3)	'	-31,079
Change in acquisition-related contingent consideration and contingent liability (Note 6)	704	'
Changes in assets and liabilities, net of impact of acquisition of Andromeda Biotech Ltd. ("Andromeda")	'	'
Accounts receivable	-15,001	-1,723
Inventories	479	-1,065
Prepaid expenses and other assets	495	345
Accounts payable	295	-120
Deferred rent	286	'
Deferred taxes	-2,885	'
Accrued liabilities and other	14,343	2,182
Net cash provided by (used in) operating activities	23,459	-12,999
Cash flows from investing activities	'	'
Acquisition of property and equipment	-291	-433
Purchase of available-for-sale investments	-5,280	'
Maturity of available-for-sale investments	4,040	'
Acquisition of Andromeda, net of cash acquired	-14,039	'
Acquisition of rights to BUPHENYL, net of AMMONUL option (Note 3)	'	10,962
Net cash provided by (used in) investing activities	-15,570	10,529
Cash flows from financing activities	'	'
Proceeds from issuance of common stock in follow-on offering, net of underwriting discounts	'	64,488
Proceeds from issuance of common stock from stock option exercises	1,232	337
Excess tax benefit from stock-based compensation	47	'
Payments of offering costs	'	-776
Principal payments under notes payable	-2,763	-1,705
Net cash provided by (used in) financing activities	-1,484	62,344
Net increase in cash and cash equivalents	6,405	59,874
Cash and cash equivalents, beginning of period	74,232	49,853
Cash and cash equivalents, end of period	80,637	109,727
Supplemental cash flow information	'	'
Cash paid for interest	313	532
Stock-based compensation capitalized into inventories	18	26
Supplemental disclosure of noncash investing and financing activities	'	'
Option to purchase rights to BUPHENYL and AMMONUL (Note 3)	'	283
Unrealized gain on available-for-sale investments	53	'
Acquisition of Andromeda (Note 4)	'	'
Cash paid for acquisition	14,345	'
Cash acquired in acquisition	-306	'
Net cash paid for acquisition	14,039	'
Fair value of common stock issued in connection with the acquisition	$7,778	'

Formation_and_Business_of_the_

Formation and Business of the Company	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Formation and Business of the Company	'
	1. Formation and Business of the Company
	Hyperion Therapeutics, Inc. (the “Company”) was incorporated in the state of Delaware on November 1, 2006. The Company was in the development stage from inception through March 31, 2013. During this period, the Company’s activities consisted primarily of raising capital, negotiating a promotion and drug development collaboration agreement, establishing a management team and performing drug development activities. The Company launched RAVICTI® (glycerol phenylbutyrate) Oral Liquid during the quarter ended March 31, 2013.
	On May 31, 2013, the Company acquired BUPHENYL, an FDA-approved therapy for treatment of three of the most prevalent UCD subtypes, from Ucyclyd Pharma Inc. (“Ucyclyd”), a subsidiary of Valeant Pharmaceuticals International, Inc. (“Valeant”). Subsequent to the acquisition on May 31, 2013, the Company started selling BUPHENYL Tablets and Powder within and outside the United States.
	As discussed in Note 4, on June 12, 2014, the Company completed the acquisition of Andromeda Biotech Ltd. (“Andromeda”), an Israeli company. This acquisition broadens the Company’s pipeline to include DiaPep277®, a potentially first-in-class immunotherapy for Type 1 diabetes in patients with residual beta cell function. DiaPep277 is currently being evaluated in a fully enrolled Phase 3 clinical study in adult patients and holds Orphan Drug designation in the U.S.
	The Company is a commercial stage biopharmaceutical company focused on the development and commercialization of novel therapeutics to treat disorders in the area of orphan diseases. The Company has developed RAVICTI to treat seven of the eight most prevalent subtypes of urea cycle disorders (“UCD”) and is developing glycerol phenylbutyrate (“GPB”) for the potential treatment of hepatic encephalopathy (“HE”). UCD and HE are generally characterized by elevated levels of ammonia in the bloodstream. Elevated levels of ammonia are potentially toxic and can lead to severe medical complications which may include death. The Company’s product, RAVICTI, is designed to lower ammonia in the blood. UCD are inherited rare genetic diseases caused by a deficiency of one or more enzymes or transporters that constitute the urea cycle, which in a healthy individual removes ammonia through conversion of ammonia to urea. HE is a serious but potentially reversible neurological disorder that can occur in patients with liver scarring, known as cirrhosis, or acute liver failure. On February 1, 2013, the U.S. Food and Drug Administration (“FDA”), granted approval of RAVICTI for the use as a nitrogen-binding agent for chronic management of adult and pediatric UCD patients greater than two years of age who cannot be managed by dietary protein restriction and/or amino acid supplementation alone. In addition, the Company is developing DiaPep277, a first-in-class immune intervention therapy for the potential treatment of Type 1 diabetes for patients with residual beta cell function. Type 1 (or insulin dependent) diabetes is an auto immune disease that results in the destruction of beta cells, the insulin secreting cells in the pancreas, resulting in loss of glycemic (glucose or blood sugar) control.
	On August 14, 2013, the Company filed a shelf registration statement on Form S-3, which was declared effective by the Securities and Exchange Commission (“SEC”) on September 13, 2013. The shelf registration statement permits: (a) the offering, issuance and sale by the Company of up to a maximum aggregate offering price of $150.0 million of its common stock, preferred stock, debt securities, warrants and/or units; (b) the sale of up to 8,727,000 shares of common stock by certain selling stockholders; and (c) the offering, issuance and sale by the Company of up to a maximum aggregate offering price of $50.0 million of its common stock that may be issued and sold under a sales agreement with Cantor Fitzgerald & Co. As of June 30, 2014, there were no sales of any securities registered pursuant to the shelf registration statement.
	At June 30, 2014, the Company had an accumulated deficit of $103.6 million. The Company expects to incur increased research and development expenses when the Company initiates a Phase 3 trial of GPB for the treatment of patients with episodic HE and as it continues the development of DiaPep277. In addition, the Company expects to incur increased sales and marketing expenses with the continued commercialization of RAVICTI and marketing of BUPHENYL in UCD. Management’s plans with respect to these matters include utilizing a substantial portion of the Company’s capital resources and efforts in completing the development and obtaining regulatory approval for DiaPep277 and for GPB in HE, expanding the Company’s organization, and commercialization of RAVICTI and marketing of BUPHENYL.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	2. Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and on a basis consistent with the annual consolidated financial statements, and in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the periods presented. These interim financial results are not necessarily indicative of the results to be expected for the year ending December 31, 2014, or for any other future annual or interim period. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013.
	Principles of Consolidation
	The consolidated financial statements include the Company’s accounts and those of its wholly-owned subsidiaries: Hyperion Therapeutics Ltd., Hyperion Therapeutics Ireland Holding Ltd., Hyperion Therapeutics Ireland Operating Ltd., Hyperion Therapeutics Israel Holding Corp. Ltd., and Andromeda Biotech Ltd. All intercompany accounts and transactions have been eliminated.
	Use of Estimates
	The preparation of the interim condensed consolidated financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates, including those related to fair value of assets and liabilities, goodwill and intangible assets valuation, acquisition-related contingent consideration, acquisition related contingent liability, stock-based compensation expense, income taxes, revenue recognition and product sales allowances. Management bases its estimates on historical experience or on various other assumptions, including information received from its service providers, which it believes to be reasonable under the circumstances. Actual results could differ from those estimates.
	Concentration of Credit Risk and Significant Customers
	The Company’s cash and cash equivalents and investments are maintained with financial institutions located in and outside the United States. Deposits in these institutions may exceed the amount of insurance provided on such deposits. The Company has not recognized any losses from credit risks during the periods presented and management does not believe that the Company is exposed to significant credit risk from its cash and cash equivalents or investments.
	The Company is also subject to credit risk from its accounts receivables related to its product sales. The Company monitors its exposure within accounts receivable and records a reserve against uncollectible accounts receivable as necessary. The Company extends credit to a specialty distributor in the United States and to international distributors, pharmacies and hospitals outside the United States. Customer creditworthiness is monitored and collateral is not required. As of June 30, 2014, there were no credit losses on the Company’s accounts receivable. As of June 30, 2014, the specialty distributor in the United States accounted for 90% of accounts receivable balance and one international distributor accounted for 5% of the accounts receivable balance.
	The specialty distributor accounted for 92% of net product revenue for the three and six months ended June 30, 2014. One international distributor accounted for 5.2% and 3.9% of net product revenue for the three and six months ended June 30, 2014.
	Fair Value of Financial Instruments
	The Company measures certain financial assets and liabilities at fair value based on the exchange price that would be received for an asset or paid for to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants. The carrying amounts of the Company’s financial instruments, including cash equivalents, short-term investments, accounts payable, and accrued liabilities, approximate fair value due to their short maturities. The carrying amounts of long-term investments, the acquisition-related contingent consideration represent their estimated fair values. The Company’s debt obligations are carried at historical cost, which approximates fair value.
	Business Combinations
	The Company allocates the purchase price of an acquired business to the tangible and intangible assets acquired and liabilities assumed based upon their estimated fair values on the acquisition date. Any excess of the purchase price over the fair value of the net assets acquired is recorded as goodwill. Acquired in-process research and development (“IPR&D”) is recognized at fair value and initially characterized as an indefinite-lived intangible asset, irrespective of whether the acquired IPR&D has an alternative future use. The purchase price allocation process requires management to make significant estimates and assumptions, especially at the acquisition date with respect to intangible assets. Direct transaction costs associated with the business combination are expensed as incurred.
	Accounts Receivable
	Trade accounts receivable are recorded net of product sales allowances for prompt-payment discounts, chargebacks, and doubtful accounts. Estimates for chargebacks and prompt-payment discounts are based on contractual terms, historical trends and our expectations regarding the utilization rates for these programs.
	Inventories
	Inventories are stated at the lower of cost or market value with cost determined under the first-in-first-out (FIFO) cost method and consists of raw materials, work-in-progress and finished goods. Costs to be capitalized as inventories include third party manufacturing costs, associated compensation related costs of personnel indirectly involved in the manufacturing process and other overhead costs such as ancillary supplies. Subsequent to FDA approval of RAVICTI on February 1, 2013, the Company began capitalizing RAVICTI inventories as the related costs were expected to be recoverable through the commercialization of the product. Costs incurred prior to the FDA approval of RAVICTI have been recorded as research and development expense in the condensed consolidated statements of operations. If information becomes available that suggest that inventories may not be realizable, the Company may be required to expense a portion or all of the previously capitalized inventories.
	Products that have been approved by the FDA or other regulatory authorities, such as RAVICTI, are also used in clinical programs, to assess the safety and efficacy of the products for usage in diseases that have not been approved by the FDA or other regulatory authorities. The form of RAVICTI utilized for both commercial and clinical programs is identical and, as a result, the inventory has an “alternative future use” as defined in authoritative guidance. Raw materials and purchased drug product associated with clinical development programs are included in inventory and charged to research and development expense when the product enters the research and development process and no longer can be used for commercial purposes and, therefore, does not have an “alternative future use”.
	On May 31, 2013, the Company acquired BUPHENYL from Ucyclyd. The Company recorded the acquired BUPHENYL inventories at fair value in the amount of $3.9 million on the acquisition date. As of March 31, 2014, the entire fair value of acquired BUPHENYL inventory has been charged to expenses, primarily cost of sales.
	Intangible Assets
	Intangible assets are recorded at acquisition cost less accumulated amortization and impairment. Intangible asset with finite lives are amortized over their estimated useful life using the economic use method, which reflects the pattern that the economic benefits of the intangible asset are consumed as revenue is generated. The pattern of consumption of the economic benefits is estimated using the future projected cash flows of the intangible asset.
	IPR&D
	The fair value of IPR&D acquired through a business combination is capitalized as an indefinite-lived intangible asset until the completion or abandonment of the related research and development activities. When the related research and development is completed, the asset will be assigned a useful life and amortized.
	The fair value of an IPR&D intangible asset is determined using an income approach. This approach starts with a forecast of the net cash flows expected to be generated by the asset over its estimated useful life. The net cash flows reflect the asset’s stage of completion, the probability of technical success, the projected costs to complete, expected market competition, and an assessment of the asset’s life-cycle. The net cash flows are then adjusted to present value by applying an appropriate discount rate that reflects the risk factors associated with the cash flow streams.
	Goodwill
	Goodwill represents the excess of the purchase price of acquired businesses over the estimated fair value of the identifiable net assets acquired. Goodwill is not amortized but is tested for impairment at least annually at the reporting unit level or more frequently if events or changes in circumstances indicate that the asset might be impaired. A reporting unit is the same as, or one level below, an operating segment.
	Impairment of Long-lived Assets
	The Company reviews its property and equipment, intangible assets subject to amortization and other long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset class may not be recoverable. Indicators of potential impairment include: an adverse change in legal factors or in the business climate that could affect the value of the asset; an adverse change in the extent or manner in which the asset is used or is expected to be used, or in its physical condition; and current or forecasted operating or cash flow losses that demonstrate continuing losses associated with the use of the asset. If indicators of impairment are present, the asset is tested for recoverability by comparing the carrying value of the asset to the related estimated undiscounted future cash flows expected to be derived from the asset. If the expected cash flows are less than the carrying value of the asset, then the asset is considered to be impaired and its carrying value is written down to fair value, based on the related estimated discounted future cash flows.
	Indefinite-lived intangible assets, including acquired IPR&D, are tested for impairment annually or more frequently if events or changes in circumstances between annual tests indicate that the asset may be impaired. Impairment losses on indefinite-lived intangible assets are recognized based solely on a comparison of the fair value of the asset to its carrying value, without consideration of any recoverability
	Acquisition-Related Contingent Consideration
	Acquisition-related contingent consideration, which consists primarily of potential milestone payments and royalty obligations, is recorded in the consolidated balance sheets at its acquisition date estimated fair value, in accordance with the acquisition method of accounting. The fair value of the acquisition-related contingent consideration is remeasured each reporting period, with changes in fair value recorded in the consolidated statements of operations. Changes in the fair value of the acquisition-related contingent consideration obligations result from several factors including changes in discount periods and rates, changes in the timing and amount of revenue estimates and changes in probability assumptions with respect to the likelihood of achieving specified milestone criteria. The fair value measurement is based on significant inputs not observable in the market and thus represents a Level 3 measurement as defined in fair value measurement accounting
	Acquisition-Related Contingent Liability
	Acquisition-related contingent liability, which consists primarily of potential milestone payments and royalty obligations, and potential payments to certain employees of Andromeda is recorded in the condensed consolidated balance sheets at its acquisition date estimated fair value. The Company reassesses the probability and estimates associated with the contingent liability at each reporting period. For liability payable to third parties, any increase in the liability is recorded in the condensed consolidated statements of operations. For liabilities payable to employees, the Company accounts for the liability in accordance with Financial Accounting Stands Board (“FASB”) Accounting Stand Codification (“ASC”) 450 Contingencies.
	Revenue Recognition
	The Company recognizes revenue in accordance with ASC 605, Revenue Recognition, when the following criteria have been met: persuasive evidence of an arrangement exists; delivery has occurred and risk of loss has passed; the seller’s price to the buyer is fixed or determinable and collectability is reasonably assured. The Company determines that persuasive evidence of an arrangement exists based on written contracts that defined the terms of the arrangements. In addition, the Company determines that services have been delivered in accordance with the arrangement. The Company assesses whether the fee is fixed or determinable based on the payment terms associated with the transaction and whether the sales price is subject to refund or adjustment. The Company assesses collectability based primarily on the customer’s payment history and on the creditworthiness of the customer.
	Product Revenue, net: The Company’s product revenue represents sales of RAVICTI and BUPHENYL which are recognized once all four revenue recognition criteria described above are met. The Company recognizes revenue net of product sales allowances. Product shipping and handling costs are included in cost of sales. Prior to June 2014, revenue from the sale of RAVICTI was recognized based on the amount of product sold through to the end user consumer. Starting June 2014, the Company could reasonably estimate and determine sales allowances, therefore the Company began recognizing RAVICTI revenue at the point of sale to the specialty distributor, which resulted in the one-time non-recurring recognition of an additional $8.6 million in net revenues.
	Product Sales Allowances: The Company establishes reserves for prompt-payment discounts, government and commercial rebates, product returns and chargebacks. Allowances relate to prompt-payment discounts and are recorded at the time of revenue recognition, resulting in a reduction in product sales revenue and a decrease in trade accounts receivables. Accruals related to government rebates, product returns and other applicable allowances such as distributor fees are recognized at the time of revenue recognition, resulting in a reduction in product sales and an increase in accrued expenses or a reduction in the related accounts receivable.
		•	Prompt-payment discounts: The specialty distributor and specialty pharmacies are offered prompt payment discounts. The Company expects the specialty distributor and specialty pharmacies will earn prompt payment discounts and, therefore deduct the full amount of these discounts from total product sales when revenues are recognized. The Company records prompt-payment discounts as allowances against accounts receivable on the condensed consolidated balance sheet.
		•	Rebates: Allowances for rebates include mandated discounts under the Medicaid Drug Rebate Program. Rebate amounts are based upon contractual agreements or legal requirements with public sector (e.g. Medicaid) benefit providers. Rebates are amounts owed after the final dispensing of the product to a benefit plan participant and are based upon contractual agreements or legal requirements with public sector benefit providers. The allowance for rebates is based on statutory discount rates and expected utilization. The Company estimates for expected utilization of rebates based on historical data and data received from the specialty pharmacies. Rebates are generally invoiced and paid in arrears so that the accrual balance consists of an estimate of the amount expected to be incurred for the current quarter’s activity, plus an accrual balance for known prior quarter’s unpaid rebates. If actual future rebates vary from estimates, the Company may need to adjust prior period accruals, which would affect revenue in the period of adjustment. Allowance for rebates are recorded in accrued liabilities on the condensed consolidated balance sheet.
		•	Chargebacks: Chargebacks are discounts that occur when contracted customers purchase directly from a specialty distributor. Contracted customers, which primarily consist of Public Health Service institutions, non-profit clinics, and Federal government entities purchasing via the Federal Supply Schedule, generally purchase the product at a discounted price. The specialty distributor, in turn, charges back to the Company the difference between the price initially paid by the specialty distributor and the discounted price paid to the specialty distributor by the customer. The allowance for chargebacks is based on historical sales data and known sales to contracted customers.
		•	Medicare Part D Coverage Gap: Medicare Part D prescription drug benefit mandates manufacturers to fund 50% of the Medicare Part D insurance coverage gap for prescription drugs sold to eligible patients. The Company estimates for the expected Medicare Part D coverage gap are based on historical invoices received and in part from data received from the specialty pharmacies. Funding of the coverage gap is generally invoiced and paid in arrears so that the accrual balance consists of an estimate of the amount expected to be incurred for the current quarter’s activity, plus an accrual balance for known prior quarters. If actual future funding varies from estimates, the Company may need to adjust prior period accruals, which would affect revenue in the period of adjustment. Estimates of the Medicare Part D coverage gap are recorded in accrued liabilities on the condensed consolidated balance sheet.
		•	Distribution Service Fees: The Company has a written contract with the specialty distributor that includes terms for distribution-related fees. Distributor fees are calculated at percentage of gross sales based upon agreed contracted rate. The Company accrues distributor fees at the time of the revenue recognition, resulting in reduction of product sales revenue and the recording of accrued liabilities on the condensed consolidated balance sheets. The Company records distribution and other fees paid to its customers as a reduction of revenue, unless it receives an identifiable and separate benefit for the consideration and it can reasonably estimate the fair value of the benefit received. If both conditions are met, the Company records the consideration paid to the customer as an operating expense. These costs are typically known at the time of sale.
		•	Product Returns: Consistent with industry practice, the Company generally offers customers a limited right to return. The Company accepts returns of products from patients resulting from breakage as defined within the Company’s returns policy. Additionally, the Company considers several other factors in the estimation process including the expiration dates of product shipped, third party data in monitoring channel inventory levels, shelf life of the product, prescription trends and other relevant factors. Provisions for estimated product returns are recorded as accrued liabilities on the condensed consolidated balance sheet.
	Co-payment assistance: The Company provides a cash donation to a non-profit third party organization which supports patients, who have commercial insurance and meet certain financial eligibility requirements, with co-payment assistance and travel costs. The amount of co-payment assistance is accounted for by the Company as a reduction of revenues.
	Cost of sales
	Cost of sales includes third-party manufacturing cost of products sold, royalty fees, and other indirect costs related to personnel compensation, shipping and supplies. Costs incurred prior to FDA approval of RAVICTI have been recorded as research and development expense in the Company’s condensed consolidated statement of operations. The Company expects that cost of RAVICTI sales as a percentage of revenue will increase in future periods as product manufactured prior to FDA approval, and therefore fully expensed, is utilized.
	Cost of BUPHENYL sales as a percentage of revenue was higher and not indicative of cost of sales in future periods due to the recording of the step-up value on BUPHENYL inventories acquired from Ucyclyd which is expensed to cost of sales as that inventory is sold. As of March 31, 2014, the entire fair value of acquired BUPHENYL inventory has been charged to expense, primarily cost of sales.
	Stock-Based Compensation
	The Company accounts for stock-based employee compensation arrangements in accordance with provisions of ASC 718, Compensation — Stock Compensation. ASC 718 requires the recognition of compensation expense, using a fair-value based method, for costs related to all share-based payments including stock options. ASC 718 requires companies to estimate the fair value of share-based payment awards on the date of grant using an option-pricing model. The Company calculates the fair value of stock options using the Black-Scholes method and expenses using the straight-line attribution approach.
	Income Taxes
	The Company accounts for income taxes under the liability method. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized.
	The Company accounts for uncertain tax positions in accordance with ASC 740-10, Accounting for Uncertainty in Income Taxes. The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized tax benefit is still appropriate. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available.
	Foreign Currency Translations
	Operations in non-U.S. entities are recorded in the functional currency of each entity. For financial reporting purposes, the functional currency of an entity is determined by a review of the source of an entity’s most predominant cash flows. The reporting and functional current of the Company and its subsidiaries is the U.S. dollar.
	Gains and losses resulting from foreign currency transactions are translated at the weighted average rate of exchange prevailing during the period. Any monetary asset or liability denominated in foreign currency and is translated at the rate of exchange in effect on the balance sheet date. Any gains and losses resulting from foreign currency translations are included in other income (expense)-net in the condensed consolidated statements of operations. The Company does not currently utilize and has not in the past utilized any foreign currency hedging strategies to mitigate the effect of its foreign currency exposure.
	Comprehensive Income
	Comprehensive income is comprised of net income and other comprehensive income. Other comprehensive income includes changes in stockholders’ equity that are excluded from net income, specifically changes in unrealized gains and losses on the Company’s available-for-sale securities.
	Net Income per Share of Common Stock
	Basic earnings per share is computed by dividing the net income by the weighted average number of shares of common stock outstanding during the periods presented. The computation of diluted earnings per share is similar to the computation of basic earnings per share, except that the denominator is increased for the assumed exercise of dilutive options and other potentially dilutive securities using the treasury stock method unless the effect is antidilutive.
	Recent Accounting Pronouncements
	In July 2013, FASB issued ASU No. 2013-11, Income Taxes (Topic 740): Presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. Under the amendments of this update an entity is required to present an unrecognized tax benefit, or a portion of an unrecognized tax benefit in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except as follows. To the extent a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date under the tax law of the applicable jurisdiction to settle any additional income taxes that would result from the disallowance of a tax position or the tax law of the applicable jurisdiction does not require the entity to use, and the entity does not intend to use, the deferred tax asset for such purpose, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be combined with deferred tax assets. The assessment of whether a deferred tax asset is available is based on the unrecognized tax benefit and deferred tax asset that exist at the reporting date and should be made presuming disallowance of the tax position at the reporting date. For example, an entity should not evaluate whether the deferred tax asset expires before the statute of limitations on the tax position or whether the deferred tax asset may be used prior to the unrecognized tax benefits being settled. The provisions of this update was effective prospectively for the Company in fiscal years beginning after December 15, 2013 with early adoption and retrospective application permitted. The Company adopted this guidance on January 1, 2014. The implementation did not have an impact on the Company’s condensed consolidated financial statements.
In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update 2014-09 (ASU 2014-09), Revenue from Contracts with Customers. ASU 2014-09 will supersede the revenue recognition requirements in Revenue Recognition (Topic 605) and requires entities to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period, which for the Company is January 1, 2017. Early adoption is not permitted. The Company is currently evaluating the potential impact the adoption of ASU 2014-09 will have on its consolidated financial statements.

