Pacira BioSciences (PCRX) 10-K 24 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 20, 2015	Jun. 30, 2014
Document and Entity Information
Entity Registrant Name	Pacira Pharmaceuticals, Inc.
Entity Central Index Key	1396814
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$1,495,161,494
Entity Common Stock, Shares Outstanding		36,236,036
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$37,520	$12,515	$10,126
Restricted cash	1,509	1,633
Short-term investments	119,138	59,637
Accounts receivable, net	22,366	14,590
Inventories	29,263	15,557
Prepaid expenses and other current assets	4,461	2,819
Total current assets	214,257	106,751
Long-term investments	24,431	0
Fixed assets, net	60,632	48,182
Goodwill	23,761	10,328	8,297
Intangibles, net	403	1,157
Other assets	2,588	3,402
Total assets	326,072	169,820
Current liabilities:
Accounts payable	6,758	3,069
Accrued expenses	28,450	17,885
Convertible senior notes	103,100	98,961
Current portion of royalty interest obligation	276	1,020
Current portion of deferred revenue	1,426	1,008
Total current liabilities	140,010	121,943
Royalty interest obligation	0	226
Deferred revenue	9,508	3,212
Other liabilities	5,409	3,190
Total liabilities	154,927	128,571
Commitments and contingencies
Stockholders’ equity:
Preferred stock, par value $0.001; 5,000,000 shares authorized, none issued and outstanding at December 31, 2014 and 2013	0	0
Common stock, par value $0.001 and 250,000,000 shares authorized; 36,150,620 shares issued and outstanding at December 31, 2014; 33,636,442 shares issued and outstanding at December 31, 2013	36	34
Additional paid-in capital	481,334	337,639
Accumulated deficit	-310,145	-296,429
Accumulated other comprehensive income (loss)	-80	5
Total stockholders’ equity	171,145	41,249	65,855
Total liabilities and stockholders’ equity	$326,072	$169,820

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$0.00	$0.00
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	36,150,620	33,636,442
Common stock, shares outstanding	36,150,620	33,636,442
Treasury stock at cost, shares	0	0

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Net product sales	$193,526	$81,956	$18,191
Collaborative licensing and development revenue	1,287	972	18,390
Royalty revenue	2,855	2,623	2,503
Total revenues	197,668	85,551	39,084
Operating expenses:
Cost of revenues	77,440	54,772	32,139
Research and development	18,731	21,560	9,937
Selling, general and administrative	106,662	62,508	46,306
Total operating expenses	202,833	138,840	88,382
Loss from operations	-5,165	-53,289	-49,298
Other (expense) income:
Interest income	382	259	275
Interest expense	-8,278	-7,253	-1,807
Loss on early extinguishment of debt	0	-3,398	-1,062
Royalty interest obligation	-323	-623	-278
Other, net	-159	-47	-111
Total other expense, net	-8,378	-11,062	-2,983
Loss before income taxes	-13,543	-64,351	-52,281
Income tax (expense) benefit	-173	442	0
Net loss	($13,716)	($63,909)	($52,281)
Net loss per share:
Basic and diluted net loss per common share (in dollars per share)	($0.39)	($1.93)	($1.72)
Weighted average common shares outstanding:
Basic and diluted (in shares)	35,299	33,182	30,332

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Loss (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net loss	($13,716)	($63,909)	($52,281)
Other comprehensive income (loss):
Net unrealized gain (loss) on investments	-85	-22	12
Total other comprehensive income (loss)	-85	-22	12
Comprehensive loss	($13,801)	($63,931)	($52,269)

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (Deficit) (USD $)	Total	Common Stock	Common Stock	Common Stock	Additional Paid-In Capital	Additional Paid-In Capital	Additional Paid-In Capital	Accumulated Deficit	Treasury Stock	Accumulated Other Comprehensive Income
In Thousands, except Share data, unless otherwise specified			2009 Convertible Notes and accrued interest	2009 Secured Notes and accrued interest		2009 Secured Notes and accrued interest	HBM Secured Notes and accrued interest and early prepayment penalty
Balances at Dec. 31, 2011	$48,269	$25			$228,470			($180,239)	($2)	$15
Balances (in shares) at Dec. 31, 2011		25,339,000
Increase (Decrease) in Stockholders' Equity
Exercise of stock options	770	1			769
Exercise of stock options (in shares)		279,000
Net loss	100				100
Exercise of warrants (in shares)		105,000
Exercise of warrants	4,776				4,776
Stock-based compensation		0
Initial public offering, net of issuance costs (in shares)		0
Exercise of stock options	62,855	7			62,848
Follow-on public offering, net of issuance costs (in shares)		6,900,000
Conversion of Convertible Notes and accrued interest			0
Conversion of Convertible Notes (in shares)			0
Conversion of Secured Notes and accrued interest and early prepayment penalty				0		0
Conversion of Secured Notes and accrued interest and early prepayment penalty (in shares)				0
Unrealized gain (loss) on short-term investments	12									12
Shares issued under employee stock purchase plan	1,354				1,354
Net loss	-52,281							-52,281
Balances at Dec. 31, 2012	65,855	33			298,317			-232,520	-2	27
Balances (in shares) at Dec. 31, 2012		32,623,000
Increase (Decrease) in Stockholders' Equity
Exercise of stock options	3,856	1			3,855
Exercise of stock options (in shares)		741,000
Net loss	0				0
Exercise of warrants (in shares)		271,000
Exercise of warrants	11,513				11,513
Exercise of stock options	110,452
Conversion of Secured Notes and accrued interest and early prepayment penalty							0
Unrealized gain (loss) on short-term investments	-22									-22
Equity component of convertible senior notes, net of issuance costs	23,956				23,956
Issuance of common stock from treasury					-2				2
Issuance of common stock from treasury (in shares)		1,000
Net loss	-63,909							-63,909
Balances at Dec. 31, 2013	41,249	34			337,639			-296,429	0	5
Balances (in shares) at Dec. 31, 2013		33,636,000
Increase (Decrease) in Stockholders' Equity
Exercise of stock options	7,239	0			7,239
Exercise of stock options (in shares)		624,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans	15,722	16,000
Stock Issued During Period, Value, Employee Stock Purchase Plan		0			1,184
Net loss	0
Exercise of warrants (in shares)		35,000
Exercise of warrants	24,822				24,822
Exercise of stock options		2			110,450
Follow-on public offering, net of issuance costs (in shares)		1,840,000
Conversion of Secured Notes and accrued interest and early prepayment penalty							0
Unrealized gain (loss) on short-term investments	-85									-85
Shares issued under employee stock purchase plan	1,184
Net loss	-13,716							-13,716
Balances at Dec. 31, 2014	$171,145	$36			$481,334			($310,145)	$0	($80)
Balances (in shares) at Dec. 31, 2014		36,151,000

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities:
Net loss	($13,716)	($63,909)	($52,281)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation of fixed assets and amortization of intangibles	10,035	5,747	5,648
Amortization of unfavorable lease obligation and debt issuance costs	487	459	-239
Amortization of debt discount	4,139	3,959	831
Loss on disposal of fixed assets	158	32	1
Loss on early extinguishment of debt	0	3,398	1,062
Stock-based compensation	24,822	11,513	4,776
Changes in operating assets and liabilities:
Restricted cash	124	-110	-224
Accounts receivable, net	-7,776	-10,238	-2,239
Inventories	-13,706	-3,480	-10,832
Prepaid expenses and other assets	-1,447	-972	-59
Accounts payable and accrued expenses	14,254	10,244	1,386
Royalty interest obligation	-970	-434	-1,076
Other liabilities	2,352	1,047	-106
Deferred revenue	6,713	-472	-16,778
Net cash provided by (used in) operating activities	25,469	-43,216	-70,130
Investing activities:
Purchases of fixed assets	-21,889	-12,794	-18,257
Proceeds from sales of fixed assets	0	0	1
Purchases of short-term investments	-139,840	-114,299	-54,047
Sales of short-term investments	80,286	85,564	53,120
Purchases of long-term investments	-24,463	0	0
Payment of contingent consideration	-13,433	-2,031	-10,339
Net cash used in investing activities	-119,339	-43,560	-29,522
Financing activities:
Proceeds from follow-on public offering, net	110,452	0	62,855
Proceeds from exercise of stock options and warrants	7,239	3,856	870
Proceeds from shares issued under employee stock purchase plan	1,184	0	0
Proceeds from borrowings on long-term debt		0	27,500
Proceeds from convertible senior notes		120,000	0
Repayment of debt	0	-27,500	-26,250
Payment of debt issuance and financing costs	0	-7,191	-1,365
Net cash provided by financing activities	118,875	89,165	63,610
Net increase (decrease) in cash and cash equivalents	25,005	2,389	-36,042
Cash and cash equivalents, beginning of year	12,515	10,126	46,168
Cash and cash equivalents, end of year	37,520	12,515	10,126
Supplemental cash flow information:
Cash paid for interest, including royalty interest obligation	5,193	3,500	4,229
Cash paid for income taxes	34	0	0
Non-cash investing and financing activities:
Equity component of convertible senior notes	0	24,936	0
Value of warrants issued with debt	$0	$0	$1,354

DESCRIPTION_OF_BUSINESS

DESCRIPTION OF BUSINESS	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS	DESCRIPTION OF BUSINESS
	Pacira Pharmaceuticals, Inc. and its subsidiaries (collectively, the “Company” or “Pacira”) is a specialty pharmaceutical company focused on the development, commercialization and manufacture of proprietary pharmaceutical products, based on its proprietary DepoFoam® extended release drug delivery technology, primarily for use in hospitals and ambulatory surgery centers. The Company’s lead product, EXPAREL®, which consists of bupivacaine encapsulated in DepoFoam, was approved by the United States Food and Drug Administration, or FDA, on October 28, 2011 and launched commercially in April 2012. DepoFoam is also the basis for the Company’s other FDA-approved product, DepoCyt(e), which the Company manufactures for its commercial partners.
	Pacira is subject to risks common to companies in similar industries and stages of development, including, but not limited to, competition from larger companies, reliance on revenue from few customers and products, reliance on a single manufacturing site, new technological innovations, dependence on key personnel, reliance on third-party service providers and sole source suppliers, protection of proprietary technology and compliance with government regulations.

SUMMARY_OF_SIGNIFICANT_ACCOUNT

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Basis of Presentation and Principles of Consolidation
	The consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America, or GAAP, and in accordance with the rules and regulations of the Securities and Exchange Commission, or SEC. The accounts of wholly owned subsidiaries are included in the consolidated financial statements. All intercompany balances and transactions have been eliminated in consolidation. Certain reclassifications were made to conform to the current presentation.
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires the use of estimates and assumptions that affect the reported amounts of assets and liabilities, including disclosure of contingent assets and contingent liabilities, at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Estimates are used for, among other things, revenue recognition, impairment of long-lived assets, stock-based compensation and valuation of deferred tax assets. The Company’s critical accounting policies are those that are both most important to the Company’s consolidated financial condition and results of operations and require the most difficult, subjective or complex judgments on the part of management in their application, often as a result of the need to make estimates about the effect of matters that are inherently uncertain. Because of the uncertainty of factors surrounding the estimates or judgments used in the preparation of the consolidated financial statements, actual results could differ from these estimates.
	Liquidity
	Management believes that the Company’s existing cash and cash equivalents, restricted cash, short-term and long-term investments and cash flows generated from product sales will be sufficient to enable the Company to meet its planned operating expenses, capital expenditure requirements, payment of the principal on any conversions of the Company’s convertible senior notes and to service its indebtedness at least through December 31, 2015. However, changing circumstances may cause the Company to expend cash significantly faster than currently anticipated, and the Company may need to spend more cash than currently expected because of circumstances beyond its control. The Company expects to continue to incur substantial additional expenditures as it continues to commercialize EXPAREL, develops and seeks regulatory approval for its product candidates, and expands its manufacturing facilities for EXPAREL and its other product candidates including costs associated with certain technical transfer activities and construction of two dedicated manufacturing suites in the United Kingdom.
	On January 23, 2013, the Company completed a private placement of $120.0 million in aggregate principal amount of 3.25% convertible senior notes, or Notes, due 2019. As further discussed in Note 8, Debt, the Company must settle the principal of the Notes in cash upon conversion, and it may settle any conversion premium in either cash, stock or a combination of cash and shares of common stock at the Company’s discretion. Based on certain conditions that were met during the three months ended December 31, 2014, the holders can convert their Notes at any time during the quarter ended March 31, 2015 and, therefore, the Notes are classified in the consolidated balance sheet at December 31, 2014 as a current obligation. In the event of conversion, holders would forgo all future interest payments, any unpaid interest and the possibility of further stock price appreciation. In the event that all of the Notes are converted, the Company would be required to repay the $120.0 million in principal value and approximately $309 million of cash or issue approximately 3.5 million shares of its common stock (or a combination of cash and shares of its common stock) to settle the conversion premium as of December 31, 2014, causing dilution to the Company’s current shareholders.
	Revenue Recognition
	The Company’s principal sources of revenue include (i) sales of EXPAREL in the United States, or U.S., (ii) sales of DepoCyt(e) in the U.S. and the European Union, or E.U., (iii) royalties based on sales by commercial partners of DepoCyt(e) and (iv) license fees, milestone payments and reimbursement for development work from third parties. The Company recognizes revenue when there is persuasive evidence that an arrangement exists, title has passed, collection is reasonably assured and the price is fixed or determinable.
	Net Product Sales
	The Company sells EXPAREL through a drop-ship program under which orders are processed through wholesalers based on orders of the product placed by end users which include hospitals, ambulatory surgery centers and doctors. EXPAREL is delivered directly to the end user without the wholesaler ever taking physical possession of the product. The Company records revenue at the time the product is delivered to the end user. The Company also recognizes revenue from products manufactured and supplied to commercial partners, such as DepoCyt(e) upon shipment. Prior to the shipment of manufactured products, the Company conducts initial product release and stability testing in accordance with current Good Manufacturing Practices.
	Revenues from sales of products are recorded net of returns allowances, prompt payment discounts, wholesaler service fees and volume rebates and chargebacks. The calculation of some of these items requires management to make estimates based on sales data, contracts, inventory data and other related information which may become known in the future. The Company reviews the adequacy of its provisions on a quarterly basis.
	Returns Allowances
	The Company allows customers to return product that is damaged or received in error. In addition, the Company allows EXPAREL to be returned beginning six months prior to, and twelve months following product expiration. As EXPAREL is a newly commercially available product, the Company estimates its sales return reserve based on return history from other hospital-based products with similar distribution models and its historical experience, which management believes is the best estimate of the anticipated product to be returned. The returns reserve is recorded at the time of sale as a reduction to gross product sales and an increase in accrued expenses.
	The Company’s commercial partners can return Depocyt(e) within contractually specified timeframes if the product does not meet the applicable inspection tests. The Company estimates its returns reserve based on its experience with historical return rates. Historically, the Company’s product returns have not been material.
	Prompt Payment Discounts
	The prompt payment reserve is based upon discounts offered to wholesalers as an incentive to meet certain payment
	terms. The Company accrues discounts to wholesalers based on contractual terms of agreements and historical experience. The Company accounts for these discounts at the time of sale as a reduction to gross product sales and a reduction to accounts receivable.
	Wholesaler Service Fees
	The Company’s customers include major and regional wholesalers with whom the Company has contracted a fee for service based on a percentage of gross product sales. This fee for service is recorded as a reduction to gross product sales and an increase to accrued expenses at the time the sale, and is recorded based on the contracted percentage.
	Volume Rebates and Chargebacks
	Volume rebates and chargeback reserves are based upon contracted discounts and promotional offers the Company provides to certain end users such as members of group purchasing organizations. Volume rebates are recorded at the time of sale as a reduction to gross product sales and an increase in accrued expenses. Chargeback reserves are recorded at the time of sale as a reduction to gross product sales and a reduction to accounts receivable.
	Royalty Revenue
	The Company recognizes revenue from royalties based on sales of its commercial partners’ net sales of products. Royalties are recognized as earned in accordance with contract terms when they can be reasonably estimated based and collection is reasonably assured. The Company’s commercial partners are obligated to report their net product sales and the resulting royalty due to the Company within 60 days from the end of each quarter. Based on historical product sales, royalty receipts and other relevant information, the Company accrues royalty revenue each quarter and subsequently trues-up its royalty revenue when it receives royalty reports from its commercial partners.
	Collaborative Licensing and Development Revenue
	The Company recognizes revenue from reimbursements received in connection with feasibility studies and development work for third parties who desire to utilize its DepoFoam extended release drug delivery technology for their products when the Company’s contractual services are performed, provided collection is reasonably assured. The Company’s principal costs under these agreements include costs for its personnel conducting research and development, its allocated overhead as well as research and development performed by outside contractors or consultants.
	The Company recognizes revenues from non-refundable up-front license fees received under collaboration agreements ratably over the performance period as determined under the collaboration agreement (estimated development period in the case of development agreements, and contract period or longest patent life in the case of supply and distribution agreements). If the estimated performance period is subsequently modified, the Company will modify the period over which the up-front license fee is recognized accordingly on a prospective basis. Upon notification of a termination of a collaboration agreement, any remaining non-refundable license fees received by the Company, which had been deferred, are recognized over the remaining contractual term. If the termination is immediate and no additional services are to be performed, the deferred revenue is generally recognized in full. All such recognized revenues are included in collaborative licensing and development revenue in the Company’s consolidated statements of operations.
	The Company recognizes revenue from milestone payments received under collaboration agreements when earned, provided that the milestone event is substantive, its achievability was not reasonably assured at the inception of the agreement, the Company has no further performance obligations relating to the event and collection is reasonably assured. If these criteria are not met, the Company recognizes milestone payments ratably over the remaining period of the Company’s performance obligations under the applicable agreements.
	Concentration of Major Customers
	The Company’s customers are national and regional wholesalers of pharmaceutical products as well as commercial, collaborative and licensing partners. The Company sells EXPAREL through a drop-ship program under which orders are processed through wholesalers (including AmerisourceBergen Health Corporation, Cardinal Health, Inc., and McKesson Drug Company), but shipments of the product are sent directly to individual accounts, such as hospitals, ambulatory surgery centers and individual doctors. The table below includes the percentage of revenue comprised by the three largest customers (i.e., wholesalers or commercial partners) in each year presented:
		Year Ended December 31,
		2014		2013		2012
	Largest customer	33	%	33	%	30	%
	Second largest customer	29	%	28	%	14	%
	Third largest customer	24	%	18	%	11	%
		86	%	79	%	55	%
	Revenues from customers outside the U.S. accounted for 2%, 5% and 23% of the Company’s revenue for the years ended December 31, 2014, 2013 and 2012, respectively.
	Research and Development Expenses
	Research and development expenses consist of costs associated with products being developed internally, and include related personnel expenses, laboratory supplies, active pharmaceutical ingredients, manufacturing supplies, facilities costs, preclinical and clinical trial costs and other outside service fees. The Company expenses research and development costs as incurred. A significant portion of the development activities are outsourced to third parties, including contract research organizations. In such cases, the Company may be required to estimate related service fees to be accrued.
	Cash and Cash Equivalents
	All highly-liquid investments with maturities of 90 days or less when purchased are considered cash equivalents.
	Restricted Cash
	As further discussed in Note 8, Debt, the Company had entered into a financing agreement with Paul Capital for the sale of a royalty interest in its DepoCyt(e) and DepoDur® product revenue and royalties. The royalty interest agreement pertained only to DepoCyt(e) and the Company’s previously-marketed product, DepoDur, and does not include revenue related to EXPAREL or any other product candidates. As part of this financing agreement, the Company and Paul Capital maintained a lockbox, where all DepoCyt(e) and DepoDur product revenue and royalties were received. The Company had no minimum payment obligations under this agreement. Commencing on April 1 of every year, the first $2.5 million received in the lockbox was restricted and was used to make quarterly payments due to Paul Capital, if any, under the agreement during the subsequent 12 month period. On March 31 of the subsequent year, the balance of cash in the lockbox, if any, is remitted to the Company. The Paul Capital agreement terminated on December 31, 2014.
	Short-Term and Long-Term Investments
	Short-term investments consist of asset-backed securities collateralized by credit card receivables, investment grade commercial paper and corporate bonds with initial maturities of greater than three months at the date of purchase, but less than one year. Long-term investments consist of corporate bonds with initial maturities greater than one year at the date of purchase. The Company determines the appropriate classification of its investments at the time of purchase and reevaluates such determination at each balance sheet date. The Company’s investment policy sets minimum credit quality criteria and maximum maturity limits on its investments to provide for preservation of capital, liquidity and a reasonable rate of return. Available-for-sale securities are recorded at fair value, based on current market valuations. Unrealized holding gains and losses on available-for-sale securities are excluded from net loss and are reported as a separate component of other comprehensive loss until realized. Realized gains and losses are included in non-operating other income (expense) on the consolidated statements of operations and are derived using the specific identification method for determining the cost of the securities sold.
	Inventories
	Inventories consist of finished goods held for sale and distribution, raw materials and work in process. Inventories are stated at the lower of cost, which includes amounts related to material, labor and overhead; or market (net realizable) value and is determined using the first-in, first-out (“FIFO”) method. The Company periodically reviews its inventory to identify obsolete, slow-moving, or otherwise unsalable inventories, and establishes allowances for situations in which the cost of the inventory is not expected to be recovered.
	Fixed Assets
	Fixed assets are recorded at cost, net of accumulated depreciation and amortization. The Company reviews its property, plant and equipment assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable.
	Depreciation of fixed assets is provided over their estimated useful lives on a straight-line basis. Leasehold improvements are amortized on a straight-line basis over the shorter of their estimated useful lives or the related remaining lease terms. Useful lives by asset category are as follows:
	Asset Category		Useful Lives
	Computer equipment and software		1 to 3 years
	Office furniture and equipment		5 years
	Manufacturing and laboratory equipment		5 to 10 years
	Goodwill and Intangible Assets
	Intangible assets are recorded at cost, net of accumulated amortization. Amortization of intangible assets is provided over their estimated useful lives on a straight-line basis. The Company evaluates the recoverability of intangible assets periodically and takes into account events and circumstances which may indicate that impairment exists. Goodwill represents the excess of purchase price over fair value acquired in a business combination and is not amortized, but subject to impairment at least annually or when a triggering event occurs that could indicate a potential impairment.
	Impairment of Long-Lived Assets
	Management reviews long-lived assets, including fixed assets, for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets.
	Convertible Debt Transactions
	The Company separately accounts for the liability and equity components of convertible debt instruments by allocating the proceeds from the issuance between the liability component and the embedded conversion option, or equity component. This is done in accordance with accounting for convertible debt instruments that may be settled in cash (including partial cash settlement) upon conversion. The value of the equity component is calculated by first measuring the fair value of the liability component, using the interest rate of a similar liability that does not have a conversion feature, as of the issuance date. The difference between the initial proceeds from the convertible debt issuance and the fair value of the liability component is recorded as the carrying amount of the equity component. The Company recognizes the amortization of the resulting discount as part of interest expense in its consolidated statement of operations.
	Upon settlement of the convertible senior notes, the liability component is measured at fair value. The Company allocates a portion of the fair value of the total settlement consideration transferred to the extinguishment of the liability component equal to the fair value of that component immediately prior to the settlement. Any difference between the consideration attributed to the liability component and the net carrying amount of the liability component, including any unamortized debt issuance costs, is recognized as a gain or loss in the consolidated statement of operations. Any remaining consideration is allocated to the reacquisition of the equity component and is recognized as a reduction of additional paid-in capital.
	Foreign Currencies
	The Company receives payment from certain commercial partners relating to royalties on DepoCyte® in Euros. Realized gains and losses from foreign currency transactions are reflected in the consolidated statements of operations and were not significant in any period. All foreign currency receivables and payables are measured at the applicable exchange rate at the end of the reporting period.
Income Taxes
The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to basis differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. As of December 31, 2014 and 2013, all deferred tax assets were fully offset by a valuation allowance.
In February 2013, the Company received $0.4 million from the sale of unused net operating losses through the State of New Jersey’s Economic Development Authority Technology Business Tax Certificate Transfer Program. As a result, the Company recorded an income tax benefit by reversing the valuation allowance for the related net deferred tax assets. The Company continues to maintain a full valuation allowance on its remaining net deferred tax assets because there is significant doubt regarding the Company’s ability to utilize such net deferred tax assets.
The Company accrues interest and penalties, if any, on underpayment of income taxes related to unrecognized tax benefits as a component of income tax expense in its consolidated statements of operations.
Per Share Data
Basic net income (loss) per share is computed by dividing net income (loss) available (attributable) to common stockholders by the weighted average number of shares of common stock outstanding during the period.
Diluted net income (loss) per share is calculated by dividing net income (loss) available (attributable) to common stockholders as adjusted for the effect of dilutive securities, if any, by the weighted average number of common stock and dilutive common stock outstanding during the period. Potential common shares include the shares of common stock issuable upon the exercise of outstanding stock options, warrants and the purchase of shares from the employee stock purchase plan (using the treasury stock method) as well as the conversion of the excess conversion value on the Notes. Potential common shares in the diluted net loss per share computation are excluded to the extent that they would be anti-dilutive. No potentially dilutive securities are included in the computation of any diluted per share amounts as the Company reported a net loss for all periods presented.
Stock-Based Compensation
The Company’s stock-based compensation program includes grants of stock options to employees, consultants, and non-employee directors in addition to the opportunity for employees to participate in an employee stock purchase plan. The expense associated with these programs is recognized in the Company’s consolidated statements of operations based on their fair values as they are earned under the applicable vesting terms or the length of an offering period.
The valuation of stock options is an inherently subjective process, since market values are generally not available for long-term, non-transferable stock options. Accordingly, the Company uses an option pricing model to derive an estimated fair value. In calculating the estimated fair value of stock options granted, the Company uses the Black-Scholes option valuation model, or Black-Scholes model, which requires the consideration of the following variables for purposes of estimating fair value:
•	Expected term of the option
•	Expected volatility
•	Expected dividends
•	Risk-free interest rate
Since its initial public offering, the Company utilizes its available historic volatility data combined with a publicly traded peer group’s historic volatility to determine expected volatility over the expected option term. In 2014, the Company used an expected term based on a weighted average combination of its historical data from stock option exercises and the simplified method. In prior years the Company utilized the “simplified” method for “plain vanilla” options to estimate the expected term of stock option grants. Under that approach, the weighted average expected life was presumed to be the average of the vesting term and the contractual term of the option. The risk-free interest rate is based on the implied yield on United States Department of the Treasury zero coupon bonds for periods commensurate with the expected term of the options. The dividend yield on the Company’s common stock is estimated to be zero as the Company has not paid any dividends since inception, nor does it have any intention to do so in the foreseeable future. The Company estimates the level of award forfeitures expected to occur based on its historical data and records compensation cost only for those awards that are ultimately expected to vest.
Segment Reporting
The Company operates in one reportable segment and, accordingly, no segment disclosures have been presented.

