Pharmacyclics (PCYC) 10-K 18 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 12, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Entity Registrant Name	PHARMACYCLICS INC
Entity Central Index Key	949699
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			$4,026,965,098
Entity Common Stock, Shares Outstanding		76,016,912
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2014

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$845,035	$623,956
Marketable securities	11,952	11,672
Accounts receivable, net	64,297	11,044
Receivable from collaboration partners	26,970	51,957
Inventory	34,446	12,603
Advances to manufacturers	12,288	20,316
Prepaid expenses and other current assets	20,571	9,253
Total current assets	1,015,559	740,801
Property and equipment, net	32,476	25,471
Intangible assets, net	8,730	0
Other assets	3,342	2,479
Total assets	1,060,107	768,751
Current liabilities:
Accounts payable	7,315	4,026
Accrued liabilities	88,279	71,188
Payable to collaboration partner	79,799	3,388
Income taxes payable	70	1,448
Deferred revenue - current portion	18,773	7,581
Total current liabilities	194,236	87,631
Deferred revenue - non-current portion	34,885	52,025
Other long-term liabilities	1,821	1,472
Total liabilities	230,942	141,128
Commitments and contingencies (Notes 5 and 12)
Stockholders’ equity:
Preferred stock, $0.0001 par value; 1,000,000 shares authorized; none issued and outstanding	0	0
Common stock, $0.0001 par value; 150,000,000 shares authorized at December 31, 2014 and December 31, 2013, respectively; shares issued and outstanding 75,933,661 and 74,167,169 at December 31, 2014 and December 31, 2013, respectively	8	7
Additional paid-in capital	959,637	844,220
Accumulated other comprehensive loss	-8	-8
Accumulated deficit	-130,472	-216,596
Total stockholders’ equity	829,165	627,623
Total liabilities and stockholders’ equity	$1,060,107	$768,751

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 (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	75,933,661	74,167,169
Common stock, shares outstanding (in shares)	75,933,661	74,167,169

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended																6 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, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Revenue:
Product revenue, net																	$0		$492,418	$13,573	$0
License and milestone revenue																	155,000	77,605	220,000	235,000	77,605
Collaboration services revenue																	5,658	335	17,311	11,596	4,385
Total revenue	290,192		207,140		113,020		119,377		123,551		79,088		54,684		2,846		160,658	77,940	729,729	260,169	81,990
Costs and expenses:
Cost of goods sold																	0		40,410	3,501	0
Research and development																	46,639	23,324	172,459	170,865	54,537
Less: Excess Amounts related to Research and development																	-17,306	0	0	-85,732	0
Research and development, net																	29,333	23,324	172,459	85,133	54,537
Selling, General and Administrative Expense, Including Excess Amounts from Collaborative Agreements																	12,093	7,294	167,955	104,016	15,575
Less: Excess Amounts related to Selling, general and administrative																	-819	0	0	-30,405	0
Selling, general and administrative																	11,274	7,294	167,955	73,611	15,575
Total costs of collaboration (Janssen's 50% share under the Agreement)																	0		226,004	0	0
Amortization of intangible assets																	0		520	0	0
Total costs and expenses	197,201		158,771		150,224		101,152		38,120		25,662		42,653		55,810		40,607	30,618	607,348	162,245	70,112
Income from operations	92,991		48,369		-37,204		18,225		85,431		53,426		12,031		-52,964		120,051	47,322	122,381	97,924	11,878
Interest income																	137	68	440	341	178
Other expense, net																	-8	-24	-374	-129	-31
Income before income taxes																	120,180	47,366	122,447	98,136	12,025
Income tax provision																	2,647	5,651	36,323	31,126	39
Net income	$63,484		$41,422		($37,057)		$18,275		$64,237		$42,333		$12,351		($51,911)		$117,533	$41,715	$86,124	$67,010	$11,986
Net income per share:
Basic (in dollars per share)	$0.84	[1]	$0.55	[1]	($0.49)	[1]	$0.24	[1]	$0.87	[1]	$0.58	[1]	$0.17	[1]	($0.73)	[1]	$1.69	$0.61	$1.14	$0.92	$0.17
Diluted (in dollars per share)	$0.81	[1]	$0.53	[1]	($0.49)	[1]	$0.23	[1]	$0.82	[1]	$0.55	[1]	$0.16	[1]	($0.73)	[1]	$1.58	$0.58	$1.10	$0.87	$0.17
Weighted average shares used to compute net income per share:
Basic (in shares)	75,692		75,392		75,139		74,754		73,868		73,316		72,953		70,933		69,676	68,491	75,247	72,777	68,728
Diluted (in shares)	78,471		78,025		75,139		78,064		77,917		77,659		77,194		70,933		74,408	71,312	78,151	77,083	72,617
[1]	Basic and diluted net income (loss) per share amounts are computed independently for each of the quarters presented. Therefore, the sum of quarterly basic and diluted net income (loss) per share information may not equal annual basic and diluted net income (loss) per share.

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Statement of Comprehensive Income [Abstract]
Net income	$117,533	$86,124	$67,010	$11,986
Change in unrealized gain (loss) on marketable securities	5	0	-4	12
Comprehensive income, net of tax	$117,538	$86,124	$67,006	$11,998

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
In Thousands, except Share data, unless otherwise specified
Beginning Balance at Jun. 30, 2011	$101,674	$7	$514,813	($21)	($413,125)
Beginning balance, shares at Jun. 30, 2011		67,915,865
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon under employee stock plans (in shares)		1,401,792
Issuance of common stock upon under employee stock plans	8,578		8,578
Stock-based compensation expense	9,873		9,873
Change in unrealized loss on marketable securities	12			12
Net income	11,986				11,986
Ending balance at Jun. 30, 2012	132,123	7	533,264	-9	-401,139
Ending balance, shares at Jun. 30, 2012		69,317,657
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon under employee stock plans (in shares)		898,729
Issuance of common stock upon under employee stock plans	5,429		5,429
Stock-based compensation expense	7,436		7,436
Change in unrealized loss on marketable securities	5			5
Net income	117,533				117,533
Ending balance at Dec. 31, 2012	262,526	7	546,129	-4	-283,606
Ending balance, shares at Dec. 31, 2012		70,216,386
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock in a public offering at $94.20 per share, net of issuance costs (in shares)		2,200,000
Issuance of common stock in a public offering at $94.20 per share, net of issuance costs	201,023		201,023
Issuance of common stock upon under employee stock plans (in shares)		1,750,783
Issuance of common stock upon under employee stock plans	16,640		16,640
Stock-based compensation expense	50,395		50,395
Excess tax benefit from stock-based compensation arrangements	30,033		30,033
Change in unrealized loss on marketable securities	-4			-4
Net income	67,010				67,010
Ending balance at Dec. 31, 2013	627,623	7	844,220	-8	-216,596
Ending balance, shares at Dec. 31, 2013	74,167,169	74,167,169
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon under employee stock plans (in shares)		1,766,492
Issuance of common stock upon under employee stock plans	25,910	1	25,909
Stock-based compensation expense	54,631		54,631
Excess tax benefit from stock-based compensation arrangements	34,877		34,877
Change in unrealized loss on marketable securities	0
Net income	86,124				86,124
Ending balance at Dec. 31, 2014	$829,165	$8	$959,637	($8)	($130,472)
Ending balance, shares at Dec. 31, 2014	75,933,661	75,933,661

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	Dec. 31, 2013
Statement of Stockholders' Equity [Abstract]
Issuance of common stock in a public offering, price per share	$94.20

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net income	$117,533	$86,124	$67,010	$11,986
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	595	4,411	2,219	563
Amortization of premium on marketable securities, net	0	0	0	89
Stock-based compensation expense	7,436	53,741	50,210	9,873
Excess tax benefit from stock-based compensation arrangements	0	-34,877	-30,033	0
Income tax benefit from stock-based compensation arrangements	0	34,877	30,033	0
Loss on property and equipment	9	0	188	25
Provision for bad debts	0	14	0	0
Changes in assets and liabilities:
Accounts receivable	0	-53,267	-11,044	0
Receivable from collaboration partners	-20,773	24,987	-25,260	-5,877
Inventory	0	-20,953	-12,419	0
Advances to manufacturers	0	8,028	-20,316	0
Prepaid expenses and other assets	1,033	-12,155	-7,184	-3,307
Accounts payable	1,557	3,289	-37	2,206
Accrued liabilities	6,495	20,114	52,365	1,874
Payable to collaboration partner	0	76,411	3,388	0
Income taxes payable	1,389	-1,378	59	0
Deferred revenue	-4,677	-5,948	-11,095	68,378
Other long-term liabilities	97	349	688	277
Net cash provided by operating activities	110,694	183,767	88,772	86,087
Cash flows from investing activities:
Purchase of property and equipment	-2,421	-13,919	-18,318	-2,975
Purchase of marketable securities	-5,645	-13,640	-14,800	-5,720
Proceeds from sales of marketable securities	0	0	480	0
Purchase of intangible assets	0	-9,250	0	0
Proceeds from maturities of marketable securities	1,680	13,360	12,325	24,504
Net cash (used in) provided by investing activities	-6,386	-23,449	-20,313	15,809
Cash flows from financing activities:
Issuance of common stock, net of issuance costs	0	0	201,023	-559
Proceeds from issuance of common stock under employee stock plan	5,229	25,884	17,008	8,802
Excess tax benefit from stock-based compensation arrangements	0	34,877	30,033	0
Net cash provided by financing activities	5,229	60,761	248,064	8,243
Increase in cash and cash equivalents	109,537	221,079	316,523	110,139
Cash and cash equivalents at beginning of period	197,896	623,956	307,433	87,757
Cash and cash equivalents at end of period	307,433	845,035	623,956	197,896
Supplemental disclosure of cash flow information:
Cash paid for income taxes	980	10,368	820	310
Supplemental disclosure of non-cash investing and financing activities:
Receivable for stock option exercises	368	36	0	167
Property and equipment purchases included in accounts payable and accrued liabilities	$883	$1,016	$4,039	$143

Description_of_the_Company_and

Description of the Company and Basis of Presentation	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Description of the Company and Basis of Presentation	DESCRIPTION OF THE COMPANY AND BASIS OF PRESENTATION
	Description of the Company
	Pharmacyclics, Inc. (Pharmacyclics or the Company) is a biopharmaceutical company focused on developing and commercializing innovative small-molecule drugs for the treatment of cancer and immune mediated diseases. Pharmacyclics markets IMBRUVICA® (ibrutinib) and has other product candidates in clinical development and several preclinical molecules in lead optimization.
	IMBRUVICA is a first-in-class, oral, once-daily therapy that inhibits a protein called Bruton's tyrosine kinase (BTK). IMBRUVICA is being jointly developed and commercialized by Pharmacyclics and Janssen Biotech, Inc. and its affiliates (Janssen), one of the Janssen Pharmaceutical companies of Johnson & Johnson.
	IMBRUVICA currently is approved for use in approximately 40 countries including the U.S., Canada, and the 28 countries within the European Union (EU).
	IMBRUVICA first came to market on November 13, 2013, when it was approved by the U.S. Food and Drug Administration (FDA) under accelerated approval as a single agent for the treatment of patients with mantle cell lymphoma (MCL) who have received at least one prior therapy. Improvements in survival or disease symptoms have not been established. On February 12, 2014, the FDA approved IMBRUVICA under accelerated approval as a single agent for the treatment of patients with chronic lymphocytic leukemia (CLL) who have received at least one prior therapy. On July 28, 2014, IMBRUVICA received regular (full) FDA approval for IMBRUVICA for the treatment of patients with CLL who have received at least one prior therapy, and for the treatment of CLL patients with deletion of the short arm of chromosome 17 (del 17p CLL), including treatment naive and previously treated del 17p patients. On October 17, 2014, the European Commission (EC) granted marketing approval for IMBRUVICA in the EU for the treatment of adult patients with relapsed or refractory MCL, or adult patients with CLL who have received at least one prior therapy, or in first line in the presence of 17p deletion or TP53 mutation in patients unsuitable for chemoimmunotherapy. On January 29, 2015, single-agent IMBRUVICA received regular (full) FDA approval for patients with Waldenström's macroglobulinemia (WM), and it is approved in all lines of therapy.
	Change in Fiscal Year End
	On November 14, 2012, the Board of Directors approved a change in the fiscal year end from June 30 to December 31, effective December 31, 2012. All references to "fiscal years", unless otherwise noted, refer to the twelve-month fiscal year, which prior to July 1, 2012, ended on June 30, and beginning on January 1, 2013, ends on December 31, of each year.
	Basis of presentation
	The accompanying consolidated financial statements include the accounts of Pharmacyclics, Inc. and its wholly-owned subsidiaries, Pharmacyclics (Europe) Limited, Pharmacyclics Switzerland GmbH, Pharmacyclics Cayman Ltd. and Pharmacyclics (Shanghai) Management Consulting Service Limited. All intercompany accounts and transactions have been eliminated. The U.S. dollar is the functional currency for all of the Company's consolidated operations.
	Reclassification
	Certain prior year balances were reclassified to conform to the current year's presentation. None of these reclassifications had an impact on reported financial position or cash flows for any of the periods presented.