Collaboration_Agreement_with_U

Collaboration Agreement with Ucyclyd Pharma, Inc.	6 Months Ended
	Jun. 30, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'
Collaboration Agreement with Ucyclyd Pharma, Inc.	'
	3. Collaboration Agreement with Ucyclyd Pharma, Inc.
	In March 2012, the Company entered into the purchase agreement with Ucyclyd under which the Company purchased the worldwide rights to RAVICTI and into an amended and restated collaboration agreement (the “restated collaboration agreement”) under which Ucyclyd granted the Company an option to purchase all of Ucyclyd’s worldwide rights to BUPHENYL and AMMONUL at a fixed price at a future defined date, plus subsequent milestone and royalty payments, subject to Ucyclyd’s right to retain AMMONUL for a predefined price. The restated collaboration agreement superseded the collaboration agreement with Ucyclyd, dated August 23, 2007, as amended. The entry into the purchase agreement and the restated collaboration agreement resolved a dispute that the two parties had with respect to their rights under the prior collaboration agreement.
	Under the purchase agreement, the Company made a payment of $6.0 million of which (i) $5.7 million was allocated to the worldwide rights to RAVICTI and (ii) $0.3 million was allocated to the option to purchase rights to BUPHENYL and AMMONUL, based on their relative fair values. The allocated amount to the rights to RAVICTI of $5.7 million was recorded to research and development expense in the consolidated statements of operations for the period ended March 31, 2012 due to the uncertainty of an alternative future use. The allocated amount for the option to purchase rights to BUPHENYL and AMMONUL in the amount of $0.3 million was included within other current assets and was subsequently offset against the gain recognized from the settlement of retention option.
	The Company will also pay tiered mid to high single digit royalties on global net sales of RAVICTI and may owe regulatory milestones of up to $15.8 million related to approval of GPB in HE, regulatory milestones of up to $7.3 million per indication for approval of GPB in indications other than UCD or HE, and net sales milestones of up to $38.8 million if GPB is approved for use in indications other than UCD (such as HE) and all annual sales targets are reached.
	In addition, the intellectual property license agreements executed between Ucyclyd and Dr. Marshall L. Summar, (“Summar”) and Ucyclyd and Brusilow Enterprises, LLC, (“Brusilow”) were assigned to the Company, and the Company has assumed the royalty and milestone obligations under the Brusilow agreement for sales of RAVICTI in any indication and the royalty obligations under the Summar agreement on sales of GPB to treat HE. The Brusilow and Summar agreements provide that royalty obligations will continue, without adjustment, even if generic versions of the licensed products are introduced and sold in the relevant country.
	Under the terms of the restated collaboration agreement, the Company had an option to purchase all of Ucyclyd’s worldwide rights in BUPHENYL and AMMONUL, subject to Ucyclyd’s option to retain rights to AMMONUL. The Company was permitted to exercise this option for 90 days beginning on the earlier of the date of the approval of RAVICTI for the treatment of UCD and June 30, 2013, but in no event earlier than January 1, 2013. The upfront purchase price for AMMONUL and BUPHENYL was $22.0 million. If the RAVICTI New Drug Application (“NDA”) for UCD was not approved by January 1, 2013, then Ucyclyd was obligated to make monthly payments of $0.5 million to the Company until the earliest of (1) FDA approval of the RAVICTI NDA for UCD, (2) June 30, 2013 and (3) the Company’s written notification of the decision not to purchase Ucyclyd’s worldwide rights to BUPHENYL and AMMONUL.
	On February 1, 2013, the FDA approved RAVICTI for the treatment of UCD in adult and pediatric patients two years of age and older. In accordance with the restated collaboration agreement, Ucyclyd made a payment of $0.5 million during the quarter ended March 31, 2013.
	On April 29, 2013, the Company exercised its option to purchase BUPHENYL and AMMONUL. Ucyclyd subsequently exercised its time-limited right to elect to retain all rights to AMMONUL (“retention option”) for a contractual purchase price of $32.0 million (“retention amount”). Upon closing of the transaction, Ucyclyd paid the Company a net payment of $11.0 million, which reflects the Company’s contractual purchase price for Ucyclyd’s worldwide rights to BUPHENYL in the amount of $19.0 million being off-set against Ucyclyd’s retention amount for AMMONUL and a $2.0 million payment due to Ucyclyd for inventory that the Company purchased from Ucyclyd. The Company has retained a right of first negotiation should Ucyclyd later decide to sell, exclusively license, or otherwise transfer the AMMONUL assets to a third party.
	On May 31, 2013, the Company completed the acquisition of BUPHENYL. Upon Ucyclyd’s exercise of its retention option, the Company recorded a gain of approximately $31.1 million in its consolidated statement of operaations. The amount of gain is comprised of (i) fair value of BUPHENYL of $20.4 million and (ii) net cash received from Ucyclyd of $10.9 million off-set by (iii) the $0.3 million carrying value of the option to purchase the rights to BUPHENYL and AMMONUL.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2014
Business Combinations [Abstract]	'
Acquisitions	'
	4. Acquisitions
	Acquisition of Andromeda
	Description of the Transaction
	On April 23, 2014, Hyperion Therapeutics Israel Holding Corp. Ltd. (“Hyperion Israel”), a wholly-owned subsidiary of the Company entered into a share purchase agreement with Clal Biotechnology Industries Ltd. to purchase all outstanding shares of Andromeda Biotech Ltd. (“Andromeda”), an Israeli company. On June 12, 2014 (the “Acquisition Date”), Hyperion Israel completed the purchase of all of the outstanding ordinary shares of Andromeda. The Andromeda acquisition is accounted for as a business combination. The results of operations of Andromeda have been included in the Company’s condensed consolidated statements of operations starting from June 12, 2014, the date on which the Company obtained effective control of Andromeda. The net loss from operations of Andromeda for the period from June 12, the acquisition date to June 30, 2014 was $1.4 million.
	Andromeda was incorporated in Israel in 2007 and is primarily focused on the development of DiaPep277, a potentially first-in-class immunotherapy for Type 1 diabetes in patients with residual beta cell function. DiaPep277 is designed to preserve endogenous insulin secretion by selectively impeding beta cell destruction without impacting other essential immunological functions or causing systemic immune suppression. DiaPep277 is currently being evaluated in a fully enrolled Phase 3 clinical study in adult patients and holds an Orphan Drug designation in the U.S.
	Fair Value of Consideration Transferred
	The Company accounted for the acquisition of Andromeda as a business combination under the acquisition method of accounting. The Acquisition Date fair value of the total consideration transferred to acquire Andromeda was as follows:
			(in thousands)
	Cash paid		$	14,345
	Fair value of Company’s common stock issued (312,869 shares)			7,778	*
	Acquisition-related contingent consideration			68,961
	Total fair value of consideration transferred		$	91,084
	*	The fair value of the common stock was measured using the Company’s closing stock price on June 12, 2014.
	The Company estimated the fair value of the acquisition-related contingent consideration on the acquisition date using a probability-weighted income approach, which reflects the probability and timing of future payments. This fair value measurement on the acquisition date is based on key assumptions such as the anticipated timelines and probability of achieving development, regulatory approval or sales-based milestone events and projected revenues. The resulting probability-weighted cash flows are discounted using estimated discount rate that commensurate with the risks of the expected cash flows attributable to the various milestones. The material factors that may impact the fair value are the probabilities of achieving the related milestones and the discount rate. Significant increases or decreases in any of the probabilities of success would result in a significantly higher or lower fair value, respectively, and commensurate changes to this liability. The fair value relating to the acquisition-related contingent consideration at each reporting date, will be updated with the changes in fair value reflected in the company’s consolidated statements of operations.
	Assets Acquired and Liabilities Assumed
	The following table summarizes the provisional allocation of purchase price to the fair values of the assets acquired and liabilities assumed as of the acquisition date:
			(in thousands)
	Assets acquired
	IPR&D		$	135,712
	Cash and cash equivalents			306
	Prepaid expenses			95
	Property and equipment, net			22
	Other assets			578
	Liabilities assumed
	Current liabilities			(9,079	)
	Deferred tax liability			(6,051	)
	Acquisition related contingent liability			(34,288	)
	Total identifiable net assets			87,295
	Goodwill			3,789
	Total consideration transferred		$	91,084
	The amounts above are considered preliminary and are subject to change once the Company finalizes the determination of the fair value of assets acquired and liabilities assumed. Thus, these amounts are subject to refinement and final determination of the fair values of net assets acquired and may result in certain adjustments to the amounts presented above.
	The contingent liabilities amounting to $34.3 million relate to potential royalties and milestone payments and potential payments to certain employees of Andromeda that is contingent upon their continued employment with the Company. The Company reassesses the probability and estimates associated with the contingent liability at each reporting period. For liability payable to third parties, any increase in the liability is recorded in the condensed consolidated statements of operations. For liabilities payable to employees, the Company accounts for the liability in accordance with ASC 450 Contingencies. The Company recorded $0.2 million of the change in value in the Company’s consolidated statements of operations for the three and six months ended June 30, 2014.
	Goodwill recorded as a result of the acquisition of Andromeda is not deductible for tax purposes. The goodwill primarily represents the tax impact of the IPR&D and acquisition related contingencies as well as acquiring Andromeda’s assembled workforce.
	Acquisition of BUPHENYL from Ucyclyd Pharma, Inc.
	As discussed in Note 3, under the terms of the restated collaboration agreement, on April 29, 2013, the Company exercised its option to purchase all of Ucyclyd’s worldwide rights in BUPHENYL and AMMONUL. On May 17, 2013 Ucyclyd exercised it’s time-limited right to elect to retain all rights to AMMONUL. On May 31, 2013 (the “Acquisition Date”), the Company completed the acquisition of BUPHENYL. Accordingly, BUPHENYL results are included in Hyperion’s consolidated financial statements from the date of the acquisition. For the period from June 1, 2013 to June 30, 2013, BUPHENYL net revenue was $1.1 million and net income was not material.
	The Company acquired BUPHENYL to enhance its commercial product portfolio and to allow the Company an opportunity to serve the entire UCD patient population, including those less than two years of age or for those patients who may prefer BUPHENYL.
	Pro forma Impact of Business Combination
	The following consolidated pro forma information is based on the assumption that the Andromeda acquisition occurred on January 1, 2013 and BUPHENYL acquisitions occurred on January 1, 2012. The unaudited pro forma information is presented for comparative purposes only and is not necessarily indicative of the financial position or results of operations which would have been reported had the Company completed the acquisitions during these periods or which might be reported in the future. The unaudited pro forma information reflects primarily the application of the following adjustments:
		•		the elimination of the historical research and development expenses and general and administration expenses related to options granted to employees which were cancelled as part of the Andromeda acquisition;
		•		the elimination of the historical interest expenses related to loans provided by former shareholders which were cancelled as part of the Andromeda acquisition
		•		the exclusion of acquisition-related costs incurred for the acquisitions;
		•		the inclusion of amortization expense related to the fair value of the intangible asset acquired relating to BUPHENYL;
		•		the inclusion of the step-up value related to inventory sold that was acquired as part of the BUPHENYL acquisition. Such amounts are included in the applicable comparative period for purposes of pro forma financial information
		•		as noted above, the Company issued 312,869 shares of its common stock as part of the Andromeda acquisition. The common shares were included in the pro-forma earnings per share calculation.
	The unaudited pro forma information is not necessarily indicative of what the Company’s consolidated results of operations actually would have been had the acquisition of Andromeda been completed on January 1, 2013 and acquisition of BUPHENYL been completed on January 1, 2012. In addition, the unaudited pro forma information does not purport to project the future results of operations of the Company.
			For the three months ended					For the six months ended
			June 30,					June 30,
			(in thousands except per share data, unaudited)
			2014			2013		2014		2013
	Total revenues		$	37,095		$	9,152	$	56,577	$	18,784
	Net income			15,202			25,767		13,001		18,330
	Net income per common share:
	Basic			0.74			1.27		0.63		0.96
	Diluted			0.7			1.19		0.59		0.9
	Acquisition-related Costs
	Acquisition-related expenses consist of transaction costs which represent external costs directly related to the acquisition of Andromeda and primarily include expenditures for professional fees such as legal, accounting and other directly related incremental costs incurred to close the acquisition. Acquisition-related expenses for the three and six month periods ended June 30, 2014 were $1.3 million for both periods. Acquisition-related expenses for the three and six months ended June 30, 2013 were $0.3 million and $0.4 million, respectively. These expenses were recorded to selling and general administrative expense in the condensed consolidated statements of operations.