RECENT_ACCOUNTING_PRONOUNCEMEN

RECENT ACCOUNTING PRONOUNCEMENTS	12 Months Ended
	Dec. 31, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
RECENT ACCOUNTING PRONOUNCEMENTS	RECENT ACCOUNTING PRONOUNCEMENTS
	In May 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update 2014-09, Revenue from Contracts with Customers, which requires that an entity recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to its customers. In order to achieve this core principle, an entity should apply the following steps: (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract and (5) recognize revenue when (or as) the entity satisfies a performance obligation. This update will replace existing revenue recognition guidance under GAAP when it becomes effective for the Company beginning January 1, 2017, with early adoption not permitted. The updated standard will permit the use of either the retrospective or cumulative effect transition method. The Company is currently evaluating the impact of this update on its consolidated financial statements.
	In August 2014, the FASB issued Accounting Standards Update 2014-15, Presentation of Financial Statements—Going Concern, which requires that management of an entity should evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued or available to be issued. This update will become effective beginning January 1, 2017, with early adoption permitted. The provisions of this standard are not expected to significantly impact the Company.
	Other pronouncements issued by the FASB or other authoritative accounting standards groups with future effective dates are either not applicable or not significant to the consolidated financial statements of the Company.

INVENTORIES

INVENTORIES	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES
	The components of inventories are as follows (in thousands):
		December 31,
		2014		2013
	Raw materials	$	9,263	$	5,290
	Work-in-process	8,617		6,321
	Finished goods	11,383		3,946
	Total	$	29,263	$	15,557

FIXED_ASSETS

FIXED ASSETS	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
FIXED ASSETS	FIXED ASSETS
	Fixed assets, net summarized by major category, consist of the following (in thousands):
		December 31,
		2014			2013
	Machinery and laboratory equipment	$	29,697		$	19,570
	Computer equipment and software	3,754			2,476
	Office furniture and equipment	1,001			441
	Leasehold improvements	26,350			24,852
	Construction in progress	19,944			13,419
	Total	80,746			60,758
	Less: accumulated depreciation	(20,114		)	(12,576		)
	Fixed assets, net	$	60,632		$	48,182
	Depreciation expense for the years ended December 31, 2014, 2013 and 2012 was $9.3 million, $3.7 million and $3.6 million, respectively. During the years ended December 31, 2014, 2013 and 2012, the Company capitalized interest of $0.4 million, $1.1 million and $2.0 million, respectively. The balance of construction in progress at December 31, 2014 relates largely to the construction of a new manufacturing facility in the United Kingdom and a new fill line for EXPAREL at the Company’s Science Center Campus in San Diego, California.

GOODWILL_AND_INTANGIBLE_ASSETS

GOODWILL AND INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	GOODWILL AND INTANGIBLE ASSETS
	In March 2007, the Company acquired from SkyePharma Holding, Inc., or Skyepharma, its California operating subsidiary, or Pacira California, referred to herein as the Acquisition. The Company’s goodwill arose in April 2012 from a contingent milestone payment to Skyepharma in connection with the Acquisition. The Acquisition was accounted for under Statement of Financial Accounting Standards 141, Accounting for Business Combinations, which was the effective GAAP at the Acquisition date. In connection with the Acquisition, the Company agreed to certain earn-out payments based on a percentage of net sales of EXPAREL collected and certain other yet-to-be-developed products as well as milestone payments for EXPAREL as follows:
	(i)	$10.0 million upon the first commercial sale in the United States;
	(ii)	$4.0 million upon the first commercial sale in a major EU country (United Kingdom, France, Germany, Italy and Spain);
	(iii)	$8.0 million when annual net sales collected reach $100.0 million;
	(iv)	$8.0 million when annual net sales collected reach $250.0 million; and
	(v)	$32.0 million when annual net sales collected reach $500.0 million.
	The first milestone was met in April 2012 resulting in a $10.0 million payment to Skyepharma. The Company recorded this payment net of a $2.0 million contingent consideration liability recognized at the time of the Acquisition, resulting in $8.0 million recorded as goodwill. In September 2014, the Company made an $8.0 million milestone payment to Skyepharma in connection with achieving $100.0 million of EXPAREL net sales collected. For purposes of meeting future milestone payments, with certain exceptions, annual net sales are measured on a rolling quarterly basis. Cumulatively through December 31, 2014, the Company has recorded an additional $7.8 million as goodwill for earn-out payments which are based on a percentage of net sales of EXPAREL collected. Any remaining earn-out payments will also be treated as additional costs of the Acquisition and, therefore, recorded as goodwill if and when each contingency is resolved.
	The change in the carrying value of goodwill is summarized as follows (in thousands):
			Carrying Value
	Balance at December 31, 2012		$	8,297
	Percentage payments on collections of net sales of EXPAREL		2,031
	Balance at December 31, 2013		10,328
	Milestone payment triggered by collections of net sales of EXPAREL		8,000
	Percentage payments on collections of net sales of EXPAREL		5,433
	Balance at December 31, 2014		$	23,761
	Intangible assets, net, consist of core technology, developed technology and trademarks and trade names acquired in the Acquisition and are summarized as follows (in thousands):
	December 31, 2014	Gross			Accumulated			Intangible		Estimated
		Carrying Value			Amortization			Assets, Net		Useful Life
	Amortizable intangible assets:
	Core technology	$	2,900		$	(2,497	)	$	403	9 Years
	Developed technology	11,700			(11,700		)	—		7 Years
	Trademarks and trade names	400			(400		)	—		7 Years
	Total intangible assets	$	15,000		$	(14,597	)	$	403
	December 31, 2013	Gross			Accumulated			Intangible		Estimated
		Carrying Value			Amortization			Assets, Net		Useful Life
	Amortizable intangible assets:
	Core technology	$	2,900		$	(2,175	)	$	725	9 years
	Developed technology	11,700			(11,282		)	418		7 years
	Trademarks and trade names	400			(386		)	14		7 years
	Total intangible assets	$	15,000		$	(13,843	)	$	1,157
	Annual amortization expense for intangibles for the years ended December 31, 2014, 2013 and 2012 was $0.8 million, $2.1 million and $2.1 million, respectively.
	Future amortization expense relates only to core technology and is as follows (in thousands):
	2015		$	322
	2016		81
	Total		$	403

ACCRUED_EXPENSES

ACCRUED EXPENSES	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
ACCRUED EXPENSES	ACCRUED EXPENSES
	Accrued expenses consist of the following (in thousands):
		December 31,
		2014		2013
	Compensation and benefits	$	8,909	$	5,488
	Accrued operating expenses	12,094		8,001
	Accrued royalties	3,213		1,526
	Accrued interest	1,625		1,625
	Product returns, rebates and other fees	2,470		1,245
	Income taxes payable	139		—
	Total	$	28,450	$	17,885