Significant_Accounting_Policie

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES
	Management's use of estimates and assumptions
	The preparation of financial statements in accordance with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reported period. Actual results could differ from those estimates.
	Basic and diluted net income per share
	Basic net income per share is computed using the weighted average number of common shares outstanding during the period. Diluted net income per share is computed using the weighted average number of shares of common stock outstanding during the period increased to include the number of additional shares of common stock that would have been outstanding if the potentially dilutive securities had been issued. Potentially dilutive securities include outstanding stock options, including performance-based stock options and restricted stock units for which performance criteria have been achieved, restricted stock units with time-based vesting and shares to be purchased under the employee stock purchase plan. The dilutive effect of potentially dilutive securities is reflected in diluted net income per common share by application of the treasury stock method. Under the treasury stock method, an increase in the fair market value of the Company's common stock can result in a greater dilutive effect from potentially dilutive securities.
	Cash and cash equivalents
	All highly liquid investments purchased with an original maturity date of three months or less that are readily convertible into cash and have an insignificant interest rate risk are considered to be cash equivalents.
	Marketable securities
	The Company's marketable securities are classified as “available-for-sale”. The Company includes these investments in current assets and carry them at fair value.  Unrealized gains and losses on available-for-sale securities are included in accumulated other comprehensive loss.  The amortized cost of debt securities is adjusted for the amortization of premiums and accretion of discounts to maturity.  Such amortization is included in interest income.  Gains and losses on securities sold are recorded based on the specific identification method and are included in other expense, net in the consolidated statement of operations.
	Management assesses whether declines in the fair value of marketable securities are other than temporary.  If the decline is judged to be other than temporary, the cost basis of the individual security is written down to fair value and the amount of the write down is included in the statement of operations within other expense, net. In determining whether a decline is other than temporary, management considers various factors including the length of time and the extent to which the market value has been less than cost, the financial condition and near-term prospects of the issuer and the Company's intent and ability to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in market value. To date, the Company has not recorded any impairment charges on marketable securities related to other-than-temporary declines in market value.
	Fair value measurements
	The fair value of the Company's financial assets is determined by using three levels of input which are defined as follows:
	Level 1 - Quoted prices in active markets for identical assets. At December 31, 2014, the Company's Level 1 assets were comprised of money market funds. At December 31, 2013, the Company's Level 1 assets were comprised of U.S. treasury securities and money market funds.
	Level 2 - Observable inputs other than Level 1 prices such as quoted prices for similar assets, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets. The Company's short-term investments primarily utilize broker quotes in markets with infrequent transactions for valuation of these securities. At December 31, 2014 and December 31, 2013, the Company's Level 2 assets were comprised of FDIC insured certificates of deposit.
	Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets. At December 31, 2014 and December 31, 2013, the Company did not hold any Level 3 assets.
	The Company utilizes the market approach to measure fair value for its financial assets. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets.
	Fair value of financial instruments
	Cash and cash equivalents and marketable securities are carried at fair value. Accounts receivable, net, receivables from collaboration partners, accounts payable and accrued liabilities are valued at their carrying amounts, which approximate fair value due to their short-term nature. As of December 31, 2014 and December 31, 2013, the Company had no liabilities measured at fair value.
	Restricted investments
	Under one of its facilities lease agreements, the Company is required to maintain a $0.3 million letter of credit as security for performance under the lease. The letter of credit is secured by a $0.3 million certificate of deposit which is included in Other assets at December 31, 2014 and December 31, 2013.
	Accounts Receivable, net
	Accounts receivable, net represents amounts due to the Company from sales of IMBRUVICA. The Accounts receivable balance is recorded net of allowances which generally include wholesaler chargebacks from third-party payers including government and other programs, cash discounts for prompt payment and doubtful accounts. Estimates for wholesaler chargebacks, cash discounts and prompt payment discounts are based on contractual payment terms and the Company's expectations about utilization rates for these programs. The Company's estimate of the allowance for doubtful accounts is based on the creditworthiness of its customers, historical payment patterns, the aging of accounts receivable balances and general economic conditions. Accounts receivables balances are written off against the allowance when it is probable that the receivable will not be collected (see Note 4).
	Inventory valuation and related reserves
	Inventories are stated at the lower of cost or market value with the approximate cost being determined on a first-in, first-out basis. Costs capitalized as inventories include third-party manufacturing costs and labor costs for personnel involved in the manufacturing process.
	During the year ended December 31, 2013, the Company began capitalizing costs associated with manufacturing inventory as a result of the FDA approval for IMBRUVICA. Until September 30, 2013, all inventory costs incurred were recorded as research and development expense in the consolidated statements of operations.
	Products that have been approved by the FDA or other regulatory agencies, such as IMBRUVICA, are also used in clinical programs to assess the safety and efficacy of the products for usage in diseases that have not been approved by the FDA or other regulatory authorities. The form of IMBRUVICA (i.e., raw materials and active pharmaceutical ingredient (API)) utilized for both commercial and clinical programs is identical and, as a result, the inventory has an "alternative future use" as defined in authoritative guidance. Raw materials and purchased drug product associated with clinical development programs are included in inventory and charged to research and development expense when the product enters the research and development process and can no longer be used for commercial purposes and, therefore, does not have "alternative future use."
	The Company evaluates inventory levels quarterly to determine if the inventory has a cost basis in excess of its expected net realizable value, inventory has expired, inventory on-hand is in excess of expected sales forecasts, and/or inventory that does not meet its quality specifications. The Company's raw materials and API has no expiration date and can be revalidated for use after testing. The Company's finished goods inventory currently has an estimated life of 24 months and, based on the Company's sales forecasts, it expects to realize the carrying value of the IMBRUVICA inventory. If any impairment of inventory is identified, the related inventory is written down with a corresponding charge to cost of goods sold in the period that the inventory impairment is first identified. The Company's inventory valuation reserve balance was zero as of December 31, 2014 and December 31, 2013, respectively.
	Inventories consist of raw materials, work-in-process and finished goods related to the production of IMBRUVICA. Raw materials include IMBRUVICA API. Work-in-process includes third-party manufacturing and associated labor costs relating to the Company’s personnel involved in the production process. Included in inventories are raw materials and work-in-process that may be used as clinical products, which are charged to research and development expense when the product enters the research and development process.
	The components of inventory are as follows (in thousands):
		As of December 31,
		2014		2013
	Raw materials	$	—	$	8,007
	Work-in-process	27,591		3,489
	Finished goods	6,855		1,107
		$	34,446	$	12,603
	Advances to manufacturers
	The Company records cash advances that it pays prior to the receipt of inventory as advances to manufacturers in the consolidated balance sheets. The cash advances may be forfeited if the Company terminates the scheduled production. The Company expects the carrying value of the advances to manufacturers to be fully realized.
	Concentration of credit risk and other risks and uncertainties
	Financial instruments that potentially subject the Company to credit risk consist principally of cash, cash equivalents, marketable securities, accounts receivable, net and receivables from collaboration partners. The Company places its cash and cash equivalents with high-credit quality financial institutions and invests in debt instruments of financial institutions, corporations and government entities with strong credit ratings. The Company's management believes it has established guidelines relative to credit quality, diversification and maturities that maintain safety and liquidity.
	The Company sells IMBRUVICA through a limited number of specialty pharmacies and specialty distributors. Therefore, the Company's accounts receivable balance is comprised of amounts due from a small number of customers. The Company continuously monitors the creditworthiness of its customers and has internal policies regarding customer credit limits. The Company's policy is to estimate the allowance for doubtful accounts based on the credit worthiness of its customers, historical payment patterns, the aging of accounts receivable balances and general economic conditions. For the year ended December 31, 2014, four individual customers accounted for 25%, 22%, 19% and 15% of accounts receivable, net, respectively. For the year ended December 31, 2013, three individual customers accounted for 26%, 26%, and 16% of accounts receivable, net, respectively.
	As of December 31, 2014, Company had $27.0 million receivable from Janssen, which consisted primarily of a milestone receivable of $20.0 million, $3.9 million related to material and product sales and $1.7 million related to value added taxes (see Note 5). As of December 31, 2013, the Company's receivable from collaboration partner balance of $52.0 million was comprised primarily of $50.2 million due from Janssen under the collaboration agreement. To date, the Company has not experienced credit losses from its receivables from collaborative partners, including Janssen. The amounts receivable from Janssen are included within Receivable from collaboration partners on the consolidated balance sheets.
	The Company's products require approvals from the FDA and international regulatory agencies prior to commercial sales. Although the FDA has approved IMBRUVICA as a single agent for the treatment of patients with mantle cell lymphoma who have received at least one prior therapy, the Company's prospects are largely dependent on (a) successful commercialization of IMBRUVICA in the U.S. to treat patients with MCL who have received at least one prior therapy, (b) obtaining regulatory approval of, and successfully commercializing, IMBRUVICA outside the U.S. to treat patients with MCL who have received at least one prior therapy, and (c) obtaining regulatory approval of, and successfully commercializing, IMBRUVICA both in and outside the U.S. to treat other indications. If the Company is unsuccessful in achieving any one or more of these critical business objectives, its ability to generate significant revenue or achieve profitability will be adversely affected and its business may fail. Further, there can be no assurance that the Company's other product candidates will receive required approvals. If the Company was denied such approvals or such approvals were delayed, it could have a materially adverse impact on the Company and the execution of its business strategy.
	The Company has expended and will continue to expend substantial funds for the commercialization, manufacturing, marketing and sales of IMBRUVICA and to complete the research, development and clinical testing of investigational uses of IMBRUVICA and additional products. The Company may be unable to entirely fund these efforts with its current financial resources and may require additional funds to continue to develop and commercialize its products. Additional funds may not be available on acceptable terms, if at all. If adequate funds are unavailable on a timely basis from operations or additional sources of financing, the Company may have to delay, reduce the scope of or eliminate one or more of its research or development programs which would materially and adversely affect its business, financial condition and operations.
	Property and equipment
	Property and equipment are stated at cost. Equipment is depreciated by the straight-line method over the estimated useful lives of the assets, generally 2 to 5 years. Furniture and fixtures are depreciated by the straight-line method over the estimated useful lives of the assets, generally 5 years. Leasehold improvements are generally amortized by the straight-line method over the shorter of the life of the related asset or the term of the underlying lease. Assets not yet placed in use are not depreciated. Substantially all of the Company's property and equipment is located within the U.S.
	Long-lived assets
	The Company evaluates long-lived assets (including finite-lived intangible assets) for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable. In accordance with Accounting Standards Codification (ASC) ASC 350-10, Goodwill and Other Intangible Assets, intangible assets with estimable useful lives are amortized over their respective estimated useful lives, and reviewed for impairment in accordance with ASC 360-10, "Accounting for the Impairment or Disposal of Long-Lived Assets." The Company reviews long-lived assets, such as acquired intangibles and property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The Company measures recoverability of assets to be held and used by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, the Company recognizes an impairment charge at the amount by which the carrying amount of the asset exceeds the fair value of the asset. The Company's impairment review requires significant judgment with respect to future revenue and expense growth rates, selection of appropriate discount rate and other assumptions and estimates. No significant impairment losses have been recorded to date with respect to the Company's long-lived assets (see Note 8).
	Donations to Third-Party Patient Assistance Foundations
	The Company provides cash and product donations to independent third-party patient assistance foundations that, in turn, make grants to help qualifying patients meet their out-of-pocket costs (including co-pay payments or co-insurance obligations) in connection with their use of the Company's products as well as those of other pharmaceutical and biotechnology companies. These independent patient assistance foundations maintain their own patient eligibility criteria and independently determine what type of assistance patients may qualify for. Given the non-reciprocal nature of these transactions with parties who are not considered direct or indirect customers, and for which the Company does not receive any consideration, and the fact that the donation of cash does not have any conditions attached to the donation, the Company accounts for the cash donations as a component of selling, general and administrative expenses in the consolidated statements of operations.
	Revenue Recognition
	Product revenue, net is recognized in accordance with the Financial Accounting Standards Board (FASB) ASC 605, Revenue Recognition, when the following criteria have been met: (1) persuasive evidence of an arrangement exists, (2) delivery has occurred or services have been rendered, (3) the price is fixed or determinable and (4) collectability is reasonably assured. Revenues are deferred for fees received before earned or until no further obligations exist. We exercise judgment in determining that collectability is reasonably assured or that services have been delivered in accordance with the arrangement. We assess whether the fee is fixed or determinable based on the payment terms associated with the transaction and whether the sales price is subject to refund or adjustment. We assess collectability based primarily on the customer's payment history and on the creditworthiness of the customer.
	Product Revenue, Net
	Product revenue, net consists of U.S. sales of IMBRUVICA and is recognized once all four revenue recognition criteria described above have been met. The Company sells IMBRUVICA directly to some customers who have in-house dispensing capabilities, specialty pharmacies (SP) that sell to individual patients, specialty distributors (SD) that sell to hospital pharmacies and other organizations that the Company has contracted with. The Company recognizes revenue from sales of IMBRUVICA when the product’s title and risk of loss transfers to the customer. The Company determined that it has the ability to make reasonable estimates of product returns in order to recognize revenue at the time that title and risk of loss transfers to the customer based on the following factors: (1) the Company believes that it has sufficient insight into the distribution channel at the SP's and SD's in order to ascertain their inventory level and dispense data, (2) due to the price of the Company's product and limited patient population, its SP and SD customers have not built up significant levels of inventory, nor does the Company expect they will do so for the foreseeable future, (3) inventory on hand at the Company's SP customers was approximately two weeks as of December 31, 2014, (4) there have been no product returns to-date since the Company's commercial launch of IMBRUVICA on November 13, 2013 and (5) the Company believes there is limited risk of return of inventory in the channel because there is significant remaining shelf life at the point of sale.
	The Company recognizes product revenue net of adjustments for customer credits, including estimated government rebates and charge-backs, returns, prompt payment discounts, U.S. Department of Veteran's Affairs (VA) negotiated discounts and administrative service fees related to its patient assistance program which includes co-payment and deductible assistance, and Medicare Part D coverage gap reimbursements. Each of the above adjustments is recorded at the time of revenue recognition, resulting in a reduction in product revenue, net and an increase in accrued expenses or a reduction in accounts receivable, net. The above adjustments require significant estimates, judgment and information obtained from external sources. If management's estimates differ from actual results, the Company will record adjustments that would affect product revenue, net in the period of adjustment.
	Gross-to-net sales adjustments
	Rebates
	The Company records an allowance for rebates including mandated discounts under the Medicaid Drug Rebate Program, discounts provided under the TRICARE Retail Pharmacy Refunds Program (TRICARE) and to members of organizations with whom the Company has contracted with. The allowance for rebates is based upon the Company's contractual agreements and/or legal requirements and public sector benefit providers, including Medicaid and TRICARE. For estimated amounts owed to public sector benefit providers, including Medicaid and TRICARE, the allowance for rebates is based on the estimated rebate percentage of forecasted eligible sales. The estimated rebate percentage is based on statutory discount rates and expected utilization. The forecasted eligible Medicaid and TRICARE sales represent those sales made by the Company that will ultimately be consumed by patients covered by Medicaid and TRICARE. To estimate the allowance for rebates, the Company uses the estimated patient mix information which is provided by its SP customers, as well as third party sources. For organizations that the Company has contracted with, the rebate is based upon contracted volume discount amounts. In addition, the Company incurs administrative fees in exchange for administrative services provided that are also accrued at the time of sale. Rebates for public sector benefit providers and organizational discounts are generally invoiced and paid in arrears. As such, the allowance for rebates consists of an estimate of the amount expected to be incurred for the current quarter's shipments to patients, plus an accrual balance for estimated unpaid rebates from prior periods. The allowance for rebates is recorded within accrued liabilities in the consolidated balance sheets.
	Charge-backs
	Charge-backs are discounts that result from the difference between the prices at which the Company makes IMBRUVICA available to wholesalers for purchase by discount customers under pricing agreements the Company has with the discount customers and the sales price paid to the Company by the wholesalers who service the discount customers. Such discount customers, which primarily consist of the U.S. Department of Defense (DOD), VA, Public Health Services (PHS), and other Federal Government institutions, purchase products through wholesalers at a lower price provided for in pricing contracts and the wholesalers then charge the Company the difference between the wholesale acquisition cost and the lower price paid by the discount customer. These reductions are settled through charge-backs from the Company's wholesalers. Charge-backs are recorded as a reduction to accounts receivable, net in the consolidated balance sheets.
	Product Returns
	Consistent with industry practice, the Company generally offers its customers a limited right to return. The Company generally allows for the return of product that is a few months prior to and up to a few months after the product expiration date. Additionally, the Company considers several other factors in the estimation process including the expiration dates of product shipped, third party data in monitoring channel inventory levels, shelf life of the product, prescription trends and other relevant factors. Provisions for estimated product returns are recorded within accrued liabilities in the consolidated balance sheets.
	Medicare Part D coverage gap
	Medicare Part D, also known as the Medicare prescription drug benefit, is a federal program to subsidize the costs of prescription drugs for Medicare beneficiaries in the United States. The Medicare Part D prescription drug benefit mandates that drug manufacturers fund 50% of the Medicare Part D insurance coverage gap for prescription drugs sold to eligible patients. Funding of the Medicare Part D gap is invoiced and paid in arrears. As such, the allowance for Medicare Part D consists of an estimate of the amount expected to be incurred for the current quarter's shipments to patients, plus an accrual balance for estimated shipments remaining in the channel at period end which are estimated to ship to Medicare Part D patients. The allowance for rebates is recorded within accrued liabilities in the consolidated balance sheets.
	Prompt payment discounts
The Company generally offers cash discounts to its customers, generally a 2% discount applied to the invoice amount, as an incentive for prompt payment. The Company expects that all of its customers to whom it offers cash discounts for prompt payment to take advantage of the full amount of the 2% discount. The Company records the prompt-payment discount as a reduction to accounts receivable, net in the consolidated balance sheets.
Co-payment assistance
Patients who have commercial insurance and meet certain eligibility requirements may receive co-payment assistance. The Company accrues for co-payment assistance based on actual program participation and estimates of program redemption using data provided by third-party administrators. The allowance for co-payment assistance is recorded within accrued liabilities in the consolidated balance sheets.
Collaboration Revenues
Revenue under the Company's license and collaboration arrangements is recognized based on the performance requirements of the contract. Determinations of whether persuasive evidence of an arrangement exists and whether delivery has occurred or services have been rendered are based on management’s judgments regarding the fixed nature of the fees charged for deliverables and the collectability of those fees. Should changes in conditions cause management to determine that these criteria are not met for any new or modified transactions, revenue recognized could be adversely affected.
The Company recognizes revenue related to collaboration and license arrangements in accordance with the provisions of Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, Topic 605-25, “Revenue Recognition – Multiple-Element Arrangements,” or ASC Topic 605-25. Additionally, the Company adopted, effective July 1, 2010, Accounting Standards Update, or ASU, No. 2009-13, “Multiple Deliverable Revenue Arrangements,” or ASU 2009-13, which amended ASC Topic 605-25 and:
•	provided guidance on how deliverables in an arrangement should be separated and how the arrangement consideration should be allocated to the separate units of accounting;
•	required an entity to determine the selling price of a separate deliverable using a hierarchy of (i) vendor-specific objective evidence, or VSOE, (ii) third-party evidence, or TPE, or (iii) best estimate of selling price, or BESP; and
•	required the allocation of the arrangement consideration, at the inception of the arrangement, to the separate units of accounting based on relative fair value.
The Company evaluates all deliverables within an arrangement to determine whether or not they provide value on a stand-alone basis. Based on this evaluation, the deliverables are separated into units of accounting. The arrangement consideration that is fixed or determinable at the inception of the arrangement is allocated to the separate units of accounting based on their relative selling prices. The Company may exercise significant judgment in determining whether a deliverable is a separate unit of accounting, as well as in estimating the selling prices of such unit of accounting.
To determine the selling price of a separate deliverable, the Company uses the hierarchy as prescribed in ASC Topic 605-25 based on VSOE, TPE or BESP. VSOE is based on the price charged when the element is sold separately and is the price actually charged for that deliverable. TPE is determined based on third-party evidence for a similar deliverable when sold separately and BESP is the price at which the Company would transact a sale if the elements of collaboration and license arrangements were sold on a stand-alone basis. The Company may not be able to establish VSOE or TPE for the deliverables within collaboration and license arrangements, as the Company does not have a history of entering into such arrangements or selling the individual deliverables within such arrangements separately. In addition, there may be significant differentiation in these arrangements, which indicates that comparable third-party pricing may not be available. The Company may determine that the selling price for the deliverables within collaboration and license arrangements should be determined using BESP. The process for determining BESP involves significant judgment on the Company's part and includes consideration of multiple factors such as estimated direct expenses and other costs, and available data.
For collaborations entered into after July 1, 2010, the Company has determined its best estimate of selling prices for the license unit of accounting based on the income approach as defined in ASC 820-10-35-32. This measurement is based on the value indicated by current estimates about those future amounts and reflects management determined estimates and assumptions. These estimates and assumptions include, but are not limited to, how a market participant would use the license, estimated market opportunity and expected market share and assumed royalty rates that would be paid for sales resulting from products developed using the license, similar arrangements entered into by third parties and entity-specific factors such as the terms of the Company's previous collaborative agreement, the Company's pricing practices and pricing objectives, the likelihood that clinical trials will be successful, the likelihood that regulatory approval will be received and that the products will become commercialized and the markets served. The Company has also determined BESP for services-related deliverables based on the nature of the services to be performed and estimates of the associated effort as well as estimated market rates for similar services.
For each unit of accounting identified within an arrangement, the Company determines the period over which the performance obligation occurs. Revenue is then recognized using either a proportional performance or straight-line method. The Company recognizes revenue using the proportional performance method when the level of effort to complete our performance obligations under an arrangement can be reasonably estimated. Direct labor hours or full time equivalents are typically used as the measurement of performance.
Effective July 1, 2010, the Company adopted ASU No. 2010-17, “Milestone Method of Revenue Recognition,” or ASU 2010-17, which provides guidance on revenue recognition using the milestone method. Under the milestone method, a payment that is contingent upon the achievement of a substantive milestone is recognized in the period in which the milestone is achieved. The determination that a milestone is substantive is subject to considerable judgment.
Cost of goods sold
Cost of goods sold includes third-party manufacturing costs of products sold, fixed manufacturing overhead, royalty fees, and other indirect costs such as personnel compensation.
During the fiscal year 2013, the Company began capitalizing costs associated with manufacturing inventory as a result of the FDA approval of IMBRUVICA for MCL on November 13, 2013. Until September 30, 2013, all inventory costs incurred were recorded as research and development expense in the consolidated statements of operations. This zero cost inventory primarily consisted of raw materials for which the shelf-life has not yet started.
Research and development expense
Research and development expenses include personnel and facility-related expenses, outside contracted services including clinical trial costs, manufacturing and process development costs, research costs and other consulting services. Research and development costs are expensed as incurred. Nonrefundable advance payments for goods or services that will be used or rendered for future research and development activities are deferred and amortized over the period that the goods are delivered or the related services are performed, subject to an assessment of recoverability.
Clinical development costs are a significant component of research and development expenses. The Company has a history of contracting with third parties that perform various clinical trial activities on its behalf in the ongoing development of its product candidates. The financial terms of these contracts are subject to negotiations and may vary from contract to contract and may result in uneven payment flow. The Company accrues and expenses costs for clinical trial activities performed by third parties based upon estimates of the percentage of work completed over the life of the individual study in accordance with agreements established with contract research organizations and clinical trial sites. The Company determines its estimates through discussions with internal clinical personnel and outside service providers as to the progress or stage of completion of trials or services and the agreed upon fee to be paid for such services.
The Company's worldwide collaboration and license agreement with Janssen (the Agreement) includes a cost sharing arrangement for certain collaboration activities. Except in certain cases, in general Janssen is responsible for approximately 60% of collaboration development costs and the Company is responsible for the remaining 40% of collaboration development costs. Further, the Agreement provides the Company with a $50.0 million annual cap of its share of collaboration costs and pre-tax commercialization losses for each calendar year until after the third profitable calendar quarter for the product and any amounts in excess of the annual cap (Excess Amounts) are funded by Janssen. Under the Agreement, total Excess Amounts plus interest may not exceed $225.0 million.
The Company's policy is to account for cost-sharing payments to Janssen related to development services as a component of research and development expense and reimbursements for development services under the cost-sharing arrangement as an offset to research and development expense, upon delivery of the related services when expenses have been incurred and reimbursements have been earned. During the year ended December 31, 2013 and the six months ended December 31, 2012, the Company recognized Excess Amounts related to development services as a reduction to research and development expenses. The Company recognizes Excess Amounts as a reduction to Costs and expenses as the Company's payment of Excess Amounts to Janssen is contingent and would become payable only after the third profitable calendar quarter for the product. Further, Excess Amounts shall be reimbursable only from the Company's share of pre-tax profits after the third profitable calendar quarter for the product (see Note 5).
Selling, general and administrative expense
The Company expenses the cost of selling, general and administrative activities as incurred. Selling, general and administrative expenses consist primarily of personnel and facility-related expenses, outside contracted services and other costs not associated with the research and development activities of the Company. In connection with the Agreement, the Company also classifies certain commercial-related collaboration costs within Selling, general and administrative expense in the consolidated statements of operations. Costs under the Agreement that are recorded within selling, general and administrative expense are generally shared 50% by the Company and 50% by Janssen and include marketing costs, patent costs and the Company's share of pre-tax commercial losses on sales of IMBRUVICA.
During the year ended December 31, 2013 and the six months ended December 31, 2012, the Company recognized Excess Amounts related to certain collaboration costs as a reduction to selling, general and administrative expenses (see Note 5).
Income taxes
The Company is subject to income taxes in both the U.S. and foreign jurisdictions, and it uses estimates in determining its provisions for income taxes. The Company provides for income taxes using the asset and liability method, whereby deferred tax assets or liability account balances are calculated at the balance sheet date using current tax laws and rates in effect for the year in which the differences are expected to affect taxable income. Recognition of deferred tax assets is appropriate when realization of such assets is more likely than not. The Company recognizes a valuation allowance against its net deferred tax assets if it is more likely than not that some portion of the deferred tax assets will not be fully realizable. This assessment requires judgment as to the likelihood and amounts of future taxable income by tax jurisdiction.
The Company applies the provisions of FASB's guidance on accounting for uncertainty in income taxes. The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and the tax benefit to be recognized is measured at the largest amount of benefit that is greater than 50 percent likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized tax benefit is still appropriate. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available.
Stock-based compensation
Stock-based compensation cost for employee and director stock options with time-based vesting and employee stock plan purchase rights is generally measured and recognized based on the fair value of the award at the grant date. Stock-based compensation cost for restricted stock units (RSUs) with time-based vesting is measured based on the closing fair market value of the Company's common stock on the date of the grant, multiplied by the number of RSUs granted. The accounting grant date for employee stock options and restricted stock units with performance obligations is the date on which the performance goals have been defined and a mutual understanding of the terms has been reached. Generally, the Company's time-based stock option and RSU grants vest over a four year period. Stock options and RSUs with performance obligations generally vest over a four year period, with the goals set and agreed upon annually. Stock-based compensation for non-employee stock options is re-estimated at each period-end through the vesting date. The Company estimates a forfeiture rate to calculate the stock-based compensation cost for its awards primarily based on an analysis of its historical pre-vesting forfeitures.
The fair value of each stock option is estimated using the Black Scholes option-pricing model. Expected volatility is based on historical volatility data of the Company's stock. The expected term of stock options granted represents the period of time that stock options are expected to be outstanding.  The Company generally does not expect substantially different exercise or post-vesting termination behavior among its employee or non-employee population. As such, for the majority of stock options granted and the Company's Employee Stock Purchase Plan, the Company generally calculates and applies an overall expected term assumption based on historical data. In certain cases, the Company uses a shorter expected term for performance-based stock options based on a combination of historical data and management's estimates of the period of time that options will be outstanding. The risk-free interest rate is based on a zero-coupon U.S. Treasury bond whose maturity period equals the expected term of the Company's options.
Options and RSUs vest upon the passage of time or a combination of time and the achievement of certain performance obligations. Vesting of performance-based options and RSUs for executive officers depends on their attainment of key corporate and departmental goals. The Compensation Committee of the Board of Directors will determine if the performance conditions have been met. Stock-based compensation expense for the options and RSUs with performance obligations is recorded when the Company believes that the vesting of these options and RSUs is probable.
Shipping and handling costs
Shipping and handling costs incurred for inventory purchases and product shipments are recorded in Selling, general and administrative, net in the consolidated statements of income. Shipping and handling costs were not material for the years ended December 31, 2014 and December 31, 2013.
Advertising expenses
The Company expenses the costs of advertising, including promotional expenses, as incurred. The Company began incurring advertising expenses during the year ended December 31, 2014 due to the commercialization of IMBRUVICA on November 13, 2013. Advertising expenses were $4.4 million for the year ended December 31, 2014 and $0.3 million for the year ended December 31, 2013.
Segment reporting
Operating segments are defined as components of an enterprise that engage in business activities for which separate financial information is available and evaluated by the chief operating decision maker in deciding how to allocate resources and assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer (CEO). The Company operates as a single reportable segment, which primarily focuses on developing and commercializing novel therapies for the treatment of cancer and immune-mediated diseases. Product revenue, net is attributed to geography based upon the country in which the product is delivered. Long-lived assets are attributed to geography based on the country where the assets are located.
Recent Accounting Pronouncements
In April 2014, the FASB issued ASU 2014-08, "Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity", or ASU 2014-08. Under ASU 2014-08, only disposals representing a strategic shift in operations should be presented as discontinued operations. Those strategic shifts should have a major effect on the organization’s operations and financial results. Additionally, ASU 2014-08 requires expanded disclosures about discontinued operations that will provide financial statement users with more information about the assets, liabilities, income, and expenses of discontinued operations. ASU 2014-08 is effective for fiscal and interim periods beginning on or after December 15, 2014, with early adoption permitted. The Company will adopt the provisions of ASU 2014-08 beginning with the Company’s fiscal 2015.
In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers (Topic 606)," which provides guidance for revenue recognition. This ASU will supersede the revenue recognition requirements in Topic 605, Revenue Recognition, and most industry-specific guidance. The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under today’s guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. This standard is effective for annual and interim reporting periods beginning after December 15, 2016. Early adoption is not permitted. The Company is currently evaluating the impact of the adoption of this accounting standard on its consolidated financial statements.
In June 2014, the FASB issued ASU 2014-12, "Accounting for Stock-based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period." ASU 2014-12 requires that a performance target that affects vesting and could be achieved after the requisite service period be treated as a performance condition. This new guidance is effective for fiscal years and interim periods within those years beginning after December 15, 2015. Early adoption is permitted. This standard is not expected to have any impact on current disclosures in the consolidated financial statements.
In August 2014, the FASB issued ASU 2014-15, "Presentation of Financial Statements - Going Concern, which requires management to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and provide related footnote disclosures." ASU 2014-15 is effective for annual and interim reporting periods beginning on or after December 15, 2016. Early adoption is permitted for financial statements that have not been previously issued. The standard allows for either a full retrospective or modified retrospective transition method. The Company does not expect this standard to have a any impact on the Company’s consolidated financial statements upon adoption.
In November 2014, the FASB issued ASU 2014-17, "Business Combinations (Topic 805): Pushdown Accounting (a consensus of the FASB Emerging Issues Task Force)." ASU 2014-17 provides an acquired entity with an option to apply pushdown accounting in its separate financial statements upon occurrence of an event in which an acquirer obtains control of the acquired entity. An acquired entity may elect the option to apply pushdown accounting in the reporting period in which the change-in-control event occurs. This new standard is effective on November 18, 2014.  Early application is prohibited.  After the effective date, an acquired entity can make an election to apply the guidance to future change-in-control events or to its most recent change-in-control event. However, if the financial statements for the period in which the most recent change-in-control event occurred already have been issued or made available to be issued, the application of this guidance would be a change in accounting principle. The Company has adopted this new guidance and there's no impact on its consolidated financial statements.