Investments

Investments	6 Months Ended
	Jun. 30, 2014
Investments Debt And Equity Securities [Abstract]	'
Investments	'
	5. Investments
	All investments were classified as available-for-sale at June 30, 2014 and December 31, 2013, respectively. The principal amounts of investments by contractual maturity at June 30, 2014 and December 31, 2013 are summarized in the tables below:
		Contractual Maturity Date for the					Total Book		Unrealized			Aggregate
		Period Ended June 30,					Value at		Gain (loss)			Fair Value at
							June 30, 2014					June 30, 2014
		2015		2016
	Certificates of deposit	$	11,970	$	2,640		$	14,610	$	(16	)	$	14,594
	Corporate notes		18,804		—			18,804		12			18,816
	U.S. Government agency securities		8,001		—			8,001		1			8,002
	Commercial paper		3,497		—			3,497		1			3,498
	Total	$	42,272	$	2,640		$	44,912	$	(2	)	$	44,910
		Contractual Maturity Date for the					Total Book		Unrealized			Aggregate
		Years Ended December 31,					Value at		Loss			Fair Value at
							December 31, 2013					December 31, 2013
		2014		2015
	Certificates of deposit	$	10,525	$	2,845		$	13,370	$	(27	)	$	13,343
	Corporate notes		6,047		12,960			19,007		(24	)		18,983
	U.S. government agency securities		8,011		—			8,011		(3	)		8,008
	Commercial paper		3,492		—			3,492		(1	)		3,491
	Total	$	28,075	$	15,805		$	43,880	$	(55	)	$	43,825
	The Company evaluated its investments and determined that there were no other-than-temporary impairments as of June 30, 2014.
	The aggregate amounts of unrealized losses and related fair value of investments with unrealized losses as of June 30, 2014 and December 31, 2013 were as follows:
		Less Than 12 Months to					12 Months or More to					Total at June 30, 2014
		Maturity					Maturity
		Aggregate		Unrealized			Aggregate		Unrealized			Aggregate		Unrealized
		Fair Value		Gain (loss)			Fair Value		Loss			Fair Value		Gain (loss)
	Certificates of deposit	$	11,962	$	(8	)	$	2,632	$	(8	)	$	14,594	$	(16	)
	Corporate notes		18,816		12			—		—			18,816		12
	U.S. government agency securities		8,002		1			—		—			8,002		1
	Commercial paper		3,498		1			—		—			3,498		1
	Total	$	42,278	$	6		$	2,632	$	(8	)	$	44,910	$	(2	)
		Less Than 12 Months to					12 Months or More to					Total at December 31, 2013
		Maturity					Maturity
		Aggregate		Unrealized			Aggregate		Unrealized			Aggregate		Unrealized
		Fair Value		Loss			Fair Value		Loss			Fair Value		Loss
	Certificates of deposit	$	10,507	$	(18	)	$	2,836	$	(9	)	$	13,343	$	(27	)
	Corporate notes		6,039		(8	)		12,944		(16	)		18,983		(24	)
	U.S. government agency securities		8,008		(3	)		—		—			8,008		(3	)
	Commercial paper		3,491		(1	)		—		—			3,491		(1	)
	Total	$	28,045	$	(30	)	$	15,780	$	(25	)	$	43,825	$	(55	)

Fair_Value_Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	6. Fair Value Measurements
	The Company follows ASC 820-10, “Fair Value Measurements and Disclosures,” which among other things, defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows:
		•		Level 1 — Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.
		•		Level 2 — Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life.
		•		Level 3 — Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.
	The following table presents the Company’s fair value hierarchy for assets and liabilities measured at fair value on a recurring basis as of June 30, 2014 and December 31, 2013 (in thousands):
			Fair Value Measurements at June 30, 2014
			Quoted Price in		Significant Other		Significant		Total
			Active Markets		Observable Inputs		Unobservable
			for Identical Assets		(Level 2)		Inputs
			(Level 1)				(Level 3)
	Assets:
	Cash equivalents:
	Money market funds		$	38,013	$	—	$	—	$	38,013
	Total cash equivalents		$	38,013	$	—	$	—	$	38,013
	Available-for-sale securities:
	Short-term:
	Certificates of deposit		$	—	$	11,962	$	—	$	11,962
	Commercial paper			—		3,498		—		3,498
	Corporate notes			—		18,816		—		18,816
	U.S. Government agency securities			—		8,002		—		8,002
	Total short-term investments			—		42,278		—		42,278
	Long-term:
	Certificates of deposit			—		2,632		—		2,632
	Total long-term investments			—		2,632		—		2,632
	Total available-for-sale securities		$	—	$	44,910	$	—	$	44,910
	Liabilities:
	Acquisition-related contingent consideration		$	—	$	—	$	69,456	$	69,456
	Total acquisition-related contingent consideration		$	—	$	—	$	69,456	$	69,456
			Fair Value Measurements at December 31, 2013
			Quoted Price in		Significant Other		Significant		Total
			Active Markets		Observable Inputs		Unobservable
			for Identical Assets		(Level 2)		Inputs
			(Level 1)				(Level 3)
	Assets:
	Cash equivalents:
	Money market funds		$	38,506	$	—	$	—	$	38,506
	Certificates of deposit			—		480		—		480
	Total cash equivalents		$	38,506	$	480	$	—	$	38,986
	Available-for-sale securities:
	Short-term:
	Certificates of deposit		$	—	$	10,507	$	—	$	10,507
	Commercial paper			—		3,491		—		3,491
	Corporate notes			—		6,039		—		6,039
	U.S. Government agency securities			—		8,008		—		8,008
	Total short-term investments			—		28,045		—		28,045
	Long-term:
	Certificates of deposit			—		2,836		—		2,836
	Corporate notes			—		12,944		—		12,944
	Total long-term investments			—		15,780		—		15,780
	Total available-for-sale securities		$	—	$	43,825	$	—	$	43,825
	The following table presents the carrying value and estimated fair value of the Company’s notes payable as of June 30, 2014 and December 31, 2013 (in thousands):
			June 30, 2014
			Carrying		Estimated
			Value		Fair Value
	April and September 2012 Notes		$	5,771	$	6,145
			December 31, 2013
			Carrying		Estimated
			Value		Fair Value
	April and September 2012 Notes		$	8,273	$	8,860
	Valuation Techniques
	Level 1 Inputs
	The Company classifies money market funds, which are valued based on quoted market prices in active markets with no valuation adjustment, as Level 1 assets within the fair value hierarchy.
Level 2 Inputs
Items classified as Level 2 within the valuation hierarchy consist of commercial paper, corporate notes, U.S. government agency securities and certificates of deposit. The Company estimates the fair values of these marketable securities by taking into consideration valuations obtained from third-party pricing sources. These pricing sources utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include market pricing based on real-time trade data for the same or similar securities, issuer credit spreads, benchmark yields, and other observable inputs. The Company validates the prices provided by our third-party pricing sources by understanding the models used, obtaining market values from other pricing sources and analyzing pricing data in certain instances.
Level 3 Inputs
Notes Payable
The Company has determined that its notes payable would be classified as a Level 3 item in the fair value hierarchy. The fair value of these notes is based on the present value of expected future cash flows and assumptions about current interest rates and the credit worthiness of the Company.
Acquisition-related Contingent Consideration and Liabilities
In connection with the acquisition of Andromeda, the Company may be required to pay future consideration that is contingent upon the achievement of specified development, regulatory approval or sales-based milestone events. The Company estimates the fair value of the contingent consideration liabilities on the acquisition date and each reporting period thereafter using a probability-weighted income approach, which reflects the probability and timing of future payments. This fair value measurement is based on significant Level 3 inputs such as the anticipated timelines and probability of achieving development, regulatory approval or sales-based milestone events and projected revenues. The resulting probability-weighted cash flows are discounted using estimated discount rate that commensurate with the risks of the expected cash flows attributable to the various milestones.
Each reporting period thereafter, the Company revalues these obligations by performing a review of the assumptions listed above and record increases or decreases in the fair value of these contingent consideration obligations in changes in fair value of contingent consideration expenses within the condensed consolidated statements of operations until such time that the related product candidate receives marketing approval. In the absence of any significant changes in key assumptions, the quarterly determination of fair values of these contingent consideration obligations would primarily reflect the passage of time.
Updates to assumptions could have a significant impact on our results of operations in any given period and actual results may differ from estimates. For example, significant increases in the probability of achieving a milestone or projected revenues would result in a significantly higher fair value measurement while significant decreases in the estimated probability of achieving a milestone or projected revenues would result in a significantly lower fair value measurement. Significant increases in the discount rate or in the anticipated timelines would result in a significantly lower fair value measurement while significant decreases in the discount rate or anticipated timelines would result in a significantly higher fair value measurement.
The following table provides a rollforward of acquisition-related contingent consideration, which is recorded in our condensed consolidated balance sheets (in thousands):
		Amount
Beginning balance as of January 1, 2014		$	—
Fair value on date of acquisition			68,961
Net changes in valuation			495
Fair value as of June 30, 2014		$	69,456

Inventories

Inventories	6 Months Ended
	Jun. 30, 2014
Inventory Disclosure [Abstract]	'
Inventories	'
	7. Inventories
	The following table represents the components of net inventories (in thousands):
		June 30,		December 31,
		2014		2013
	Raw Materials	$	1,416	$	697
	Work-in-process		46		—
	Finished goods		1,445		2,816
	Total	$	2,907	$	3,513
	On May 31, 2013, the Company acquired BUPHENYL from Ucyclyd. As part of the acquisition, the Company purchased inventories from Ucyclyd and the Company recorded these inventories at fair value in the amount of $3.9 million on the Acquisition Date. As of March 31, 2014, the entire fair value of acquired BUPHENYL inventory has been charged to expenses, primarily cost of sales.