DEBT

DEBT	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
DEBT	DEBT
	The composition of the Company’s debt and financing obligations is as follows (in thousands):
		December 31,
		2014			2013
	Debt:
	Convertible senior notes	$	120,000		$	120,000
	Discount on debt	(16,900		)	(21,039		)
	Total debt, net of discount	103,100			98,961
	Royalty interest obligation	276			1,246
	Total debt and financing obligations	$	103,376		$	100,207
	Senior Convertible Notes
	On January 23, 2013, the Company completed a private placement of $120.0 million in aggregate principal amount of 3.25% Notes, and entered into an indenture agreement, or Indenture, with respect to the Notes. The Notes accrue interest at a fixed rate of 3.25% per year, payable semiannually in arrears on February 1 and August 1 of each year, beginning on August 1, 2013. The Notes mature on February 1, 2019.
	The net proceeds from the offering were $115.3 million after deducting the initial purchasers’ discounts, commissions and the offering expenses payable by the Company. The net proceeds from the Notes were used by the Company to repay the entire balance of the Company’s then existing credit facility. In connection with the extinguishment of the credit facility, the Company prepaid the remaining principal amount of $27.5 million, a $1.7 million end of term fee, an $0.8 million early prepayment penalty and $0.2 million of accrued interest. The Company recorded a loss on extinguishment of debt of $3.4 million, comprised of the early prepayment penalty, the remaining unamortized debt issuance costs and end of term fee.
	Holders may convert their Notes prior to the close of business on the business day immediately preceding August 1, 2018, only under the following circumstances:
	(i) during any calendar quarter commencing after the calendar quarter ending on June 30, 2013, if the last reported sale price of the Company’s common stock for at least 20 trading days during the period including the last 30 consecutive trading days of the quarter (ending on the last trading day of the immediately preceding calendar quarter) is greater than 130% of the conversion price then applicable (the “Consecutive Sales Price”), on each applicable trading day;
	(ii) during the five business-day period after any five consecutive trading-day period (the ‘‘measurement period’’) in which the trading price (as defined in the Indenture) per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day;
	(iii) upon the occurrence of specified corporate events, including a merger or a sale of all or substantially all of the Company’s assets; or
	(iv) if the Company calls the Notes for redemption until the close of business on the business day immediately preceding the redemption date.
	On or after August 1, 2018, until the close of business on the second scheduled trading day immediately preceding February 1, 2019, holders may convert their Notes at any time, regardless of the foregoing circumstances. Upon conversion, holders will receive cash up to the principal amount of the Notes and, with respect to any excess conversion value, cash, shares of the Company’s common stock or a combination of cash and shares of the Company’s common stock, at the Company’s option. The initial conversion rate for the Notes was 40.2945 shares of common stock per $1,000 principal amount, which is equivalent to an initial conversion price of approximately $24.82 per share of the Company’s common stock. The conversion rate will be subject to adjustment for some events, but will not be adjusted for any accrued and unpaid interest. The initial conversion price of the Notes represented a premium of approximately 32.5% to the closing sale price of $18.73 per share of the Company’s common stock on The NASDAQ Global Select Market on January 16, 2013, the date that the Company priced the private offering of the Notes.
	During the quarter ended December 31, 2014, the requirements with respect to the Consecutive Sales Price were met. As a result, the Notes are classified as a current obligation and will be convertible until March 31, 2015. As of December 31, 2014, the Notes had a market price of $3,579 per $1,000 principal amount, compared to an estimated conversion value of $3,572. In the event of conversion, holders would forgo all future interest payments, any unpaid accrued interest and the possibility of further stock price appreciation. Upon the receipt of conversion requests, the settlement of the Notes will be paid pursuant to the terms of the Indenture, which state that the principal must be settled in cash. In the event that all of the Notes are converted, the Company would be required to repay the $120.0 million in principal value and approximately $309 million of cash or issue approximately 3.5 million shares of its common stock (or a combination of cash and shares of its common stock) to settle the conversion premium as of December 31, 2014, causing dilution to the Company’s shareholders and/or significant expenditures of the Company’s cash and liquid securities. See Note 19, Subsequent Events, for further discussion of a conversion request received in February 2015.
	While the Notes are classified in the Company’s consolidated balance sheets at December 31, 2014 and 2013 as a current obligation, the future convertibility and resulting balance sheet classification of this liability will be monitored at each quarterly reporting date and will be analyzed dependent upon market prices of the Company’s common stock during the prescribed measurement periods. In the event that the holders of the Notes continue to have the election to convert the Notes at any time during the prescribed measurement period, the Notes will continue to be considered a current obligation and classified as such. Prior to February 1, 2018, in the event that none of the conversion conditions are satisfied, the Notes would be reclassified as a long-term liability.
	Prior to February 1, 2017, the Company may not redeem the Notes. On or after February 1, 2017, the Company may redeem for cash all or part of the Notes if the last reported sale price (as defined in the Indenture) of the Company’s common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading-day period ending within five trading days prior to the date on which the Company provides notice of redemption. The redemption price will equal the sum of (i) 100% of the principal amount of the Notes being redeemed, plus (ii) accrued and unpaid interest, including additional interest, if any, to, but excluding, the redemption date, plus (iii) a “make-whole premium” payment in cash equal to the sum of the present values of the remaining scheduled payments of interest that would have been made on the Notes to be redeemed had such Notes remained outstanding from the redemption date to the maturity date (excluding interest accrued to, but excluding, the redemption date that is otherwise paid pursuant to the preceding clause (ii)). The present values of the remaining interest payments will be computed using a discount rate equal to 2.0%. The Company must make the make-whole premium payments on all Notes called for redemption prior to the maturity date, including Notes converted after the date the Company provides the notice of redemption. No sinking fund is provided for the Notes, which means that the Company is not required to redeem or retire the Notes periodically.
	If the Company undergoes a fundamental change as defined in the Indenture, subject to certain conditions, holders of the Notes may require the Company to repurchase for cash all or part of their Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date.
	The Notes are senior unsecured obligations of the Company and will rank senior in right of payment to the Company’s future indebtedness, if any, that is expressly subordinated in right of payment to the Notes and equal in right of payment to the Company’s existing and future unsecured indebtedness that is not so subordinated. The Notes are effectively junior in right of payment to any secured indebtedness of the Company to the extent of the value of the assets securing such indebtedness and are structurally junior to all existing and future indebtedness and other liabilities (including trade payables) incurred by the Company’s subsidiaries.
	The Notes do not contain any financial or operating covenants or any restrictions on the payment of dividends, the incurrence of other indebtedness or the issuance or repurchase of securities by the Company. The Indenture contains customary events of default with respect to the Notes, including that upon certain events of default, 100% of the principal of and accrued and unpaid interest on the Notes will automatically become due and payable.
	Under Accounting Standards Codification 470-20, Debt with Conversion and Other Options, an entity must separately account for the liability and equity components of convertible debt instruments (such as the Notes) that may be settled entirely or partially in cash upon conversion in a manner that reflects the issuer’s economic interest cost. The equity component is recorded in additional paid-in capital in the consolidated balance sheet at the issuance date and the equity component is treated as a discount on the liability component of the Notes. The initial carrying value of the liability component of $95.1 million was calculated by measuring the fair value of a similar liability that does not have an associated convertible feature. The carrying value of the equity component, representing the conversion option, was determined by deducting the fair value of the liability component from the par value of the Notes. The equity component is not re-measured as long as it continues to meet the conditions for equity classification.
	The Company allocated the total transaction costs of $4.7 million related to the issuance of the Notes to the liability and equity components of the Notes based on their relative values. Transaction costs attributable to the liability component are amortized to interest expense over the six-year term of the Notes, and transaction costs attributable to the equity component are netted with the equity components in stockholders’ equity.
	The following table sets forth the total interest expense recognized related to the Notes issued in January 2013 (in thousands):
		Year Ended December 31,
		2014			2013
	Contractual interest expense	$	3,900		$	3,662
	Amortization of debt issuance costs	620			584
	Amortization of debt discount	4,139			3,897
		$	8,659		$	8,143
	Effective interest rate	7.22		%	7.22		%
	Oxford Loan Facility
	On May 2, 2012, the Company entered into a definitive loan and security agreement, or the Loan Agreement, with Oxford Finance LLC, or the Lender, and borrowed the principal amount of $27.5 million, or the Loan Facility, at a fixed rate of 9.75%, with the first principal payment due December 1, 2013. The term loan under the Oxford Loan Facility was repaid and terminated in January 2013, and the Company recorded a loss on extinguishment of debt of $3.4 million comprised of the early prepayment penalty and the remaining unamortized debt issuance costs.
	In connection with the Loan Agreement, the Company issued to the Lender warrants that were exercisable for an aggregate of 162,885 shares of its common stock at a per share exercise price of $10.97. The value of the warrants, $1.4 million, was recorded as a debt discount and amortized over the term of the loan to interest expense. The warrants were exercised in 2012.
	Sale of Royalty Interests
	In 2000, Pacira California and SkyePharma PLC entered into a Royalty Interests Assignment Agreement, or PLC Royalty Agreement, with an affiliate of Paul Capital Advisors, LLC, or Paul Capital, to raise $30.0 million. Under the PLC Royalty Agreement, Paul Capital had the right to receive a royalty interest in four of SkyePharma PLC’s product sales including product sales of, and other payments related to DepoCyt(e) and the no-longer marketed DepoDur. Payments began for product sales realized on or after January 1, 2003 and continued through December 31, 2014.
	In connection with the Acquisition, the PLC Royalty Agreement was amended (“Amended and Restated Royalty Interests Assignment Agreement”). As part of this amendment the responsibility to pay the royalty interest in product sales of DepoCyt(e) and DepoDur were transferred to the Company, and the payment to Paul Capital in a “Purchase Option Event” of the Company, as described below, was defined. The net present value of royalties expected to be repaid to Paul Capital (the “royalty interest obligation”) was valued at $13.0 million.
	The Company recorded the royalty interest obligation as a liability in the consolidated balance sheets in accordance with ASC 470-10-25, Sales of Future Revenues. The Company imputed interest expense associated with this liability using the effective interest rate method. The effective interest rate varied during the term of the agreement depending on a number of factors including the actual sales of DepoCyt(e) and DepoDur and a significant estimation, performed quarterly, of certain future cash flows of the Company related to these products during the remaining term of the Royalty Interests Assignment Agreement which terminated on December 31, 2014. Any adjustment to the estimates was reflected in the Company’s consolidated statements of operations as interest income (expense). In addition, such cash flows were subject to foreign exchange movements related to sales of DepoCyt(e) and DepoDur denominated in currencies other than U.S. dollars.
	The Company had no minimum payment obligations under the PLC Royalty Agreement. However, the repayment of the Paul Capital liability was supported through a jointly controlled lockbox, where all DepoCyt(e) and DepoDur product revenue and royalties were received as discussed in Note 2, Summary of Significant Accounting Policies.

FINANCIAL_INSTRUMENTS

FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
FINANCIAL INSTRUMENTS	FINANCIAL INSTRUMENTS
	Fair Value Measurements
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market in an orderly transaction. To increase consistency and comparability in fair value measurements, the FASB established a three-level hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The three levels are:
	•	Level 1: Quoted prices (unadjusted) in active markets that are accessible at the measurement date for assets or liabilities. The fair value hierarchy gives the highest priority to Level 1 inputs.
	•	Level 2: Observable prices that are based on inputs not quoted on active markets, but corroborated by market data.
	•	Level 3: Unobservable inputs that are used when little or no market data is available. The fair value hierarchy gives the lowest priority to Level 3 inputs.
	The carrying value of financial instruments including cash and cash equivalents, restricted cash, accounts receivable and accounts payable approximate their respective fair values due to the short-term nature of these items. The fair value of the Company’s Notes at December 31, 2014 is calculated utilizing market quotations from an over-the-counter trading market for such notes (Level 2). The carrying amount and fair value of the Notes are as follows (in thousands):
			Carrying		Fair Value Measurements Using
	Financial Liabilities Carried at Historical Cost		Value		Level 1		Level 2			Level 3
	December 31, 2014
	Convertible senior notes *		$	103,100	$	—	$	429,438		$	—
	* The fair value of the Notes was based on the Company’s closing stock price of $88.66 per share at December 31, 2014 compared to a conversion price of $24.82 per share which, if converted, would result in an approximate conversion premium of 3.5 million shares or $309 million of cash. The maximum conversion premium that can be due on the Notes is 4.8 million shares, which assumes no increases in the conversion rate for certain corporate events.
	Short-term investments consist of asset-backed securities collateralized by credit card receivables, investment grade commercial paper and corporate bonds with initial maturities of greater than three months at the date of purchase, but less than one year. Long-term investments consist of corporate bonds with initial maturities greater than one year at the date of purchase. The net unrealized gains from the Company’s short-term and long-term investments are reported in other comprehensive income (loss). At December 31, 2014, all of the Company’s short-term and long-term investments are classified as available for sale investments and are determined to be Level 2 instruments, which are measured at fair value using standard industry models with observable inputs. The fair value of the commercial paper is measured based on a standard industry model that uses the three-month Treasury bill rate as an observable input. The fair value of the asset-backed securities and corporate bonds is principally measured or corroborated by trade data for identical issues in which related trading activity is not sufficiently frequent to be considered a Level 1 input or that of comparable securities. At December 31, 2014, the Company had $119.1 million invested in short-term investments which were rated A or better by Standard & Poor’s and had maturities ranging from 175 to 365 days from date of purchase. At December 31, 2014, the Company had $24.4 million invested in long-term investments which were also rated A or better by Standard & Poor’s and had maturities ranging from 20 to 37 months from the date of purchase.
	The following summarizes the Company’s short-term and long-term investments at December 31, 2014 and 2013 (in thousands):
	December 31, 2014		Cost		Gross		Gross			Fair Value
					Unrealized		Unrealized			(Level 2)
					Gains		Losses
	Debt securities:
	Short-term:
	Asset-backed securities		$	15,009	$	—	$	(9	)	$	15,000
	Commercial paper		1,747		3		—			1,750
	Corporate bonds		102,430		—		(42		)	102,388
	Subtotal		119,186		3		(51		)	119,138
	Long-term:
	Corporate bonds		24,463		10		(42		)	24,431
	Total		$	143,649	$	13	$	(93	)	$	143,569
	December 31, 2013		Cost		Gross		Gross			Fair Value
					Unrealized		Unrealized			(Level 2)
					Gains		Losses
	Debt securities:
	Asset-backed securities		$	10,838	$	1	$	(1	)	$	10,838
	Commercial paper		17,986		11		—			17,997
	Corporate bonds		30,808		1		(7		)	30,802
	Total		$	59,632	$	13	$	(8	)	$	59,637
	Certain assets and liabilities are measured at fair value on a nonrecurring basis, including assets and liabilities acquired in a business combination and long-lived assets, which would be recognized at fair value if deemed to be impaired or if reclassified as assets held for sale. The fair value in these instances would be determined using Level 3 inputs. At December 31, 2014, the Company had no financial instruments that were measured using Level 3 inputs.
	Credit Risk
	Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, short-term investments, long-term investments and accounts receivable. The Company maintains its cash and cash equivalents with high-credit quality financial institutions. At times, such amounts may exceed federally-insured limits. The Company performs ongoing credit evaluations of its customers as warranted and generally does not require collateral.
	As of December 31, 2014, three customers accounted for over 10% of the Company’s accounts receivable; 33%, 29% and 27%, respectively. At December 31, 2013, three customers accounted for over 10% of the Company’s accounts receivable; 31%, 31% and 20%, respectively. Revenues are primarily derived from major wholesalers and pharmaceutical companies that generally have significant cash resources. Allowances for doubtful accounts receivable are maintained based on historical payment patterns, aging of accounts receivable and actual write-off history. As of December 31, 2014 and 2013, no allowances for doubtful accounts were deemed necessary by the Company on its accounts receivable.

STOCKHOLDERS_EQUITY

STOCKHOLDERS' EQUITY	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS’ EQUITY
	Common Stock
	The Company is authorized to issue up to 250,000,000 shares of common stock, of which 36,150,620 and 33,636,442 were outstanding at December 31, 2014 and 2013, respectively.
	In April 2014, the Company completed a follow-on underwritten public offering of 1,840,000 shares of common stock, including the shares issued to cover the underwriters’ overallotment option, at $64.00 per share. The Company received proceeds of $110.5 million as a result of the offering, net of underwriters’ fees and related expenses.
	In April 2012, the Company sold 6,900,000 shares of common stock at a price of $9.75 per share in a registered public offering, which included the underwriters’ exercise of the overallotment option. The Company raised $62.9 million in net proceeds after deducting discounts and offering expenses.
	Preferred Stock
	The Company is authorized to issue up to 5,000,000 shares of preferred stock. No preferred stock was outstanding at December 31, 2014 or 2013.
	Warrants
	At December 31, 2014 and 2013, the Company had 7,216 and 58,354 warrants outstanding at a weighted average exercise price of $13.44 and $11.73, respectively. The warrants currently outstanding expire in February 2016.
	Accumulated Other Comprehensive Income
	The following table illustrates the changes in the balances of the Company’s accumulated other comprehensive income (in thousands):
		Net Unrealized Gains
		(Losses) From Available
		For Sale Investments
	Balance at December 31, 2012	$	27
	Other comprehensive loss before reclassifications	(23		)
	Amounts reclassified from accumulated other comprehensive income	1
	Balance at December 31, 2013	5
	Other comprehensive loss before reclassifications	(85		)
	Amounts reclassified from accumulated other comprehensive income	—
	Balance at December 31, 2014	$	(80	)

STOCK_PLANS

STOCK PLANS	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK PLANS	STOCK PLANS
	Stock Incentive Plans
	The Company’s 2011 stock incentive plan, or 2011 Plan, was adopted by its board of directors and approved by its stockholders in December 2010. The 2011 Plan allows the granting of incentive stock options, non-statutory stock options, restricted stock awards and other stock-based awards. The 2011 Plan was amended in June 2014, primarily to increase the number of shares of common stock available for grants by 2.75 million shares. Any shares forfeited or canceled from the Company’s 2007 Stock Incentive Plan are transferred to the 2011 Plan. In April 2014, the Company’s Board of Directors adopted the 2014 Inducement Plan which authorized 175,000 shares of common stock to be granted as equity awards to new employees.
	All of the Company’s stock option grants have an exercise price equal to the closing price of the fair market value of the Company’s common stock on the date of grant, generally have a 10-year contractual term and vest in increments (generally over four years from the date of grant although the Company may occasionally grant options with different vesting terms). The Company uses authorized and unissued shares to satisfy its obligations under these plans.
	2014 Employee Stock Purchase Plan
	In April 2014, the Company’s Board of Directors adopted the 2014 Employee Stock Purchase Plan, or ESPP, which was subsequently approved by the Company’s stockholders. The purpose of the ESPP is to provide a vehicle for eligible employees to purchase shares of the Company’s common stock at a discounted price and to help retain and motivate current employees as well as attract new talent. Under the ESPP, up to 500,000 shares of common stock may be sold under the plan which expires in June 2024. The ESPP is intended to qualify as an “employee stock purchase plan” within the meaning of Section 423 of the Internal Revenue Code. The maximum fair market value of stock which can be purchased by a participant in a calendar year is $25,000. The initial offering period of the ESPP began on September 1, 2014 and ended on December 31, 2014. Beginning in 2015, six-month offering periods will begin on January 1st and July 1st of each year. During an offering period, eligible employees will have the opportunity to elect to purchase shares of the Company’s common stock on the purchase dates of June 30 and December 31. The per share purchase price will be equal to the lesser of 85% of the fair market value of the Company’s common stock on either the offering date or the purchase date. During the year ended December 31, 2014, 15,722 shares were purchased under the plan.
	The following table contains information about the Company’s plans at December 31, 2014:
	Stock Incentive Plans		Awards Reserved for Issuance			Awards Issued			Awards Available for Grant
	2007 Stock incentive plan		2,022,837			2,022,837			—
	2011 Plan		5,931,700			4,400,525			1,531,175
	2014 Inducement plan		175,000			77,000			98,000
			8,129,537			6,500,362			1,629,175
	Employee Stock Purchase Plan		Shares Reserved for Purchase			Shares Purchased			Shares Available for Purchase
	2014 Employee stock purchase plan		500,000			15,722			484,278
	Stock-Based Compensation
	Compensation expense for stock options granted to employees and directors is based on the estimated grant date fair value of options recognized over the requisite service period on a straight-line expense attribution method. Compensation expense for options granted to non-employees is based on the fair value of options, which are revalued each reporting period until vested and are recognized as expense over the requisite service period. Compensation expense for ESPP options is based on the grant date fair value of the ESPP shares and the grant date number of shares that can be purchased, which is recognized as expense over the length of an offering period.
	The Company recognized stock-based compensation expense (net of forfeitures) in its consolidated statements of operations for the years ended December 31, 2014, 2013 and 2012 as follows (in thousands):
			Year Ended December 31,
			2014				2013			2012
	Cost of revenues		$	3,582			$	1,526		$	563
	Research and development		6,490				4,345			1,155
	Selling, general and administrative		14,750				5,642			3,058
	Total		$	24,822			$	11,513		$	4,776
	Stock-based compensation from:
	Stock options		$	24,477			$	11,513		$	4,776
	Employee stock purchase plan		345				—			—
	Total		$	24,822			$	11,513		$	4,776
	In November 2014, the Company’s Board of Directors approved amendments to stock options held by a departing Vice President. The amendments accelerated the vesting of nine months’ worth of options and as a result the Company recognized an additional $0.6 million in stock-based compensation expense for the year ended December 31, 2014. In September 2013, the Company’s Board of Directors approved amendments to stock options held by two departing directors. The amendments (i) accelerated the vesting of the unvested portion of certain options, and (ii) extended the period during which each departing director could exercise all vested options to September 30, 2015. As a result of these amendments, the Company recognized an additional $0.2 million in stock-based compensation for the year ended December 31, 2013.
	The following table summarizes the Company’s stock option activity and related information for the period from January 1, 2012 to December 31, 2014 (in thousands except share and per share amounts):
		Number of			Weighted				Weighted Average	Aggregate
		Shares			Average				Remaining	Intrinsic Value
					Exercise Price				Contractual	(in Thousands)
									Term (Years)
	Outstanding at January 1, 2012	2,337,017			$	3.92			8.8	$	11,829
	Granted	2,120,250			11.55
	Exercised	(279,476	)		2.75					$	3,005
	Forfeited	(174,610	)		7.94
	Expired	(15	)		7.07
	Outstanding at December 31, 2012	4,003,166			7.86				8.66	$	38,485
	Granted	918,915			30.42
	Exercised	(742,211	)		5.19					$	21,679
	Forfeited	(338,145	)		10.93
	Expired	(1,687	)		7.24
	Outstanding at December 31, 2013	3,840,038			13.5				8.01	$	168,905
	Granted	1,638,575			79.68
	Exercised	(624,229	)		11.6					$	45,289
	Forfeited	(175,967	)		44.32
	Expired	(561	)		21.7
	Outstanding at December 31, 2014	4,677,856			$	35.78			7.86	$	248,276
	Exercisable at December 31, 2014	2,085,829			$	11.61			6.75	$	160,707
	Vested and expected to vest at December 31, 2014	4,486,980			$	34.59			7.81	$	243,438
	As of December 31, 2014, $73.1 million of total unrecognized compensation cost related to non-vested stock options is expected to be recognized over a weighted average period of 3.1 years. The Company’s stock options have a maximum expiration date of ten years from the date of grant.
	The weighted average fair value of stock options granted for the years ended December 31, 2014, 2013 and 2012 was $42.62, $19.22 and $8.52 per share, respectively. The fair values of stock options granted were estimated using the Black-Scholes model with the following weighted average assumptions:
		Year Ended December 31,
		2014		2013		2012
	Expected dividend yield	None		None		None
	Risk free interest rate	0.02 - 2.16%		0.33 - 2.83%		0.84 - 1.70%
	Expected volatility	57.20%		68.70%		74.00%
	Expected term of options	5.86 years		6.22 years		6.76 years
	The $23.27 fair value of the ESPP share options granted in September 2014 was estimated using the Black-Scholes model assuming: no expected dividends, a risk free interest rate of 0.37%, an expected volatility of 28.2% and an expected term of four months.