Product_Revenue_Net

Product Revenue, Net	12 Months Ended
	Dec. 31, 2014
Revenues [Abstract]
Product Revenue, Net	PRODUCT REVENUE, NET
	Product revenue, net consists of revenue recorded on the sale of IMBRUVICA which was approved by the FDA and commercially launched by the Company on November 13, 2013 for MCL. All product revenue, net for the years ended December 31, 2014 and December 31, 2013 was from sales to U.S. customers.
	The Company recorded no product revenue, net for the six months ended December 31, 2012 and the year ended June 30, 2012 as these periods were prior to FDA approval for IMBRUVICA.
	For the years ended December 31, 2014 and December 31, 2013, product revenue, net was calculated as follows (in thousands):
		Years Ended December 31,
		2014				2013
	Product revenue, gross	$	553,143			$	14,968
	Government rebates, return reserve and other	(34,502		)		(1,024		)
	Chargebacks and cash discounts	(26,223		)		(371		)
	Product revenue, net	$	492,418			$	13,573
	The following table summarizes the provisions, and credits/payments, for product revenue, net adjustments for the years ended December 31, 2014 and December 31, 2013 (in thousands):
		Total
	2013
	Beginning Balance	$	—
	Provision related to current period sales	1,395
	Credits/payments	(189		)
	Ending Balance	$	1,206
	2014
	Beginning Balance	$	1,206
	Provision related to current period sales	60,725
	Credits/payments	(35,196		)
	Ending Balance	$	26,735
	The following table sets forth customers who represented 10% or more of the Company's product revenue, net for the years ended December 31, 2014 and December 31, 2013.
		Years Ended December 31,
	Customers:	2014			2013
	A	30	%		24	%
	B	20	%		15	%
	C	15	%		12	%
	D	14	%		20	%
	E	11	%		12	%

Accounts_Receivable_Net

Accounts Receivable, Net	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Accounts Receivable, Net	ACCOUNTS RECEIVABLE, NET
	Accounts receivable, net includes (in thousands):
		As of December 31,
		2014			2013
	Accounts receivable, gross	$	72,921		$	11,345
	Allowance for doubtful accounts	(14		)	—
	Allowance for chargebacks related to government and other programs	(7,105		)	(72		)
	Allowance for cash discounts	(1,505		)	(229		)
	Accounts receivable, net	$	64,297		$	11,044