Property_and_Equipment

Property and Equipment	6 Months Ended
	Jun. 30, 2014
Property Plant And Equipment [Abstract]	'
Property and Equipment	'
	8. Property and Equipment
	The following table represents the components of property and equipment (in thousands):
		June 30,			December 31,
		2014			2013
	Computers and Software	$	931		$	563
	Furniture and Fixtures		320			320
	Office Equipment		53			53
	Capital work in progress		209			264
			1,513			1,200
	Less: Accumulated depreciation		(457	)		(264	)
	Total property and equipment, net	$	1,056		$	936
	Depreciation expense for the three and six months ended June 30, 2014 was $0.1 million and $0.2 million, respectively. Depreciation expense for the three and six months ended June 30, 2013 was $32,000 and $0.1 million, respectively.

Intangible_Assets_and_Goodwill

Intangible Assets and Goodwill	6 Months Ended
	Jun. 30, 2014
Goodwill And Intangible Assets Disclosure [Abstract]	'
Intangible Assets and Goodwill	'
	9. Intangible Assets and Goodwill
	Finite lived intangible asset
	In May 2013, the Company acquired BUPHENYL and as part of this transaction, the Company recognized $16.5 million of an intangible asset relating to BUPHENYL product rights. The intangible asset is amortized over the estimated useful life using the economic use method, which reflects the pattern that the economic benefit of the intangible asset is consumed as revenue is generated. The pattern of consumption of the economic benefit is estimated using the future projected cash flow of the intangible asset. The Company estimated the useful life of the BUPHENYL product rights to be 10 years. The weighted average life remaining as of June 30, 2014 is 8.5 years.
	Intangible asset amortization expense was $1.0 million and $0.3 million for the three months ended June 30, 2014 and 2013, respectively. Intangible asset amortization expense was $2.0 million and $0.3 million for the six months ended June 30, 2014 and 2013, respectively.
	Estimated aggregate amortization expense for each of the five succeeding years ending December 31 is as follows (in thousands):
		2014		2015		2016		2017		2018
	Amortization expense	$	4,053	$	3,294	$	1,157	$	1,048	$	1,012
	Indefinite lived intangible asset and Goodwill
	In June 2014, the Company acquired Andromeda and as part of this transaction, the Company recognized $135.7 million of an intangible asset relating to purchased IPR&D and $3.8 million of goodwill. The intangible asset related to the IPR&D projects is considered to be an indefinite-lived asset until the completion or abandonment of the associated research and development efforts. The Company does not amortize goodwill and intangible asset with indefinite useful lives. The Company tests goodwill and its indefinite-lived intangible asset for impairment on an annual basis and in between annual tests if they become aware of any events or changes that would indicate a reduction in the fair value of the assets below their carrying amounts.

Accrued_Liabilities

Accrued Liabilities	6 Months Ended
	Jun. 30, 2014
Payables And Accruals [Abstract]	'
Accrued Liabilities	'
	10. Accrued Liabilities
	The following table represents the components of accrued liabilities (in thousands):
		June 30,		December 31,
		2014		2013
	Clinical trial expenses	$	226	$	246
	Payroll and related expenses		2,780		4,278
	Gross to net sales accruals		7,991		5,235
	Royalty payable		2,525		1,154
	Legal accrual		368		45
	Taxes payable		629		326
	Interest payable		40		61
	Liability with respect to acquisition of Andromeda		4,615		—
	Other liabilities		12,161		842
	Total	$	31,335	$	12,187
	For the period ended June 30, 2014, Other liabilities includes an amount of $10.9 million relating to acquisition related consideration which was subsequently paid in July 2014.

Notes_Payable

Notes Payable	6 Months Ended
	Jun. 30, 2014
Debt Disclosure [Abstract]	'
Notes Payable	'
	11. Notes Payable
	In April 2012, the Company borrowed $10.0 million (the “April 2012 Notes”) pursuant to a loan and security agreement (the “Loan Agreement”) with Silicon Valley Bank and Leader Lending, LLC—Series B (the “Lenders”). The loan carries an interest rate of 8.88%, with interest only payments for the period of 9 months from May 1, 2012. The loan is then payable in equal monthly principal payments plus interest over a period of 27 months from February 1, 2013. In connection with the Loan Agreement, the Company granted a security interest in all of its assets, except intellectual property. The Company’s obligations to the Lenders include restrictions on borrowing, asset transfers, placing liens or security interest on its assets including the Company’s intellectual property, mergers and acquisitions and distributions to stockholders. The Loan Agreement also requires the Company to provide the Lenders monthly financials and compliance certificate within 30 days of each month end, annual audited financials within 180 days of each fiscal year-end and annual approved financial projections. The Company issued warrants to the Lenders to purchase a total of 75,974 shares of common stock with an exercise price of $4.08 per share. The Loan Agreement requires immediate repayment of amounts outstanding upon an event of default, as defined in the Loan Agreement, which includes events such as a payment default, a covenant default or the occurrence of a material adverse change, as defined in the Loan Agreement. In addition, a final payment equal to 6.5% of the principal loan amount is due on the earlier of (i) maturity date, (ii) prepayment of the loan or (iii) an event of default.
	Pursuant to the terms of the Loan Agreement, once the Company raised at least $30.0 million from the sale of equity securities or subordinated debt, the Lenders agreed to lend the Company a one-time single loan in the amount of $2.5 million (the “Bank Term Loan”). In September 2012, the Company borrowed an additional $2.5 million (the “September 2012 Note”) from Silicon Valley Bank pursuant to the terms of the Bank Term Loan. In addition, the Company issued warrants to Silicon Valley Bank to purchase a total of 8,408 shares of common stock with an exercise price of $5.05 per share. A final payment equal to 6.5% of the principal loan amount is due on the earlier of (i) maturity date, (ii) prepayment of the loan or (iii) an event of default. The principal amount outstanding under the Bank Term Loan accrues interest at a per annum rate equal to the greater of (i) 8.88% and (ii) the Treasury Rate, as defined in the Loan Agreement, on the date the loan is funded plus 8.50%, with interest only payments for the period of 9 months from the date the loan is funded. The loan is then payable in equal monthly principal payments plus interest over a period of 27 months from the date the loan is funded.
	Amortization of debt discount for the three and six month periods ended June 30, 2014 and 2013 was $0.1 million and $0.3 million, respectively.
	As discussed in Note 19, the outstanding notes payable were paid in full on July 18, 2014.

Warrants

Warrants	6 Months Ended
	Jun. 30, 2014
Text Block [Abstract]	'
Warrants	'
	12. Warrants
	In connection with a Loan and Security Agreement entered into in October 2007, the Company issued warrants to purchase 274 shares of Series B convertible preferred stock. In June 2009, as part of the recapitalization, these warrants were converted into warrants to purchase shares of common stock. The warrants are exercisable at $1,913.05 per share and will expire in October 2017 (the “October 2007 common stock warrants”).
	The following table summarizes the outstanding warrants and the corresponding exercise price as of March 31, 2014 and December 31, 2013:
		Number of Shares Outstanding
		June 30,		December 31,		Per Share
		2014		2013		Exercise Price
	October 2007 common stock warrants		274		274	$	1,913.05
	Total		274		274

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	13. Commitments and Contingencies
	Contingencies
	In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for general indemnifications. The Company’s exposure under these agreements is unknown because it involves claims that may be made against the Company in the future, but have not yet been made. Further, the Company may be subject to certain contingent liabilities that arise in the ordinary course of its business activities. The Company accrues a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated.
	In accordance with the Company’s amended and restated certificate of incorporation and amended and restated bylaws, the Company has indemnification obligations to its officers and directors for certain events or occurrences, subject to certain limits, while they are serving at the Company’s request in such capacity. There have been no claims to date and the Company has a director and officer insurance policy that may enable it to recover a portion of any amounts paid for future claims.
	The Company is contingently committed for development milestone payments as well as sales-related milestone payments and royalties relating to potential future product sales under the restated collaboration agreement and purchase agreement with Ucyclyd (Note 3). The amount, timing and likelihood of these payments are unknown as they are dependent on the occurrence of future events that may or may not occur, including approval by the FDA of GPB for HE.
	In addition to above, due to the acquisition of Andromeda (Note 4), the Company may be liable to pay the former shareholders of Andromeda and other third parties for potential regulatory and milestone payments and royalties relating to future product sales and has recorded an acquisition related contingent consideration and contingent liability on its condensed consolidated balance sheets. The amount, timing and likelihood of these payments are unknown as they are dependent on the occurrence of future events that may or may not occur.
	Other Matters
	From time to time, the Company is a party to or otherwise involved in legal proceedings, claims and government inspections and other legal matters arising in the ordinary course of business or otherwise. On March 17, 2014, the Company received notification of a Paragraph IV certification from the generic drug manufacturer Par Pharmaceutical, Inc. (“Par”) that it had filed an Abbreviated New Drug Application with the FDA seeking approval for a generic version of RAVICTI Oral Liquid. The Paragraph IV certification alleges that certain of the Company’s patents are invalid and/or will not be infringed by Par’s manufacture, use or sale of the product for which the ANDA was submitted. The Company filed suit against Par on April 23, 2014 to protect its patents and to obtain a stay of the FDA’s approval of Par’s ANDA. On July 22, 2014, Par filed a motion to dismiss for lack of personal jurisdiction, or in the alternative, a motion to transfer the case to the Southern District of New York.

Equity_Incentive_Plan_and_Stoc

Equity Incentive Plan and Stock-Based Compensation	6 Months Ended
	Jun. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Equity Incentive Plan and Stock-Based Compensation	'
	14. Equity Incentive Plan and Stock-Based Compensation
	Equity Incentive Plans
	In April 2012, the board of directors of the Company adopted the 2012 Omnibus Incentive Plan (the “2012 Plan”). The Company’s stockholders approved the 2012 Plan in July 2012. The 2012 Plan provides for the grant of stock options, stock appreciation rights, restricted stock, unrestricted stock, stock units, dividend equivalent rights, other equity-based awards and cash bonus awards. The 2012 Plan became effective on July 25, 2012
	Effective January 1, 2014, pursuant to the provisions of the 2012 Plan providing for an annual automatic increase in the number of shares of common stock reserved for issuance under the plan, the shares available for issuance under the 2012 Plan increased by 805,485 shares. As of June 30, 2014, the Company had 793,351 shares of common stock available for issuance and 1,672,768 options, 126,705 restricted stock units (“RSU’s”) and 8,988 performance stock units (“PSU’s”) were outstanding under the 2012 Plan. During the six months ended June 30, 2014, the board of directors approved the grants of 620,769 stock options at exercise prices in the range of $24.64 - $31.00, 115,455 RSU’s and 8,988 PSU’s under the 2012 Plan.
	On July 25, 2012, the effective date of the 2012 Plan, the 2006 Equity Incentive Plan was frozen and no additional awards will be made under the 2006 Plan. Any shares remaining available for future grant were allocated to the 2012 Plan and any shares underlying outstanding options that terminate by expiration, forfeiture, cancellation, or otherwise without issuance of such shares, will be allocated to the 2012 Plan. As of June 30, 2014, there were 1,441,158 options outstanding under the 2006 Plan.
	In March 2014, the Company recorded an expense of $0.1 million related to the modification of certain stock options.
	Stock-Based Compensation
	The Company estimates the fair value of stock options using the Black-Scholes option valuation model. The fair value of employee stock options and RSU’s is being amortized on a straight-line basis over the requisite service period of the awards.
	Total stock-based compensation expense related to options and awards granted was allocated as follows (in thousands):
		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2014		2013		2014		2013
	Cost of sales	$	40	$	2	$	42	$	3
	Research and development		278		143		425		235
	Selling general and administrative		1,576		1,108		2,795		1,521
	Total	$	1,894	$	1,253	$	3,262	$	1,759
	Stock-based compensation of $10,000 and $18,000 was capitalized into inventories for the three and six months ended June 30, 2014. Stock-based compensation of $17,000 and $26,000 was capitalized into inventories for the three and six months ended June 30, 2013. Capitalized stock-based compensation is recognized as cost of sales when the related product is sold. Allocations to research and development, selling, general and administrative expenses are based upon the department to which the associated employee reported.

Income_Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	15. Income Taxes
	At December 31, 2013, the Company had U.S. net operating loss carryforwards of approximately $72.5 million and $112.5 million available to reduce future taxable income, if any, for both federal and California state income tax purposes, respectively. The net operating loss carryforwards will begin to expire in 2026 for federal and 2016 for state purposes. At June 12, 2014, the Company had Israeli net operating loss carryforwards of $61.6 million which do not expire.
	GPB was granted orphan drug designation in 2009 by the FDA for the maintenance treatment of patients with UCD and for the intermittent or chronic treatment of patients with any grade of HE. The orphan drug designation allows the Company to claim increased federal tax credits for its research and development activities. The Company had $18.0 million of federal credit carryforwards of which $17.4 million relates to Orphan Drug Credit claims for 2009 through 2013. The Company has claimed tax credits for its research and development activities in Israel and has $3.0 million of credit carryforwards.
	The Company intends to continue maintaining a full valuation allowance on its deferred tax assets until there is sufficient evidence to support the reversal of all or some portion of these allowances. However, considering the Company’s current assessment of income from potential future sales, there is a reasonable possibility that, within the next year, sufficient positive evidence may become available to reach a conclusion that a significant portion of the valuation allowance will no longer be needed. As such, the Company may release a significant portion of its valuation allowance against its deferred tax assets within the next 12 months. This release would result in the recognition of certain deferred tax assets and a decrease to income tax expense for the period such release is recorded.
	Income tax benefit was $2.1 million and $2.0 million for the three and six months ended June 30, 2014, respectively. Expected taxable income in 2014 in the U.S. will largely be offset by federal and state net operating losses and credits. Expected losses in 2014 in Israel will create additional net operating losses, which are currently benefited as there is sufficient future taxable income to offset them.
	There was no interest or penalties accrued through June 30, 2014. The Company’s policy is to recognize any related interest or penalties in income tax expense. The Company is subject to potential examination by tax authorities for tax years ended 2006 through the current period include the United States federal and California jurisdictions and for the years 2010 through the current period in Israel. The Company is not currently under income tax examinations by any tax authorities.

Net_Income_per_Share_of_Common

Net Income per Share of Common Stock	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Net Income per Share of Common Stock	'
	16. Net Income per Share of Common Stock
	The following table sets forth the computation of basic and diluted net income per share of common stock for the periods indicated (in thousands, except share and per share amounts):
		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2014		2013		2014		2013
	Net income per share
	Numerator:
	Net income	$	17,479	$	25,022	$	18,735	$	16,047
	Denominator:
	Weighted-average number of common shares outstanding – basic		20,335,618		20,050,987		20,263,803		18,716,332
	Dilutive effect of stock-options and awards		1,278,378		1,307,288		1,308,913		1,261,757
	Weighted average common shares outstanding – dilutive		21,613,996		21,358,275		21,572,716		19,978,089
	Net income per share:
	Basic	$	0.86	$	1.25	$	0.92	$	0.86
	Diluted	$	0.81	$	1.17	$	0.87	$	0.8
	The following outstanding potentially dilutive securities were excluded from the computation of diluted net income per share, as the effect of including them would have been antidilutive:
		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2014		2013		2014		2013
	Stock options		1,366,021		675,969		1,365,873		380,745
	October 2007, April 2008 and 2012 common stock warrants		274		274		274		274
	Total		1,366,295		676,243		1,366,147		381,019

Related_Party_Transaction

Related Party Transaction	6 Months Ended
	Jun. 30, 2014
Related Party Transactions [Abstract]	'
Related Party Transaction	'
	17. Related Party Transaction
	As part of the Company’s acquisition of BUPHENYL, the Company assumed the existing BUPHENYL distributor’s agreements, including the distribution agreement with Swedish Orphan Biovitrum AB (“SOBI”). Additionally, in the third quarter of 2013 SOBI was granted exclusive rights by the Company to distribute RAVICTI on a named patient basis for the chronic treatment of UCD in various territories in the Middle East. SOBI’s chairman, Bo Jesper Hansen, is a member of the Company’s Board of Directors. During the three and six months ended June 30, 2014 the Company recognized $1.9 million and $2.2 million, respectively, from sales to SOBI. During the first half of 2013 there were no revenues recognized from SOBI. As of June 30, 2014, trade receivable from SOBI amounted to $1.0 million.