NET_INCOME_LOSS_PER_SHARE

NET INCOME (LOSS) PER SHARE	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
EARNINGS PER SHARE	PER SHARE
	Basic net income (loss) per share is calculated by dividing the net income (loss) attributable to common shares by the weighted average number of common shares outstanding during the period. Diluted net income (loss) per share is calculated by dividing the net income (loss) attributable to common shares by the weighted average number of shares outstanding plus dilutive potential common stock outstanding during the period. Potential common shares include the shares of common stock issuable upon the exercise of outstanding stock options, warrants and the purchase of shares from the employee stock purchase plan (using the treasury stock method) as well as the conversion of the excess conversion value on the Notes. As discussed in Note 8, Debt, the Company must settle the principal of the Notes in cash upon conversion, and it may settle any conversion premium in either cash or stock at the Company’s discretion. For purposes of calculating the dilutive impact, it is presumed that the conversion premium will be settled in common stock.
	Potential common shares are excluded from the diluted net income (loss) per share computation to the extent that they would be antidilutive. Because the Company reported a net loss for all periods presented, no potentially dilutive securities have been included in the computation of diluted net loss per share.
	The following table sets forth the computation of basic and diluted loss per share for the years ended December 31, 2014, 2013 and 2012 (in thousands except per share amounts):
		Year Ended December 31,
		2014				2013			2012
	Numerator:
	Net loss	$	(13,716	)		$	(63,909	)	$	(52,281	)
	Denominator:
	Weighted average shares of common stock outstanding	35,299				33,182			30,332
	Net loss per share:
	Basic and diluted net loss per share of common stock	$	(0.39	)		$	(1.93	)	$	(1.72	)
	For the years ended December 31, 2014, 2013 and 2012, the number of potential common shares which were excluded from the diluted net loss per share calculation using the treasury stock method was 5.4 million, 3.4 million and 1.4 million, respectively.
	The following outstanding stock options, conversion premium on the Notes, warrants and employee stock purchase plan units which could dilute basic earnings per share in the future are as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Weighted average number of stock options outstanding	3,534			3,980			3,304
	Conversion premium on the Notes	2,483			1,194			—
	Weighted average number of warrants outstanding	21			204			585
	Weighted average purchase options under ESPP	1			—			—
	Total	6,039			5,378			3,889

INCOME_TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES
	A reconciliation of income taxes at the U.S. federal statutory rate to the provision for income taxes is as follows:
		Year Ended December 31,
		2014			2013			2012
	Benefit at U.S. Federal statutory rate	35	%		35	%		35	%
	State taxes	(32.75	)%		4.79	%		6.73	%
	Increase in valuation allowance	(17.71	)%		(42.91	)%		(39.62	)%
	Tax credits	5.49	%		1.69	%		—	%
	Interest expense	10.68	%		0.3	%		(0.22	)%
	Other	(1.99	)%		1.82	%		(1.89	)%
	Provision for income taxes	(1.28	)%		0.69	%		—	%
	There has been no provision for federal income taxes since the Company has incurred net operating losses since inception. The income tax provision of $0.2 million at December 31, 2014 is a result of minimum and apportionment based state taxes.
	In 2013, the Company sold a portion of its unused New Jersey State net operating losses through a program sponsored by the New Jersey Economic Development Authority. Cash proceeds of $0.4 million were received by the Company resulting in a state tax benefit recognized during the year ended December 31, 2013.
	Significant components of the Company’s deferred tax assets and liabilities are as follows (in thousands):
		December 31,
		2014				2013
	Deferred tax assets:
	Federal and state net operating loss carry-forwards	$	111,086			$	114,819
	Federal and state research credits	6,043				5,149
	Depreciation and amortization	3,494				3,248
	Accruals and reserves	3,861				1,696
	Deferred revenue	4,065				1,707
	Stock based compensation	8,487				2,622
	Other	588				752
	Total deferred tax assets	137,624				129,993
	Deferred tax liabilities:
	Discount on convertible senior notes	(6,283		)		(8,507		)
		131,341				121,486
	Less: valuation allowance	(131,341		)		(121,486		)
	Net deferred tax assets	$	—			$	—
	As of December 31, 2014, the available federal net operating loss carryforward and the federal research and development tax credit carryforwards totaled $331.0 million and $4.4 million , respectively. Approximately $41.3 million of the federal net operating loss carryforward related to excess tax benefits arising from the exercise of stock options for which future tax benefits will be credited to equity when realized through a reduction in taxes payable. The Company also had state net operating loss carryforwards and state research and development tax credit carryforwards of approximately $196.3 million and $2.5 million, respectively which are subject to change on an annual basis due to variations in the Company’s annual state apportionment factors. The Company had non-U.S. tax net operating losses of approximately $0.3 million at December 31, 2014.
	The net operating loss carryforwards will begin expiring in 2026 for federal purposes and 2015 for state purposes if the Company has not used them prior to that time, and the federal tax credits will begin expiring in 2028 unless previously used. The state tax credits carry forward indefinitely.
	Since the Company had cumulative changes in ownership of more than 50% within a three-year period, under Internal Revenue Code sections 382 and 383, the Company’s ability to use any net operating loss and credit carryforwards to offset taxable income or tax will be limited. Such ownership changes were triggered by the initial acquisition of the Company’s stock in 2007 as well as cumulative ownership changes arising as a result of the completion of the initial public offering and other financing transactions. As a result of these ownership changes, the Company estimates that approximately $197.2 million of federal net operating losses are subject to annual limitations. At December 31, 2014, approximately $72.3 million of these federal net operating losses were available. The Company estimates that an additional $26.3 million will become available annually in 2015 and 2016, $14.8 million in 2017, $10.3 million annually from 2018 through 2022, and the remaining $6.0 million thereafter through 2025. In addition, California and certain states have suspended use of net operating loss carryforwards for certain taxable years, and other states are considering similar measures. As a result, the Company may incur higher state income tax expense in the future.
	The valuation allowance for deferred tax assets increased by approximately $9.9 million, $17.5 million and $20.7 million during the years ended December 31, 2014, 2013 and 2012, respectively. There is significant doubt regarding the Company’s ability to utilize its net deferred tax assets and, therefore, the Company has recorded a full valuation allowance.
	The 2007 Acquisition was treated as a stock acquisition for tax purposes and, therefore, the acquired intangibles for book purposes are not deductible for income tax purposes. The Company also recorded goodwill relating to contingent payments due under the Acquisition during the years ended December 31, 2014 and 2013, which are not deductible for income tax purposes. See Note 6, Goodwill and Intangible Assets, for further discussion.
	In connection with the adoption of stock-based compensation guidance in 2006, the Company elected to follow the with-and-without approach to determine the sequence in which deductions and net operating loss carryforwards are utilized. Accordingly, no tax benefit related to stock options was recognized in the current year.
	The Company evaluates its uncertain tax positions in a two-step process. The Company first determines whether it is more-likely-than-not that a tax position will be sustained upon examination. If a tax position meets the more-likely-than-not recognition threshold it is then measured to determine the amount of benefit to be recognized in the financial statements. The tax position is measured as the largest amount of benefit that has a greater than 50% likelihood of being realized upon ultimate settlement.
	The Company did not have a liability related to unrecognized tax benefits as of December 31, 2014 and 2013 due to operating losses but has reduced its deferred tax assets by $0.4 million at December 31, 2014 and 2013. Further, because the Company has recorded a full valuation allowance on its net deferred tax assets, the effect of implementing ASC 740 has been a reduction of the tax valuation allowance by the amount above.
	The Company recognizes interest and penalties related to unrecognized tax benefits as tax expense. No interest or penalties were accrued for 2014, 2013 or 2012. The Company is currently open for audit by the United States Internal Revenue Service, or IRS, and state tax jurisdictions for 2008 through 2014. However, the IRS or state may still examine and adjust a net operating loss arising from a closed year to the extent it is utilized in an open tax year. The American Tax Relief Act of 2012, enacted on January 2, 2013, retroactively reinstated the research and development tax credit for 2012. The Company reported credits of approximately $0.2 million for federal income tax purposes in the first quarter of 2013 related to 2012.

OTHER_EMPLOYEE_BENEFITS

OTHER EMPLOYEE BENEFITS	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
OTHER EMPLOYEE BENEFITS	OTHER EMPLOYEE BENEFITS
	The Company sponsors a 401(k) savings plan. Under the plan, employees may make contributions which are eligible for a discretionary percentage match as defined in the plan and determined by the Board of Directors. The Company recognized $1.0 million, $0.6 million and $0.3 million of related compensation expense for the years ended December 31, 2014, 2013 and 2012, respectively.

COMMERCIAL_PARTNERS_AND_OTHER_

COMMERCIAL PARTNERS AND OTHER AGREEMENTS	12 Months Ended
	Dec. 31, 2014
COMMERCIAL PARTNERS AND OTHER AGREEMENTS
COMMERCIAL PARTNERS AND OTHER AGREEMENTS	COMMERCIAL PARTNERS AND OTHER AGREEMENTS
	Commercial Partners
	Patheon UK Limited
	In April 2014, the Company and Patheon UK Limited, or Patheon, entered into a Strategic Co-Production Agreement and Technical Transfer and Service Agreement to collaborate in the manufacture and packaging of EXPAREL. Under the terms of the Technical Transfer and Service Agreement, Patheon has agreed to undertake certain technical transfer activities and construction services needed to prepare its Swindon, United Kingdom facility for the manufacture and packaging of EXPAREL in two dedicated manufacturing suites. This agreement will remain in full effect unless and until it expires or is terminated. Upon termination of this agreement (other than termination by the Company in the event that Patheon does not meet the construction and manufacturing milestones or for a breach by Patheon), the Company will pay for the make good costs occasioned by the removal of its manufacturing equipment and for Patheon’s termination costs up to a maximum amount of $2.0 million.
	The Company also entered into a Manufacturing and Supply Agreement with Patheon. Under the terms of the Manufacturing and Supply Agreement, following the FDA approval date of the suites, the Company has agreed to purchase EXPAREL product from Patheon. Unless earlier terminated, this agreement will expire on the 10th anniversary of the FDA approval date for the initial manufacturing suite.
	Future expenditures associated with the aforementioned agreements are primarily driven by the potential commercial requirements and demand for the Company’s products which cannot be fully determined at this time.
	Aratana Therapeutics, Inc.
	On December 5, 2012, the Company entered into a worldwide license, development and commercialization agreement with Aratana Therapeutics, Inc., or Aratana. Under the agreement, the Company granted Aratana an exclusive royalty-bearing license, including the limited right to grant sublicenses, for the development and commercialization of the Company’s bupivacaine liposome injectable suspension product for animal health indications. Under the agreement, Aratana will develop and seek approval for the use of the product in veterinary surgery to manage postsurgical pain, focusing initially on developing the product for cats, dogs and other companion animals. In connection with its entry into the license agreement, the Company received a one-time payment of $1.0 million and is eligible to receive up to an additional aggregate $42.5 million upon the achievement of development and commercial milestones. Once the product has been approved by the FDA for sale in the United States, Aratana will be required to pay the Company a tiered double digit royalty on net sales made in the United States. If the product is approved by foreign regulatory agencies for sale outside of the United States, Aratana will be required to pay the Company a tiered double digit royalty on such net sales. Royalty rates will be reduced by a certain percentage upon the entry of a generic competitor for animal health indications into a jurisdiction or if Aratana must pay royalties to third parties under certain circumstances. In December 2013, the Company received a $0.5 million milestone payment under the agreement.
	Mundipharma International Corporation Limited
	In June 2003, the Company entered into an agreement granting Mundipharma International Corporation Limited, or Mundipharma, exclusive marketing and distribution rights to DepoCyte in the E.U. and certain other European countries. Under the agreement, as amended, and a separate supply agreement, the Company receives a fixed payment for supplying vials of DepoCyte and a double-digit royalty, net of supply price, on sales in the applicable territories. In April 2014, the Company and Mundipharma amended their agreements to, among other things, (i) extend the term of such agreements by an additional 15 years to June 2033, and (ii) expand the territories where Mundipharma can market and distribute DepoCyte to all countries other than the United States of America, Canada and Japan. In connection with the agreements, the Company received a non-refundable upfront payment of $8.0 million in May 2014 which was deferred and is being recognized over the contractual term.
	Sigma-Tau Pharmaceuticals, Inc.
	In December 2002, the Company entered into a supply and distribution agreement with Enzon Pharmaceuticals Inc., subsequently acquired by Sigma-Tau Pharmaceuticals, Inc., or Sigma-Tau, regarding the sale of DepoCyt®. Pursuant to the agreement, Sigma-Tau was appointed the exclusive distributor of DepoCyt in the United States and Canada. Under the supply and distribution agreement, the Company supplies unlabeled DepoCyt vials to Sigma-Tau for finished packaging by Sigma-Tau. Under these agreements, the Company receives a fixed payment for supplying the vials of DepoCyt and a double-digit royalty on sales, net of supply price, in the United States and Canada.
	CrossLink BioScience, LLC
	Effective October 1, 2013, the Company and CrossLink BioScience, LLC, or CrossLink, commenced a five-year arrangement for the promotion and sale of EXPAREL pursuant to the terms of a Master Distributor Agreement. Under the agreement, the Company appointed CrossLink as a third-party distributor during the term to promote and sell EXPAREL to orthopedic surgeons in the United States, with the exception of certain geographical areas and accounts. The prices and purchasing terms related to sales of EXPAREL are determined by the Company, and all orders are subject to acceptance or rejection by the Company. CrossLink is entitled to receive commissions on its sales of EXPAREL in the applicable territories, subject to certain conditions and adjustments. CrossLink may receive additional performance-based payments if it achieves certain sales goals. The Company may terminate the agreement if CrossLink fails to meet certain minimum performance metrics or if the Company pays a termination fee. Effective March 1, 2015, the agreement was amended to, among other things, amend certain payment terms and specify certain sub-distributors that may promote and sell EXPAREL under the agreement.
	Research Development Foundation
	Pursuant to an agreement with Research Development Foundation, or RDF, the Company is required to pay RDF a low single-digit royalty on the collection of revenues from its DepoFoam-based products, for as long as certain patents assigned to the Company under the agreement remain valid. RDF has the right to terminate the agreement for an uncured material breach by the Company, in connection with its bankruptcy or insolvency or if it directly or indirectly opposes or disputes the validity of the assigned patent rights.
	Amylin Pharmaceuticals, Inc.
	In March 2008, the Company entered into a development and licensing agreement with Amylin Pharmaceuticals, Inc., or Amylin. Under the development and licensing agreement, the Company provided Amylin with access to its proprietary DepoFoam drug delivery technology to conduct research, feasibility and formulation work, and for the manufacturing of pre-clinical and clinical material for various Amylin products. The Company is entitled to payments from Amylin for its work on the formulation and development of compounds with the DepoFoam technology, its achievement of certain clinical development milestones, its achievement of certain worldwide sales and a tiered royalty based upon sales. The development and licensing agreement with Amylin remains in effect until January 2017, however, neither party is currently performing any activities under the agreement.
	Terminated Agreements
	EKR Therapeutics, Inc.
	On January 3, 2012, EKR Therapeutics, Inc., delivered a notice to the Company to terminate the licensing, distribution and marketing agreement relating to DepoDur. The associated supply agreement also terminated concurrently with the termination of the licensing, distribution and marketing agreement, effective June 8, 2012. As a result of the termination, the Company recognized any unamortized deferred revenue relating to the agreement on a straight-line basis through the termination date in June 2012.
	Flynn Pharmaceuticals Limited
	On October 29, 2012, the Company terminated the marketing agreement with Flynn Pharmaceuticals Limited, which had granted exclusive distribution rights to DepoDur in the E.U., certain other European countries, South Africa and the Middle East. The supply agreement terminated concurrently with the marketing agreement. The termination was effective immediately. As a result of the termination, the Company recognized any unamortized deferred revenue relating to the agreement upon termination.
	Novo Nordisk AS
	On June 29, 2012, the Company received a notice of termination from Novo Nordisk AS, or Novo, of the Development and License Agreement, dated January 14, 2011, which had granted non-exclusive rights to Novo under certain of its patents and know-how to develop, manufacture and commercialize formulations of a Novo proprietary drug using the Company’s DepoFoam drug delivery technology. The Company received a one-time upfront payment of $1.5 million in January 2011 and a milestone payment of $2.0 million in November 2011, both of which had been deferred and were being recognized on a straight-line basis over the estimated contract period to collaborative licensing and development revenue in the consolidated statements of operations. Pursuant to the terms of the agreement, the termination of the agreement was effective on August 28, 2012. The agreement was terminated due to Novo’s decision to discontinue development of the proprietary drug subject to the agreement. As a result of the termination, the Company recognized any unamortized deferred revenue relating to the agreement on a straight-line basis through the termination date in August 2012.