Collaboration_and_Other_Agreem

Collaboration and Other Agreements	12 Months Ended
	Dec. 31, 2014
Collaboration and Other Agreements [Abstract]
Collaboration and Other Agreements	COLLABORATIONS AND OTHER AGREEMENTS
	The Company recognized revenue related to its collaboration and license arrangements as follows (in thousands):
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	Janssen	$	237,164		$	245,970		$	154,878		$	74,622
	Les Laboratoires Servier (Servier)	139			159			93			7,157
	Novo Nordisk A/S (Novo Nordisk)	8			454			5,631			—
	Other	—			13			56			211
	Total	$	237,311		$	246,596		$	160,658		$	81,990
	Worldwide Collaboration and License Agreement with Janssen Biotech, Inc.
	Background
	In December 2011, the Company entered into a worldwide collaboration and license agreement (the Agreement) with Janssen for the joint development and commercialization of IMBRUVICA, a novel, orally active, selective covalent inhibitor of Bruton’s Tyrosine Kinase (BTK), and certain compounds structurally related to IMBRUVICA, for oncology and other indications, excluding all immune and inflammatory mediated diseases or conditions and all psychiatric or psychological diseases or conditions, in the U.S. and outside the U.S.
	The collaboration provides Janssen with an exclusive license to exploit the underlying technology outside of the U.S. (the License Territory) and co-exclusively with Pharmacyclics in the U.S. Both parties are responsible for the development, manufacturing and marketing of any products resulting from the Agreement. The Company continues to work with Janssen on protocols and the design, schedules and timing of trials.
	The collaboration has no fixed duration or expiration date and provided for payments by Janssen to the Company of a $150.0 million non-refundable upfront payment upon execution, as well as potential future milestone payments of up to $825.0 million, based upon continued development progress ($250.0 million), regulatory progress ($225.0 million) and approval of the product in both the U.S. and the License Territory ($350.0 million). As of December 31, 2014, $605.0 million in milestone payments had been earned by the Company under the Agreement and it may receive up to an additional $220.0 million in development, regulatory and approval milestone payments. However, clinical developments entails risks and the Company has no assurance as to whether or when the milestone targets might be achieved.
	The development, regulatory and approval milestones represents non-refundable amounts that would be paid by Janssen to the Company if certain milestones are achieved in the future. The Company has elected to apply the guidance in ASC 605-28 to the milestones. These milestones, if achieved, are substantive as they relate solely to past performance, are commensurate with estimated enhancement of value associated with the achievement of each milestone as a result of the Company's performance, which are reasonable relative to the other deliverables and terms of the arrangement, and are unrelated to the delivery of any further elements under the arrangement.
	The Agreement includes a cost sharing arrangement for associated collaboration activities. Except in certain cases, in general, Janssen is responsible for approximately 60% of collaboration development costs and the Company is responsible for the remaining 40% of collaboration development costs. Generally, costs associated with commercialization will be included in determining pre-tax commercial profits or pre-tax commercial losses, which are to be shared 50% by the Company and 50% by Janssen.
	The collaboration with Janssen provides the Company with an annual cap of its share of IMBRUVICA related research and development and commercial-related expenses, offset by pre-tax commercial profits for each calendar year. In the event that the Company's share of aggregate development costs in any given calendar year, together with any other amounts that become due from the Company, plus the Company's share of pre-tax commercial losses for any calendar quarter in such calendar year, less the Company's share of pre-tax commercial profits for any calendar quarter in such calendar year, exceeds $50.0 million, then Excess Amounts are funded by Janssen. Under the Agreement, total Excess Amounts plus interest may not exceed $225.0 million at any given time.  Interest shall be accrued on the outstanding balance with interest calculated at the average annual European Interbank Offered Rate (EURIBOR) for the EURO or average annual London Interbank Offered Rate (LIBOR) for U.S. Dollars as reported in the Wall Street Journal, plus 2%, calculated on the number of days from the date on which the Company's payment would be due to Janssen. The interest rate on outstanding Excess Amounts shall not exceed 5% per annum, and the cumulative interest on Excess Amounts shall not in the aggregate exceed $25.0 million.
	In the event the Excess Amounts plus interest reaches a maximum of $225.0 million, the Company shall be responsible for its share of development costs, together with any other amounts that become due from the Company, plus its share of any pre-tax commercial loss beyond such maximum. For all calendar quarters following the Company's third profitable calendar quarter for the collaboration, as determined in the Agreement, the Company can no longer add to Excess Amounts and shall be responsible for its own share of development costs along with its share of pre-tax commercial losses incurred in such quarters. Janssen may only recoup the Excess Amounts, together with interest from the Company's share of pre-tax commercial profits in calendar quarters subsequent to its third profitable calendar quarter for the collaboration until the Excess Amounts and applicable interest has been fully paid.
	As per the Agreement, a profitable quarter shall mean a full calendar quarter beginning after the first commercial sale of IMBRUVICA in which the combined pre-tax profit or loss for the U.S. and the License Territory is positive and exceeds the development costs for such calendar quarter.
	The Company recognizes Excess Amounts as a reduction to costs and expenses as the Company's payment of Excess Amounts to Janssen is contingent and would become payable from the Company's share of pre-tax commercial profits only after the third profitable calendar quarter for the collaboration. As of December 31, 2014, total Excess Amounts were $138.3 million, which was comprised of the cumulative amount funded by Janssen to date of $134.3 million and interest of $4.0 million. As of December 31, 2014, the Company has achieved two profitable quarters for the collaboration.
	The Agreement also provides that any net profits from the commercialization of products resulting from the collaboration will be shared 50% by the Company and 50% by Janssen. Janssen has sole responsibility and exclusive rights to commercialize the products in the License Territory. The parties hold joint responsibility and co-exclusive rights to commercialize the products in the U.S., and Pharmacyclics will serve as the lead party in such effort. Janssen is commercializing IMBRUVICA outside the U.S.
	In accordance with ASU No. 2009-13 (and as incorporated into ASC Topic 605-25), the Company identified all of the deliverables at the inception of the Agreement. The significant deliverables were determined to be the license, committee services, development services and commercialization services. The commercialization services represent a contingent deliverable for which there is not a significant incremental discount.
	The Company has determined that the license represents a separate unit of accounting as the license, which includes rights to the underlying technologies for IMBRUVICA, has standalone value apart from the committee and development services because the development, manufacturing and commercialization rights conveyed would permit Janssen to perform all efforts necessary to bring the compound to commercialization and begin selling the drug upon regulatory approval. The Company has also determined that the committee and development services each represent individual units of accounting as they have standalone value from each other.  The Company has determined its best estimate of selling prices for the license unit of accounting based on the income approach as defined in ASC 820-10-35-32. This measurement is based on the value indicated by current estimates about those future amounts and reflects management determined estimates and assumptions. These estimates and assumptions include, but are not limited to, how a market participant would use the license, estimated market opportunity and expected market share and assumed royalty rates that would be paid for sales resulting from products developed using the license, similar arrangements entered into by third parties and entity-specific factors such as the terms of the Company's previous collaborative agreement, the Company's pricing practices and pricing objectives, the likelihood that clinical trials will be successful, the likelihood that regulatory approval will be received and that the products will become commercialized and the markets served. These estimates and assumptions led to an expected future cash flow which was discounted based on estimated weighted average cost of capital of 12% and royalty rates ranging from 30% to 40%. The Company has also determined its best estimate of selling prices for the committee and development services, based on the nature of the services to be performed and estimates of the associated effort as well as estimated market rates for similar services. The arrangement consideration of $150.0 million was allocated to the units of accounting based on the relative selling price method.
	Of the $150.0 million upfront payment received, $70.6 million was allocated to the licenses, $15.0 million to the committee services and $64.4 million to the development services. The Company has recognized license revenue upon execution of the arrangement as the associated unit of accounting had been delivered pursuant to the terms of the Agreement. Since inception, the $15.0 million and $64.4 million allocated to committee and development services, respectively, is being recognized as revenue as the related services are provided over the estimated service periods of 17 years and 9 years, which are equivalent to the estimated remaining life of the underlying technology and the estimated remaining development period, respectively.
	Janssen Collaboration Revenue
	Total revenue recognized with respect to the Agreement consisted of the following (in thousands):
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	License and milestone revenue	$	220,000		$	235,000		$	150,000		$	70,605
	Collaboration services revenue	17,164			10,970			4,878			4,017
	Total	$	237,164		$	245,970		$	154,878		$	74,622
	For the year ended December 31, 2014, total collaboration services revenue from Janssen included $4.2 million of net income from the sale of the Company's product to Janssen.
	As of December 31, 2014, total deferred revenue related to committee and development services under the Agreement with Janssen was $46.5 million, of which $34.9 million was included in deferred revenue non-current portion.
	License and milestone revenue recognized with respect to the Agreement with Janssen consisted of the following (in thousands):
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	License revenue	$	—		$	—		$	—		$	70,605
	Approval milestone revenue	170,000			60,000			—			—
	Regulatory milestone revenue	50,000			125,000			—			—
	Development milestone revenue	—			50,000			150,000			—
	Total	$	220,000		$	235,000		$	150,000		$	70,605
	Janssen Collaboration Cost Sharing and Excess Amounts
	The Company recognized development costs under the collaboration as a component of Research and development expense, net in the consolidated statements of operations. The Company also recognized certain selling, general and administrative expenses under the collaboration, including marketing costs, patent costs and the Company's share of pre-tax commercial losses on sales of IMBRUVICA outside of the U.S. as a component of Selling, general and administrative, net in the consolidated statements of operations. Expenses which were charged to the collaboration are as follows (in thousands):
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	Collaboration expenses, unadjusted	$	155,027		$	175,567		$	57,690		$	43,272
	Increase (decrease) for cost sharing	(40,121		)	(48,223		)	(17,339		)	(18,381		)
	Excess Amounts	—			(85,732		)	(17,306		)	—
	Research and development, net	$	114,906		$	41,612		$	23,045		$	24,891
	Collaboration expenses, unadjusted	$	88,110		$	28,118		$	2,426		$	1,070
	Increase (decrease) for cost sharing	5,775			10,675			247			(4		)
	Excess Amounts	—			(30,405		)	(819		)	—
	Selling, general and administrative, net	$	93,885		$	8,388		$	1,854		$	1,066
	Under the Agreement, Excess Amounts would become payable only after the third profitable quarter for the collaboration from the Company's share of pre-tax commercial profits, commencing in the fourth quarter of profitability under the Agreement until the Excess Amounts and applicable interest has been fully paid. The quarters ended September 30, 2014 and December 31, 2014 represented the first and second profitable quarters for the collaboration, respectively. The Company's net profit (loss) under the Agreement for its first and second profitable quarters for the collaboration was calculated as follows (in thousands):
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
						December 31,
	2014			2013			2012			2012
50% of Pharmacyclics' U.S. product revenue, net	$	246,209		$	—		$	—		$	—
Less: 50% of Pharmacyclics' U.S. cost of goods sold	(20,205		)	—			—			—
Pharmacyclics' 50% share of U.S. net product revenue, less cost of goods sold	226,004			—			—			—
Less: Pharmacyclics' share of U.S. commercial expenses under the Agreement	(70,597		)	(8,006		)	(1,073		)	(1,058		)
Pharmacyclics' share of U.S. pre-tax profits from the commercialization of IMBRUVICA under the Agreement	155,407			(8,006		)	(1,073		)	(1,058		)
Less: Pharmacyclics' share of outside-U.S. pre-tax commercial loss under the Agreement	(23,288		)	(382		)	(781		)	(8		)
Pharmacyclics' share of worldwide pre-tax profits from the commercialization of IMBRUVICA under the Agreement	132,119			(8,388		)	(1,854		)	(1,066		)
Less: Pharmacyclics' share of world-wide research and development expenses under the Agreement	(114,906		)	(41,612		)	(23,045		)	(24,891		)
Pharmacyclics' share of IMBRUVICA related pre-tax net profit under the Agreement	$	17,213		$	(50,000	)	$	(24,899	)	$	(25,957	)
For the year ended December 31, 2013, Janssen's 50% share of U.S. product revenue, net less cost of goods sold of IMBRUVICA of $5.0 million was fully absorbed by Excess Amounts funded by Janssen that were recorded as a reduction to selling, general and administrative, net. For the year ended December 31, 2014, the Company determined Janssen's 50% share of U.S. net product revenue less cost of goods sold of IMBRUVICA, which was included in costs of collaboration in the Company's consolidated statement of operations as follows (in thousands):
	Year Ended
	December 31,
	2014
Product revenue, net	$	492,418
Less: Cost of goods sold	40,410
	452,008
Janssen's share of U.S. pre-tax commercial profits	50		%
Total costs of collaboration (Janssen's 50% share under the Agreement)	$	226,004
Pharmacyclics' 50% share of U.S. net product revenue less cost of goods sold	$	226,004
Under the Agreement, the Company recorded Excess Amounts as follows:
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
Research and development		$	—		$	85,732		$	17,306		$	—
General and administrative		—			30,405			819			—
Total Excess Amounts		$	—		$	116,137		$	18,125		$	—
As of December 31, 2014, the Company's had $27.0 million receivable from Janssen, which consisted primarily of a milestone of $20.0 million, $3.9 million related to material and product sales and $1.7 million related to value added taxes. As of December 31, 2013, the Company's receivable from collaboration partner balance of $52.0 million was comprised primarily of $50.2 million due from Janssen under the collaboration agreement. The receivable from Janssen is included within Receivable from collaboration partners on the consolidated balance sheets.
As of December 31, 2014, the Company had $79.8 million payable to Janssen, of which $76.7 million was related to Janssen's share of pre-tax commercial profits, $2.8 million was related to cost-sharing under the Agreement and $0.3 million was related to value added taxes.
As of December 31, 2014, total Excess Amounts of $138.3 million (which comprises the cumulative amount funded by Janssen to-date of $134.3 million and interest of $4.0 million) would become payable once the Company reaches a third profitable calendar quarter for the product. Further, Excess Amounts shall be reimbursable only from the Company's share of pre-tax profits after the third profitable calendar quarter for the product.
Collaboration and License Agreement with Servier
In April 2009, the Company entered into a collaboration and license agreement with Servier to research, develop and commercialize abexinostat (PCI-24781), an orally active, novel, small molecule inhibitor of pan-HDAC enzymes. Under the terms of the agreement, Servier acquired the exclusive right to develop and commercialize the pan-HDAC inhibitor product worldwide except for the U.S. The Company and Servier terminated the collaboration and license agreement effective November 23, 2014. Upon the termination of the alliance, Servier’s rights to ex-U.S. development and commercialization of the Company's pan-HDAC inhibitor compounds will be returned to the Company, giving the Company full global development and commercialization rights. As of December 31, 2014, the Company's estimated costs associated with the termination of the Servier agreement of $0.8 million was recorded within accrued liabilities on the consolidated balance sheet.
Total revenue recognized with respect to the Company's collaboration and license agreement with Servier consisted of the following (in thousands):
	Years Ended						Six			Year Ended
	December 31,						Months Ended			June 30,
							December 31,
	2014			2013			2012			2012
License and milestone revenue	$	—		$	—		$	—		$	7,000
Collaboration services revenue	139			159			93			157
Total	$	139		$	159		$	93		$	7,157
License Agreement with Novo Nordisk A/S
In October 2012, the Company entered into a license agreement with Novo Nordisk A/S (Novo Nordisk). Under the terms of the agreement, Novo Nordisk acquired the exclusive worldwide rights for the Company's small molecule Factor VIIa inhibitor, PCI-27483, as an excipient in a product containing a Novo Nordisk active pharmaceutical ingredient for a restricted disease indication outside of oncology. Novo Nordisk will utilize PCI-27483 as an excipient in a product within Novo Nordisk's biopharmaceutical unit. Novo Nordisk is solely responsible for all further research and development activities within the restricted disease indication outside of oncology.
In connection with entering into the license agreement with Novo Nordisk, the Company received an upfront payment of $5.0 million in October 2012. In addition, the Company may receive up to $55.0 million based on the achievement of certain development, regulatory and sales milestones. Upon commercialization, the Company will also receive low single digit tiered royalties on Novo Nordisk's net sales of biopharmaceutical formulations utilizing the addition of PCI-27483.
On June 28, 2013, the Company entered into an amended and restated license agreement with Novo Nordisk to expand the scope of the license granted by the Company to Novo Nordisk in October 2012. Under the amended and restated license agreement with Novo Nordisk, the Company has no additional obligations related to the delivery of the license.
Total revenue recognized with respect to the Company's license agreement with Novo Nordisk consisted of the following (in thousands):
	Years Ended						Six			Year Ended
	December 31,						Months Ended			June 30,
							December 31,
	2014			2013			2012			2012
License and milestone revenue	$	—		$	—		$	5,000		$	—
Collaboration services revenue	8			454			631			—
Total	$	8		$	454		$	5,631		$	—
Acquired Products
Celera Corporation
Background
In April 2006, the Company acquired multiple small molecule drug candidates for the treatment of cancer and other diseases from Celera Genomics, an Applera Corporation business  (now Celera Corporation - a subsidiary of Quest Diagnostics Incorporated). Future milestone payments under the agreement, as amended, could total as much as approximately $97.0 million although the Company currently cannot predict if or when any of the milestones will be achieved. Approximately two-thirds of the milestone payments relate to the Company's HDAC inhibitor program and approximately one-third relates to the Company's Factor VIIa inhibitor program. Approximately 90% of the potential future milestone payments would be paid to Celera after obtaining regulatory approval in various countries. To date, no milestone payments have been triggered related to the Company's HDAC inhibitor or Factor VIIa programs.
In addition to the milestone payments, the Company is required to make single-digit royalty payments based on annual sales of IMBRUVICA and would be required to make single-digit royalty payments based on annual sales of drugs commercialized from the Company's HDAC inhibitor, Factor VIIa inhibitor and certain other BTK inhibitor programs. For the year ended December 31, 2014 and year ended December 31, 2013, the Company recognized royalty expense under the Celera agreement of approximately $27.4 million and $1.0 million, respectively, on net product sales of IMBRUVICA. Royalty expense related to net product sales of IMBRUVICA is included within cost of goods sold in the consolidated statement of operations. No royalty expense was incurred under the Celera agreement prior to the year ended December 31, 2013.
For any BTK inhibitor product or Factor VIIa inhibitor product obtained from Celera, the agreement with Celera expires on a product-by-product and country-by-country basis. The term of the agreement for a given BTK inhibitor product or Factor VIIa inhibitor product shall expire in a given country upon the expiration of the last-to-expire Celera patent assigned to the Company that covers the manufacture, use, sale, offer for sale, or importation of such product in such country. For any HDAC inhibitor product obtained from Celera, the agreement with Celera expires on a product-by-product and country-by-country basis. The term of the agreement for a given HDAC inhibitor product shall expire in a given country upon the expiration of the last-to-expire Celera patent assigned to the Company that covers the sale of such product in such country.
The Company may terminate the agreement with Celera in its entirety, or with respect to one or more of the three classes of products (BTK inhibitor products, HDAC inhibitor products and Factor VIIa inhibitor products) obtained from Celera, at any time by giving Celera at least 60 days' prior written notice. If the Company terminates the agreement with respect to a particular class of products, ownership of the Celera intellectual property assigned to the Company relating to the products in the terminated product class will revert to Celera. If the Company terminates the agreement in its entirety, ownership of all of the Celera intellectual property assigned to the Company will revert to Celera.
The agreement with Celera may be terminated effective immediately upon a party's written notice to the other party for a breach by the other party that remains uncured for 90 days after notice of the breach is given to the breaching party. If the Company breaches the agreement only with respect to one or two of the three classes of products obtained from Celera, but not with respect to all three classes of products, and if the Company's breach remains uncured for 90 days after the Company has received notice of breach from Celera, Celera may terminate the agreement solely with respect to the class or classes of products affected by the Company's breach, but may not terminate the agreement with respect to the class or classes of products unaffected by the Company's breach.

Cash_Cash_Equivalents_and_Mark

Cash, Cash Equivalents and Marketable Securities	12 Months Ended
	Dec. 31, 2014
Assets, Fair Value Disclosure [Abstract]
Cash, Cash Equivalents and Marketable Securities	CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES
	The following tables set forth the Company's cash, cash equivalents and marketable securities (in thousands):
		As of December 31,
		2014			2013
	Cash - Demand deposits	$	471,916		$	225,035
	Cash equivalents - money market funds	373,119			129,193
	Cash equivalents - U.S. treasury bills	—			269,488
	Cash equivalents - Certificates of deposit - FDIC insured	—			240
	Cash and cash equivalents	$	845,035		$	623,956
		As of December 31,
		2014			2013
	Certificates of deposit - FDIC insured	$	11,952		$	11,672
	Marketable securities	$	11,952		$	11,672
	To date, the Company has not recorded any impairment charges on marketable securities related to other-than-temporary declines in market value. In determining whether a decline is other than temporary, the Company considers various factors including the length of time and extent to which the market value has been less than cost, the financial condition and near-term prospects of the issuer and the Company's intent and ability to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in market value.
	For the year ended December 31, 2014 and year ended December 31, 2013, gross realized losses and gains on the sale of available-for-sale securities were not material.
	The following is a summary of the Company's available-for-sale securities measured a amortized costs, gross unrealized gains, gross unrealized losses and fair value (in thousands):
	As of December 31, 2014		Amortized Cost			Gross Unrealized Gain			Gross Unrealized Loss				Fair Value
	Certificates of deposit – FDIC insured		$	11,960		$	—		$	(8	)		$	11,952
	Marketable Securities		$	11,960		$	—		$	(8	)		$	11,952
	As of December 31, 2013		Amortized Cost			Gross Unrealized Gain			Gross Unrealized Loss				Fair Value
	Certificates of deposit – FDIC insured		$	11,680		$	—		$	(8	)		$	11,672
	Marketable Securities		$	11,680		$	—		$	(8	)		$	11,672
	As of December 31, 2014, the Company's marketable securities had the following remaining contractual maturities (in thousands):
		Amortized Cost			Fair Value
	Less than one year	$	11,960		$	11,952
	The following table sets forth the basis of fair value measurements for the Company's cash equivalents and available-for-sale securities (in thousands):
		As of December 31, 2014
		Level 1			Level 2			Level 3				Fair Value
	Cash equivalents:
	Money market funds	$	373,119		$	—		$	—			$	373,119
	Marketable securities:
	Certificates of deposit- FDIC insured	—			11,952			—				11,952
		$	373,119		$	11,952		$	—			$	385,071
		As of December 31, 2013
		Level 1			Level 2			Level 3				Fair value
	Cash equivalents:
	U.S. treasury bills	$	269,488		$	—		$	—			$	269,488
	Money market funds	129,193			—			—				129,193
	Certificates of deposit - FDIC insured	—			240			—				240
	Marketable securities:
	Certificates of deposit - FDIC insured	—			11,672			—				11,672
		$	398,681		$	11,912		$	—			$	410,593
	There were no transfers between levels of the fair value hierarchy during fiscal year 2014.