Segment_Reporting

Segment Reporting	6 Months Ended
	Jun. 30, 2014
Segment Reporting [Abstract]	'
Segment Reporting	'
	18. Segment Reporting
	The Company operates as one operating segment and uses one measurement of profitability to manage its business.
	Net product revenue for RAVICTI and BUPHENYL for the three and six months ended June 30, 2014 and 2013 are as follows (in thousands):
		Three Months Ended					Six Months Ended
		June 30,					June 30,
		2014			2013		2014			2013
	RAVICTI		31,553			6,210		47,069			6,993
	BUPHENYL		5,742			1,095		9,708			1,095
	Co-payment assistance		(200	)		—		(200	)		—
	Total		37,095			7,305		56,577			8,088
	Net product revenue for RAVICTI and BUPHENYL by geographic region are as follows (in thousands):
		Three Months Ended					Six Months Ended
		June 30,					June 30,
		2014			2013		2014			2013
	United States		34,056			7,223		52,052			8,006
	Canada		983			—		1,783			—
	Rest of the world		2,056			82		2,742			82
	Total		37,095			7,305		56,577			8,088
	Long lived assets consist of property and equipment which at June 30, 2014 and December 31, 2013 are primarily in the U.S.

Subsequent_Events

Subsequent Events	6 Months Ended
	Jun. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	19. Subsequent Events
	On July 18, 2014, the Company entered into a Loan and Security Agreement with Silicon Valley Bank, providing for two tranches of term loans of up to $16.0 million (the “Term Loans”) and a revolving credit line of up to $5.0 million (the “Revolving Loans” and together with the Term Loans, the “Loans”). The Company drew down both tranches of the Term Loans at closing, of which approximately $5.8 million was used to pre-pay the Company’s existing notes payable (as discussed in Note 11). The actual amount of Revolving Loans that are available from time to time under the Loan and Security Agreement is limited to a borrowing base amount that is determined according to, among other things, a percentage of the value of eligible accounts.
	The Company’s obligations under the Loan and Security Agreement are collateralized by a first priority security interest in substantially all of the Company’s assets, excluding its intellectual property. The Company has also agreed not to pledge or otherwise encumber its intellectual property assets, except that the Company may grant licenses of its intellectual property as set forth in the Loan and Security Agreement.
	The Company is required to pay interest only for the first 18 months of the Term Loans, followed by 30 equal monthly payments of interest and principal. The Term Loans will mature on June 30, 2018. The Revolving Loans will mature on July 18, 2017. The Loan and Security Agreement provides for an interest rate of 4.0% per year on the Term Loans and the prime rate plus 0.75% per year on the Revolving Loans, with a minimum interest requirement on the Revolving Loans. Upon the maturity date of the Term Loans, a final payment fee of 6.75% of the original principal amount of such Term Loans (the “Final Payment”) will be due.
	The Loan and Security Agreement contains customary representations, warranties and covenants (including the requirement to meet one of two financial covenants) by the Company, as well as customary events of default and indemnification obligations of the Company. Upon an event of default, after any applicable grace or cure period, all amounts owed under the Loan Agreement may be declared due and payable, including the original principal amount of the Loans, the accrued but unpaid interest thereon, the Final Payment and the prepayment fee.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and on a basis consistent with the annual consolidated financial statements, and in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the periods presented. These interim financial results are not necessarily indicative of the results to be expected for the year ending December 31, 2014, or for any other future annual or interim period. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013.
Principles of Consolidation	'
	Principles of Consolidation
	The consolidated financial statements include the Company’s accounts and those of its wholly-owned subsidiaries: Hyperion Therapeutics Ltd., Hyperion Therapeutics Ireland Holding Ltd., Hyperion Therapeutics Ireland Operating Ltd., Hyperion Therapeutics Israel Holding Corp. Ltd., and Andromeda Biotech Ltd. All intercompany accounts and transactions have been eliminated.
Use of Estimates	'
	Use of Estimates
	The preparation of the interim condensed consolidated financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates, including those related to fair value of assets and liabilities, goodwill and intangible assets valuation, acquisition-related contingent consideration, acquisition related contingent liability, stock-based compensation expense, income taxes, revenue recognition and product sales allowances. Management bases its estimates on historical experience or on various other assumptions, including information received from its service providers, which it believes to be reasonable under the circumstances. Actual results could differ from those estimates.
Concentration of Credit Risk and Significant Customers	'
	Concentration of Credit Risk and Significant Customers
	The Company’s cash and cash equivalents and investments are maintained with financial institutions located in and outside the United States. Deposits in these institutions may exceed the amount of insurance provided on such deposits. The Company has not recognized any losses from credit risks during the periods presented and management does not believe that the Company is exposed to significant credit risk from its cash and cash equivalents or investments.
	The Company is also subject to credit risk from its accounts receivables related to its product sales. The Company monitors its exposure within accounts receivable and records a reserve against uncollectible accounts receivable as necessary. The Company extends credit to a specialty distributor in the United States and to international distributors, pharmacies and hospitals outside the United States. Customer creditworthiness is monitored and collateral is not required. As of June 30, 2014, there were no credit losses on the Company’s accounts receivable. As of June 30, 2014, the specialty distributor in the United States accounted for 90% of accounts receivable balance and one international distributor accounted for 5% of the accounts receivable balance.
	The specialty distributor accounted for 92% of net product revenue for the three and six months ended June 30, 2014. One international distributor accounted for 5.2% and 3.9% of net product revenue for the three and six months ended June 30, 2014.
Fair Value of Financial Instruments	'
	Fair Value of Financial Instruments
	The Company measures certain financial assets and liabilities at fair value based on the exchange price that would be received for an asset or paid for to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants. The carrying amounts of the Company’s financial instruments, including cash equivalents, short-term investments, accounts payable, and accrued liabilities, approximate fair value due to their short maturities. The carrying amounts of long-term investments, the acquisition-related contingent consideration represent their estimated fair values. The Company’s debt obligations are carried at historical cost, which approximates fair value.
Business Combinations	'
	Business Combinations
	The Company allocates the purchase price of an acquired business to the tangible and intangible assets acquired and liabilities assumed based upon their estimated fair values on the acquisition date. Any excess of the purchase price over the fair value of the net assets acquired is recorded as goodwill. Acquired in-process research and development (“IPR&D”) is recognized at fair value and initially characterized as an indefinite-lived intangible asset, irrespective of whether the acquired IPR&D has an alternative future use. The purchase price allocation process requires management to make significant estimates and assumptions, especially at the acquisition date with respect to intangible assets. Direct transaction costs associated with the business combination are expensed as incurred.
Accounts Receivable	'
	Accounts Receivable
	Trade accounts receivable are recorded net of product sales allowances for prompt-payment discounts, chargebacks, and doubtful accounts. Estimates for chargebacks and prompt-payment discounts are based on contractual terms, historical trends and our expectations regarding the utilization rates for these programs.
Inventories	'
	Inventories
	Inventories are stated at the lower of cost or market value with cost determined under the first-in-first-out (FIFO) cost method and consists of raw materials, work-in-progress and finished goods. Costs to be capitalized as inventories include third party manufacturing costs, associated compensation related costs of personnel indirectly involved in the manufacturing process and other overhead costs such as ancillary supplies. Subsequent to FDA approval of RAVICTI on February 1, 2013, the Company began capitalizing RAVICTI inventories as the related costs were expected to be recoverable through the commercialization of the product. Costs incurred prior to the FDA approval of RAVICTI have been recorded as research and development expense in the condensed consolidated statements of operations. If information becomes available that suggest that inventories may not be realizable, the Company may be required to expense a portion or all of the previously capitalized inventories.
	Products that have been approved by the FDA or other regulatory authorities, such as RAVICTI, are also used in clinical programs, to assess the safety and efficacy of the products for usage in diseases that have not been approved by the FDA or other regulatory authorities. The form of RAVICTI utilized for both commercial and clinical programs is identical and, as a result, the inventory has an “alternative future use” as defined in authoritative guidance. Raw materials and purchased drug product associated with clinical development programs are included in inventory and charged to research and development expense when the product enters the research and development process and no longer can be used for commercial purposes and, therefore, does not have an “alternative future use”.
	On May 31, 2013, the Company acquired BUPHENYL from Ucyclyd. The Company recorded the acquired BUPHENYL inventories at fair value in the amount of $3.9 million on the acquisition date. As of March 31, 2014, the entire fair value of acquired BUPHENYL inventory has been charged to expenses, primarily cost of sales.
Intangible Assets	'
	Intangible Assets
	Intangible assets are recorded at acquisition cost less accumulated amortization and impairment. Intangible asset with finite lives are amortized over their estimated useful life using the economic use method, which reflects the pattern that the economic benefits of the intangible asset are consumed as revenue is generated. The pattern of consumption of the economic benefits is estimated using the future projected cash flows of the intangible asset.
IPR&D	'
	IPR&D
	The fair value of IPR&D acquired through a business combination is capitalized as an indefinite-lived intangible asset until the completion or abandonment of the related research and development activities. When the related research and development is completed, the asset will be assigned a useful life and amortized.
	The fair value of an IPR&D intangible asset is determined using an income approach. This approach starts with a forecast of the net cash flows expected to be generated by the asset over its estimated useful life. The net cash flows reflect the asset’s stage of completion, the probability of technical success, the projected costs to complete, expected market competition, and an assessment of the asset’s life-cycle. The net cash flows are then adjusted to present value by applying an appropriate discount rate that reflects the risk factors associated with the cash flow streams.
Goodwill	'
	Goodwill
	Goodwill represents the excess of the purchase price of acquired businesses over the estimated fair value of the identifiable net assets acquired. Goodwill is not amortized but is tested for impairment at least annually at the reporting unit level or more frequently if events or changes in circumstances indicate that the asset might be impaired. A reporting unit is the same as, or one level below, an operating segment.
Impairment of Long-lived Assets	'
	Impairment of Long-lived Assets
	The Company reviews its property and equipment, intangible assets subject to amortization and other long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset class may not be recoverable. Indicators of potential impairment include: an adverse change in legal factors or in the business climate that could affect the value of the asset; an adverse change in the extent or manner in which the asset is used or is expected to be used, or in its physical condition; and current or forecasted operating or cash flow losses that demonstrate continuing losses associated with the use of the asset. If indicators of impairment are present, the asset is tested for recoverability by comparing the carrying value of the asset to the related estimated undiscounted future cash flows expected to be derived from the asset. If the expected cash flows are less than the carrying value of the asset, then the asset is considered to be impaired and its carrying value is written down to fair value, based on the related estimated discounted future cash flows.
	Indefinite-lived intangible assets, including acquired IPR&D, are tested for impairment annually or more frequently if events or changes in circumstances between annual tests indicate that the asset may be impaired. Impairment losses on indefinite-lived intangible assets are recognized based solely on a comparison of the fair value of the asset to its carrying value, without consideration of any recoverability
Acquisition-Related Contingent Consideration	'
	Acquisition-Related Contingent Consideration
	Acquisition-related contingent consideration, which consists primarily of potential milestone payments and royalty obligations, is recorded in the consolidated balance sheets at its acquisition date estimated fair value, in accordance with the acquisition method of accounting. The fair value of the acquisition-related contingent consideration is remeasured each reporting period, with changes in fair value recorded in the consolidated statements of operations. Changes in the fair value of the acquisition-related contingent consideration obligations result from several factors including changes in discount periods and rates, changes in the timing and amount of revenue estimates and changes in probability assumptions with respect to the likelihood of achieving specified milestone criteria. The fair value measurement is based on significant inputs not observable in the market and thus represents a Level 3 measurement as defined in fair value measurement accounting
Revenue Recognition	'
	Revenue Recognition
	The Company recognizes revenue in accordance with ASC 605, Revenue Recognition, when the following criteria have been met: persuasive evidence of an arrangement exists; delivery has occurred and risk of loss has passed; the seller’s price to the buyer is fixed or determinable and collectability is reasonably assured. The Company determines that persuasive evidence of an arrangement exists based on written contracts that defined the terms of the arrangements. In addition, the Company determines that services have been delivered in accordance with the arrangement. The Company assesses whether the fee is fixed or determinable based on the payment terms associated with the transaction and whether the sales price is subject to refund or adjustment. The Company assesses collectability based primarily on the customer’s payment history and on the creditworthiness of the customer.
	Product Revenue, net: The Company’s product revenue represents sales of RAVICTI and BUPHENYL which are recognized once all four revenue recognition criteria described above are met. The Company recognizes revenue net of product sales allowances. Product shipping and handling costs are included in cost of sales. Prior to June 2014, revenue from the sale of RAVICTI was recognized based on the amount of product sold through to the end user consumer. Starting June 2014, the Company could reasonably estimate and determine sales allowances, therefore the Company began recognizing RAVICTI revenue at the point of sale to the specialty distributor, which resulted in the one-time non-recurring recognition of an additional $8.6 million in net revenues.
	Product Sales Allowances: The Company establishes reserves for prompt-payment discounts, government and commercial rebates, product returns and chargebacks. Allowances relate to prompt-payment discounts and are recorded at the time of revenue recognition, resulting in a reduction in product sales revenue and a decrease in trade accounts receivables. Accruals related to government rebates, product returns and other applicable allowances such as distributor fees are recognized at the time of revenue recognition, resulting in a reduction in product sales and an increase in accrued expenses or a reduction in the related accounts receivable.
		•	Prompt-payment discounts: The specialty distributor and specialty pharmacies are offered prompt payment discounts. The Company expects the specialty distributor and specialty pharmacies will earn prompt payment discounts and, therefore deduct the full amount of these discounts from total product sales when revenues are recognized. The Company records prompt-payment discounts as allowances against accounts receivable on the condensed consolidated balance sheet.
		•	Rebates: Allowances for rebates include mandated discounts under the Medicaid Drug Rebate Program. Rebate amounts are based upon contractual agreements or legal requirements with public sector (e.g. Medicaid) benefit providers. Rebates are amounts owed after the final dispensing of the product to a benefit plan participant and are based upon contractual agreements or legal requirements with public sector benefit providers. The allowance for rebates is based on statutory discount rates and expected utilization. The Company estimates for expected utilization of rebates based on historical data and data received from the specialty pharmacies. Rebates are generally invoiced and paid in arrears so that the accrual balance consists of an estimate of the amount expected to be incurred for the current quarter’s activity, plus an accrual balance for known prior quarter’s unpaid rebates. If actual future rebates vary from estimates, the Company may need to adjust prior period accruals, which would affect revenue in the period of adjustment. Allowance for rebates are recorded in accrued liabilities on the condensed consolidated balance sheet.
		•	Chargebacks: Chargebacks are discounts that occur when contracted customers purchase directly from a specialty distributor. Contracted customers, which primarily consist of Public Health Service institutions, non-profit clinics, and Federal government entities purchasing via the Federal Supply Schedule, generally purchase the product at a discounted price. The specialty distributor, in turn, charges back to the Company the difference between the price initially paid by the specialty distributor and the discounted price paid to the specialty distributor by the customer. The allowance for chargebacks is based on historical sales data and known sales to contracted customers.
		•	Medicare Part D Coverage Gap: Medicare Part D prescription drug benefit mandates manufacturers to fund 50% of the Medicare Part D insurance coverage gap for prescription drugs sold to eligible patients. The Company estimates for the expected Medicare Part D coverage gap are based on historical invoices received and in part from data received from the specialty pharmacies. Funding of the coverage gap is generally invoiced and paid in arrears so that the accrual balance consists of an estimate of the amount expected to be incurred for the current quarter’s activity, plus an accrual balance for known prior quarters. If actual future funding varies from estimates, the Company may need to adjust prior period accruals, which would affect revenue in the period of adjustment. Estimates of the Medicare Part D coverage gap are recorded in accrued liabilities on the condensed consolidated balance sheet.
		•	Distribution Service Fees: The Company has a written contract with the specialty distributor that includes terms for distribution-related fees. Distributor fees are calculated at percentage of gross sales based upon agreed contracted rate. The Company accrues distributor fees at the time of the revenue recognition, resulting in reduction of product sales revenue and the recording of accrued liabilities on the condensed consolidated balance sheets. The Company records distribution and other fees paid to its customers as a reduction of revenue, unless it receives an identifiable and separate benefit for the consideration and it can reasonably estimate the fair value of the benefit received. If both conditions are met, the Company records the consideration paid to the customer as an operating expense. These costs are typically known at the time of sale.
		•	Product Returns: Consistent with industry practice, the Company generally offers customers a limited right to return. The Company accepts returns of products from patients resulting from breakage as defined within the Company’s returns policy. Additionally, the Company considers several other factors in the estimation process including the expiration dates of product shipped, third party data in monitoring channel inventory levels, shelf life of the product, prescription trends and other relevant factors. Provisions for estimated product returns are recorded as accrued liabilities on the condensed consolidated balance sheet.
	Co-payment assistance: The Company provides a cash donation to a non-profit third party organization which supports patients, who have commercial insurance and meet certain financial eligibility requirements, with co-payment assistance and travel costs. The amount of co-payment assistance is accounted for by the Company as a reduction of revenues.
Cost of sales	'
	Cost of sales
	Cost of sales includes third-party manufacturing cost of products sold, royalty fees, and other indirect costs related to personnel compensation, shipping and supplies. Costs incurred prior to FDA approval of RAVICTI have been recorded as research and development expense in the Company’s condensed consolidated statement of operations. The Company expects that cost of RAVICTI sales as a percentage of revenue will increase in future periods as product manufactured prior to FDA approval, and therefore fully expensed, is utilized.
	Cost of BUPHENYL sales as a percentage of revenue was higher and not indicative of cost of sales in future periods due to the recording of the step-up value on BUPHENYL inventories acquired from Ucyclyd which is expensed to cost of sales as that inventory is sold. As of March 31, 2014, the entire fair value of acquired BUPHENYL inventory has been charged to expense, primarily cost of sales.
Acquisition-Related Contingent Liability	'
	Acquisition-Related Contingent Liability
	Acquisition-related contingent liability, which consists primarily of potential milestone payments and royalty obligations, and potential payments to certain employees of Andromeda is recorded in the condensed consolidated balance sheets at its acquisition date estimated fair value. The Company reassesses the probability and estimates associated with the contingent liability at each reporting period. For liability payable to third parties, any increase in the liability is recorded in the condensed consolidated statements of operations. For liabilities payable to employees, the Company accounts for the liability in accordance with Financial Accounting Stands Board (“FASB”) Accounting Stand Codification (“ASC”) 450 Contingencies.
Stock-Based Compensation	'
	Stock-Based Compensation
	The Company accounts for stock-based employee compensation arrangements in accordance with provisions of ASC 718, Compensation — Stock Compensation. ASC 718 requires the recognition of compensation expense, using a fair-value based method, for costs related to all share-based payments including stock options. ASC 718 requires companies to estimate the fair value of share-based payment awards on the date of grant using an option-pricing model. The Company calculates the fair value of stock options using the Black-Scholes method and expenses using the straight-line attribution approach.
Income Taxes	'
	Income Taxes
	The Company accounts for income taxes under the liability method. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized.
	The Company accounts for uncertain tax positions in accordance with ASC 740-10, Accounting for Uncertainty in Income Taxes. The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized tax benefit is still appropriate. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available.
Foreign Currency Translations	'
	Foreign Currency Translations
	Operations in non-U.S. entities are recorded in the functional currency of each entity. For financial reporting purposes, the functional currency of an entity is determined by a review of the source of an entity’s most predominant cash flows. The reporting and functional current of the Company and its subsidiaries is the U.S. dollar.
	Gains and losses resulting from foreign currency transactions are translated at the weighted average rate of exchange prevailing during the period. Any monetary asset or liability denominated in foreign currency and is translated at the rate of exchange in effect on the balance sheet date. Any gains and losses resulting from foreign currency translations are included in other income (expense)-net in the condensed consolidated statements of operations. The Company does not currently utilize and has not in the past utilized any foreign currency hedging strategies to mitigate the effect of its foreign currency exposure.
Comprehensive Income	'
	Comprehensive Income
	Comprehensive income is comprised of net income and other comprehensive income. Other comprehensive income includes changes in stockholders’ equity that are excluded from net income, specifically changes in unrealized gains and losses on the Company’s available-for-sale securities.
Net Income per Share of Common Stock	'
	Net Income per Share of Common Stock
	Basic earnings per share is computed by dividing the net income by the weighted average number of shares of common stock outstanding during the periods presented. The computation of diluted earnings per share is similar to the computation of basic earnings per share, except that the denominator is increased for the assumed exercise of dilutive options and other potentially dilutive securities using the treasury stock method unless the effect is antidilutive.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In July 2013, FASB issued ASU No. 2013-11, Income Taxes (Topic 740): Presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. Under the amendments of this update an entity is required to present an unrecognized tax benefit, or a portion of an unrecognized tax benefit in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except as follows. To the extent a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date under the tax law of the applicable jurisdiction to settle any additional income taxes that would result from the disallowance of a tax position or the tax law of the applicable jurisdiction does not require the entity to use, and the entity does not intend to use, the deferred tax asset for such purpose, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be combined with deferred tax assets. The assessment of whether a deferred tax asset is available is based on the unrecognized tax benefit and deferred tax asset that exist at the reporting date and should be made presuming disallowance of the tax position at the reporting date. For example, an entity should not evaluate whether the deferred tax asset expires before the statute of limitations on the tax position or whether the deferred tax asset may be used prior to the unrecognized tax benefits being settled. The provisions of this update was effective prospectively for the Company in fiscal years beginning after December 15, 2013 with early adoption and retrospective application permitted. The Company adopted this guidance on January 1, 2014. The implementation did not have an impact on the Company’s condensed consolidated financial statements.
	In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update 2014-09 (ASU 2014-09), Revenue from Contracts with Customers. ASU 2014-09 will supersede the revenue recognition requirements in Revenue Recognition (Topic 605) and requires entities to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period, which for the Company is January 1, 2017. Early adoption is not permitted. The Company is currently evaluating the potential impact the adoption of ASU 2014-09 will have on its consolidated financial statements.