RELATED_PARTY_TRANSACTIONS

RELATED PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS
	The Company’s Chief Medical Officer, Dr. Gary Patou, is a partner of MPM Asset Management LLC, or MPM, an investor in the Company. David Stack, the Company’s President, Chief Executive Officer and Chairman is also a managing director at MPM. The Company contracted with MPM and Dr. Patou for the services of Dr. Patou, or Consultant. MPM earned monthly consulting fees between $16,000 and $26,000 in exchange for 50% to 80% of the Consultant’s business time. The Company incurred expenses of $0.5 million, $0.3 million and $0.4 million for the years ended December 31, 2014, 2013 and 2012, respectively. At December 31, 2014 and 2013, the amount payable to MPM was $0.2 million and $0.1 million, respectively.
	In December 2012, the Company entered into a worldwide license, development and commercialization agreement with Aratana as discussed in Note 15, Commercial Partners and Other Agreements. MPM and its affiliates are holders of capital stock of Aratana.
	In April 2012, the Company entered into a consulting agreement with Dr. Gary Pace, a director of the Company, whereby Dr. Pace would provide consulting services. Pursuant to the consulting agreement and subsequent amendments, the consulting services are paid at the rate of $5,000 to $15,000 per month based on the number of days worked. The Company recorded expenses under the consulting arrangement for the years ended December 31, 2014, 2013 and 2012 of $0.1 million, $0.1 million, and $0.2 million, respectively. In connection with the consulting arrangement, Dr. Pace received an option to purchase 20,000 shares of common stock at an exercise price of $11.02 per share and received an option to purchase 70,000 shares of common stock at an exercise price of $16.67 per share. The amounts payable at December 31, 2014 and 2013 to Dr. Pace for the consulting services were less than $0.1 million.

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES
	Leases
	The Company leases research and development, manufacturing and warehouse facilities in San Diego, California and its corporate headquarters in Parsippany, New Jersey. The three leases in San Diego run through August 2020. In March 2014, the Company amended the lease for its corporate headquarters which increased the size of the leased premises and extended the lease term through March 2028. In November 2014, the Company entered into lease contracts for additional research and development space at the Company’s Science Center Campus in San Diego. The leases will commence in August 2015 and expire in October 2020.
	In connection with the Acquisition, the Company determined that its lease rates associated with the Science Center Campus were in excess of market rates resulting in a $3.3 million unfavorable lease accrual as of the Acquisition date. The unfavorable lease accrual, which is recorded in other long-term liabilities in the Company’s consolidated balance sheets, is amortized over the remaining terms of the leases. The annual amortization of the unfavorable lease accrual for each of the years ended December 31, 2014, 2013 and 2012 was $0.1 million, $0.1 million and $0.4 million, respectively.
	As of December 31, 2014, the aggregate annual minimum payments due under the Company’s lease obligations are as follows (in thousands):
	Year
	2015	$	6,133
	2016	7,263
	2017	7,459
	2018	7,660
	2019	7,876
	2020 through 2028	11,786
	Total	$	48,177
	Total rent expense, net of amortization of unfavorable lease obligation and tenant improvements, under all operating leases for years ended December 31, 2014, 2013 and 2012 was $4.9 million, $4.9 million and $4.8 million, respectively. Deferred rent at December 31, 2014 and 2013 was $4.5 million and $2.3 million, respectively.
	Litigation
	From time to time, the Company has been and may again become involved in legal proceedings arising in the ordinary course of its business. Except as described below, the Company is not presently a party to any litigation which it believes to be material, and is not aware of any pending or threatened litigation against the Company which it believes could have a material adverse effect on its business, operating results, financial condition or cash flows.
	On October 3, 2014, a purported class action lawsuit was filed in the United States District Court for the District of New Jersey against the Company and three of its current officers, Nicholas R. Lovallo v. Pacira Pharmaceuticals, Inc., et al., Case No. 2:14-cv-06172-WHW-CLW. The lawsuit asserts claims under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended, and is premised on allegedly false and/or misleading statements, and non-disclosure of material facts, regarding the Company’s business, operations, prospects and performance during the proposed class period of April 9, 2012 to September 24, 2014. The Company intends to vigorously defend all claims asserted, including by filing a motion to dismiss. Given the early stage of the litigation, at this time the Company is unable to reasonably estimate possible losses or form a judgment that an unfavorable outcome is either probable or remote. It is not currently possible to assess whether or not the outcome of these proceedings will have a material adverse effect on the Company.
	Other Commitments and Contingencies
	The FDA, as a condition of the approval of EXPAREL has required the Company to study EXPAREL in pediatric patients. The Company has agreed to a trial timeline where, over several years, it will study pediatric patient populations in descending order starting with 12-18 year olds and ending with children under two years of age. The cost to complete the trial may be significant.
	In addition to the initial $19.6 million purchase price for the Acquisition, the Company entered into an earn-out agreement with Skyepharma which was based on the Company reaching certain revenue milestones following the Acquisition. Pursuant to this agreement, the Company is required to pay Skyepharma milestone payments up to an aggregate of $62.0 million, of which $18.0 million has been paid. Additionally, the Company agreed to pay to Skyepharma a 3% percentage payment on collections of EXPAREL sales in the United States, Japan, the United Kingdom, France, Germany, Italy and Spain.
	Such obligations to make percentage payments will continue for the term in which such sales related to EXPAREL are covered by a valid claim in certain patent rights related to EXPAREL and other biologics products. The expiration date of the last valid claim will occur in 2018. The Company has the right to cease paying the 3% percentage payments in the event that Skyepharma breaches certain covenants not to compete contained in the stock purchase agreement. In the event that the Company ceases to sell EXPAREL and begin marketing a similar replacement product for EXPAREL, it would no longer be obligated to make percentage payments, but it may be required to make certain milestone payments upon reaching certain sales milestones.
	Refer to Note 6, Goodwill and Intangible Assets, for further discussion.

SELECTED_QUARTERLY_FINANCIAL_D

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)
	The following table presents selected quarterly financial data for the years ended December 31, 2014 and 2013 (in thousands, except per share data):
		Three Months Ended
		March 31,			June 30,			September 30,			December 31,
		2014			2014			2014			2014
	Total revenues	$	36,662		$	47,165		$	52,048		$	61,793
	Cost of revenues	18,127			19,954			20,391			18,968
	Total operating expenses	45,920			50,007			53,033			53,873
	Net income (loss)	(11,477		)	(5,037		)	(3,004		)	5,802
	Basic net income (loss) per common share	$	(0.34	)	$	(0.14	)	$	(0.08	)	$	0.16
	Diluted net income (loss) per common share	$	(0.34	)	$	(0.14	)	$	(0.08	)	$	0.14
		Three Months Ended
		March 31,			June 30,			September 30,			December 31,
		2013			2013			2013			2013
	Total revenues	$	11,587		$	17,141		$	23,259		$	33,564
	Cost of revenues	11,391			10,214			14,791			18,376
	Total operating expenses	30,232			29,151			36,073			43,384
	Net loss	(23,138		)	(14,031		)	(14,784		)	(11,956		)
	Basic net loss per common share	$	(0.71	)	$	(0.42	)	$	(0.44	)	$	(0.36	)
	Diluted net loss per common share	$	(0.71	)	$	(0.42	)	$	(0.44	)	$	(0.36	)
	For periods where the Company reported a net loss, no potentially dilutive securities have been included in the computation of diluted net loss per share.

SUBSEQUENT_EVENTS_Notes

SUBSEQUENT EVENTS (Notes)	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS
	In February 2015, the Company received notice of an election for conversion from one of the holders of the Notes. The principal amount of the conversion request was $1.5 million which must be paid in cash pursuant to the terms of the Indenture. The Company elected to settle the conversion premium in shares of its common stock, calculated using a 40 trading-day observation period ending April 8, 2015.

SUMMARY_OF_SIGNIFICANT_ACCOUNT1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation
	The consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America, or GAAP, and in accordance with the rules and regulations of the Securities and Exchange Commission, or SEC. The accounts of wholly owned subsidiaries are included in the consolidated financial statements. All intercompany balances and transactions have been eliminated in consolidation. Certain reclassifications were made to conform to the current presentation.
Use of Estimates	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires the use of estimates and assumptions that affect the reported amounts of assets and liabilities, including disclosure of contingent assets and contingent liabilities, at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Estimates are used for, among other things, revenue recognition, impairment of long-lived assets, stock-based compensation and valuation of deferred tax assets. The Company’s critical accounting policies are those that are both most important to the Company’s consolidated financial condition and results of operations and require the most difficult, subjective or complex judgments on the part of management in their application, often as a result of the need to make estimates about the effect of matters that are inherently uncertain. Because of the uncertainty of factors surrounding the estimates or judgments used in the preparation of the consolidated financial statements, actual results could differ from these estimates.
Liquidity	Liquidity
	Management believes that the Company’s existing cash and cash equivalents, restricted cash, short-term and long-term investments and cash flows generated from product sales will be sufficient to enable the Company to meet its planned operating expenses, capital expenditure requirements, payment of the principal on any conversions of the Company’s convertible senior notes and to service its indebtedness at least through December 31, 2015. However, changing circumstances may cause the Company to expend cash significantly faster than currently anticipated, and the Company may need to spend more cash than currently expected because of circumstances beyond its control. The Company expects to continue to incur substantial additional expenditures as it continues to commercialize EXPAREL, develops and seeks regulatory approval for its product candidates, and expands its manufacturing facilities for EXPAREL and its other product candidates including costs associated with certain technical transfer activities and construction of two dedicated manufacturing suites in the United Kingdom.
Senior convertible notes	On January 23, 2013, the Company completed a private placement of $120.0 million in aggregate principal amount of 3.25% convertible senior notes, or Notes, due 2019. As further discussed in Note 8, Debt, the Company must settle the principal of the Notes in cash upon conversion, and it may settle any conversion premium in either cash, stock or a combination of cash and shares of common stock at the Company’s discretion. Based on certain conditions that were met during the three months ended December 31, 2014, the holders can convert their Notes at any time during the quarter ended March 31, 2015 and, therefore, the Notes are classified in the consolidated balance sheet at December 31, 2014 as a current obligation. In the event of conversion, holders would forgo all future interest payments, any unpaid interest and the possibility of further stock price appreciation. In the event that all of the Notes are converted, the Company would be required to repay the $120.0 million in principal value and approximately $309 million of cash or issue approximately 3.5 million shares of its common stock (or a combination of cash and shares of its common stock) to settle the conversion premium as of December 31, 2014, causing dilution to the Company’s current shareholders.
Revenue Recognition	Revenue Recognition
	The Company’s principal sources of revenue include (i) sales of EXPAREL in the United States, or U.S., (ii) sales of DepoCyt(e) in the U.S. and the European Union, or E.U., (iii) royalties based on sales by commercial partners of DepoCyt(e) and (iv) license fees, milestone payments and reimbursement for development work from third parties. The Company recognizes revenue when there is persuasive evidence that an arrangement exists, title has passed, collection is reasonably assured and the price is fixed or determinable.
	Net Product Sales
	The Company sells EXPAREL through a drop-ship program under which orders are processed through wholesalers based on orders of the product placed by end users which include hospitals, ambulatory surgery centers and doctors. EXPAREL is delivered directly to the end user without the wholesaler ever taking physical possession of the product. The Company records revenue at the time the product is delivered to the end user. The Company also recognizes revenue from products manufactured and supplied to commercial partners, such as DepoCyt(e) upon shipment. Prior to the shipment of manufactured products, the Company conducts initial product release and stability testing in accordance with current Good Manufacturing Practices.
	Revenues from sales of products are recorded net of returns allowances, prompt payment discounts, wholesaler service fees and volume rebates and chargebacks. The calculation of some of these items requires management to make estimates based on sales data, contracts, inventory data and other related information which may become known in the future. The Company reviews the adequacy of its provisions on a quarterly basis.
	Returns Allowances
	The Company allows customers to return product that is damaged or received in error. In addition, the Company allows EXPAREL to be returned beginning six months prior to, and twelve months following product expiration. As EXPAREL is a newly commercially available product, the Company estimates its sales return reserve based on return history from other hospital-based products with similar distribution models and its historical experience, which management believes is the best estimate of the anticipated product to be returned. The returns reserve is recorded at the time of sale as a reduction to gross product sales and an increase in accrued expenses.
	The Company’s commercial partners can return Depocyt(e) within contractually specified timeframes if the product does not meet the applicable inspection tests. The Company estimates its returns reserve based on its experience with historical return rates. Historically, the Company’s product returns have not been material.
	Prompt Payment Discounts
	The prompt payment reserve is based upon discounts offered to wholesalers as an incentive to meet certain payment
	terms. The Company accrues discounts to wholesalers based on contractual terms of agreements and historical experience. The Company accounts for these discounts at the time of sale as a reduction to gross product sales and a reduction to accounts receivable.
	Wholesaler Service Fees
	The Company’s customers include major and regional wholesalers with whom the Company has contracted a fee for service based on a percentage of gross product sales. This fee for service is recorded as a reduction to gross product sales and an increase to accrued expenses at the time the sale, and is recorded based on the contracted percentage.
	Volume Rebates and Chargebacks
	Volume rebates and chargeback reserves are based upon contracted discounts and promotional offers the Company provides to certain end users such as members of group purchasing organizations. Volume rebates are recorded at the time of sale as a reduction to gross product sales and an increase in accrued expenses. Chargeback reserves are recorded at the time of sale as a reduction to gross product sales and a reduction to accounts receivable.
	Royalty Revenue
	The Company recognizes revenue from royalties based on sales of its commercial partners’ net sales of products. Royalties are recognized as earned in accordance with contract terms when they can be reasonably estimated based and collection is reasonably assured. The Company’s commercial partners are obligated to report their net product sales and the resulting royalty due to the Company within 60 days from the end of each quarter. Based on historical product sales, royalty receipts and other relevant information, the Company accrues royalty revenue each quarter and subsequently trues-up its royalty revenue when it receives royalty reports from its commercial partners.
	Collaborative Licensing and Development Revenue
	The Company recognizes revenue from reimbursements received in connection with feasibility studies and development work for third parties who desire to utilize its DepoFoam extended release drug delivery technology for their products when the Company’s contractual services are performed, provided collection is reasonably assured. The Company’s principal costs under these agreements include costs for its personnel conducting research and development, its allocated overhead as well as research and development performed by outside contractors or consultants.
	The Company recognizes revenues from non-refundable up-front license fees received under collaboration agreements ratably over the performance period as determined under the collaboration agreement (estimated development period in the case of development agreements, and contract period or longest patent life in the case of supply and distribution agreements). If the estimated performance period is subsequently modified, the Company will modify the period over which the up-front license fee is recognized accordingly on a prospective basis. Upon notification of a termination of a collaboration agreement, any remaining non-refundable license fees received by the Company, which had been deferred, are recognized over the remaining contractual term. If the termination is immediate and no additional services are to be performed, the deferred revenue is generally recognized in full. All such recognized revenues are included in collaborative licensing and development revenue in the Company’s consolidated statements of operations.
	The Company recognizes revenue from milestone payments received under collaboration agreements when earned, provided that the milestone event is substantive, its achievability was not reasonably assured at the inception of the agreement, the Company has no further performance obligations relating to the event and collection is reasonably assured. If these criteria are not met, the Company recognizes milestone payments ratably over the remaining period of the Company’s performance obligations under the applicable agreements.
Concentration of Major Customers	Concentration of Major Customers
	The Company’s customers are national and regional wholesalers of pharmaceutical products as well as commercial, collaborative and licensing partners. The Company sells EXPAREL through a drop-ship program under which orders are processed through wholesalers (including AmerisourceBergen Health Corporation, Cardinal Health, Inc., and McKesson Drug Company), but shipments of the product are sent directly to individual accounts, such as hospitals, ambulatory surgery centers and individual doctors. The table below includes the percentage of revenue comprised by the three largest customers (i.e., wholesalers or commercial partners) in each year presented:
		Year Ended December 31,
		2014		2013		2012
	Largest customer	33	%	33	%	30	%
	Second largest customer	29	%	28	%	14	%
	Third largest customer	24	%	18	%	11	%
		86	%	79	%	55	%
	Revenues from customers outside the U.S. accounted for 2%, 5% and 23% of the Company’s revenue for the years ended December 31, 2014, 2013 and 2012, respectively.
Research and Development Expenses	Research and Development Expenses
	Research and development expenses consist of costs associated with products being developed internally, and include related personnel expenses, laboratory supplies, active pharmaceutical ingredients, manufacturing supplies, facilities costs, preclinical and clinical trial costs and other outside service fees. The Company expenses research and development costs as incurred. A significant portion of the development activities are outsourced to third parties, including contract research organizations. In such cases, the Company may be required to estimate related service fees to be accrued.
Cash and Cash Equivalents	Cash and Cash Equivalents
	All highly-liquid investments with maturities of 90 days or less when purchased are considered cash equivalents.
Restricted Cash	Restricted Cash
	As further discussed in Note 8, Debt, the Company had entered into a financing agreement with Paul Capital for the sale of a royalty interest in its DepoCyt(e) and DepoDur® product revenue and royalties. The royalty interest agreement pertained only to DepoCyt(e) and the Company’s previously-marketed product, DepoDur, and does not include revenue related to EXPAREL or any other product candidates. As part of this financing agreement, the Company and Paul Capital maintained a lockbox, where all DepoCyt(e) and DepoDur product revenue and royalties were received. The Company had no minimum payment obligations under this agreement. Commencing on April 1 of every year, the first $2.5 million received in the lockbox was restricted and was used to make quarterly payments due to Paul Capital, if any, under the agreement during the subsequent 12 month period. On March 31 of the subsequent year, the balance of cash in the lockbox, if any, is remitted to the Company. The Paul Capital agreement terminated on December 31, 2014.
Short-Term Investments	Short-Term and Long-Term Investments
	Short-term investments consist of asset-backed securities collateralized by credit card receivables, investment grade commercial paper and corporate bonds with initial maturities of greater than three months at the date of purchase, but less than one year. Long-term investments consist of corporate bonds with initial maturities greater than one year at the date of purchase. The Company determines the appropriate classification of its investments at the time of purchase and reevaluates such determination at each balance sheet date. The Company’s investment policy sets minimum credit quality criteria and maximum maturity limits on its investments to provide for preservation of capital, liquidity and a reasonable rate of return. Available-for-sale securities are recorded at fair value, based on current market valuations. Unrealized holding gains and losses on available-for-sale securities are excluded from net loss and are reported as a separate component of other comprehensive loss until realized. Realized gains and losses are included in non-operating other income (expense) on the consolidated statements of operations and are derived using the specific identification method for determining the cost of the securities sold.
Inventories	Inventories
	Inventories consist of finished goods held for sale and distribution, raw materials and work in process. Inventories are stated at the lower of cost, which includes amounts related to material, labor and overhead; or market (net realizable) value and is determined using the first-in, first-out (“FIFO”) method. The Company periodically reviews its inventory to identify obsolete, slow-moving, or otherwise unsalable inventories, and establishes allowances for situations in which the cost of the inventory is not expected to be recovered.
Fixed Assets	Fixed Assets
	Fixed assets are recorded at cost, net of accumulated depreciation and amortization. The Company reviews its property, plant and equipment assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable.
	Depreciation of fixed assets is provided over their estimated useful lives on a straight-line basis. Leasehold improvements are amortized on a straight-line basis over the shorter of their estimated useful lives or the related remaining lease terms. Useful lives by asset category are as follows:
	Asset Category		Useful Lives
	Computer equipment and software		1 to 3 years
	Office furniture and equipment		5 years
	Manufacturing and laboratory equipment		5 to 10 years
Goodwill and Intangible Assets	Goodwill and Intangible Assets
	Intangible assets are recorded at cost, net of accumulated amortization. Amortization of intangible assets is provided over their estimated useful lives on a straight-line basis. The Company evaluates the recoverability of intangible assets periodically and takes into account events and circumstances which may indicate that impairment exists. Goodwill represents the excess of purchase price over fair value acquired in a business combination and is not amortized, but subject to impairment at least annually or when a triggering event occurs that could indicate a potential impairment.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets
	Management reviews long-lived assets, including fixed assets, for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets.
Convertible Debt Transactions	Convertible Debt Transactions
	The Company separately accounts for the liability and equity components of convertible debt instruments by allocating the proceeds from the issuance between the liability component and the embedded conversion option, or equity component. This is done in accordance with accounting for convertible debt instruments that may be settled in cash (including partial cash settlement) upon conversion. The value of the equity component is calculated by first measuring the fair value of the liability component, using the interest rate of a similar liability that does not have a conversion feature, as of the issuance date. The difference between the initial proceeds from the convertible debt issuance and the fair value of the liability component is recorded as the carrying amount of the equity component. The Company recognizes the amortization of the resulting discount as part of interest expense in its consolidated statement of operations.
	Upon settlement of the convertible senior notes, the liability component is measured at fair value. The Company allocates a portion of the fair value of the total settlement consideration transferred to the extinguishment of the liability component equal to the fair value of that component immediately prior to the settlement. Any difference between the consideration attributed to the liability component and the net carrying amount of the liability component, including any unamortized debt issuance costs, is recognized as a gain or loss in the consolidated statement of operations. Any remaining consideration is allocated to the reacquisition of the equity component and is recognized as a reduction of additional paid-in capital.
Foreign Currencies	Foreign Currencies
	The Company receives payment from certain commercial partners relating to royalties on DepoCyte® in Euros. Realized gains and losses from foreign currency transactions are reflected in the consolidated statements of operations and were not significant in any period. All foreign currency receivables and payables are measured at the applicable exchange rate at the end of the reporting period.
Income Taxes	Income Taxes
	The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to basis differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. As of December 31, 2014 and 2013, all deferred tax assets were fully offset by a valuation allowance.
	In February 2013, the Company received $0.4 million from the sale of unused net operating losses through the State of New Jersey’s Economic Development Authority Technology Business Tax Certificate Transfer Program. As a result, the Company recorded an income tax benefit by reversing the valuation allowance for the related net deferred tax assets. The Company continues to maintain a full valuation allowance on its remaining net deferred tax assets because there is significant doubt regarding the Company’s ability to utilize such net deferred tax assets.
	The Company accrues interest and penalties, if any, on underpayment of income taxes related to unrecognized tax benefits as a component of income tax expense in its consolidated statements of operations.
Per Share Data	Per Share Data
	Basic net income (loss) per share is computed by dividing net income (loss) available (attributable) to common stockholders by the weighted average number of shares of common stock outstanding during the period.
	Diluted net income (loss) per share is calculated by dividing net income (loss) available (attributable) to common stockholders as adjusted for the effect of dilutive securities, if any, by the weighted average number of common stock and dilutive common stock outstanding during the period. Potential common shares include the shares of common stock issuable upon the exercise of outstanding stock options, warrants and the purchase of shares from the employee stock purchase plan (using the treasury stock method) as well as the conversion of the excess conversion value on the Notes. Potential common shares in the diluted net loss per share computation are excluded to the extent that they would be anti-dilutive. No potentially dilutive securities are included in the computation of any diluted per share amounts as the Company reported a net loss for all periods presented.
Stock-Based Compensation	Stock-Based Compensation
	The Company’s stock-based compensation program includes grants of stock options to employees, consultants, and non-employee directors in addition to the opportunity for employees to participate in an employee stock purchase plan. The expense associated with these programs is recognized in the Company’s consolidated statements of operations based on their fair values as they are earned under the applicable vesting terms or the length of an offering period.
	The valuation of stock options is an inherently subjective process, since market values are generally not available for long-term, non-transferable stock options. Accordingly, the Company uses an option pricing model to derive an estimated fair value. In calculating the estimated fair value of stock options granted, the Company uses the Black-Scholes option valuation model, or Black-Scholes model, which requires the consideration of the following variables for purposes of estimating fair value:
	•	Expected term of the option
	•	Expected volatility
	•	Expected dividends
	•	Risk-free interest rate
	Since its initial public offering, the Company utilizes its available historic volatility data combined with a publicly traded peer group’s historic volatility to determine expected volatility over the expected option term. In 2014, the Company used an expected term based on a weighted average combination of its historical data from stock option exercises and the simplified method. In prior years the Company utilized the “simplified” method for “plain vanilla” options to estimate the expected term of stock option grants. Under that approach, the weighted average expected life was presumed to be the average of the vesting term and the contractual term of the option. The risk-free interest rate is based on the implied yield on United States Department of the Treasury zero coupon bonds for periods commensurate with the expected term of the options. The dividend yield on the Company’s common stock is estimated to be zero as the Company has not paid any dividends since inception, nor does it have any intention to do so in the foreseeable future. The Company estimates the level of award forfeitures expected to occur based on its historical data and records compensation cost only for those awards that are ultimately expected to vest.
Segment Reporting	Segment Reporting
	The Company operates in one reportable segment and, accordingly, no segment disclosures have been presented.
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS
	In May 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update 2014-09, Revenue from Contracts with Customers, which requires that an entity recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to its customers. In order to achieve this core principle, an entity should apply the following steps: (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract and (5) recognize revenue when (or as) the entity satisfies a performance obligation. This update will replace existing revenue recognition guidance under GAAP when it becomes effective for the Company beginning January 1, 2017, with early adoption not permitted. The updated standard will permit the use of either the retrospective or cumulative effect transition method. The Company is currently evaluating the impact of this update on its consolidated financial statements.
	In August 2014, the FASB issued Accounting Standards Update 2014-15, Presentation of Financial Statements—Going Concern, which requires that management of an entity should evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued or available to be issued. This update will become effective beginning January 1, 2017, with early adoption permitted. The provisions of this standard are not expected to significantly impact the Company.
	Other pronouncements issued by the FASB or other authoritative accounting standards groups with future effective dates are either not applicable or not significant to the consolidated financial statements of the Company.