Balance_Sheet_Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2014
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	BALANCE SHEET COMPONENTS
	Property and equipment, net consists of the following (in thousands):
		As of December 31,
		2014			2013
	Equipment	$	13,363		$	11,827
	Leasehold improvements	9,951			5,493
	Furniture and fixtures	1,278			1,278
	Construction in progress	19,461			14,592
		44,053			33,190
	Less: Accumulated depreciation and amortization	(11,577		)	(7,719		)
		$	32,476		$	25,471
	Depreciation and amortization of property and equipment was $3.9 million for the year ended December 31, 2014, $2.2 million for the year ended December 31, 2013, $0.6 million for the six months ended December 31, 2012 and $0.6 million for the year ended June 30, 2012.
	Accrued liabilities consist of the following (in thousands):
		As of December 31,
		2014			2013
	Accrued payroll and employee related expenses	$	19,645		$	20,500
	Accrued discounts and rebates	18,125			906
	Accrued clinical related	14,806			17,062
	Accrued royalty to Celera (see Note 5)	10,646			949
	Accrued value added taxes	7,395			7,041
	Accrued outside services	5,114			5,077
	Accrued contract manufacturing	2,380			1,556
	Accrued marketing	1,288			—
	Accrued property and equipment purchases	934			4,039
	Accrued inventory	101			7,592
	Accrued other	7,845			6,466
		$	88,279		$	71,188
	Deferred revenue consists of the following (in thousands):
	Current portion:	As of December 31,
		2014			2013
	Deferred revenue related to the Agreement (see Note 5)	$	11,656		$	7,505
	Deferred revenue from sales to collaboration partner (see Note 5)	7,117			76
		$	18,773		$	7,581
	Non-current portion:	As of December 31,
		2014			2013
	Deferred revenue related to the Agreement (see Note 5)	$	34,885		$	52,025

Intangible_Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Intangible Assets
	On April 15, 2014, the Company entered into an agreement with a third party to acquire technology assets in the amount of $9.3 million in cash. The Company expects to amortize the technology assets over 13 years which reflects the estimated remaining useful life of the technology assets. Amortization expense was $0.5 million for the year ended December 31, 2014. Accumulated amortization as of December 31, 2014 was $0.5 million.
	As of December 31, 2014, the future annual amortization expense for the Company's intangible assets is expected to be as follows (in thousands):
	Fiscal Year	Future Amortization of Intangible Assets
	2015	$	728
	2016	730
	2017	728
	2018	728
	2019	728
	Thereafter	5,088
	Total	$	8,730

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Stockholders' Equity	STOCKHOLDERS' EQUITY
	Common stock
	Public Offering
	In March 2013, the Company sold 2.2 million shares of its common stock in an underwritten public offering at $94.20 per share for net proceeds of $201.0 million after deducting expenses of the offering. The closing of the offering took place on March 13, 2013.
	Preferred stock
	As amended, the Company's Certificate of Incorporation authorizes 1.0 million shares of preferred stock, par value $0.0001 per share. The Board of Directors is authorized to issue the preferred stock in one or more series and to fix the rights, preferences, privileges and restrictions thereof, including dividend rights, dividend rates, conversion rights, voting rights, terms of redemption, redemption prices, liquidation preferences and the number of shares constituting any series or the designation of such series, without further vote or action by the stockholders. As of December 31, 2014 and 2013, no preferred stock was issued or outstanding.
	The ability of the Company's Board of Directors to issue shares of preferred stock without stockholder approval may have certain anti-takeover effects. The Company is also subject to provisions of the Delaware General Corporation Law, which may make certain business combinations more difficult.
	Stock plans
	Equity Incentive Award Plans
	The Company maintains three stock-based compensation plans: the 2014 Equity Incentive Award Plan (2014 Plan), which was approved during the Company's annual meeting of stockholders on May 8, 2014, the 2004 Equity Incentive Award Plan (2004 Plan) and the Employee Stock Purchase Plan (ESPP). The 2014 Plan serves as the successor to the 2004 Plan and provides for the issuance of various forms of awards including among others, incentive and non-qualified stock options and restricted stock units (RSUs). The exercise price of all stock options granted under the 2014 Plan may not be less than the fair market value of the Company's common stock on the date of grant and no stock option will be exercisable more than ten years after the date it is granted. Stock options and restricted stock units granted to employees generally vest over four years. The Company settles employee stock option exercises, ESPP purchases, and the vesting of RSUs with newly issued common shares.
	The following table summarizes stock option activity related to shares of common stock under the Company's stock option plans (in thousands, except per share amounts and years data):
			Options Outstanding
			Number of Options			Weighted Average Exercise Price per Share				Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value
	Balance at December 31, 2013		5,111			$	23.54
	Exercised		(1,682	)		11.93
	Granted		1,142			91.68
	Forfeited or expired		(371	)		59.84
	Balance at December 31, 2014		4,200			43.5				5.7		$	332,507
	Vested and expected to vest at December 31, 2014		4,073			$	41.72			6.6		$	328,684
	The above table excludes approximately 0.8 million options which comprise the portion of performance options granted for which the performance criteria had not been established as of December 31, 2014.
	The following table summarizes restricted stock unit activity under the Company's 2014 Plan (in thousands, except per share amounts and years data):
			Number of Options			Weighted Average Grant Date Fair Value				Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value
	Outstanding at December 31, 2013		—			$	—
	Granted		211			114.98
	Vested and released		(13	)		121.89
	Forfeited		(10	)		100.09
	Outstanding and unvested at December 31, 2014		188			$	115.32			2		$	23,052
	Expected to vest at December 31, 2014		163			$	115.61			1.9		$	19,960
	The above table excludes approximately 0.1 million restricted stock units which comprise the portion of performance RSUs granted for which the performance criteria had not been established as of December 31, 2014.
	The components of stock-based compensation recognized in the Company's consolidated statements of operations were as follows (in thousands):
			Years Ended								Six			Year Ended June 30,
			December 31,								Months Ended
											December 31,
			2014				2013				2012			2012
	Cost of goods sold		$	1,453			$	436			$	—		$	—
	Research and development		22,710				24,041				5,357			6,947
	Selling, general and administrative		29,578				25,733				2,079			2,926
	Total stock-based compensation		$	53,741			$	50,210			$	7,436		$	9,873
	During the year ended December 31, 2014 and the year ended December 31, 2013, the Company capitalized stock-based compensation of approximately $0.9 million and $0.2 million, respectively. The Company capitalized no stock-based compensation during the six months ended December 31, 2012 and the year ended June 30, 2012, as these periods were prior to the commercialization of its product.
	The fair value of each stock option is estimated using the Black Scholes option-pricing model. The expected term of stock options granted represents the period of time that stock options are expected to be outstanding.  The Company generally does not expect substantially different exercise or post-vesting termination behavior among its employee or non-employee population. As such, for the majority of stock options granted and the Company's Employee Stock Purchase Plan, the Company generally calculates and applies an overall expected term assumption based on historical data. In certain cases, the Company uses a shorter expected term for performance-based stock options based on a combination of historical data and management's estimates of the period of time that options will be outstanding. The risk-free interest rate is based on a zero-coupon U.S. Treasury bond whose maturity period equals the expected term of the Company's options.
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	Employee stock options (1):
	Expected dividend yield	—			—			—			—
	Expected stock price volatility (2)	46.9% - 67.4%			50.9% - 84.8%			51.5% - 85.5%			88	%
	Risk free interest rate (2)	0.7% - 1.8%			0.5% - 1.5%			0.3% - 0.8%			1	%
	Expected life (years) (2)	2.52 - 5.04			2.52 - 5.20			2.60 - 5.20			5
	Non-employee stock options:
	Expected dividend yield	—			—			—			—
	Expected stock price volatility	79	%		79	%		89	%		84% - 89%
	Risk free interest rate	2.6	%		1.9	%		3.89	%		2.00% - 3.89%
	Expected life (years)	10			10			8			8.10 – 10.00
	(1) The above table includes assumptions used in the valuation of performance-based stock option grants for which the Company set performance criteria during the period.
	(2) Amounts for the year ended June 30, 2012 are presented on a weighted average basis.
	The weighted average grant date fair value for employee options granted under the Company's stock option plans during the year ended December 31, 2014, the year ended December 31, 2013, the six months ended December 31, 2012, and the year ended June 30, 2012 was $59.28, $55.32, $43.55 and $11.44, respectively.
	The total pre-tax intrinsic value of stock options exercised during the year ended December 31, 2014, the year ended December 31, 2013, the six months ended December 31, 2012, and the year ended June 30, 2012 was $196.6 million, $145.5 million, $45.8 million and $17.3 million, respectively.
	For the year ended December 31, 2014 and year ended December 31, 2013, the Company recognized a tax benefit from stock-based compensation of $34.9 million and $30.0 million, respectively, as a decrease to income taxes payable, with a corresponding increase to additional paid-in capital. No income tax benefits were recognized during the six months ended December 31, 2012 and the year ended June 30, 2012.
	As of December 31, 2014, there were approximately 2.0 million shares reserved for issuance and available for grant under the 2014 Plan.
	As of December 31, 2014, $87.6 million of total unrecognized compensation costs related to non vested employee options are scheduled to be recognized over a weighted average period of 2.6 years.
	The total fair value of shares vested for the year ended December 31, 2014, the year ended December 31, 2013, the six months ended December 31, 2012 and the year ended June 30, 2012 was $43.3 million, $37.4 million, $3.7 million and $5.6 million, respectively.
	A summary of outstanding, exercisable and vested stock options as of December 31, 2014 is as follows (in thousands, except per share amounts):
			Options Outstanding												Exercisable						Exercisable and Vested
Range of Exercise Prices		Number of Shares			Weighted Average Remaining Contractual Life		Weighted Average Exercise Price Per Share				Aggregate Intrinsic Value			Number of Shares	Weighted Average Remaining Contractual Life	Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value		Number of Shares	Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value
$0.75 - $6.49		837			4.28		$	2.57						837	4.28	$	2.57			822	$	2.5
$6.52 - $12.00		851			5.41		$	7.73						831	5.43	$	7.67			815	$	7.61
$12.10 - $32.38		863			6.78		$	20.28						796	6.76	$	20.28			489	$	18.62
$36.73 - $86.78		924			7.72		$	68.11						924	7.72	$	68.11			437	$	66.52
$87.19 - $102.22		1,013			9.11		$	96.07						91	8.58	$	90.62			91	$	90.62
$102.77 - $151.48		521			9.26		$	119.51						44	8.69	$	113.87			43	$	113.87
		5,009			7.03		$	49.67			$	364,377		3,523	6.18	$	28.62	$	329,982	2,697	$	22.11	$	270,222
Employee Stock Purchase Plan
The Company adopted an Employee Stock Purchase Plan (the "Purchase Plan") in August 1995. Qualified employees may elect to have a certain percentage of their salary withheld to purchase shares of the Company's common stock under the Purchase Plan. The purchase price per share is equal to 85% of the fair market value of the stock on specified dates.
The number of shares purchased under the Purchase Plan in the year ended December 31, 2014, the year ended December 31, 2013, the six months ended December 31, 2012, and the year ended June 30, 2012 were approximately 0.1 million, 0.2 million, 0.1 million, and 0.2 million shares of common stock at an average price of $80.55, $21.65, $13.06, and $5.19 per share, respectively. In May 2013, stockholders approved an increase of 0.3 million shares available for issuance under the Purchase Plan. As of December 31, 2014, approximately 0.5 million shares were available for future purchase under the Purchase Plan.
Compensation cost is estimated using the Black Scholes option-pricing model using the weighted average assumptions noted in the following table:
	Years Ended						Six			Year Ended
	December 31,						Months Ended			June 30,
							December 31,
	2014			2013			2012			2012
Expected dividend yield	—			—			—			—
Stock price volatility	49	%		48	%		50	%		54	%
Risk free interest rate	0.3	%		0.16	%		0.16	%		0.15	%
Expected life (years)	1.59			1.1			0.68			1.14
The weighted average estimated grant date fair value of purchase awards under the Company's employee stock purchase plan during the year ended December 31, 2014, the year ended December 31, 2013, six months ended December 31, 2012, and the year ended June 30, 2012 was $36.79, $41.19, $33.32 and $6.38 per share, respectively.
As of December 31, 2014, $4.4 million of total unrecognized compensation costs related to purchase awards under the Company's employee stock purchase plan were scheduled to be recognized over a weighted average period of 1 year.