Acquisitions_Tables

Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2014
Business Combinations [Abstract]	'
Consideration for Acquisition Transferred	'
	The Acquisition Date fair value of the total consideration transferred to acquire Andromeda was as follows:
			(in thousands)
	Cash paid		$	14,345
	Fair value of Company’s common stock issued (312,869 shares)			7,778	*
	Acquisition-related contingent consideration			68,961
	Total fair value of consideration transferred		$	91,084
	*	The fair value of the common stock was measured using the Company’s closing stock price on June 12, 2014.
Allocation of Purchase Price to the Fair Values of Assets Acquired and Liabilities Assumed	'
	The following table summarizes the provisional allocation of purchase price to the fair values of the assets acquired and liabilities assumed as of the acquisition date:
			(in thousands)
	Assets acquired
	IPR&D		$	135,712
	Cash and cash equivalents			306
	Prepaid expenses			95
	Property and equipment, net			22
	Other assets			578
	Liabilities assumed
	Current liabilities			(9,079	)
	Deferred tax liability			(6,051	)
	Acquisition related contingent liability			(34,288	)
	Total identifiable net assets			87,295
	Goodwill			3,789
	Total consideration transferred		$	91,084
Consolidated Pro Forma Information	'
	In addition, the unaudited pro forma information does not purport to project the future results of operations of the Company.
			For the three months ended					For the six months ended
			June 30,					June 30,
			(in thousands except per share data, unaudited)
			2014			2013		2014		2013
	Total revenues		$	37,095		$	9,152	$	56,577	$	18,784
	Net income			15,202			25,767		13,001		18,330
	Net income per common share:
	Basic			0.74			1.27		0.63		0.96
	Diluted			0.7			1.19		0.59		0.9

Investments_Tables

Investments (Tables)	6 Months Ended
	Jun. 30, 2014
Investments Debt And Equity Securities [Abstract]	'
Schedule of Investments by Contractual Maturity	'
	The principal amounts of investments by contractual maturity at June 30, 2014 and December 31, 2013 are summarized in the tables below:
		Contractual Maturity Date for the					Total Book		Unrealized			Aggregate
		Period Ended June 30,					Value at		Gain (loss)			Fair Value at
							June 30, 2014					June 30, 2014
		2015		2016
	Certificates of deposit	$	11,970	$	2,640		$	14,610	$	(16	)	$	14,594
	Corporate notes		18,804		—			18,804		12			18,816
	U.S. Government agency securities		8,001		—			8,001		1			8,002
	Commercial paper		3,497		—			3,497		1			3,498
	Total	$	42,272	$	2,640		$	44,912	$	(2	)	$	44,910
		Contractual Maturity Date for the					Total Book		Unrealized			Aggregate
		Years Ended December 31,					Value at		Loss			Fair Value at
							December 31, 2013					December 31, 2013
		2014		2015
	Certificates of deposit	$	10,525	$	2,845		$	13,370	$	(27	)	$	13,343
	Corporate notes		6,047		12,960			19,007		(24	)		18,983
	U.S. government agency securities		8,011		—			8,011		(3	)		8,008
	Commercial paper		3,492		—			3,492		(1	)		3,491
	Total	$	28,075	$	15,805		$	43,880	$	(55	)	$	43,825
Schedule of Unrealized Losses and Related Fair Value of Investments with Unrealized Losses	'
	The aggregate amounts of unrealized losses and related fair value of investments with unrealized losses as of June 30, 2014 and December 31, 2013 were as follows:
		Less Than 12 Months to					12 Months or More to					Total at June 30, 2014
		Maturity					Maturity
		Aggregate		Unrealized			Aggregate		Unrealized			Aggregate		Unrealized
		Fair Value		Gain (loss)			Fair Value		Loss			Fair Value		Gain (loss)
	Certificates of deposit	$	11,962	$	(8	)	$	2,632	$	(8	)	$	14,594	$	(16	)
	Corporate notes		18,816		12			—		—			18,816		12
	U.S. government agency securities		8,002		1			—		—			8,002		1
	Commercial paper		3,498		1			—		—			3,498		1
	Total	$	42,278	$	6		$	2,632	$	(8	)	$	44,910	$	(2	)
		Less Than 12 Months to					12 Months or More to					Total at December 31, 2013
		Maturity					Maturity
		Aggregate		Unrealized			Aggregate		Unrealized			Aggregate		Unrealized
		Fair Value		Loss			Fair Value		Loss			Fair Value		Loss
	Certificates of deposit	$	10,507	$	(18	)	$	2,836	$	(9	)	$	13,343	$	(27	)
	Corporate notes		6,039		(8	)		12,944		(16	)		18,983		(24	)
	U.S. government agency securities		8,008		(3	)		—		—			8,008		(3	)
	Commercial paper		3,491		(1	)		—		—			3,491		(1	)
	Total	$	28,045	$	(30	)	$	15,780	$	(25	)	$	43,825	$	(55	)

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Hierarchy for Assets and Liabilities Measured at Fair Value on Recurring Basis	'
	The following table presents the Company’s fair value hierarchy for assets and liabilities measured at fair value on a recurring basis as of June 30, 2014 and December 31, 2013 (in thousands):
		Fair Value Measurements at June 30, 2014
		Quoted Price in		Significant Other		Significant		Total
		Active Markets		Observable Inputs		Unobservable
		for Identical Assets		(Level 2)		Inputs
		(Level 1)				(Level 3)
	Assets:
	Cash equivalents:
	Money market funds	$	38,013	$	—	$	—	$	38,013
	Total cash equivalents	$	38,013	$	—	$	—	$	38,013
	Available-for-sale securities:
	Short-term:
	Certificates of deposit	$	—	$	11,962	$	—	$	11,962
	Commercial paper		—		3,498		—		3,498
	Corporate notes		—		18,816		—		18,816
	U.S. Government agency securities		—		8,002		—		8,002
	Total short-term investments		—		42,278		—		42,278
	Long-term:
	Certificates of deposit		—		2,632		—		2,632
	Total long-term investments		—		2,632		—		2,632
	Total available-for-sale securities	$	—	$	44,910	$	—	$	44,910
	Liabilities:
	Acquisition-related contingent consideration	$	—	$	—	$	69,456	$	69,456
	Total acquisition-related contingent consideration	$	—	$	—	$	69,456	$	69,456
		Fair Value Measurements at December 31, 2013
		Quoted Price in		Significant Other		Significant		Total
		Active Markets		Observable Inputs		Unobservable
		for Identical Assets		(Level 2)		Inputs
		(Level 1)				(Level 3)
	Assets:
	Cash equivalents:
	Money market funds	$	38,506	$	—	$	—	$	38,506
	Certificates of deposit		—		480		—		480
	Total cash equivalents	$	38,506	$	480	$	—	$	38,986
	Available-for-sale securities:
	Short-term:
	Certificates of deposit	$	—	$	10,507	$	—	$	10,507
	Commercial paper		—		3,491		—		3,491
	Corporate notes		—		6,039		—		6,039
	U.S. Government agency securities		—		8,008		—		8,008
	Total short-term investments		—		28,045		—		28,045
	Long-term:
	Certificates of deposit		—		2,836		—		2,836
	Corporate notes		—		12,944		—		12,944
	Total long-term investments		—		15,780		—		15,780
	Total available-for-sale securities	$	—	$	43,825	$	—	$	43,825
Carrying Value and Estimated Fair Value of Company's Notes Payable	'
	The following table presents the carrying value and estimated fair value of the Company’s notes payable as of June 30, 2014 and December 31, 2013 (in thousands):
		June 30, 2014
		Carrying		Estimated
		Value		Fair Value
	April and September 2012 Notes	$	5,771	$	6,145
		December 31, 2013
		Carrying		Estimated
		Value		Fair Value
	April and September 2012 Notes	$	8,273	$	8,860
Rollforward of Acquisition-Related Contingent Consideration	'
	The following table provides a rollforward of acquisition-related contingent consideration, which is recorded in our condensed consolidated balance sheets (in thousands):
		Amount
	Beginning balance as of January 1, 2014	$	—
	Fair value on date of acquisition		68,961
	Net changes in valuation		495
	Fair value as of June 30, 2014	$	69,456