SUMMARY_OF_SIGNIFICANT_ACCOUNT2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Schedule of percentage of revenue comprised by the three largest customers	The table below includes the percentage of revenue comprised by the three largest customers (i.e., wholesalers or commercial partners) in each year presented:
		Year Ended December 31,
		2014		2013		2012
	Largest customer	33	%	33	%	30	%
	Second largest customer	29	%	28	%	14	%
	Third largest customer	24	%	18	%	11	%
		86	%	79	%	55	%
Schedule of useful lives by asset category	Useful lives by asset category are as follows:
	Asset Category		Useful Lives
	Computer equipment and software		1 to 3 years
	Office furniture and equipment		5 years
	Manufacturing and laboratory equipment		5 to 10 years

INVENTORIES_Tables

INVENTORIES (Tables)	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Schedule of components of inventories	The components of inventories are as follows (in thousands):
		December 31,
		2014		2013
	Raw materials	$	9,263	$	5,290
	Work-in-process	8,617		6,321
	Finished goods	11,383		3,946
	Total	$	29,263	$	15,557

FIXED_ASSETS_Tables

FIXED ASSETS (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Schedule of fixed assets summarized by major category	Fixed assets, net summarized by major category, consist of the following (in thousands):
		December 31,
		2014			2013
	Machinery and laboratory equipment	$	29,697		$	19,570
	Computer equipment and software	3,754			2,476
	Office furniture and equipment	1,001			441
	Leasehold improvements	26,350			24,852
	Construction in progress	19,944			13,419
	Total	80,746			60,758
	Less: accumulated depreciation	(20,114		)	(12,576		)
	Fixed assets, net	$	60,632		$	48,182

GOODWILL_AND_INTANGIBLE_ASSETS1

GOODWILL AND INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of change in carrying value of goodwill	The change in the carrying value of goodwill is summarized as follows (in thousands):
			Carrying Value
	Balance at December 31, 2012		$	8,297
	Percentage payments on collections of net sales of EXPAREL		2,031
	Balance at December 31, 2013		10,328
	Milestone payment triggered by collections of net sales of EXPAREL		8,000
	Percentage payments on collections of net sales of EXPAREL		5,433
	Balance at December 31, 2014		$	23,761
Summary of intangible assets	Intangible assets, net, consist of core technology, developed technology and trademarks and trade names acquired in the Acquisition and are summarized as follows (in thousands):
	December 31, 2014	Gross			Accumulated			Intangible		Estimated
		Carrying Value			Amortization			Assets, Net		Useful Life
	Amortizable intangible assets:
	Core technology	$	2,900		$	(2,497	)	$	403	9 Years
	Developed technology	11,700			(11,700		)	—		7 Years
	Trademarks and trade names	400			(400		)	—		7 Years
	Total intangible assets	$	15,000		$	(14,597	)	$	403
	December 31, 2013	Gross			Accumulated			Intangible		Estimated
		Carrying Value			Amortization			Assets, Net		Useful Life
	Amortizable intangible assets:
	Core technology	$	2,900		$	(2,175	)	$	725	9 years
	Developed technology	11,700			(11,282		)	418		7 years
	Trademarks and trade names	400			(386		)	14		7 years
	Total intangible assets	$	15,000		$	(13,843	)	$	1,157
Schedule of approximate amortization expense for intangibles subject to amortization	uture amortization expense relates only to core technology and is as follows (in thousands):
	2015		$	322
	2016		81
	Total		$	403

ACCRUED_EXPENSES_Tables

ACCRUED EXPENSES (Tables)	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Schedule of accrued expenses	Accrued expenses consist of the following (in thousands):
		December 31,
		2014		2013
	Compensation and benefits	$	8,909	$	5,488
	Accrued operating expenses	12,094		8,001
	Accrued royalties	3,213		1,526
	Accrued interest	1,625		1,625
	Product returns, rebates and other fees	2,470		1,245
	Income taxes payable	139		—
	Total	$	28,450	$	17,885

DEBT_Tables

DEBT (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Schedule of composition of the Company's debt and financing obligations	The composition of the Company’s debt and financing obligations is as follows (in thousands):
		December 31,
		2014			2013
	Debt:
	Convertible senior notes	$	120,000		$	120,000
	Discount on debt	(16,900		)	(21,039		)
	Total debt, net of discount	103,100			98,961
	Royalty interest obligation	276			1,246
	Total debt and financing obligations	$	103,376		$	100,207
Schedule of total interest expense recognized related to the Notes	The following table sets forth the total interest expense recognized related to the Notes issued in January 2013 (in thousands):
		Year Ended December 31,
		2014			2013
	Contractual interest expense	$	3,900		$	3,662
	Amortization of debt issuance costs	620			584
	Amortization of debt discount	4,139			3,897
		$	8,659		$	8,143
	Effective interest rate	7.22		%	7.22		%

FINANCIAL_INSTRUMENTS_Tables

FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Schedule of carrying amount and fair value of the long-term debt	The carrying amount and fair value of the Notes are as follows (in thousands):
		Carrying		Fair Value Measurements Using
	Financial Liabilities Carried at Historical Cost	Value		Level 1		Level 2			Level 3
	December 31, 2014
	Convertible senior notes *	$	103,100	$	—	$	429,438		$	—
	* The fair value of the Notes was based on the Company’s closing stock price of $88.66 per share at December 31, 2014 compared to a conversion price of $24.82 per share which, if converted, would result in an approximate conversion premium of 3.5 million shares or $309 million of cash. The maximum conversion premium that can be due on the Notes is 4.8 million shares, which assumes no increases in the conversion rate for certain corporate events.
Schedule of short-term investments	The following summarizes the Company’s short-term and long-term investments at December 31, 2014 and 2013 (in thousands):
	December 31, 2014	Cost		Gross		Gross			Fair Value
				Unrealized		Unrealized			(Level 2)
				Gains		Losses
	Debt securities:
	Short-term:
	Asset-backed securities	$	15,009	$	—	$	(9	)	$	15,000
	Commercial paper	1,747		3		—			1,750
	Corporate bonds	102,430		—		(42		)	102,388
	Subtotal	119,186		3		(51		)	119,138
	Long-term:
	Corporate bonds	24,463		10		(42		)	24,431
	Total	$	143,649	$	13	$	(93	)	$	143,569
	December 31, 2013	Cost		Gross		Gross			Fair Value
				Unrealized		Unrealized			(Level 2)
				Gains		Losses
	Debt securities:
	Asset-backed securities	$	10,838	$	1	$	(1	)	$	10,838
	Commercial paper	17,986		11		—			17,997
	Corporate bonds	30,808		1		(7		)	30,802
	Total	$	59,632	$	13	$	(8	)	$	59,637

STOCKHOLDERS_EQUITY_Tables

STOCKHOLDERS' EQUITY (Tables)	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Schedule of accumulated other comprehensive income	Accumulated Other Comprehensive Income
	The following table illustrates the changes in the balances of the Company’s accumulated other comprehensive income (in thousands):
		Net Unrealized Gains
		(Losses) From Available
		For Sale Investments
	Balance at December 31, 2012	$	27
	Other comprehensive loss before reclassifications	(23		)
	Amounts reclassified from accumulated other comprehensive income	1
	Balance at December 31, 2013	5
	Other comprehensive loss before reclassifications	(85		)
	Amounts reclassified from accumulated other comprehensive income	—
	Balance at December 31, 2014	$	(80	)

STOCK_PLANS_Tables

STOCK PLANS (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of information about the plans	The following table contains information about the Company’s plans at December 31, 2014:
	Stock Incentive Plans		Awards Reserved for Issuance			Awards Issued			Awards Available for Grant
	2007 Stock incentive plan		2,022,837			2,022,837			—
	2011 Plan		5,931,700			4,400,525			1,531,175
	2014 Inducement plan		175,000			77,000			98,000
			8,129,537			6,500,362			1,629,175
	Employee Stock Purchase Plan		Shares Reserved for Purchase			Shares Purchased			Shares Available for Purchase
	2014 Employee stock purchase plan		500,000			15,722			484,278
Schedule of recognized stock-based compensation in consolidated statements of operations
			Year Ended December 31,
			2014				2013			2012
	Cost of revenues		$	3,582			$	1,526		$	563
	Research and development		6,490				4,345			1,155
	Selling, general and administrative		14,750				5,642			3,058
	Total		$	24,822			$	11,513		$	4,776
	Stock-based compensation from:
	Stock options		$	24,477			$	11,513		$	4,776
	Employee stock purchase plan		345				—			—
	Total		$	24,822			$	11,513		$	4,776
Schedule of the Company's stock option activity and related information	The following table summarizes the Company’s stock option activity and related information for the period from January 1, 2012 to December 31, 2014 (in thousands except share and per share amounts):
		Number of			Weighted				Weighted Average	Aggregate
		Shares			Average				Remaining	Intrinsic Value
					Exercise Price				Contractual	(in Thousands)
									Term (Years)
	Outstanding at January 1, 2012	2,337,017			$	3.92			8.8	$	11,829
	Granted	2,120,250			11.55
	Exercised	(279,476	)		2.75					$	3,005
	Forfeited	(174,610	)		7.94
	Expired	(15	)		7.07
	Outstanding at December 31, 2012	4,003,166			7.86				8.66	$	38,485
	Granted	918,915			30.42
	Exercised	(742,211	)		5.19					$	21,679
	Forfeited	(338,145	)		10.93
	Expired	(1,687	)		7.24
	Outstanding at December 31, 2013	3,840,038			13.5				8.01	$	168,905
	Granted	1,638,575			79.68
	Exercised	(624,229	)		11.6					$	45,289
	Forfeited	(175,967	)		44.32
	Expired	(561	)		21.7
	Outstanding at December 31, 2014	4,677,856			$	35.78			7.86	$	248,276
	Exercisable at December 31, 2014	2,085,829			$	11.61			6.75	$	160,707
	Vested and expected to vest at December 31, 2014	4,486,980			$	34.59			7.81	$	243,438
Schedule of weighted average assumptions used to estimate the fair values of each option grant using the Black-Scholes option pricing model	The fair values of stock options granted were estimated using the Black-Scholes model with the following weighted average assumptions:
		Year Ended December 31,
		2014		2013		2012
	Expected dividend yield	None		None		None
	Risk free interest rate	0.02 - 2.16%		0.33 - 2.83%		0.84 - 1.70%
	Expected volatility	57.20%		68.70%		74.00%
	Expected term of options	5.86 years		6.22 years		6.76 years

NET_INCOME_LOSS_PER_SHARE_Tabl

NET INCOME (LOSS) PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted loss per share	The following table sets forth the computation of basic and diluted loss per share for the years ended December 31, 2014, 2013 and 2012 (in thousands except per share amounts):
		Year Ended December 31,
		2014				2013			2012
	Numerator:
	Net loss	$	(13,716	)		$	(63,909	)	$	(52,281	)
	Denominator:
	Weighted average shares of common stock outstanding	35,299				33,182			30,332
	Net loss per share:
	Basic and diluted net loss per share of common stock	$	(0.39	)		$	(1.93	)	$	(1.72	)
Schedule of potential dilutive effect of the securities excluded from the calculation of diluted loss per share
		Year Ended December 31,
		2014			2013			2012
	Weighted average number of stock options outstanding	3,534			3,980			3,304
	Conversion premium on the Notes	2,483			1,194			—
	Weighted average number of warrants outstanding	21			204			585
	Weighted average purchase options under ESPP	1			—			—
	Total	6,039			5,378			3,889

INCOME_TAXES_Tables

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of reconciliation of income taxes at the U.S. Federal statutory rate to the provision for income taxes	A reconciliation of income taxes at the U.S. federal statutory rate to the provision for income taxes is as follows:
		Year Ended December 31,
		2014			2013			2012
	Benefit at U.S. Federal statutory rate	35	%		35	%		35	%
	State taxes	(32.75	)%		4.79	%		6.73	%
	Increase in valuation allowance	(17.71	)%		(42.91	)%		(39.62	)%
	Tax credits	5.49	%		1.69	%		—	%
	Interest expense	10.68	%		0.3	%		(0.22	)%
	Other	(1.99	)%		1.82	%		(1.89	)%
	Provision for income taxes	(1.28	)%		0.69	%		—	%
Schedule of significant components of the Company's deferred tax assets	Significant components of the Company’s deferred tax assets and liabilities are as follows (in thousands):
		December 31,
		2014				2013
	Deferred tax assets:
	Federal and state net operating loss carry-forwards	$	111,086			$	114,819
	Federal and state research credits	6,043				5,149
	Depreciation and amortization	3,494				3,248
	Accruals and reserves	3,861				1,696
	Deferred revenue	4,065				1,707
	Stock based compensation	8,487				2,622
	Other	588				752
	Total deferred tax assets	137,624				129,993
	Deferred tax liabilities:
	Discount on convertible senior notes	(6,283		)		(8,507		)
		131,341				121,486
	Less: valuation allowance	(131,341		)		(121,486		)
	Net deferred tax assets	$	—			$	—

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of annual minimum payments due under the Company's lease obligations	As of December 31, 2014, the aggregate annual minimum payments due under the Company’s lease obligations are as follows (in thousands):
	Year
	2015	$	6,133
	2016	7,263
	2017	7,459
	2018	7,660
	2019	7,876
	2020 through 2028	11,786
	Total	$	48,177

SELECTED_QUARTERLY_FINANCIAL_D1

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Data	The following table presents selected quarterly financial data for the years ended December 31, 2014 and 2013 (in thousands, except per share data):
		Three Months Ended
		March 31,			June 30,			September 30,			December 31,
		2014			2014			2014			2014
	Total revenues	$	36,662		$	47,165		$	52,048		$	61,793
	Cost of revenues	18,127			19,954			20,391			18,968
	Total operating expenses	45,920			50,007			53,033			53,873
	Net income (loss)	(11,477		)	(5,037		)	(3,004		)	5,802
	Basic net income (loss) per common share	$	(0.34	)	$	(0.14	)	$	(0.08	)	$	0.16
	Diluted net income (loss) per common share	$	(0.34	)	$	(0.14	)	$	(0.08	)	$	0.14
		Three Months Ended
		March 31,			June 30,			September 30,			December 31,
		2013			2013			2013			2013
	Total revenues	$	11,587		$	17,141		$	23,259		$	33,564
	Cost of revenues	11,391			10,214			14,791			18,376
	Total operating expenses	30,232			29,151			36,073			43,384
	Net loss	(23,138		)	(14,031		)	(14,784		)	(11,956		)
	Basic net loss per common share	$	(0.71	)	$	(0.42	)	$	(0.44	)	$	(0.36	)
	Diluted net loss per common share	$	(0.71	)	$	(0.42	)	$	(0.44	)	$	(0.36	)
	For periods where the Company reported a net loss, no potentially dilutive securities have been included in the computation of diluted net loss per share.