Employee_Benefit_Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2014
Employee Benefit Plan [Abstract]
Employee Benefit Plan	EMPLOYEE BENEFIT PLAN
	The Company maintains a defined contribution plan covering substantially all U.S. employees under Section 401(k) of the Internal Revenue Code and a defined contribution plan for non-U.S. employees. The Company's matching contribution to the plan was $1.9 million, $1.0 million, $0.1 million, $0.2 million for the year ended December 31, 2014, the year ended December 31, 2013, the six months ended December 31, 2012, and the year ended June 30, 2012, respectively.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES
	The components of the provision for income taxes are as follows (in thousands):
		Years Ended								Six			Year Ended
		December 31,								Months Ended			June 30,
										December 31,
		2014				2013				2012			2012
	Current:
	Federal	$	31,938			$	30,879			$	2,047		$	26
	State	4,294				202				599			—
	Foreign	91				45				1			13
	Total provision for income taxes	36,323				31,126				2,647			39
	Income before taxes	$	122,447			$	98,136			$	120,180		$	12,025
	Tax rate	29.66		%		31.72		%		2.2		%	0.33		%
	The following is a geographical breakdown of consolidated income before income taxes by income tax jurisdiction (in thousands):
		Years Ended								Six			Year Ended
		December 31,								Months Ended			June 30,
										December 31,
		2014				2013				2012			2012
	United States	$	100,270			$	70,254			$	69,563		$	(4,596	)
	Foreign	22,177				27,882				50,617			16,621
	Income before taxes	$	122,447			$	98,136			$	120,180		$	12,025
	Net deferred tax assets (liabilities) are summarized as follows (in thousands):
			As of December 31,
			2014				2013
	Deferred tax assets:
	Net operating loss carryforwards		$	4,546			$	3,552
	Tax credit carryforwards		25,978				26,110
	Capitalized research and development costs		200				230
	Depreciation and amortization		775				916
	Partnership investment		4,922				—
	Stock-based compensation		16,320				9,712
	Reserves and accruals		18,039				18,557
	Gross deferred tax assets		70,780				59,077
	Less: valuation allowance		(70,350		)		(58,679		)
	Net deferred tax assets		430				398
	Deferred tax liabilities:
	Depreciation		(430		)		(398		)
	Net Deferred tax assets		$	—			$	—
	A full valuation allowance has been established for the Company's deferred tax assets as of December 31, 2014 and December 31, 2013, since realization of such assets through the generation of future taxable income is uncertain. The increases in the valuation allowance were $11.7 million, and $26.8 million for year ended December 31, 2014 and the year ended December 31, 2013, respectively.
	The Company intends to continue maintaining a full valuation allowance on its deferred tax assets until there is sufficient evidence to support the reversal of all or some portion of these allowances. However, should there be greater market demand for or greater market acceptance of IMBRUVICA than management has currently forecasted, there is a reasonable possibility that within the next year sufficient positive evidence may become available to reach a conclusion that a significant portion of the valuation allowance will no longer be needed. As such, the Company may release a significant portion of its valuation allowance against its deferred tax assets within the next 12 months. This release would result in the recognition of certain deferred tax assets and a decrease to income tax expense for the period such release is recorded.
	The provision for income taxes differs from the amount determined by applying the U.S. statutory income tax rate of 35% for the year ended December 31, 2014, year ended December 31, 2013, the six months ended December 31, 2012, and year ended June 30, 2012 to the income before income taxes as summarized below (in thousands):
		Years Ended								Six			Year Ended
		December 31,								Months Ended			June 30,
										December 31,
		2014				2013				2012			2012
	Tax provision (benefit) at statutory rate	$	42,857			$	34,347			$	42,064		$	4,209
	State Tax, net of federal benefit	3,156				202				389			—
	Research and development and orphan drug credits	(16,944		)		(21,774		)		—			(529		)
	Deferred tax assets benefited (not benefited)	7,151				28,376				(35,181		)	(5,727		)
	Stock-based compensation	4,532				5,261				1,056			2,009
	Other	3,238				744				(629		)	38
	Federal – alternative minimum tax	—				—				2,047			26
	Foreign taxes greater than (less than) U.S. rates	(7,667		)		(16,030		)		(7,099		)	13
		$	36,323			$	31,126			$	2,647		$	39
	At December 31, 2014 and December 31, 2013, the Company had federal net operating loss carryforwards of approximately $9.4 million and $10.1 million, respectively. At December 31, 2014 and December 31, 2013, the Company had state net operating loss carryforwards of approximately $58.0 million and $37.3 million, respectively. The state operating losses are attributable to stock option benefits which will be recorded to equity when they reduce cash taxes payable. The federal and state net operating loss carryforwards will begin to expire in 2016. At December 31, 2014 and December 31, 2013, federal tax research credit carryforwards of $9.1 million and $6.9 million, respectively and state tax research credit carryforwards of $8.9 million and $5.5 million, respectively, are available to offset future taxable income. At December 31, 2014 and December 31, 2013, federal orphan drug credits of $71.1 million and $48.6 million, respectively, are also available to offset future taxable income. The federal tax research and orphan drug credits can be carried forward 20 years and will begin to expire in 2032. State tax research credits can be carried forward indefinitely. At December 31, 2014 and December 31, 2013, the Company also had federal and state alternative minimum tax credits of $1.5 million and $2.4 million, respectively, that can be used in the future that have no expiration date.
	The Company is tracking the portion of its net operating losses attributable to stock option benefits in a separate memo account pursuant to ASC 718-740. Therefore, these amounts are no longer included in the Company's gross or net deferred tax assets. Pursuant to ASC 718-740-25-10, the stock option benefits of approximately $2.1 million will be only recorded to equity when they reduce cash taxes payable.
	The Company reviewed whether the utilization of its net operating losses and research credits are subject to a substantial annual limitation due to the ownership change limitations provided by the Internal Revenue Code and similar state provisions. Utilization of these carryforwards is restricted and results in some amount of these carryforwards expiring prior to benefiting the Company. The deferred tax assets shown above have been adjusted to reflect these expiring carryforwards.
	The following table summarizes the activity related to the Company's gross amounts of unrecognized tax benefits (in thousands):
		Years Ended								Six			Year Ended
		December 31,								Months Ended			June 30,
										December 31,
		2014				2013				2012			2012
	Beginning balance	$	15,976			$	2,845			$	2,307		$	1,726
	Additions based on tax positions related to current year	11,520				10,075				538			581
Additions (reduction) for tax positions of prior years	(623		)		3,056				—			—
Ending balance	$	26,873			$	15,976			$	2,845		$	2,307
The total amount of the unrecognized tax benefits if recognized would be an adjustment to the amount of deferred tax assets reported. The Company may from time to time be assessed interest or penalties by major tax jurisdictions, although there have been no such assessments historically.  In the event the Company receives an assessment for interest and/or penalties, it would be classified in the financial statements as income tax expense. As of December 31, 2014, all tax years in the U.S. remain open due to the taxing authorities' ability to adjust operating loss carry forwards. The Company does not expect any material changes to the unrecognized tax benefits reported above during the next twelve months.
U.S. income taxes were not provided on approximately $65.9 million of undistributed earnings of certain non-U.S. subsidiaries. The amount of the unrecognized deferred tax liability for temporary differences relates to investments in these non-U.S. subsidiaries that are essentially permanent in duration and the Company anticipates that, if ever distributed, such amounts would not be taxed at greater than 40%. The Company has not provided U.S. income taxes and foreign withholding taxes on the undistributed earnings of foreign subsidiaries as of December 31, 2014, because the Company intends to permanently reinvest such earnings outside the U.S. As of December 31, 2014, the amount of potential U.S. income tax of a future hypothetical distribution would not trigger a significant U.S. tax liability because the Company has tax attribute carryovers available that it can use to reduce its liability.
During the year ended December 31, 2013, the Company was notified by the Internal Revenue Service (IRS) that it will be audited for the tax years ended June 30, 2012 and 2011. In the third quarter of 2014, the IRS issued an Agreed Tax Change (Form 4549) accepting a proposed adjustment to reduce the Company's R&D credit forward by $0.3 million for the tax year ended June 30, 2011. As of December 31, 2014, no additional adjustments have been proposed by the IRS.
In December 2014, Congress passed the Tax Increase Prevention Act which included a retroactive renewal of the Federal R&D credit back to January 1, 2014, which had previously expired. The impact of this retroactive tax legislation will not affect the Company's fiscal 2014 effective tax rate, but will reduce future income tax payments.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES
	Facilities Lease
	As of December 31, 2014, the Company leases a total of 132,176 square feet for its corporate headquarters in Sunnyvale, California. Of this total space, 79,776 square feet are leased under an operating lease that expires in November 2017, with an option to extend the lease term for an additional five years. The remaining 52,400 square feet are leased under an operating lease that expires in February 2023, which provides for an option to early terminate the lease in 2018 and has an option to extend the lease term for an additional five years. In addition, the Company leases approximately 8,000 square feet for its Pharmacyclics Switzerland GmbH office under an agreement that expires in May 2015 and leases 7,000 square feet of office space in South San Francisco, California under an operating lease which expires in March 2015. In January 2015, the Company entered into a lease agreement for additional office space for its corporate headquarters in Sunnyvale, California for approximately 36,000 square feet with annual rental expense of $0.5 million under an operating lease that expires in May 2016. In addition, in February 2015, the Company entered into a lease agreement for approximately 10,000 square feet of office space in South San Francisco, California, with annual rental expense of $0.3 million under an operating lease, expiring in February 2017.
	The Company recognizes rental expense under the lease on a straight line basis over the lease term. Differences between the straight line rent expense and rent payments are classified as deferred rent liability on the balance sheet. As of December 31, 2014, future minimum lease payments under non-cancelable operating leases are as follows (in thousands):
		Operating Lease Commitments
	2015	$	2,226
	2016	2,161
	2017	2,112
	2018	857
	2019	882
	Thereafter	2,890
	Total	$	11,128
	Rent expense for the year ended December 31, 2014, year ended December 31, 2013, six months ended December 31, 2012, and the year ended June 30, 2012 was $2.5 million, $1.8 million, $0.6 million, and $1.0 million, respectively.
	Purchase Commitments
	The Company had non-cancelable purchase obligations for approximately $85.9 million, and $34.8 million as of December 31, 2014 and December 31, 2013, respectively.
	Excess amounts under collaboration and license agreement with Janssen
	The Company's worldwide collaboration and license agreement with Janssen provides the Company with an annual cap of its share of development costs and pre-tax commercial losses for each calendar year until the third profitable calendar quarter for the collaboration, as determined in the agreement, and any Excess Amounts are funded by Janssen. Janssen may recoup the Excess Amounts, together with interest, from the Company's share of pre-tax commercial profits after the third profitable calendar quarter for the collaboration until the Excess Amounts and applicable interest has been fully paid. As of December 31, 2014, total Excess Amounts were $138.3 million, which was comprised of the cumulative amount funded by Janssen to-date of $134.3 million and interest of $4.0 million. As of December 31, 2014, we have achieved two profitable quarters for the collaboration (see Note 5).
	Legal Proceedings
	The Company may be involved, from time to time, in legal proceedings and claims arising in the ordinary course of its business. Such matters are subject to many uncertainties and outcomes are not predictable with assurance. The Company accrues amounts, to the extent they can be reasonably estimated, that it believes are adequate to address any liabilities related to legal proceedings and other loss contingencies that the Company believe will result in a probable loss. While there can be no assurances as to the ultimate outcome of any legal proceeding or other loss contingency involving the Company, management does not believe any pending matter will be resolved in a manner that would have a material adverse effect on the Company's consolidated financial position, results of operations or cash flows.

Basic_and_Diluted_Net_Income_P

Basic and Diluted Net Income Per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share, Basic and Diluted [Abstract]
Basic and Diluted Net Income Per Share	BASIC AND DILUTED NET INCOME PER SHARE
	The computations of basic and diluted net income per share are as follows (in thousands, except per share amounts):
		Years Ended				Six		Year Ended
		December 31,				Months Ended		June 30,
						December 31,
		2014		2013		2012		2012
	Numerator:
	Net income	$	86,124	$	67,010	$	117,533	$	11,986
	Denominator:
	Weighted average common shares-basic	75,247		72,777		69,676		68,728
	Effect of dilutive securities:
	Employee stock options	2,873		4,237		4,607		3,781
	Employee stock purchase plan	16		69		125		108
	Restricted stock units	15		—		—		—
	Weighted average common shares - diluted	78,151		77,083		74,408		72,617
	Net income per share:
	Basic	$	1.14	$	0.92	$	1.69	$	0.17
	Diluted	$	1.1	$	0.87	$	1.58	$	0.17
	Potentially dilutive securities excluded from net income per share - diluted because their effect is anti-dilutive	1,243		848		445		441

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION
	The Company operates as a single reportable segment, which primarily focuses on developing and commercializing novel therapies for the treatment of cancer and immune-mediated diseases (see Note 2). The following table summarizes total revenue from external customers by geographic region, which consists of product revenue, net. IMBRUVICA first came to market on November 13, 2013.
		Years Ended				Six		Year Ended
		December 31,				Months Ended		June 30,
						December 31,
		2014		2013		2012		2012
	United States	$	492,418	$	13,573	$	—	$	—
	Other	—		—		—		—
	Total	$	492,418	$	13,573	$	—	$	—
	As of December 31, 2014, substantially all of the Company's long-lived assets were located in the U.S.

Quarterly_Results_Unaudited

Quarterly Results (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results (Unaudited)	QUARTERLY RESULTS (UNAUDITED)
	The following table is in thousands, except per share amounts:
		Quarters Ended
		March 31,			June 30,			September 30,		December 31,
		2014			2014			2014		2014
	Total revenue	$	119,377		$	113,020		$	207,140	$	290,192
	Total costs and expenses	$	101,152		$	150,224		$	158,771	$	197,201
	Net income (loss) from operations	$	18,225		$	(37,204	)	$	48,369	$	92,991
	Net income (loss)	$	18,275		$	(37,057	)	$	41,422	$	63,484
	Net income (loss) per share: (1)
	Basic	$	0.24		$	(0.49	)	$	0.55	$	0.84
	Diluted	$	0.23		$	(0.49	)	$	0.53	$	0.81
	Shares used in computation of net income (loss) per share:
	Basic	74,754			75,139			75,392		75,692
	Diluted	78,064			75,139			78,025		78,471
		Quarters Ended
		March 31,			June 30,			September 30,		December 31,
		2013			2013			2013		2013
	Total revenue	$	2,846		$	54,684		$	79,088	$	123,551
	Total costs and expenses	$	55,810		$	42,653		$	25,662	$	38,120
	Net income (loss) from operations	$	(52,964	)	$	12,031		$	53,426	$	85,431
	Net income (loss)	$	(51,911	)	$	12,351		$	42,333	$	64,237
	Net income (loss) per share: (1)
	Basic	$	(0.73	)	$	0.17		$	0.58	$	0.87
	Diluted	$	(0.73	)	$	0.16		$	0.55	$	0.82
	Shares used in computation of net income (loss) per share:
	Basic	70,933			72,953			73,316		73,868
	Diluted	70,933			77,194			77,659		77,917
	(1) Basic and diluted net income (loss) per share amounts are computed independently for each of the quarters presented.  Therefore, the sum of quarterly basic and diluted net income (loss) per share information may not equal annual basic and diluted net income (loss) per share.

Transition_Period_Comparative_

Transition Period Comparative Data (unaudited)	12 Months Ended
	Dec. 31, 2014
Income Statement [Abstract]
Transition Period Comparative Data (unaudited)	Transition Period Comparative Data (unaudited)
		(in thousands, except per share data)
		Six Months Ended December 31,
		2012			2011
					(unaudited)
	Statement of Operations Data:
	Revenue:
	License and milestone revenue	$	155,000		$	77,605
	Collaboration services revenue	5,658			335
	Total revenue	160,658			77,940
	Costs and expenses:
	Research and development	46,639			23,324
	Less: Excess Amounts related to Research and development (See Note 5)	(17,306		)	—
	Research and development, net	29,333			23,324
	Selling, general and administrative	12,093			7,294
	Less: Excess Amounts related to Selling, general and administrative (See Note 5)	(819		)	—
	Selling, general and administrative, net	11,274			7,294
	Total costs and expenses	40,607			30,618
	Income from operations	120,051			47,322
	Interest income	137			68
	Other expense, net	(8		)	(24		)
	Income before income taxes	120,180			47,366
	Income tax provision	(2,647		)	(5,651		)
	Net income	$	117,533		$	41,715
	Net income per share:
	Basic	$	1.69		$	0.61
	Diluted	$	1.58		$	0.58
	Weighted average shares used to compute net income (loss) per share:
	Basic	69,676			68,491
	Diluted	74,408			71,312
	Statement of Cash Flows Data:
	Net cash provided by (used in) operating activities	$	110,694		$	123,904
	Net cash (used in) provided by investing activities	(6,386		)	13,063
	Net cash provided by financing activities	5,229			5,490
	Increase in cash and cash equivalents	$	109,537		$	142,457

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS
	Kenneth A. Clark, a director of the Company since November 2012, is a member of the law firm of Wilson Sonsini Goodrich & Rosati (WSGR). The Company retains WSGR as legal counsel for various matters, primarily consisting of intellectual property matters. During the years ended December 31, 2014 and 2013, the Company made payments to WSGR of $3.7 million and $2.9 million, respectively. In addition, from the time that Mr. Clark was elected as a director on November 9, 2012 until December 31, 2012, the Company made payments to WSGR of approximately $0.4 million. As of December 31, 2014 and 2013, $1.3 million and $0.9 million, respectively, was included in accrued liabilities in the consolidated balance sheet for amounts due to WSGR.
	During the year ended June 30, 2012, the Company paid Dr. Gwen Fyfe, a former member of its Board of Directors, approximately $0.1 million for consulting services under a Consulting Agreement entered into prior to Dr. Fyfe joining the Company's Board in December 2010. The Company made no payments to Dr. Fyfe during the year ended December 31, 2014, the year ended December 31, 2013 or the six months ended December 31, 2012. In November 2011, the Company entered into an amendment (the “Amendment”) to its Consulting Agreement with Dr. Fyfe. The Amendment provided that Dr. Fyfe would receive a lump sum of $0.1 million and that she will continue to provide limited consulting services to the Company for a period of two years. Payment of the $0.1 million lump sum occurred in November 2011. In addition, the options to purchase 330,000 shares of the Company's common stock previously granted to Dr. Fyfe in connection with her consulting services continued to vest through November 30, 2011 and were to remain exercisable for a period of two years following the date of the Amendment. Dr. Fyfe did not stand for reelection at the Company's December 15, 2011 Annual Meeting of Stockholders. Options granted to Dr. Fyfe upon her initial election to the Board continued to vest through December 15, 2011; all such vested options and all additional options received by Dr. Fyfe in connection with her Board service were to remain exercisable for a period of three years from this date. During the year ended December 31, 2014, Dr. Fyfe exercised all remaining stock options.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	NOTE 18 – SUBSEQUENT EVENT
	In January 2015, the Company entered into a six month consulting services agreement with Dr. Robert Booth, a member of its Board of Directors (the Consulting Agreement). In addition, on January 22, 2015, Dr. Booth was granted 10,000 RSUs which vest over four years. The grant date fair value of the RSUs is $1.6 million based on the Company’s closing stock price on January 22, 2015. The Consulting Agreement provides for maximum payments to Dr. Booth of $0.1 million over the six month term and for the reimbursement of documented, authorized travel and out-of-pocket expenses.