Inventories_Tables

Inventories (Tables)	6 Months Ended
	Jun. 30, 2014
Inventory Disclosure [Abstract]	'
Components of Net Inventories	'
	The following table represents the components of net inventories (in thousands):
		June 30,		December 31,
		2014		2013
	Raw Materials	$	1,416	$	697
	Work-in-process		46		—
	Finished goods		1,445		2,816
	Total	$	2,907	$	3,513

Property_and_Equipment_Tables

Property and Equipment (Tables)	6 Months Ended
	Jun. 30, 2014
Property Plant And Equipment [Abstract]	'
Components of Property and Equipment	'
	The following table represents the components of property and equipment (in thousands):
		June 30,			December 31,
		2014			2013
	Computers and Software	$	931		$	563
	Furniture and Fixtures		320			320
	Office Equipment		53			53
	Capital work in progress		209			264
			1,513			1,200
	Less: Accumulated depreciation		(457	)		(264	)
	Total property and equipment, net	$	1,056		$	936

Intangible_Assets_and_Goodwill1

Intangible Assets and Goodwill (Tables)	6 Months Ended
	Jun. 30, 2014
Goodwill And Intangible Assets Disclosure [Abstract]	'
Schedule of Expected Amortization Expense	'
	Estimated aggregate amortization expense for each of the five succeeding years ending December 31 is as follows (in thousands):
		2014		2015		2016		2017		2018
	Amortization expense	$	4,053	$	3,294	$	1,157	$	1,048	$	1,012

Accrued_Liabilities_Tables

Accrued Liabilities (Tables)	6 Months Ended
	Jun. 30, 2014
Payables And Accruals [Abstract]	'
Components of Accrued Liabilities	'
	The following table represents the components of accrued liabilities (in thousands):
		June 30,		December 31,
		2014		2013
	Clinical trial expenses	$	226	$	246
	Payroll and related expenses		2,780		4,278
	Gross to net sales accruals		7,991		5,235
	Royalty payable		2,525		1,154
	Legal accrual		368		45
	Taxes payable		629		326
	Interest payable		40		61
	Liability with respect to acquisition of Andromeda		4,615		—
	Other liabilities		12,161		842
	Total	$	31,335	$	12,187

Warrants_Tables

Warrants (Tables)	6 Months Ended
	Jun. 30, 2014
Text Block [Abstract]	'
Summary of Outstanding Warrants and Corresponding Exercise Price	'
	The following table summarizes the outstanding warrants and the corresponding exercise price as of March 31, 2014 and December 31, 2013:
		Number of Shares Outstanding
		June 30,		December 31,		Per Share
		2014		2013		Exercise Price
	October 2007 common stock warrants		274		274	$	1,913.05
	Total		274		274

Equity_Incentive_Plan_and_Stoc1

Equity Incentive Plan and Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Allocation of Stock-Based Compensation Expense	'
	Total stock-based compensation expense related to options and awards granted was allocated as follows (in thousands):
		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2014		2013		2014		2013
	Cost of sales	$	40	$	2	$	42	$	3
	Research and development		278		143		425		235
	Selling general and administrative		1,576		1,108		2,795		1,521
	Total	$	1,894	$	1,253	$	3,262	$	1,759

Net_Income_per_Share_of_Common1

Net Income per Share of Common Stock (Tables)	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Net Income Per Share of Common Stock	'
	The following table sets forth the computation of basic and diluted net income per share of common stock for the periods indicated (in thousands, except share and per share amounts):
		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2014		2013		2014		2013
	Net income per share
	Numerator:
	Net income	$	17,479	$	25,022	$	18,735	$	16,047
	Denominator:
	Weighted-average number of common shares outstanding – basic		20,335,618		20,050,987		20,263,803		18,716,332
	Dilutive effect of stock-options and awards		1,278,378		1,307,288		1,308,913		1,261,757
	Weighted average common shares outstanding – dilutive		21,613,996		21,358,275		21,572,716		19,978,089
	Net income per share:
	Basic	$	0.86	$	1.25	$	0.92	$	0.86
	Diluted	$	0.81	$	1.17	$	0.87	$	0.8
Antidilutive Securities Excluded from Computation of Earnings Per Share	'
	The following outstanding potentially dilutive securities were excluded from the computation of diluted net income per share, as the effect of including them would have been antidilutive:
		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2014		2013		2014		2013
	Stock options		1,366,021		675,969		1,365,873		380,745
	October 2007, April 2008 and 2012 common stock warrants		274		274		274		274
	Total		1,366,295		676,243		1,366,147		381,019

Segment_Reporting_Tables

Segment Reporting (Tables)	6 Months Ended
	Jun. 30, 2014
Segment Reporting [Abstract]	'
Net Product Revenue for Ravicti and Buphenyl	'
	Net product revenue for RAVICTI and BUPHENYL for the three and six months ended June 30, 2014 and 2013 are as follows (in thousands):
		Three Months Ended					Six Months Ended
		June 30,					June 30,
		2014			2013		2014			2013
	RAVICTI		31,553			6,210		47,069			6,993
	BUPHENYL		5,742			1,095		9,708			1,095
	Co-payment assistance		(200	)		—		(200	)		—
	Total		37,095			7,305		56,577			8,088
Net Product Revenue for Ravicti and Buphenyl by Geographic Region	'
	Net product revenue for RAVICTI and BUPHENYL by geographic region are as follows (in thousands):
		Three Months Ended					Six Months Ended
		June 30,					June 30,
		2014			2013		2014			2013
	United States		34,056			7,223		52,052			8,006
	Canada		983			—		1,783			—
	Rest of the world		2,056			82		2,742			82
	Total		37,095			7,305		56,577			8,088

Formation_and_Business_of_the_1

Formation and Business of the Company - Additional Information (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013	Aug. 14, 2013	Jun. 30, 2014	Jun. 30, 2014
				Andromeda	BUPHENYL
Nature Of Operations [Line Items]	'	'	'	'	'
Business acquisition date	'	'	'	12-Jun-14	31-May-13
Aggregate offering price	'	'	$150,000,000	'	'
Common stock shares sold by selling stockholders	'	'	8,727,000	'	'
Aggregate offering price under sales agreement	'	'	50,000,000	'	'
Sales of securities	'	'	0	'	'
Accumulated deficit	($103,635,000)	($122,370,000)	'	'	'

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended			6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2013	31-May-13	Jun. 30, 2014
					Sales Revenue, Goods, Net [Member]	Sales Revenue, Goods, Net [Member]	Sales Revenue, Goods, Net [Member]	Sales Revenue, Goods, Net [Member]	BUPHENYL	BUPHENYL	RAVICTI
					Customer Concentration Risk [Member]	Customer Concentration Risk [Member]	Customer Concentration Risk [Member]	Customer Concentration Risk [Member]
					Specialty Distributor	Specialty Distributor	International Distributor	International Distributor
Summary Of Significant Accounting Policies [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Credit losses on accounts receivable	$0	'	$0	'	'	'	'	'	'	'	'
Percentage of domestic accounts receivable	90.00%	'	90.00%	'	'	'	'	'	'	'	'
Percentage of accounts receivable by international distributor	5.00%	'	5.00%	'	'	'	'	'	'	'	'
Specialty distributor accounted for net product revenue	'	'	'	'	92.00%	92.00%	5.20%	3.90%	'	'	'
Acquisition of inventory	'	'	'	'	'	'	'	'	'	3,900,000	'
Net revenues	$37,095,000	$7,305,000	$56,577,000	$8,088,000	'	'	'	'	$1,100,000	'	$8,600,000
Percentage of Medicare Part D insurance coverage gap to eligible patients	'	'	50.00%	'	'	'	'	'	'	'	'

Collaboration_Agreement_with_U1

Collaboration Agreement with Ucyclyd Pharma, Inc. - Additional Information (Detail) (USD $)	0 Months Ended	1 Months Ended	3 Months Ended	6 Months Ended
	31-May-13	Mar. 31, 2012	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	31-May-13
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]	'	'	'	'	'	'
Purchase option exercise period	'	'90 days	'	'	'	'
Purchase price for AMMONUL and BUPHENYL	'	$22,000,000	'	'	'	'
Monthly payments	'	'	'	'	500,000	'
Purchase price to retain product rights	'	'	'	32,000,000	'	'
Net payment to be received for purchase transaction	'	'	'	11,000,000	'	'
Cash paid to Ucyclyd for BUPHENYL product rights	'	'	'	19,000,000	'	'
Cash due to Ucyclyd for inventory	'	'	'	2,000,000	'	'
Gain from settlement of retention option	31,100,000	'	31,079,000	'	31,079,000	'
Fair value of BUPHENYL	'	'	'	'	'	20,400,000
Net payment received from Ucyclyd	10,900,000	'	'	'	10,962,000	'
Option to purchase rights to BUPHENYL and AMMONUL	300,000	'	'	'	283,000	'
Purchase agreement with Ucyclyd	'	'	'	'	'	'
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]	'	'	'	'	'	'
Payment under purchase agreement	'	6,000,000	'	'	'	'
Purchase agreement with Ucyclyd | RAVICTI	'	'	'	'	'	'
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]	'	'	'	'	'	'
Payment under purchase agreement	'	5,700,000	'	'	'	'
Purchase agreement with Ucyclyd | RAVICTI | Scenario One	'	'	'	'	'	'
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]	'	'	'	'	'	'
Maximum amount of regulatory milestones, product approval	'	15,800,000	'	'	'	'
Regulatory milestones, product approval, description	'	'	'	'Regulatory milestones related to approval of GPB in HE	'	'
Purchase agreement with Ucyclyd | RAVICTI | Scenario Two	'	'	'	'	'	'
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]	'	'	'	'	'	'
Regulatory milestones, product approval, description	'	'	'	'Regulatory milestones approval of GPB in indications other than UCD or HE	'	'
Maximum amount of regulatory milestones, approval in other indications	'	7,300,000	'	'	'	'
Purchase agreement with Ucyclyd | RAVICTI | Scenario Three	'	'	'	'	'	'
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]	'	'	'	'	'	'
Regulatory milestones, product approval, description	'	'	'	'Net sales milestones if GPB is approved for use in indications other than UCD (such as HE) and all annual sales targets are reached	'	'
Maximum amount of regulatory milestones, approval in other indications	'	38,800,000	'	'	'	'
Purchase agreement with Ucyclyd | BUPHENYL and AMMONUL	'	'	'	'	'	'
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]	'	'	'	'	'	'
Option to purchase rights to BUPHENYL and AMMONUL	'	$300,000	'	'	'	'

Acquisitions_Additional_Inform

Acquisitions - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended		6 Months Ended
	Jun. 12, 2014	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 12, 2014
Business Acquisition [Line Items]	'	'	'	'	'	'
Net revenue	'	$37,095,000	$7,305,000	$56,577,000	$8,088,000	'
Andromeda	'	'	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'	'	'
Acquisition date	'	'	'	12-Jun-14	'	'
Net loss as of acquisition date	'	1,400,000	'	1,400,000	'	'
Contingent liabilities	'	34,288,000	'	34,288,000	'	34,300,000
Change in value of contingent liability	'	200,000	'	200,000	'	'
Issuance of common stock as part of acquisition	312,869	'	'	'	'	'
Acquisition-related expenses	'	1,300,000	300,000	1,300,000	400,000	'
BUPHENYL	'	'	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'	'	'
Acquisition date	'	'	'	31-May-13	'	'
Net revenue	'	'	'	'	$1,100,000	'

Consideration_for_Acquisition_

Consideration for Acquisition Transferred (Detail) (USD $)	6 Months Ended	0 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 12, 2014
		Andromeda
Business Acquisition, Contingent Consideration [Line Items]	'	'
Cash paid	($14,345)	$14,345
Fair value of Company's common stock issued (312,869 shares)	'	7,778
Acquisition-related contingent consideration	68,961	68,961
Total fair value of consideration transferred	'	$91,084

Consideration_for_Acquisition_1

Consideration for Acquisition Transferred (Parenthetical) (Detail) (Andromeda)	0 Months Ended
	Jun. 12, 2014
Andromeda	'
Business Acquisition, Contingent Consideration [Line Items]	'
Fair value of Company's common stock issued, shares	312,869

Allocation_of_Purchase_Price_t

Allocation of Purchase Price to the Fair Values of Assets Acquired and Liabilities Assumed (Detail) (USD $)	Jun. 30, 2014	Jun. 12, 2014
In Thousands, unless otherwise specified
Liabilities assumed	'	'
Goodwill	$3,789	'
Andromeda	'	'
Assets acquired	'	'
IPR&D	135,712	'
Cash and cash equivalents	306	'
Prepaid expenses	95	'
Property and equipment, net	22	'
Other assets	578	'
Liabilities assumed	'	'
Current liabilities	-9,079	'
Deferred tax liability	-6,051	'
Acquisition related contingent liability	-34,288	-34,300
Total identifiable net assets	87,295	'
Goodwill	3,789	'
Total consideration transferred	$91,084	'

Consolidated_Pro_Forma_Informa

Consolidated Pro Forma Information (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Business Combinations [Abstract]	'	'	'	'
Total revenues	$37,095	$9,152	$56,577	$18,784
Net income	$15,202	$25,767	$13,001	$18,330
Net income per common share:	'	'	'	'
Basic	$0.74	$1.27	$0.63	$0.96
Diluted	$0.70	$1.19	$0.59	$0.90

Schedule_of_Investments_by_Con

Schedule of Investments by Contractual Maturity (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Contractual Maturity Year One	$42,272	$28,075
Contractual Maturity Year Two	2,640	15,805
Contractual Maturity, Total Book Value	44,912	43,880
Unrealized Gain (loss)	-2	-55
Aggregate Fair Value	44,910	43,825
Certificates of deposit	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Contractual Maturity Year One	11,970	10,525
Contractual Maturity Year Two	2,640	2,845
Contractual Maturity, Total Book Value	14,610	13,370
Unrealized Gain (loss)	-16	-27
Aggregate Fair Value	14,594	13,343
Corporate notes	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Contractual Maturity Year One	18,804	6,047
Contractual Maturity Year Two	0	12,960
Contractual Maturity, Total Book Value	18,804	19,007
Unrealized Gain (loss)	12	-24
Aggregate Fair Value	18,816	18,983
U.S. Government agency securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Contractual Maturity Year One	8,001	8,011
Contractual Maturity Year Two	0	'
Contractual Maturity, Total Book Value	8,001	8,011
Unrealized Gain (loss)	1	-3
Aggregate Fair Value	8,002	8,008
Commercial paper	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Contractual Maturity Year One	3,497	3,492
Contractual Maturity Year Two	0	'
Contractual Maturity, Total Book Value	3,497	3,492
Unrealized Gain (loss)	1	-1
Aggregate Fair Value	$3,498	$3,491

Investments_Additional_Informa

Investments - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014
Investments Debt And Equity Securities [Abstract]	'
Other-than-temporary impairments	$0