SUMMARY_OF_SIGNIFICANT_ACCOUNT3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	12 Months Ended	0 Months Ended
	Dec. 31, 2014	Jan. 23, 2013	Jan. 23, 2013
Liquidity
Estimated conversion value	$309,000,000
Shares issuable upon conversion	3,500,000
Revenue Recognition
Beginning period prior to product expiration allowed for the product to be returned	6 months
Period following product expiration upto which the product is allowed to be returned	12 months
Notes
Liquidity
Stated interest rate (as a percent)	3.25%	3.25%	3.25%
Proceeds from Issuance of Debt		$120,000,000	$120,000,000

SUMMARY_OF_SIGNIFICANT_ACCOUNT4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Cash
Amount received in lockbox restricted for payment of royalty interest	2,500,000
Period for making payment from amount received in lockbox restricted for payment of royalty interest	12 months
Net revenue | Customer concentration
Concentration of Major Customers
Percentage of revenue from customers to total revenue	86.00%	79.00%	55.00%
Net revenue | Customer concentration | Largest customer
Concentration of Major Customers
Percentage of revenue from customers to total revenue	33.00%	33.00%	30.00%
Net revenue | Customer concentration | Second largest customer
Concentration of Major Customers
Percentage of revenue from customers to total revenue	29.00%	28.00%	14.00%
Net revenue | Customer concentration | Third largest customer
Concentration of Major Customers
Percentage of revenue from customers to total revenue	24.00%	18.00%	11.00%
Net revenue | Customer concentration | Customers outside U.S.
Concentration of Major Customers
Percentage of revenue from customers to total revenue	2.00%	5.00%	23.00%

SUMMARY_OF_SIGNIFICANT_ACCOUNT5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 3) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Feb. 28, 2013	Dec. 31, 2014
		segment
Income Taxes
Amount received from sale of unused net operating losses	$0.40
Segment Reporting
Number of reportable segments		1
Manufacturing and laboratory equipment | Minimum
Fixed Assets
Useful life		5 years
Manufacturing and laboratory equipment | Maximum
Fixed Assets
Useful life		10 years
Computer equipment and software | Minimum
Fixed Assets
Useful life		1 year
Computer equipment and software | Maximum
Fixed Assets
Useful life		3 years
Office furniture and equipment
Fixed Assets
Useful life		5 years

INVENTORIES_Details

INVENTORIES (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Raw materials	$9,263	$5,290
Work-in-process	8,617	6,321
Finished goods	11,383	3,946
Total	$29,263	$15,557

FIXED_ASSETS_Details

FIXED ASSETS (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
FIXED ASSETS
Total	$80,746,000	$60,758,000
Less accumulated depreciation	-20,114,000	-12,576,000
Fixed assets, net	60,632,000	48,182,000
Depreciation expense	9,300,000	3,700,000	3,600,000
Capitalized interest	400,000	1,100,000	2,000,000
Manufacturing and laboratory equipment
FIXED ASSETS
Total	29,697,000	19,570,000
Computer equipment and software
FIXED ASSETS
Total	3,754,000	2,476,000
Office furniture and equipment
FIXED ASSETS
Total	1,001,000	441,000
Leasehold improvements
FIXED ASSETS
Total	26,350,000	24,852,000
Construction in progress
FIXED ASSETS
Total	$19,944,000	$13,419,000

GOODWILL_AND_INTANGIBLE_ASSETS2

GOODWILL AND INTANGIBLE ASSETS (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Apr. 30, 2012	Sep. 30, 2014
Goodwill
Goodwill Recorded on Milestone Payments	$8,000,000
Payment obligation arising in connection with the acquisition			10,000,000
Contingent consideration liability recognized at the time of the acquisition			2,000,000
Goodwill recorded in connection with the acquisition	23,761,000	10,328,000	8,000,000
Goodwill [Roll Forward]
Beginning balance	10,328,000	8,297,000	8,000,000
Percentage payments on collections of net sales of EXPAREL	5,433,000	2,031,000
Ending balance	23,761,000	10,328,000	8,000,000
Total Goodwill Recorded for Earn Out Payments	7,800,000
Upon first commercial sale in the United States
Goodwill
Milestone payments for EXPAREL agreed in connection with acquisition	10,000,000
Upon first commercial sale in a major EU country (United Kingdom, France, Germany, Italy and Spain)
Goodwill
Milestone payments for EXPAREL agreed in connection with acquisition	4,000,000
When annual net sales collected reach $100.0 million
Goodwill
Payment Obligation Arising Due to Net Sales Collected Threshold of $100 Million				8,000,000
Milestone payments for EXPAREL agreed in connection with acquisition	8,000,000
Annual net sales threshold	100,000,000
Goodwill [Roll Forward]
Net Sales Collected Threshold Which Triggers a Payment Obligation				100,000,000
When annual net sales collected reach $250.0 million
Goodwill
Milestone payments for EXPAREL agreed in connection with acquisition	8,000,000
Annual net sales threshold	250,000,000
When annual net sales collected reach $500.0 million
Goodwill
Milestone payments for EXPAREL agreed in connection with acquisition	32,000,000
Annual net sales threshold	$500,000,000

GOODWILL_AND_INTANGIBLE_ASSETS3

GOODWILL AND INTANGIBLE ASSETS (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Intangible Assets
Gross amount	$15,000,000	$15,000,000
Accumulated amortization	-14,597,000	-13,843,000
Intangibles, net	403,000	1,157,000
Amortization expense for intangibles	800,000	2,100,000	2,100,000
Approximate amortization expense for intangibles
Intangibles, net	403,000	1,157,000
Core Technology
Intangible Assets
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	322,000
Gross amount	2,900,000	2,900,000
Accumulated amortization	-2,497,000	-2,175,000
Intangibles, net	403,000	725,000
Estimated Useful Life	9 years	9 years
Approximate amortization expense for intangibles
2014	81,000
Intangibles, net	403,000	725,000
Developed Technology
Intangible Assets
Gross amount	11,700,000	11,700,000
Accumulated amortization	-11,700,000	-11,282,000
Intangibles, net	0	418,000
Estimated Useful Life	7 years	7 years
Approximate amortization expense for intangibles
Intangibles, net	0	418,000
Trademarks and trade names
Intangible Assets
Gross amount	400,000	400,000
Accumulated amortization	-400,000	-386,000
Intangibles, net	0	14,000
Estimated Useful Life	7 years	7 years
Approximate amortization expense for intangibles
Intangibles, net	$0	$14,000

ACCRUED_EXPENSES_Details

ACCRUED EXPENSES (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]
Compensation and benefits	$8,909	$5,488
Accrued operating expenses	12,094	8,001
Accrued royalties	3,213	1,526
Accrued interest	1,625	1,625
Product returns, rebates and other fees	2,470	1,245
Income taxes payable	139	0
Total	$28,450	$17,885

DEBT_Details

DEBT (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt:
Current portion of long-term debt	$120,000	$120,000
Discount on debt	-16,900	-21,039
Total debt, net of debt discount	103,100	98,961
Royalty Interest Obligation	276	1,246
Total debt and financing obligations	$103,376	$100,207

DEBT_Details_2

DEBT (Details 2) (USD $)	3 Months Ended	12 Months Ended				0 Months Ended		1 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2000	Jan. 23, 2013	Jan. 23, 2013	Jan. 31, 2013	31-May-12	Apr. 30, 2014	2-May-12	Apr. 30, 2012	Jan. 16, 2013
					product
Debt disclosures
Loss on early extinguishment of debt		$0	$3,398,000	$1,062,000
Closing sale price (in dollars per share)	$88.66	$88.66								$64		$9.75
Estimated conversion value	309,000,000	309,000,000
Debt Conversion, Converted Instrument, Shares Issued	3,500,000
Interest Expense, Debt [Abstract]
Amortization of debt discount		4,139,000	3,959,000	831,000
Oxford Loan Facility
Debt Instrument, Unamortized Discount	16,900,000	16,900,000	21,039,000
Number of shares exercisable for warrants issued to holders of the debt											162,885
Exercise price per share (in dollars per share)											10.97
Affiliate of Paul Capital
Assumptions used in determining fair value of the warrants
Amount to be raised					30,000,000
Number of product sales on which there is a right to receive royalty interest					4
Net present value of royalties expected to be repaid					13,000,000
Notes
Financing obligations:
Gross Proceeds From Issuance of Debt							120,000,000
Debt disclosures
Debt issued in private offering						120,000,000	120,000,000
Stated interest rate (as a percent)	3.25%	3.25%				3.25%	3.25%
Net proceeds from private placement of debt							115,300,000
Principal amount used for debt instrument conversion ratio	1,000	1,000
Initial conversion rate of common stock per $1000 of principal amount of Notes (in shares)		40.2945
Initial conversion price of notes into common stock (in dollars per share)	$24.82	$24.82
Premium on sale price to calculate conversion price of notes (as a percent)													32.50%
Closing sale price (in dollars per share)													$18.73
Debt Redemption Price Due to Fundamental Change as Percentage of Principal Amount		100.00%
In event of default, the percentage of principal amount due and payable		100.00%
Liability component of convertible debt	95,100,000	95,100,000
Total transaction costs related to the issuance of Notes							4,700,000
Term of Notes							6 years
Interest Expense, Debt [Abstract]
Contractual interest expense		3,900,000	3,662,000
Amortization of debt issuance costs		620,000	584,000
Amortization of debt discount		4,139,000	3,897,000
Total interest expense recognized		8,659,000	8,143,000
Effective interest rate (as a percent)		7.22%	7.22%
Notes | Conversion terms business day immediately preceding August 1, 2018
Debt disclosures
Minimum number of days within 30 consecutive trading days in which the closing price of the entity's common stock must exceed the conversion price for the notes to be convertible		20 days
Number of consecutive trading days during which the closing price of the entity's common stock must exceed the conversion price for at least 20 days in order for the notes to be convertible		30 days
Percentage of the conversion price that the closing sales price of the entity's common stock must exceed in order for the notes to be convertible		130.00%
Number of consecutive business days immediately after any five consecutive trading day period during the note measurement period		5 days
Number of consecutive trading days before five consecutive business days during the note measurement period		5 days
Principal amount used for debt instrument conversion ratio	1,000	1,000
Percentage of the trading price to the product of the last reported sale price of the entity's common stock and the conversion rate		98.00%
Market price per $1000 of principal amount of notes	3,579	3,579
Estimated conversion value	3,572	3,572
Notes | Debt redemption terms on or after February 1, 2017
Debt disclosures
Minimum number of days within 30 consecutive trading days in which the closing price of the entity's common stock must exceed the conversion price for the notes to be convertible		20 days
Number of consecutive trading days during which the closing price of the entity's common stock must exceed the conversion price for at least 20 days in order for the notes to be convertible		30 days
Percentage of the conversion price that the closing sales price of the entity's common stock must exceed in order for the notes to be convertible		130.00%
Number of trading days prior to the date on which the company provides notice of redemption during which the closing price of the entity's common stock must exceed the conversion price for the notes to be redeemed		5 days
Redemption price as percentage of principal amount of notes plus accrued and unpaid interest plus make-whole premium payment		100.00%
Assumptions used in determining fair value of the warrants
Discount rate (as a percent)		2.00%
Oxford Loan Facility
Debt disclosures
Debt issued in private offering									27,500,000
Stated interest rate (as a percent)											9.75%
Repayment of remaining principal amount of debt							27,500,000
End of term charge on early termination							1,700,000
Prepayment fees on early termination							800,000
Repayment of accrued interest							200,000
Loss on early extinguishment of debt							3,400,000	3,400,000
Oxford Loan Facility
Number of shares exercisable for warrants issued to holders of the debt	162,885	162,885
Exercise price per share (in dollars per share)	10.97	10.97
Assumptions used in determining fair value of the warrants
Relative fair value of the warrants	$1,400,000	$1,400,000

FINANCIAL_INSTRUMENTS_Details

FINANCIAL INSTRUMENTS (Details) (USD $)	12 Months Ended		9 Months Ended
	Dec. 31, 2014		Sep. 30, 2014	Apr. 30, 2014	Dec. 31, 2013	Apr. 30, 2012	Jan. 16, 2013
Fair Value Measurements
Available-for-sale Debt Securities, Amortized Cost Basis	$143,649,000				$59,632,000
Long-term investments	24,431,000				0
Price per share (in dollars per share)	$88.66			$64		$9.75
Debt Instrument, Convertible, Conversion Premium, Shares	3,500,000
Estimated conversion value	309,000,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	13,000				13,000
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	93,000				8,000
Level 1
Fair Value Measurements
Long-term debt-current and long-term	0	[1]
Level 2
Fair Value Measurements
Long-term debt-current and long-term	429,438,000	[1]
Available-for-sale Securities	143,569,000				59,637,000
Level 3
Fair Value Measurements
Long-term debt-current and long-term	0	[1]
Notes
Fair Value Measurements
Price per share (in dollars per share)							$18.73
Initial conversion price of notes into common stock (in dollars per share)	$24.82
Maximum
Fair Value Measurements
Long Term Investments Maturity Period			37 months
Debt Instrument, Convertible, Conversion Premium, Shares	4,800,000
Minimum
Fair Value Measurements
Long Term Investments Maturity Period	20 months
Standard & Poor's, A Rating
Fair Value Measurements
Long-term investments	24,400,000
Short-term Investments [Member]
Fair Value Measurements
Available-for-sale Debt Securities, Amortized Cost Basis	119,186,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	3,000
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	51,000
Short-term Investments [Member] | Level 2
Fair Value Measurements
Available-for-sale Securities	119,138,000
Asset-backed Securities
Fair Value Measurements
Available-for-sale Debt Securities, Amortized Cost Basis					30,808,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments					1,000
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments					7,000
Asset-backed Securities | Level 2
Fair Value Measurements
Available-for-sale Securities					30,802,000
Asset-backed Securities | Short-term Investments [Member]
Fair Value Measurements
Available-for-sale Debt Securities, Amortized Cost Basis	15,009,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	9,000
Asset-backed Securities | Short-term Investments [Member] | Level 2
Fair Value Measurements
Available-for-sale Securities	15,000,000
Commercial Paper
Fair Value Measurements
Available-for-sale Debt Securities, Amortized Cost Basis					10,838,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments					1,000
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments					1,000
Commercial Paper | Level 2
Fair Value Measurements
Available-for-sale Securities					10,838,000
Commercial Paper | Short-term Investments [Member]
Fair Value Measurements
Available-for-sale Debt Securities, Amortized Cost Basis	1,747,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	3,000
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0
Commercial Paper | Short-term Investments [Member] | Level 2
Fair Value Measurements
Available-for-sale Securities	1,750,000
Corporate Bond Securities [Member]
Fair Value Measurements
Available-for-sale Debt Securities, Amortized Cost Basis					17,986,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments					11,000
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments					0
Corporate Bond Securities [Member] | Level 2
Fair Value Measurements
Available-for-sale Securities					17,997,000
Corporate Bond Securities [Member] | Short-term Investments [Member]
Fair Value Measurements
Available-for-sale Debt Securities, Amortized Cost Basis	102,430,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	42,000
Corporate Bond Securities [Member] | Short-term Investments [Member] | Level 2
Fair Value Measurements
Available-for-sale Securities	102,388,000
Corporate Bond Securities [Member] | Long-Term Investments [Member]
Fair Value Measurements
Available-for-sale Debt Securities, Amortized Cost Basis	24,463,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	10,000
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	42,000
Corporate Bond Securities [Member] | Long-Term Investments [Member] | Level 2
Fair Value Measurements
Available-for-sale Securities	24,431,000
Carrying Value
Fair Value Measurements
Long-term debt-current and long-term	$103,100,000	[1]
[1]	The fair value of the Notes was based on the Company’s closing stock price of $88.66 per share at December 31, 2014 compared to a conversion price of $24.82 per share which, if converted, would result in an approximate conversion premium of 3.5 million shares or $309 million of cash. The maximum conversion premium that can be due on the Notes is 4.8 million shares, which assumes no increases in the conversion rate for certain corporate events.