Schedule_II_Valuation_and_Qual

Schedule II - Valuation and Qualifying Accounts and Reserves	12 Months Ended
	Dec. 31, 2014
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts and Reserves	Schedule II - Valuation and Qualifying Accounts and Reserves
	Schedule II: Valuation and Qualifying Accounts and Reserves
	(in thousands)
		Balance at Beginning of Period		Additions		Write-offs/Adjustments			Balance at End of Period
	Income Tax Valuation Allowance:
	Fiscal year ended December 31, 2014	$	58,679	$	11,671	$	—		$	70,350
	Fiscal year ended December 31, 2013	$	31,915	$	26,764	$	—		$	58,679
	Six months ended December 31, 2012	$	70,001	$	—	$	(38,086	)	$	31,915
	Fiscal year ended June 30, 2012	$	79,161	$	—	$	(9,160	)	$	70,001
	Allowance for Cash Discounts and Other Programs:
	Fiscal year ended December 31, 2014	$	301	$	26,641	$	(18,332	)	$	8,610
	Fiscal year ended December 31, 2013	$	—	$	371	$	(70	)	$	301
	Six months ended December 31, 2012	$	—	$	—	$	—		$	—
	Fiscal year ended June 30, 2012	$	—	$	—	$	—		$	—
	Allowance for Doubtful Accounts:
	Fiscal year ended December 31, 2014	$	—	$	14	$	—		$	14
	Fiscal year ended December 31, 2013	$	—	$	—	$	—		$	—
	Six months ended December 31, 2012	$	—	$	—	$	—		$	—
	Fiscal year ended June 30, 2012	$	—	$	—	$	—		$	—

Significant_Accounting_Policie1

Significant Accounting Policies - (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Change in Fiscal Year End	Change in Fiscal Year End
	On November 14, 2012, the Board of Directors approved a change in the fiscal year end from June 30 to December 31, effective December 31, 2012. All references to "fiscal years", unless otherwise noted, refer to the twelve-month fiscal year, which prior to July 1, 2012, ended on June 30, and beginning on January 1, 2013, ends on December 31, of each year.
Reclassification	Reclassification
	Certain prior year balances were reclassified to conform to the current year's presentation. None of these reclassifications had an impact on reported financial position or cash flows for any of the periods presented.
Management's use of estimates and assumptions	Management's use of estimates and assumptions
	The preparation of financial statements in accordance with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reported period. Actual results could differ from those estimates.
Basic and diluted net income per share	Basic and diluted net income per share
	Basic net income per share is computed using the weighted average number of common shares outstanding during the period. Diluted net income per share is computed using the weighted average number of shares of common stock outstanding during the period increased to include the number of additional shares of common stock that would have been outstanding if the potentially dilutive securities had been issued. Potentially dilutive securities include outstanding stock options, including performance-based stock options and restricted stock units for which performance criteria have been achieved, restricted stock units with time-based vesting and shares to be purchased under the employee stock purchase plan. The dilutive effect of potentially dilutive securities is reflected in diluted net income per common share by application of the treasury stock method. Under the treasury stock method, an increase in the fair market value of the Company's common stock can result in a greater dilutive effect from potentially dilutive securities.
Cash and cash equivalents	Cash and cash equivalents
	All highly liquid investments purchased with an original maturity date of three months or less that are readily convertible into cash and have an insignificant interest rate risk are considered to be cash equivalents.
Marketable securities	Marketable securities
	The Company's marketable securities are classified as “available-for-sale”. The Company includes these investments in current assets and carry them at fair value.  Unrealized gains and losses on available-for-sale securities are included in accumulated other comprehensive loss.  The amortized cost of debt securities is adjusted for the amortization of premiums and accretion of discounts to maturity.  Such amortization is included in interest income.  Gains and losses on securities sold are recorded based on the specific identification method and are included in other expense, net in the consolidated statement of operations.
	Management assesses whether declines in the fair value of marketable securities are other than temporary.  If the decline is judged to be other than temporary, the cost basis of the individual security is written down to fair value and the amount of the write down is included in the statement of operations within other expense, net. In determining whether a decline is other than temporary, management considers various factors including the length of time and the extent to which the market value has been less than cost, the financial condition and near-term prospects of the issuer and the Company's intent and ability to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in market value. To date, the Company has not recorded any impairment charges on marketable securities related to other-than-temporary declines in market value.
Fair value measurements	Fair value measurements
	The fair value of the Company's financial assets is determined by using three levels of input which are defined as follows:
	Level 1 - Quoted prices in active markets for identical assets. At December 31, 2014, the Company's Level 1 assets were comprised of money market funds. At December 31, 2013, the Company's Level 1 assets were comprised of U.S. treasury securities and money market funds.
	Level 2 - Observable inputs other than Level 1 prices such as quoted prices for similar assets, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets. The Company's short-term investments primarily utilize broker quotes in markets with infrequent transactions for valuation of these securities. At December 31, 2014 and December 31, 2013, the Company's Level 2 assets were comprised of FDIC insured certificates of deposit.
	Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets. At December 31, 2014 and December 31, 2013, the Company did not hold any Level 3 assets.
	The Company utilizes the market approach to measure fair value for its financial assets. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets.
Fair value of financial instruments	Fair value of financial instruments
	Cash and cash equivalents and marketable securities are carried at fair value. Accounts receivable, net, receivables from collaboration partners, accounts payable and accrued liabilities are valued at their carrying amounts, which approximate fair value due to their short-term nature.
Restricted investments	Restricted investments
	Under one of its facilities lease agreements, the Company is required to maintain a $0.3 million letter of credit as security for performance under the lease. The letter of credit is secured by a $0.3 million certificate of deposit which is included in Other assets at December 31, 2014 and December 31, 2013.
Accounts Receivable, net	Accounts Receivable, net
	Accounts receivable, net represents amounts due to the Company from sales of IMBRUVICA. The Accounts receivable balance is recorded net of allowances which generally include wholesaler chargebacks from third-party payers including government and other programs, cash discounts for prompt payment and doubtful accounts. Estimates for wholesaler chargebacks, cash discounts and prompt payment discounts are based on contractual payment terms and the Company's expectations about utilization rates for these programs. The Company's estimate of the allowance for doubtful accounts is based on the creditworthiness of its customers, historical payment patterns, the aging of accounts receivable balances and general economic conditions. Accounts receivables balances are written off against the allowance when it is probable that the receivable will not be collected (see Note 4).
Inventory valuation and related reserves	Inventory valuation and related reserves
	Inventories are stated at the lower of cost or market value with the approximate cost being determined on a first-in, first-out basis. Costs capitalized as inventories include third-party manufacturing costs and labor costs for personnel involved in the manufacturing process.
	During the year ended December 31, 2013, the Company began capitalizing costs associated with manufacturing inventory as a result of the FDA approval for IMBRUVICA. Until September 30, 2013, all inventory costs incurred were recorded as research and development expense in the consolidated statements of operations.
	Products that have been approved by the FDA or other regulatory agencies, such as IMBRUVICA, are also used in clinical programs to assess the safety and efficacy of the products for usage in diseases that have not been approved by the FDA or other regulatory authorities. The form of IMBRUVICA (i.e., raw materials and active pharmaceutical ingredient (API)) utilized for both commercial and clinical programs is identical and, as a result, the inventory has an "alternative future use" as defined in authoritative guidance. Raw materials and purchased drug product associated with clinical development programs are included in inventory and charged to research and development expense when the product enters the research and development process and can no longer be used for commercial purposes and, therefore, does not have "alternative future use."
	The Company evaluates inventory levels quarterly to determine if the inventory has a cost basis in excess of its expected net realizable value, inventory has expired, inventory on-hand is in excess of expected sales forecasts, and/or inventory that does not meet its quality specifications. The Company's raw materials and API has no expiration date and can be revalidated for use after testing. The Company's finished goods inventory currently has an estimated life of 24 months and, based on the Company's sales forecasts, it expects to realize the carrying value of the IMBRUVICA inventory. If any impairment of inventory is identified, the related inventory is written down with a corresponding charge to cost of goods sold in the period that the inventory impairment is first identified. The Company's inventory valuation reserve balance was zero as of December 31, 2014 and December 31, 2013, respectively.
	Inventories consist of raw materials, work-in-process and finished goods related to the production of IMBRUVICA. Raw materials include IMBRUVICA API. Work-in-process includes third-party manufacturing and associated labor costs relating to the Company’s personnel involved in the production process. Included in inventories are raw materials and work-in-process that may be used as clinical products, which are charged to research and development expense when the product enters the research and development process.
Advances to manufacturers	Advances to manufacturers
	The Company records cash advances that it pays prior to the receipt of inventory as advances to manufacturers in the consolidated balance sheets. The cash advances may be forfeited if the Company terminates the scheduled production. The Company expects the carrying value of the advances to manufacturers to be fully realized.
Concentration of credit risk and other risks and uncertainties	Concentration of credit risk and other risks and uncertainties
	Financial instruments that potentially subject the Company to credit risk consist principally of cash, cash equivalents, marketable securities, accounts receivable, net and receivables from collaboration partners. The Company places its cash and cash equivalents with high-credit quality financial institutions and invests in debt instruments of financial institutions, corporations and government entities with strong credit ratings. The Company's management believes it has established guidelines relative to credit quality, diversification and maturities that maintain safety and liquidity.
	The Company sells IMBRUVICA through a limited number of specialty pharmacies and specialty distributors. Therefore, the Company's accounts receivable balance is comprised of amounts due from a small number of customers. The Company continuously monitors the creditworthiness of its customers and has internal policies regarding customer credit limits. The Company's policy is to estimate the allowance for doubtful accounts based on the credit worthiness of its customers, historical payment patterns, the aging of accounts receivable balances and general economic conditions. For the year ended December 31, 2014, four individual customers accounted for 25%, 22%, 19% and 15% of accounts receivable, net, respectively. For the year ended December 31, 2013, three individual customers accounted for 26%, 26%, and 16% of accounts receivable, net, respectively.
	As of December 31, 2014, Company had $27.0 million receivable from Janssen, which consisted primarily of a milestone receivable of $20.0 million, $3.9 million related to material and product sales and $1.7 million related to value added taxes (see Note 5). As of December 31, 2013, the Company's receivable from collaboration partner balance of $52.0 million was comprised primarily of $50.2 million due from Janssen under the collaboration agreement. To date, the Company has not experienced credit losses from its receivables from collaborative partners, including Janssen. The amounts receivable from Janssen are included within Receivable from collaboration partners on the consolidated balance sheets.
	The Company's products require approvals from the FDA and international regulatory agencies prior to commercial sales. Although the FDA has approved IMBRUVICA as a single agent for the treatment of patients with mantle cell lymphoma who have received at least one prior therapy, the Company's prospects are largely dependent on (a) successful commercialization of IMBRUVICA in the U.S. to treat patients with MCL who have received at least one prior therapy, (b) obtaining regulatory approval of, and successfully commercializing, IMBRUVICA outside the U.S. to treat patients with MCL who have received at least one prior therapy, and (c) obtaining regulatory approval of, and successfully commercializing, IMBRUVICA both in and outside the U.S. to treat other indications. If the Company is unsuccessful in achieving any one or more of these critical business objectives, its ability to generate significant revenue or achieve profitability will be adversely affected and its business may fail. Further, there can be no assurance that the Company's other product candidates will receive required approvals. If the Company was denied such approvals or such approvals were delayed, it could have a materially adverse impact on the Company and the execution of its business strategy.
	The Company has expended and will continue to expend substantial funds for the commercialization, manufacturing, marketing and sales of IMBRUVICA and to complete the research, development and clinical testing of investigational uses of IMBRUVICA and additional products. The Company may be unable to entirely fund these efforts with its current financial resources and may require additional funds to continue to develop and commercialize its products. Additional funds may not be available on acceptable terms, if at all. If adequate funds are unavailable on a timely basis from operations or additional sources of financing, the Company may have to delay, reduce the scope of or eliminate one or more of its research or development programs which would materially and adversely affect its business, financial condition and operations.
Property and equipment	Property and equipment
	Property and equipment are stated at cost. Equipment is depreciated by the straight-line method over the estimated useful lives of the assets, generally 2 to 5 years. Furniture and fixtures are depreciated by the straight-line method over the estimated useful lives of the assets, generally 5 years. Leasehold improvements are generally amortized by the straight-line method over the shorter of the life of the related asset or the term of the underlying lease. Assets not yet placed in use are not depreciated. Substantially all of the Company's property and equipment is located within the U.S.
Long-lived assets	Long-lived assets
	The Company evaluates long-lived assets (including finite-lived intangible assets) for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable. In accordance with Accounting Standards Codification (ASC) ASC 350-10, Goodwill and Other Intangible Assets, intangible assets with estimable useful lives are amortized over their respective estimated useful lives, and reviewed for impairment in accordance with ASC 360-10, "Accounting for the Impairment or Disposal of Long-Lived Assets." The Company reviews long-lived assets, such as acquired intangibles and property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The Company measures recoverability of assets to be held and used by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, the Company recognizes an impairment charge at the amount by which the carrying amount of the asset exceeds the fair value of the asset. The Company's impairment review requires significant judgment with respect to future revenue and expense growth rates, selection of appropriate discount rate and other assumptions and estimates. No significant impairment losses have been recorded to date with respect to the Company's long-lived assets (see Note 8).
Donations to Third-Party Patient Assistance Foundations	Donations to Third-Party Patient Assistance Foundations
	The Company provides cash and product donations to independent third-party patient assistance foundations that, in turn, make grants to help qualifying patients meet their out-of-pocket costs (including co-pay payments or co-insurance obligations) in connection with their use of the Company's products as well as those of other pharmaceutical and biotechnology companies. These independent patient assistance foundations maintain their own patient eligibility criteria and independently determine what type of assistance patients may qualify for. Given the non-reciprocal nature of these transactions with parties who are not considered direct or indirect customers, and for which the Company does not receive any consideration, and the fact that the donation of cash does not have any conditions attached to the donation, the Company accounts for the cash donations as a component of selling, general and administrative expenses in the consolidated statements of operations.
Collaboration Revenues	Collaboration Revenues
	Revenue under the Company's license and collaboration arrangements is recognized based on the performance requirements of the contract. Determinations of whether persuasive evidence of an arrangement exists and whether delivery has occurred or services have been rendered are based on management’s judgments regarding the fixed nature of the fees charged for deliverables and the collectability of those fees. Should changes in conditions cause management to determine that these criteria are not met for any new or modified transactions, revenue recognized could be adversely affected.
	The Company recognizes revenue related to collaboration and license arrangements in accordance with the provisions of Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, Topic 605-25, “Revenue Recognition – Multiple-Element Arrangements,” or ASC Topic 605-25. Additionally, the Company adopted, effective July 1, 2010, Accounting Standards Update, or ASU, No. 2009-13, “Multiple Deliverable Revenue Arrangements,” or ASU 2009-13, which amended ASC Topic 605-25 and:
	•	provided guidance on how deliverables in an arrangement should be separated and how the arrangement consideration should be allocated to the separate units of accounting;
	•	required an entity to determine the selling price of a separate deliverable using a hierarchy of (i) vendor-specific objective evidence, or VSOE, (ii) third-party evidence, or TPE, or (iii) best estimate of selling price, or BESP; and
	•	required the allocation of the arrangement consideration, at the inception of the arrangement, to the separate units of accounting based on relative fair value.
	The Company evaluates all deliverables within an arrangement to determine whether or not they provide value on a stand-alone basis. Based on this evaluation, the deliverables are separated into units of accounting. The arrangement consideration that is fixed or determinable at the inception of the arrangement is allocated to the separate units of accounting based on their relative selling prices. The Company may exercise significant judgment in determining whether a deliverable is a separate unit of accounting, as well as in estimating the selling prices of such unit of accounting.
	To determine the selling price of a separate deliverable, the Company uses the hierarchy as prescribed in ASC Topic 605-25 based on VSOE, TPE or BESP. VSOE is based on the price charged when the element is sold separately and is the price actually charged for that deliverable. TPE is determined based on third-party evidence for a similar deliverable when sold separately and BESP is the price at which the Company would transact a sale if the elements of collaboration and license arrangements were sold on a stand-alone basis. The Company may not be able to establish VSOE or TPE for the deliverables within collaboration and license arrangements, as the Company does not have a history of entering into such arrangements or selling the individual deliverables within such arrangements separately. In addition, there may be significant differentiation in these arrangements, which indicates that comparable third-party pricing may not be available. The Company may determine that the selling price for the deliverables within collaboration and license arrangements should be determined using BESP. The process for determining BESP involves significant judgment on the Company's part and includes consideration of multiple factors such as estimated direct expenses and other costs, and available data.
	For collaborations entered into after July 1, 2010, the Company has determined its best estimate of selling prices for the license unit of accounting based on the income approach as defined in ASC 820-10-35-32. This measurement is based on the value indicated by current estimates about those future amounts and reflects management determined estimates and assumptions. These estimates and assumptions include, but are not limited to, how a market participant would use the license, estimated market opportunity and expected market share and assumed royalty rates that would be paid for sales resulting from products developed using the license, similar arrangements entered into by third parties and entity-specific factors such as the terms of the Company's previous collaborative agreement, the Company's pricing practices and pricing objectives, the likelihood that clinical trials will be successful, the likelihood that regulatory approval will be received and that the products will become commercialized and the markets served. The Company has also determined BESP for services-related deliverables based on the nature of the services to be performed and estimates of the associated effort as well as estimated market rates for similar services.
	For each unit of accounting identified within an arrangement, the Company determines the period over which the performance obligation occurs. Revenue is then recognized using either a proportional performance or straight-line method. The Company recognizes revenue using the proportional performance method when the level of effort to complete our performance obligations under an arrangement can be reasonably estimated. Direct labor hours or full time equivalents are typically used as the measurement of performance.
	Effective July 1, 2010, the Company adopted ASU No. 2010-17, “Milestone Method of Revenue Recognition,” or ASU 2010-17, which provides guidance on revenue recognition using the milestone method. Under the milestone method, a payment that is contingent upon the achievement of a substantive milestone is recognized in the period in which the milestone is achieved. The determination that a milestone is substantive is subject to considerable judgment.
Costs of goods sold	Cost of goods sold
	Cost of goods sold includes third-party manufacturing costs of products sold, fixed manufacturing overhead, royalty fees, and other indirect costs such as personnel compensation.
	During the fiscal year 2013, the Company began capitalizing costs associated with manufacturing inventory as a result of the FDA approval of IMBRUVICA for MCL on November 13, 2013. Until September 30, 2013, all inventory costs incurred were recorded as research and development expense in the consolidated statements of operations. This zero cost inventory primarily consisted of raw materials for which the shelf-life has not yet started.
Research and development expense	Research and development expense
	Research and development expenses include personnel and facility-related expenses, outside contracted services including clinical trial costs, manufacturing and process development costs, research costs and other consulting services. Research and development costs are expensed as incurred. Nonrefundable advance payments for goods or services that will be used or rendered for future research and development activities are deferred and amortized over the period that the goods are delivered or the related services are performed, subject to an assessment of recoverability.
	Clinical development costs are a significant component of research and development expenses. The Company has a history of contracting with third parties that perform various clinical trial activities on its behalf in the ongoing development of its product candidates. The financial terms of these contracts are subject to negotiations and may vary from contract to contract and may result in uneven payment flow. The Company accrues and expenses costs for clinical trial activities performed by third parties based upon estimates of the percentage of work completed over the life of the individual study in accordance with agreements established with contract research organizations and clinical trial sites. The Company determines its estimates through discussions with internal clinical personnel and outside service providers as to the progress or stage of completion of trials or services and the agreed upon fee to be paid for such services.
	The Company's worldwide collaboration and license agreement with Janssen (the Agreement) includes a cost sharing arrangement for certain collaboration activities. Except in certain cases, in general Janssen is responsible for approximately 60% of collaboration development costs and the Company is responsible for the remaining 40% of collaboration development costs. Further, the Agreement provides the Company with a $50.0 million annual cap of its share of collaboration costs and pre-tax commercialization losses for each calendar year until after the third profitable calendar quarter for the product and any amounts in excess of the annual cap (Excess Amounts) are funded by Janssen. Under the Agreement, total Excess Amounts plus interest may not exceed $225.0 million.
	The Company's policy is to account for cost-sharing payments to Janssen related to development services as a component of research and development expense and reimbursements for development services under the cost-sharing arrangement as an offset to research and development expense, upon delivery of the related services when expenses have been incurred and reimbursements have been earned. During the year ended December 31, 2013 and the six months ended December 31, 2012, the Company recognized Excess Amounts related to development services as a reduction to research and development expenses. The Company recognizes Excess Amounts as a reduction to Costs and expenses as the Company's payment of Excess Amounts to Janssen is contingent and would become payable only after the third profitable calendar quarter for the product. Further, Excess Amounts shall be reimbursable only from the Company's share of pre-tax profits after the third profitable calendar quarter for the product (see Note 5).
Selling, general and administrative expense	Selling, general and administrative expense
	The Company expenses the cost of selling, general and administrative activities as incurred. Selling, general and administrative expenses consist primarily of personnel and facility-related expenses, outside contracted services and other costs not associated with the research and development activities of the Company. In connection with the Agreement, the Company also classifies certain commercial-related collaboration costs within Selling, general and administrative expense in the consolidated statements of operations. Costs under the Agreement that are recorded within selling, general and administrative expense are generally shared 50% by the Company and 50% by Janssen and include marketing costs, patent costs and the Company's share of pre-tax commercial losses on sales of IMBRUVICA.
	During the year ended December 31, 2013 and the six months ended December 31, 2012, the Company recognized Excess Amounts related to certain collaboration costs as a reduction to selling, general and administrative expenses (see Note 5).
Income taxes	Income taxes
	The Company is subject to income taxes in both the U.S. and foreign jurisdictions, and it uses estimates in determining its provisions for income taxes. The Company provides for income taxes using the asset and liability method, whereby deferred tax assets or liability account balances are calculated at the balance sheet date using current tax laws and rates in effect for the year in which the differences are expected to affect taxable income. Recognition of deferred tax assets is appropriate when realization of such assets is more likely than not. The Company recognizes a valuation allowance against its net deferred tax assets if it is more likely than not that some portion of the deferred tax assets will not be fully realizable. This assessment requires judgment as to the likelihood and amounts of future taxable income by tax jurisdiction.
	The Company applies the provisions of FASB's guidance on accounting for uncertainty in income taxes. The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and the tax benefit to be recognized is measured at the largest amount of benefit that is greater than 50 percent likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized tax benefit is still appropriate. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available.
Share-based compensation	Stock-based compensation
	Stock-based compensation cost for employee and director stock options with time-based vesting and employee stock plan purchase rights is generally measured and recognized based on the fair value of the award at the grant date. Stock-based compensation cost for restricted stock units (RSUs) with time-based vesting is measured based on the closing fair market value of the Company's common stock on the date of the grant, multiplied by the number of RSUs granted. The accounting grant date for employee stock options and restricted stock units with performance obligations is the date on which the performance goals have been defined and a mutual understanding of the terms has been reached. Generally, the Company's time-based stock option and RSU grants vest over a four year period. Stock options and RSUs with performance obligations generally vest over a four year period, with the goals set and agreed upon annually. Stock-based compensation for non-employee stock options is re-estimated at each period-end through the vesting date. The Company estimates a forfeiture rate to calculate the stock-based compensation cost for its awards primarily based on an analysis of its historical pre-vesting forfeitures.
	The fair value of each stock option is estimated using the Black Scholes option-pricing model. Expected volatility is based on historical volatility data of the Company's stock. The expected term of stock options granted represents the period of time that stock options are expected to be outstanding.  The Company generally does not expect substantially different exercise or post-vesting termination behavior among its employee or non-employee population. As such, for the majority of stock options granted and the Company's Employee Stock Purchase Plan, the Company generally calculates and applies an overall expected term assumption based on historical data. In certain cases, the Company uses a shorter expected term for performance-based stock options based on a combination of historical data and management's estimates of the period of time that options will be outstanding. The risk-free interest rate is based on a zero-coupon U.S. Treasury bond whose maturity period equals the expected term of the Company's options.
	Options and RSUs vest upon the passage of time or a combination of time and the achievement of certain performance obligations. Vesting of performance-based options and RSUs for executive officers depends on their attainment of key corporate and departmental goals. The Compensation Committee of the Board of Directors will determine if the performance conditions have been met. Stock-based compensation expense for the options and RSUs with performance obligations is recorded when the Company believes that the vesting of these options and RSUs is probable.
Shipping and handling costs	Shipping and handling costs
	Shipping and handling costs incurred for inventory purchases and product shipments are recorded in Selling, general and administrative, net in the consolidated statements of income.
Advertising expenses	Advertising expenses
	The Company expenses the costs of advertising, including promotional expenses, as incurred. The Company began incurring advertising expenses during the year ended December 31, 2014 due to the commercialization of IMBRUVICA on November 13, 2013.
Segment reporting	Segment reporting
	Operating segments are defined as components of an enterprise that engage in business activities for which separate financial information is available and evaluated by the chief operating decision maker in deciding how to allocate resources and assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer (CEO). The Company operates as a single reportable segment, which primarily focuses on developing and commercializing novel therapies for the treatment of cancer and immune-mediated diseases. Product revenue, net is attributed to geography based upon the country in which the product is delivered. Long-lived assets are attributed to geography based on the country where the assets are located.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In April 2014, the FASB issued ASU 2014-08, "Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity", or ASU 2014-08. Under ASU 2014-08, only disposals representing a strategic shift in operations should be presented as discontinued operations. Those strategic shifts should have a major effect on the organization’s operations and financial results. Additionally, ASU 2014-08 requires expanded disclosures about discontinued operations that will provide financial statement users with more information about the assets, liabilities, income, and expenses of discontinued operations. ASU 2014-08 is effective for fiscal and interim periods beginning on or after December 15, 2014, with early adoption permitted. The Company will adopt the provisions of ASU 2014-08 beginning with the Company’s fiscal 2015.
	In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers (Topic 606)," which provides guidance for revenue recognition. This ASU will supersede the revenue recognition requirements in Topic 605, Revenue Recognition, and most industry-specific guidance. The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under today’s guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. This standard is effective for annual and interim reporting periods beginning after December 15, 2016. Early adoption is not permitted. The Company is currently evaluating the impact of the adoption of this accounting standard on its consolidated financial statements.
	In June 2014, the FASB issued ASU 2014-12, "Accounting for Stock-based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period." ASU 2014-12 requires that a performance target that affects vesting and could be achieved after the requisite service period be treated as a performance condition. This new guidance is effective for fiscal years and interim periods within those years beginning after December 15, 2015. Early adoption is permitted. This standard is not expected to have any impact on current disclosures in the consolidated financial statements.
	In August 2014, the FASB issued ASU 2014-15, "Presentation of Financial Statements - Going Concern, which requires management to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and provide related footnote disclosures." ASU 2014-15 is effective for annual and interim reporting periods beginning on or after December 15, 2016. Early adoption is permitted for financial statements that have not been previously issued. The standard allows for either a full retrospective or modified retrospective transition method. The Company does not expect this standard to have a any impact on the Company’s consolidated financial statements upon adoption.
	In November 2014, the FASB issued ASU 2014-17, "Business Combinations (Topic 805): Pushdown Accounting (a consensus of the FASB Emerging Issues Task Force)." ASU 2014-17 provides an acquired entity with an option to apply pushdown accounting in its separate financial statements upon occurrence of an event in which an acquirer obtains control of the acquired entity. An acquired entity may elect the option to apply pushdown accounting in the reporting period in which the change-in-control event occurs. This new standard is effective on November 18, 2014.  Early application is prohibited.  After the effective date, an acquired entity can make an election to apply the guidance to future change-in-control events or to its most recent change-in-control event. However, if the financial statements for the period in which the most recent change-in-control event occurred already have been issued or made available to be issued, the application of this guidance would be a change in accounting principle. The Company has adopted this new guidance and there's no impact on its consolidated financial statements.