Schedule_of_Unrealized_Losses_

Schedule of Unrealized Losses and Related Fair Value of Investments with Unrealized Losses (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months to Maturity, Aggregate Fair Value	$42,278	$28,045
Less Than 12 Months to Maturity, Unrealized Gain (Loss)	6	-30
12 Months or More to Maturity, Aggregate Fair Value	2,632	15,780
12 Months or More to Maturity, Unrealized Loss	-8	-25
Aggregate Fair Value, Total	44,910	43,825
Unrealized Gain (loss), Total	-2	-55
Certificates of deposit	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months to Maturity, Aggregate Fair Value	11,962	10,507
Less Than 12 Months to Maturity, Unrealized Gain (Loss)	-8	-18
12 Months or More to Maturity, Aggregate Fair Value	2,632	2,836
12 Months or More to Maturity, Unrealized Loss	-8	-9
Aggregate Fair Value, Total	14,594	13,343
Unrealized Gain (loss), Total	-16	-27
Corporate notes	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months to Maturity, Aggregate Fair Value	18,816	6,039
Less Than 12 Months to Maturity, Unrealized Gain (Loss)	12	-8
12 Months or More to Maturity, Aggregate Fair Value	0	12,944
12 Months or More to Maturity, Unrealized Loss	0	-16
Aggregate Fair Value, Total	18,816	18,983
Unrealized Gain (loss), Total	12	-24
U.S. Government agency securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months to Maturity, Aggregate Fair Value	8,002	8,008
Less Than 12 Months to Maturity, Unrealized Gain (Loss)	1	-3
12 Months or More to Maturity, Aggregate Fair Value	0	'
12 Months or More to Maturity, Unrealized Loss	0	'
Aggregate Fair Value, Total	8,002	8,008
Unrealized Gain (loss), Total	1	-3
Commercial paper	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months to Maturity, Aggregate Fair Value	3,498	3,491
Less Than 12 Months to Maturity, Unrealized Gain (Loss)	1	-1
12 Months or More to Maturity, Aggregate Fair Value	0	'
12 Months or More to Maturity, Unrealized Loss	0	'
Aggregate Fair Value, Total	3,498	3,491
Unrealized Gain (loss), Total	$1	($1)

Hierarchy_for_Assets_and_Liabi

Hierarchy for Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total cash equivalents	$38,013	$38,986
Fair value of available-for-sale securities	44,910	43,825
Total acquisition-related contingent consideration	69,456	'
Certificates of deposit	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total cash equivalents	'	480
Fair value of available-for-sale securities	14,594	13,343
Commercial paper	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	3,498	3,491
Corporate notes	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	18,816	18,983
U.S. Government agency securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	8,002	8,008
Available-for-sale securities, Short-term	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	42,278	28,045
Available-for-sale securities, Short-term | Certificates of deposit	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	11,962	10,507
Available-for-sale securities, Short-term | Commercial paper	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	3,498	3,491
Available-for-sale securities, Short-term | Corporate notes	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	18,816	6,039
Available-for-sale securities, Short-term | U.S. Government agency securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	8,002	8,008
Available-for-sale securities, Long-term	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	2,632	15,780
Available-for-sale securities, Long-term | Certificates of deposit	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	2,632	2,836
Available-for-sale securities, Long-term | Corporate notes	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	'	12,944
Money market funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total cash equivalents	38,013	38,506
Quoted Prices in Active Markets for Identical Items (Level 1)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total cash equivalents	38,013	38,506
Quoted Prices in Active Markets for Identical Items (Level 1) | Money market funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total cash equivalents	38,013	38,506
Significant Other Observable Inputs (Level 2)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total cash equivalents	'	480
Fair value of available-for-sale securities	44,910	43,825
Significant Other Observable Inputs (Level 2) | Certificates of deposit	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total cash equivalents	'	480
Significant Other Observable Inputs (Level 2) | Available-for-sale securities, Short-term	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	42,278	28,045
Significant Other Observable Inputs (Level 2) | Available-for-sale securities, Short-term | Certificates of deposit	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	11,962	10,507
Significant Other Observable Inputs (Level 2) | Available-for-sale securities, Short-term | Commercial paper	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	3,498	3,491
Significant Other Observable Inputs (Level 2) | Available-for-sale securities, Short-term | Corporate notes	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	18,816	6,039
Significant Other Observable Inputs (Level 2) | Available-for-sale securities, Short-term | U.S. Government agency securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	8,002	8,008
Significant Other Observable Inputs (Level 2) | Available-for-sale securities, Long-term	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	2,632	15,780
Significant Other Observable Inputs (Level 2) | Available-for-sale securities, Long-term | Certificates of deposit	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	2,632	2,836
Significant Other Observable Inputs (Level 2) | Available-for-sale securities, Long-term | Corporate notes	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of available-for-sale securities	'	12,944
Significant Unobservable Inputs (Level 3)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total acquisition-related contingent consideration	$69,456	'

Carrying_Value_and_Estimated_F

Carrying Value and Estimated Fair Value of Company's Notes Payable (Detail) (April and September 2012 Notes, USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Carrying Value	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total	$5,771	$8,273
Estimated Fair Value	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total	$6,145	$8,860

Rollforward_of_AcquisitionRela

Rollforward of Acquisition-Related Contingent Consideration (Detail) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Business Combinations [Abstract]	'
Beginning balance as of January 1, 2014	'
Fair value on date of acquisition	68,961
Net changes in valuation	495
Fair value as of June 30, 2014	$69,456

Components_of_Net_Inventories_

Components of Net Inventories (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Raw Materials	$1,416	$697
Work-in-process	46	'
Finished goods	1,445	2,816
Total	$2,907	$3,513

Inventories_Additional_Informa

Inventories - Additional Information (Detail) (BUPHENYL, USD $)	31-May-13
In Millions, unless otherwise specified
BUPHENYL	'
Inventory [Line Items]	'
Remaining inventory at balance sheet date	$3.90

Components_of_Property_and_Equ

Components of Property and Equipment (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	$1,513	$1,200
Less: Accumulated depreciation	-457	-264
Total property and equipment, net	1,056	936
Computers and Software	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	931	563
Furniture and Fixtures	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	320	320
Office Equipment	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	53	53
Capital work in progress	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	$209	$264

Property_and_Equipment_Additio

Property and Equipment - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Property Plant And Equipment [Abstract]	'	'	'	'
Depreciation expense	$100	$32	$193	$51

Intangible_Assets_and_Goodwill2

Intangible Assets and Goodwill - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended			1 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014
					BUPHENYL	Andromeda	Andromeda
							In-Process Research and Development (IPR&D)
Finite-Lived Intangible Assets [Line Items]	'	'	'	'	'	'	'
Intangible asset acquired	'	'	'	'	$16,500,000	$135,712,000	$135,700,000
Estimated useful life of intangible assets	'	'	'	'	'10 years	'	'
Remaining weighted average useful life	'	'	'	'	'8 years 6 months	'	'
Amortization of intangible asset	1,014,000	329,000	2,028,000	329,000	'	'	'
Goodwill acquired	'	'	'	'	'	$3,800,000	'

Schedule_of_Expected_Amortizat

Schedule of Expected Amortization Expense (Detail) (USD $)	Jun. 30, 2014
In Thousands, unless otherwise specified
Goodwill And Intangible Assets Disclosure [Abstract]	'
2014	$4,053
2015	3,294
2016	1,157
2017	1,048
2018	$1,012

Components_of_Accrued_Liabilit

Components of Accrued Liabilities (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables And Accruals [Abstract]	'	'
Clinical trial expenses	$226	$246
Payroll and related expenses	2,780	4,278
Gross to net sales accruals	7,991	5,235
Royalty payable	2,525	1,154
Legal accrual	368	45
Taxes payable	629	326
Interest payable	40	61
Liability with respect to acquisition of Andromeda	4,615	'
Other liabilities	12,161	842
Accrued liabilities	$31,335	$12,187

Accrued_Liabilities_Additional

Accrued Liabilities - Additional Information (Detail) (USD $)	Jun. 30, 2014
In Millions, unless otherwise specified
Payables And Accruals [Abstract]	'
Acquisition related consideration payable	$10.90

Notes_Payable_Additional_Infor

Notes Payable - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended				1 Months Ended	6 Months Ended
In Millions, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Apr. 30, 2012	Sep. 30, 2012	Jun. 30, 2014
					April 2012 Notes Payable	April 2012 Notes Payable	September 2012 Notes Payable	September 2012 Notes Payable
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'
Aggregate principal amount of notes issued	'	'	'	'	'	$10	'	'
Stated interest rate on notes	'	'	'	'	8.88%	'	'	8.88%
Interest only payment period	'	'	'	'	'9 months	'	'	'9 months
Payment of loan principal and interest	'	'	'	'	'27 months	'	'	'27 months
Period for monthly financials and compliance certificate	'	'	'	'	'30 days	'	'	'
Period for annual audited financial report	'	'	'	'	'180 days	'	'	'
Number of warrants issued	'	'	'	'	'	75,974	8,408	'
Exercise price of warrants	'	'	'	'	'	4.08	5.05	'
Final payment due as a percentage of principal loan amount	'	'	'	'	6.50%	'	'	6.50%
Sale of equity securities or debt, minimum amount for term loan	'	'	'	'	30	'	'	'
Bank Term Loan	'	'	'	'	2.5	'	'	'
Additional borrowing	'	'	'	'	'	'	2.5	'
Percentage in addition to Treasury rate, term loan	'	'	'	'	'	'	'	8.50%
Amortization of debt discount	$0.10	$0.10	$0.30	$0.30	'	'	'	'

Warrants_Additional_Informatio

Warrants - Additional Information (Detail) (October 2007 Common Stock Warrants)	6 Months Ended
	Jun. 30, 2014	Oct. 31, 2007
October 2007 Common Stock Warrants	'	'
Class of Warrant or Right [Line Items]	'	'
Number of warrants issued	'	274
Exercise price of warrants	1,913.05	'
Expiration date of warrants	'October 2017	'

Summary_of_Outstanding_Warrant

Summary of Outstanding Warrants and Corresponding Exercise Price (Detail)	Jun. 30, 2014	Dec. 31, 2013
Class of Warrant or Right [Line Items]	'	'
Number of Shares Outstanding	274	274
October 2007 Common Stock Warrants	'	'
Class of Warrant or Right [Line Items]	'	'
Number of Shares Outstanding	274	274
Per Share Exercise Price	1,913.05	'

Equity_Incentive_Plan_and_Stoc2

Equity Incentive Plan and Stock-Based Compensation - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014
		Inventories	Inventories	Inventories	Inventories	2012 Plan	2012 Plan	2012 Plan	2006 Plan
							Restricted stock units ("RSU's")	Performance RSU's
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'	'	'	'	'	'
Shares available for issuance under plan	'	'	'	'	'	793,351	'	'	'
Share options outstanding under plan	'	'	'	'	'	1,672,768	'	'	1,441,158
Stock units outstanding under plan	'	'	'	'	'	'	126,705	8,988	'
Options granted during period	'	'	'	'	'	620,769	'	'	'
Stock units, Granted	'	'	'	'	'	'	115,455	8,988	'
Option exercise price, minimum	'	'	'	'	'	$24.64	'	'	'
Option exercise price, maximum	'	'	'	'	'	$31	'	'	'
Increase in shares approved for issuance under plan	'	'	'	'	'	805,485	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost	$100,000	'	'	'	'	'	'	'	'
Stock-based compensation capitalized into inventories	'	$10,000	$17,000	$18,000	$26,000	'	'	'	'

Allocation_of_StockBased_Compe

Allocation of Stock-Based Compensation Expense (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation expenses related to employees	$1,894	$1,253	$3,262	$1,759
Cost of sales	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation expenses related to employees	40	2	42	3
Research and development	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation expenses related to employees	278	143	425	235
Selling general and administrative	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation expenses related to employees	$1,576	$1,108	$2,795	$1,521

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended	6 Months Ended					6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Jun. 12, 2014	Jun. 30, 2014
			United States	United States	United States	United States	California	California	Israeli	Israeli
					Research and development tax credit carryforward	Federal Orphan Drug Credit				Research And Development
						Research and development tax credit carryforward				Research and development tax credit carryforward
Tax Credit Carryforward [Line Items]	'	'	'	'	'	'	'	'	'	'
Net operating loss carryforwards	'	'	'	$72,500,000	'	'	'	$112,500,000	$61,600,000	'
Operating loss expirations	'	'	'Begin to expire in 2026	'	'	'	'Begin to expire in 2016	'	'	'
Tax credit carryforward	'	'	'	'	18,000,000	17,400,000	'	'	'	3,000,000
Income tax expense or benefit	-2,119,000	-2,031,000	'	'	'	'	'	'	'	'
Interest or penalties accrued	'	$0	'	'	'	'	'	'	'	'

Recovered_Sheet1

Net Income Per Share of Common Stock (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net income per share Numerator:	'	'	'	'
Net income	$17,479	$25,022	$18,735	$16,047
Denominator:	'	'	'	'
Basic	20,335,618	20,050,987	20,263,803	18,716,332
Dilutive effect of stock-options and awards	1,278,378	1,307,288	1,308,913	1,261,757
Diluted	21,613,996	21,358,275	21,572,716	19,978,089
Net income per share:	'	'	'	'
Basic	$0.86	$1.25	$0.92	$0.86
Diluted	$0.81	$1.17	$0.87	$0.80

Antidilutive_Securities_Exclud

Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Potentially dilutive securities excluded from the computation of diluted net loss per share	1,366,295	676,243	1,366,147	381,019
Stock options	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Potentially dilutive securities excluded from the computation of diluted net loss per share	1,366,021	675,969	1,365,873	380,745
Common stock warrants	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Potentially dilutive securities excluded from the computation of diluted net loss per share	274	274	274	274

Related_Party_Transaction_Addi

Related Party Transaction - Additional Information (Detail) (Swedish Orphan Biovitrum AB, USD $)	3 Months Ended	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2013
Swedish Orphan Biovitrum AB	'	'	'
Related Party Transaction [Line Items]	'	'	'
Sales recognized	$1.90	$2.20	$0
Accounts receivable from SOBI	$1	$1	'

Net_Product_Revenue_for_Ravict

Net Product Revenue for Ravicti and Buphenyl (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenue from External Customer [Line Items]	'	'	'	'
Revenue	$37,095	$7,305	$56,577	$8,088
RAVICTI	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'
Revenue	31,553	6,210	47,069	6,993
BUPHENYL	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'
Revenue	5,742	1,095	9,708	1,095
Co-payment assistance	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'
Revenue	($200)	'	($200)	'

Net_Product_Revenue_for_Ravict1

Net Product Revenue for Ravicti and Buphenyl by Geographic Region (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	$37,095	$7,305	$56,577	$8,088
United States	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	34,056	7,223	52,052	8,006
Canada	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	983	'	1,783	'
Rest of the world	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	$2,056	$82	$2,742	$82

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (Silicon Valley Bank, USD $)	6 Months Ended			0 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jul. 18, 2014	Jul. 18, 2014	Jul. 18, 2014
		Term loans	Revolving credit	Subsequent Events	Subsequent Events	Subsequent Events
					Term loans	Revolving credit
					Tranche
Subsequent Event [Line Items]	'	'	'	'	'	'
Number of tranches	'	'	'	'	2	'
Loan and security agreement, maximum borrowings	'	'	'	'	$16	$5
Pre-payment of term loan	'	'	'	$5.80	'	'
Repayment of loans, description	'The Company is required to pay interest only for the first 18 months of the Term Loans, followed by 30 equal monthly payments of interest and principal.	'	'	'	'	'
Term loans maturity date	'	30-Jun-18	18-Jul-17	'	'	'
Interest rate on loans, description	'The Loan and Security Agreement provides for an interest rate of 4.0% per year on the Term Loans and the prime rate plus 0.75% per year on the Revolving Loans, with a minimum interest requirement on the Revolving Loans.	'	'	'	'	'
Final payment due as a percentage of principal loan amount	6.75%	'	'	'	'	'