FINANCIAL_INSTRUMENTS_Details_

FINANCIAL INSTRUMENTS (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Short-term investments
Short-term investments	119,138	$59,637
Available-for-sale Debt Securities, Amortized Cost Basis	143,649	59,632
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	13	13
Gross Unrealized Losses	-93	-8
Level 2
Short-term investments
Fair Value	143,569	59,637
Commercial Paper
Short-term investments
Available-for-sale Debt Securities, Amortized Cost Basis		10,838
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments		1
Gross Unrealized Losses		-1
Commercial Paper | Level 2
Short-term investments
Fair Value		10,838
Corporate Bond Securities [Member]
Short-term investments
Available-for-sale Debt Securities, Amortized Cost Basis		17,986
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments		11
Gross Unrealized Losses		0
Corporate Bond Securities [Member] | Level 2
Short-term investments
Fair Value		17,997
Asset-backed Securities
Short-term investments
Available-for-sale Debt Securities, Amortized Cost Basis		30,808
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments		1
Gross Unrealized Losses		-7
Asset-backed Securities | Level 2
Short-term investments
Fair Value		30,802
Minimum
Short-term investments
Maturity period	175 days
Maximum
Short-term investments
Maturity period	365 days
Standard & Poor's, A Rating
Short-term investments
Short-term investments	119,100
Short-term Investments [Member]
Short-term investments
Available-for-sale Debt Securities, Amortized Cost Basis	119,186
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	3
Gross Unrealized Losses	-51
Short-term Investments [Member] | Level 2
Short-term investments
Fair Value	119,138
Short-term Investments [Member] | Commercial Paper
Short-term investments
Available-for-sale Debt Securities, Amortized Cost Basis	1,747
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	3
Gross Unrealized Losses	0
Short-term Investments [Member] | Commercial Paper | Level 2
Short-term investments
Fair Value	1,750
Short-term Investments [Member] | Corporate Bond Securities [Member]
Short-term investments
Available-for-sale Debt Securities, Amortized Cost Basis	102,430
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0
Gross Unrealized Losses	-42
Short-term Investments [Member] | Corporate Bond Securities [Member] | Level 2
Short-term investments
Fair Value	102,388
Short-term Investments [Member] | Asset-backed Securities
Short-term investments
Available-for-sale Debt Securities, Amortized Cost Basis	15,009
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0
Gross Unrealized Losses	-9
Short-term Investments [Member] | Asset-backed Securities | Level 2
Short-term investments
Fair Value	15,000
Long-Term Investments [Member] | Corporate Bond Securities [Member]
Short-term investments
Available-for-sale Debt Securities, Amortized Cost Basis	24,463
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	10
Gross Unrealized Losses	-42
Long-Term Investments [Member] | Corporate Bond Securities [Member] | Level 2
Short-term investments
Fair Value	24,431

FINANCIAL_INSTRUMENTS_Details_1

FINANCIAL INSTRUMENTS (Details 3)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
	customer	customer
Credit Risk
Number of major customers	3	3
Accounts receivable | Credit risk | Major customer one
Credit Risk
Concentration risk (as a percent)	33.00%	31.00%
Accounts receivable | Credit risk | Major customer two
Credit Risk
Concentration risk (as a percent)	29.00%	31.00%
Accounts receivable | Credit risk | Major customer three
Credit Risk
Concentration risk (as a percent)	27.00%	20.00%

STOCKHOLDERS_EQUITY_Details

STOCKHOLDERS' EQUITY (Details) (USD $)	1 Months Ended
In Millions, except Share data, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2012	Dec. 31, 2014	Dec. 31, 2013
Stockholders' Equity Note [Abstract]
Common stock, shares authorized			250,000,000	250,000,000
Common stock, shares outstanding			36,150,620	33,636,442
Stock Issued During Period, Shares, New Issues	1,840,000
Additional common stock issued in registered public offering (in shares)		6,900,000
Price per share (in dollars per share)	$64	$9.75	$88.66
Proceeds from Issuance Initial Public Offering	$110.50
Net proceeds in a registered public offering		$62.90
Preferred stock, shares authorized			5,000,000	5,000,000
Warrants
Warrants outstanding (in shares)			7,216	58,354
Exercise price per share (in dollars per share)			$13.44	$11.73

STOCKHOLDERS_EQUITY_Details_2

STOCKHOLDERS' EQUITY (Details 2) (USD $)	3 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2014
Total Accumulated Other Comprehesive Income (Loss)
Balances at the beginning of the period				($80)
Balances at the end of the period			5	-80
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Total Accumulated Other Comprehesive Income (Loss)
Balances at the beginning of the period	5	27	27	-80
Other comprehensive loss before reclassifications	-85	-23
Amounts reclassified from accumulated other comprehensive income	0		1
Balances at the end of the period			$5	($80)

STOCK_PLANS_Details

STOCK PLANS (Details) (USD $)	12 Months Ended	1 Months Ended
	Dec. 31, 2014	Jun. 30, 2014	Apr. 30, 2014
Stock Incentive Plans
Shares Issued During Period, Employee Stock Purchase Plan	15,722
Awards Reserved for Issuance (in shares)	8,129,537
Awards Issued (in shares)	6,500,362
Awards Available for Grant (in shares)	1,629,175
Employee Stock Purchase Plan, Number of Shares Authorized	500,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans	15,722
Employee Stock Purchase Plan (ESPP), Shares in ESPP	500,000
Maximum Fair Market Value Purchase of ESPP Shares	$25,000
Employee Stock Purchase Plan fair value	85.00%
Employee Stock Purchase Plan, Number of Shares Available For Purchase	484,278
Two Thousand Seven Stock Incentive Plan [Member]
Stock Incentive Plans
Awards Reserved for Issuance (in shares)	2,022,837
Awards Issued (in shares)	2,022,837
Awards Available for Grant (in shares)	0
Stock Incentive Plan 2011 [Member]
Stock Incentive Plans
Awards Reserved for Issuance (in shares)	5,931,700
Awards Issued (in shares)	4,400,525
Awards Available for Grant (in shares)	1,531,175
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized		2,750,000
Inducement Plan 2014 [Member]
Stock Incentive Plans
Awards Reserved for Issuance (in shares)	175,000		175,000
Awards Issued (in shares)	77,000
Awards Available for Grant (in shares)	98,000

STOCK_PLANS_Details_2

STOCK PLANS (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-Based Compensation
Stock-based compensation expense	$24,822	$11,513	$4,776
Compensation expense from stock options	24,477	11,513	4,776
Compensation expense from employee stock purchase plan	345	0	0
Stock-based compensation	24,822	11,513	4,776
Cost of revenues
Share-Based Compensation
Stock-based compensation expense	3,582	1,526	563
Research and development
Share-Based Compensation
Stock-based compensation expense	6,490	4,345	1,155
Selling, general and administrative
Share-Based Compensation
Stock-based compensation expense	14,750	5,642	3,058
Stock options
Share-Based Compensation
Stock-based compensation expense	$600	$200

STOCK_PLANS_Details_3

STOCK PLANS (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Additional disclosures
Weighted average contractual term of the unrecognized stock-based compensation	3 years 0 months 25 days
Stock options
Number of Shares
Balance at the beginning of the period (in shares)	3,840,038	4,003,166	2,337,017
Granted (in shares)	1,638,575	918,915	2,120,250
Exercised (in shares)	-624,229	-742,211	-279,476
Forfeited (in shares)	-175,967	-338,145	-174,610
Expired (in shares)	-561	-1,687	-15
Balance at the end of the period (in shares)	4,677,856	3,840,038	4,003,166	2,337,017
Exercisable at the end of the period (in shares)	2,085,829
Vested and expected to vest at the end of the period (in shares)	4,486,980
Weighted Average Exercise Price
Balance at the beginning of the period (in dollars per share)	$13.50	$7.86	$3.92
Granted (in dollars per share)	$79.68	$30.42	$11.55
Exercised (in dollars per share)	$11.60	$5.19	$2.75
Forfeited (in dollars per share)	$44.32	$10.93	$7.94
Expired (in dollars per share)	$21.70	$7.24	$7.07
Balance at the end of the period (in dollars per share)	$35.78	$13.50	$7.86	$3.92
Exercisable at the end of the period (in dollars per share)	$11.61
Vested and expected to vest at the end of the period (in dollars per share)	$34.59
Weighted Average remaining contractual term
Balance at the end of the period	7 years 10 months 8 days	8 years 0 months 3 days	8 years 7 months 28 days	8 years 9 months 18 days
Exercisable at the end of the period	6 years 9 months 0 days
Vested and expected to vest at the end of the period	7 years 9 months 23 days
Aggregate intrinsic value
Balance at the beginning of the period (in dollars)	$168,905,000	$38,485,000	$11,829,000
Exercised (in dollars)	45,289,000	21,679,000	3,005,000
Balance at the end of the period (in dollars)	248,276,000	168,905,000	38,485,000	11,829,000
Exercisable at the end of the period (in dollars)	160,707,000
Vested and expected to vest at the end of the period (in dollars)	243,438,000
Additional disclosures
Unrecognized compensation cost related to non-vested stock options (in dollars)	$73,100,000
Weighted average fair value of options granted (in dollars per share)	$42.62	$19.22	$8.52
Weighted average assumptions used to estimate the fair values of each option grant
Risk free interest rate, minimum (as a percent)	0.02%	0.33%	0.84%
Risk free interest rate, maximum (as a percent)	2.16%	2.80%	1.70%
Expected volatility (as a percent)	57.20%	68.70%	74.00%
Expected life of options	5 years 10 months 11 days	6 years 2 months 19 days	6 years 9 months 4 days
Employee Stock [Member]
Weighted average assumptions used to estimate the fair values of each option grant
Expected volatility (as a percent)	28.20%
Expected life of options	0 years 4 months
Per Share Fair Value of Employee Stock Purchase Plan Shares	$23.27
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	0.37%

NET_INCOME_LOSS_PER_SHARE_Deta

NET INCOME (LOSS) PER SHARE (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Numerator:
Net loss	$5,802	($3,004)	($5,037)	($11,477)	($11,956)	($14,784)	($14,031)	($23,138)	($13,716)	($63,909)	($52,281)
Denominator:
Weighted average shares of common stock outstanding									35,299,000	33,182,000	30,332,000
Net loss per share:
Basic and diluted net loss per share of common stock (in dollars per share)									($0.39)	($1.93)	($1.72)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (Treasury Stock Method)									5,400,000	3,400,000	1,400,000

NET_INCOME_LOSS_PER_SHARE_Deta1

NET INCOME (LOSS) PER SHARE (Details 2)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive effect of securities (in shares)	6,039	5,378	3,889
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive effect of securities (in shares)	3,534	3,980	3,304
Convertible debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive effect of securities (in shares)	2,483	1,194	0
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive effect of securities (in shares)	21	204	585
Employee Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive effect of securities (in shares)	1	0	0

INCOME_TAXES_Details

INCOME TAXES (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013
Income Tax Provision [Line Items]
Income Tax Provision	$200,000
Non-US Net Operating Loss	300,000
Minimum Cumulative Percentage of Change in Ownership as Condition to Offset Taxable Income or Tax	50.00%
Reconciliation of income taxes at U.S. Federal statutory rate to the provision for income taxes
Benefit at U.S. Federal statutory rate (as a percent)	35.00%	35.00%	35.00%
State taxes-deferred (as a percent)	-32.75%	4.79%	6.73%
Increase in valuation allowance (as a percent)	-17.71%	-42.91%	-39.62%
Tax credits (as a percent)	5.49%	1.69%	0.00%
Interest expense (as a percent)	10.68%	0.30%	-0.22%
Other (as a percent)	-1.99%	1.82%	-1.89%
Provision for income taxes (as a percent)	-1.28%	0.69%	0.00%
Deferred tax assets:
Federal and state net operating loss carry-forwards	111,086,000	114,819,000
Federal and state research credits	6,043,000	5,149,000
Depreciation and amortization	3,494,000	3,248,000
Accruals and reserves	3,861,000	1,696,000
Deferred revenue	4,065,000	1,707,000
Deferred Tax Assets, Stock Based Compensation	8,487,000	2,622,000
Other	588,000	752,000
Total deferred tax assets	137,624,000	129,993,000
Equity component of convertible notes	-6,283,000	-8,507,000
Net deferred tax assets, before valuation allowance	131,341,000	121,486,000
Less: valuation allowance for deferred tax assets	-131,341,000	-121,486,000
Net deferred tax assets	0	0
Federal
Income Tax Provision [Line Items]
Net Operating Loss, Subject to Limitation	197,200,000
Available Net Operating Loss, Subject to Limitation	72,300,000
Future NOL's Which Will Become Available	26,300,000
Future NOL's Which Will Become Available (2017)	14,800,000
Future NOL's Which Will Become Available (2018-2022)	10,300,000
Future NOL's Which Will Become Available (2015-Onward)	6,000,000
Research Tax Credit Carryforward [Member] | Federal
Income Tax Provision [Line Items]
Tax Credit Carryforward, Amount	$4,400,000			$200,000

INCOME_TAXES_Details_2

INCOME TAXES (Details 2) (USD $)	1 Months Ended	12 Months Ended
	Feb. 28, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013
INCOME TAXES
Amount received from sale of unused net operating losses	$400,000
Deferred Tax Assets, Valuation Allowance		131,341,000	121,486,000
Increase in valuation allowance for deferred tax assets		9,900,000	17,500,000	20,700,000
Minimum Cumulative Percentage of Change in Ownership as Condition to Offset Taxable Income or Tax		50.00%
NOL carryforwards that relate to stock-based compensation		41,300,000
Decrease in deferred tax assets		400,000	400,000
Federal
INCOME TAXES
Net operating losses		331,000,000
Federal | Research Tax Credit Carryforward [Member]
INCOME TAXES
Tax Credit Carryforward, Amount		4,400,000			200,000
State
INCOME TAXES
Amount received from sale of unused net operating losses			400,000
Net operating losses		196,300,000
State | Research Tax Credit Carryforward [Member]
INCOME TAXES
Tax Credit Carryforward, Amount		$2,500,000

OTHER_EMPLOYEE_BENEFITS_Detail

OTHER EMPLOYEE BENEFITS (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Savings Plan
Compensation expense recognized	$1	$0.60	$0.30

COMMERCIAL_PARTNERS_AND_OTHER_1

COMMERCIAL PARTNERS AND OTHER AGREEMENTS (Details) (USD $)	0 Months Ended	1 Months Ended
	Dec. 05, 2012	Dec. 31, 2013	Nov. 30, 2011	Jan. 31, 2011	Apr. 30, 2014	Dec. 31, 2014
Aratana
COMMERCIAL PARTNERS AND OTHER AGREEMENTS
Up-front payment received	$1,000,000
Milestone payment received		500,000
Aratana | Maximum | Achievement of development and commercial milestones
COMMERCIAL PARTNERS AND OTHER AGREEMENTS
Milestone payments Company is entitled to receive based on terms of agreement	42,500,000
Novo Nordisk
COMMERCIAL PARTNERS AND OTHER AGREEMENTS
Up-front payment received				1,500,000
Milestone payment received			2,000,000
Patheon [Member]
COMMERCIAL PARTNERS AND OTHER AGREEMENTS
Contract Termination Fee						2,000,000
Initial Term of Manufacturing Supply Agreement					10th
Mundipharma Ltd [Member]
COMMERCIAL PARTNERS AND OTHER AGREEMENTS
Term Extension of 2003 Agreements					P15Y
European Rights Expansion & New Distribution Payment					0

RELATED_PARTY_TRANSACTIONS_Det

RELATED PARTY TRANSACTIONS (Details) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Aug. 31, 2012	Apr. 30, 2012
MPM
RELATED PARTY TRANSACTIONS
Outstanding amount payable to related party	$200,000	$100,000
MPM | Consulting agreement
RELATED PARTY TRANSACTIONS
Expenses incurred by the entity	500,000	300,000	400,000
MPM | Consulting agreement | Minimum
RELATED PARTY TRANSACTIONS
Monthly rate payable to related party	16,000
Percentage of consultant's business time devoted in exchange of monthly fee payable under the consulting agreement	50.00%
MPM | Consulting agreement | Maximum
RELATED PARTY TRANSACTIONS
Monthly rate payable to related party	26,000
Percentage of consultant's business time devoted in exchange of monthly fee payable under the consulting agreement	80.00%
Member of board of directors
RELATED PARTY TRANSACTIONS
Outstanding amount payable to related party	100,000	100,000
Member of board of directors | Consulting agreement
RELATED PARTY TRANSACTIONS
Number of shares that can be purchased under option (in shares)				70,000	20,000
Exercise price of shares that can be purchased under option (in dollars per share)				$16.67	$11.02
Member of board of directors | Consulting agreement | Minimum
RELATED PARTY TRANSACTIONS
Monthly rate payable to related party					5,000
Member of board of directors | Consulting agreement | Maximum
RELATED PARTY TRANSACTIONS
Monthly rate payable to related party					15,000
Expenses incurred by the entity	$100,000	$100,000	$200,000

COMMITMENTS_AND_CONTINGENCIES_1

COMMITMENTS AND CONTINGENCIES (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2007
Commitments and Contingencies Disclosure [Abstract]
Unfavorable lease accrual				$3,300,000
Amortization of the unfavorable lease accrual	100,000	100,000	400,000
Annual minimum payments due
2014	6,133,000
2015	7,263,000
2016	7,459,000
2017	7,660,000
2018	7,876,000
Thereafter	11,786,000
Total	48,177,000
Rent expense	4,900,000	4,900,000	4,800,000
Deferred rent	$4,500,000	$2,300,000

COMMITMENTS_AND_CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES (Details 2)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Minimum age of pediatric patients in descending order to study EXPAREL	12 years
Maximum age of pediatric patients in descending order to study EXPAREL	18 years
Age of children to study EXPAREL in pediatric patients	2 years

COMMITMENTS_AND_CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES (Details 3) (USD $)	12 Months Ended	0 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Mar. 21, 2007
Commitments
Royalty on sale of product (as a percent)	3.00%
SkyePharma Holding, Inc.
Commitments
Total milestone payments paid	18
SkyePharma Holding, Inc. | Maximum
Commitments
Milestone payments for EXPAREL agreed in connection with acquisition	62
PPI-California
Commitments
Initial purchase price for acquisition		$19.60

SELECTED_QUARTERLY_FINANCIAL_D2

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$61,793	$52,048	$47,165	$36,662	$33,564	$23,259	$17,141	$11,587	$197,668	$85,551	$39,084
Cost of revenues	18,968	20,391	19,954	18,127	18,376	14,791	10,214	11,391	77,440	54,772	32,139
Total operating expenses	53,873	53,033	50,007	45,920	43,384	36,073	29,151	30,232	202,833	138,840	88,382
Net loss	$5,802	($3,004)	($5,037)	($11,477)	($11,956)	($14,784)	($14,031)	($23,138)	($13,716)	($63,909)	($52,281)
Earnings Per Share, Basic	$0.16	($0.08)	($0.14)	($0.34)	($0.36)	($0.44)	($0.42)	($0.71)
Earnings Per Share, Diluted	$0.14	($0.08)	($0.14)	($0.34)	($0.36)	($0.44)	($0.42)	($0.71)

SUBSEQUENT_EVENTS_Details

SUBSEQUENT EVENTS (Details) (Subsequent Event [Member], USD $)	1 Months Ended
In Millions, unless otherwise specified	Feb. 28, 2015	Feb. 06, 2015
Subsequent Event [Member]
Subsequent Event [Line Items]
Conversion Request Convertible Senior Notes		$1.50
Trading-Day Observation Period [Table Text Block]	40 days