Significant_Accounting_Policie2

Significant Accounting Policies - (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Schedule of Inventory	The components of inventory are as follows (in thousands):
		As of December 31,
		2014		2013
	Raw materials	$	—	$	8,007
	Work-in-process	27,591		3,489
	Finished goods	6,855		1,107
		$	34,446	$	12,603

Product_Revenue_Net_Tables

Product Revenue, Net - (Tables)	12 Months Ended
	Dec. 31, 2014
Revenues [Abstract]
Schedule of Product Revenue, Net	For the years ended December 31, 2014 and December 31, 2013, product revenue, net was calculated as follows (in thousands):
		Years Ended December 31,
		2014				2013
	Product revenue, gross	$	553,143			$	14,968
	Government rebates, return reserve and other	(34,502		)		(1,024		)
	Chargebacks and cash discounts	(26,223		)		(371		)
	Product revenue, net	$	492,418			$	13,573
Schedule of Provisions, Credits and Payments	The following table summarizes the provisions, and credits/payments, for product revenue, net adjustments for the years ended December 31, 2014 and December 31, 2013 (in thousands):
		Total
	2013
	Beginning Balance	$	—
	Provision related to current period sales	1,395
	Credits/payments	(189		)
	Ending Balance	$	1,206
	2014
	Beginning Balance	$	1,206
	Provision related to current period sales	60,725
	Credits/payments	(35,196		)
	Ending Balance	$	26,735
Schedules of Customers Who Represented 10% or More of the Company's Product Revenue, Net	The following table sets forth customers who represented 10% or more of the Company's product revenue, net for the years ended December 31, 2014 and December 31, 2013.
		Years Ended December 31,
	Customers:	2014			2013
	A	30	%		24	%
	B	20	%		15	%
	C	15	%		12	%
	D	14	%		20	%
	E	11	%		12	%

Accounts_Receivable_Net_Tables

Accounts Receivable, Net - (Tables)	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Schedule of Accounts Receivable, Net	Accounts receivable, net includes (in thousands):
		As of December 31,
		2014			2013
	Accounts receivable, gross	$	72,921		$	11,345
	Allowance for doubtful accounts	(14		)	—
	Allowance for chargebacks related to government and other programs	(7,105		)	(72		)
	Allowance for cash discounts	(1,505		)	(229		)
	Accounts receivable, net	$	64,297		$	11,044

Collaboration_and_Other_Agreem1

Collaboration and Other Agreements - (Tables)	12 Months Ended
	Dec. 31, 2014
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Schedule of Collaborative and License Arrangements	The Company recognized revenue related to its collaboration and license arrangements as follows (in thousands):
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	Janssen	$	237,164		$	245,970		$	154,878		$	74,622
	Les Laboratoires Servier (Servier)	139			159			93			7,157
	Novo Nordisk A/S (Novo Nordisk)	8			454			5,631			—
	Other	—			13			56			211
	Total	$	237,311		$	246,596		$	160,658		$	81,990
Janssen [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Schedule of Collaborative and License Arrangements	Under the Agreement, the Company recorded Excess Amounts as follows:
			Years Ended						Six			Year Ended
			December 31,						Months Ended			June 30,
									December 31,
			2014			2013			2012			2012
	Research and development		$	—		$	85,732		$	17,306		$	—
	General and administrative		—			30,405			819			—
	Total Excess Amounts		$	—		$	116,137		$	18,125		$	—
	Janssen Collaboration Cost Sharing and Excess Amounts
	The Company recognized development costs under the collaboration as a component of Research and development expense, net in the consolidated statements of operations. The Company also recognized certain selling, general and administrative expenses under the collaboration, including marketing costs, patent costs and the Company's share of pre-tax commercial losses on sales of IMBRUVICA outside of the U.S. as a component of Selling, general and administrative, net in the consolidated statements of operations. Expenses which were charged to the collaboration are as follows (in thousands):
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	Collaboration expenses, unadjusted	$	155,027		$	175,567		$	57,690		$	43,272
	Increase (decrease) for cost sharing	(40,121		)	(48,223		)	(17,339		)	(18,381		)
	Excess Amounts	—			(85,732		)	(17,306		)	—
	Research and development, net	$	114,906		$	41,612		$	23,045		$	24,891
	Collaboration expenses, unadjusted	$	88,110		$	28,118		$	2,426		$	1,070
	Increase (decrease) for cost sharing	5,775			10,675			247			(4		)
	Excess Amounts	—			(30,405		)	(819		)	—
	Selling, general and administrative, net	$	93,885		$	8,388		$	1,854		$	1,066
	License and milestone revenue recognized with respect to the Agreement with Janssen consisted of the following (in thousands):
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	License revenue	$	—		$	—		$	—		$	70,605
	Approval milestone revenue	170,000			60,000			—			—
	Regulatory milestone revenue	50,000			125,000			—			—
	Development milestone revenue	—			50,000			150,000			—
	Total	$	220,000		$	235,000		$	150,000		$	70,605
	The Company's net profit (loss) under the Agreement for its first and second profitable quarters for the collaboration was calculated as follows (in thousands):
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	50% of Pharmacyclics' U.S. product revenue, net	$	246,209		$	—		$	—		$	—
	Less: 50% of Pharmacyclics' U.S. cost of goods sold	(20,205		)	—			—			—
	Pharmacyclics' 50% share of U.S. net product revenue, less cost of goods sold	226,004			—			—			—
	Less: Pharmacyclics' share of U.S. commercial expenses under the Agreement	(70,597		)	(8,006		)	(1,073		)	(1,058		)
	Pharmacyclics' share of U.S. pre-tax profits from the commercialization of IMBRUVICA under the Agreement	155,407			(8,006		)	(1,073		)	(1,058		)
	Less: Pharmacyclics' share of outside-U.S. pre-tax commercial loss under the Agreement	(23,288		)	(382		)	(781		)	(8		)
	Pharmacyclics' share of worldwide pre-tax profits from the commercialization of IMBRUVICA under the Agreement	132,119			(8,388		)	(1,854		)	(1,066		)
	Less: Pharmacyclics' share of world-wide research and development expenses under the Agreement	(114,906		)	(41,612		)	(23,045		)	(24,891		)
	Pharmacyclics' share of IMBRUVICA related pre-tax net profit under the Agreement	$	17,213		$	(50,000	)	$	(24,899	)	$	(25,957	)
	Total revenue recognized with respect to the Agreement consisted of the following (in thousands):
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	License and milestone revenue	$	220,000		$	235,000		$	150,000		$	70,605
	Collaboration services revenue	17,164			10,970			4,878			4,017
	Total	$	237,164		$	245,970		$	154,878		$	74,622
	For the year ended December 31, 2013, Janssen's 50% share of U.S. product revenue, net less cost of goods sold of IMBRUVICA of $5.0 million was fully absorbed by Excess Amounts funded by Janssen that were recorded as a reduction to selling, general and administrative, net. For the year ended December 31, 2014, the Company determined Janssen's 50% share of U.S. net product revenue less cost of goods sold of IMBRUVICA, which was included in costs of collaboration in the Company's consolidated statement of operations as follows (in thousands):
		Year Ended
		December 31,
		2014
	Product revenue, net	$	492,418
	Less: Cost of goods sold	40,410
		452,008
	Janssen's share of U.S. pre-tax commercial profits	50		%
	Total costs of collaboration (Janssen's 50% share under the Agreement)	$	226,004
	Pharmacyclics' 50% share of U.S. net product revenue less cost of goods sold	$	226,004
Servier [Member}
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Schedule of Collaborative and License Arrangements	Total revenue recognized with respect to the Company's collaboration and license agreement with Servier consisted of the following (in thousands):
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	License and milestone revenue	$	—		$	—		$	—		$	7,000
	Collaboration services revenue	139			159			93			157
	Total	$	139		$	159		$	93		$	7,157
Novo Nordisk [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Schedule of Collaborative and License Arrangements	Total revenue recognized with respect to the Company's license agreement with Novo Nordisk consisted of the following (in thousands):
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	License and milestone revenue	$	—		$	—		$	5,000		$	—
	Collaboration services revenue	8			454			631			—
	Total	$	8		$	454		$	5,631		$	—

Cash_Cash_Equivalents_and_Mark1

Cash, Cash Equivalents and Marketable Securities - (Tables)	12 Months Ended
	Dec. 31, 2014
Assets, Fair Value Disclosure [Abstract]
Schedule of Cash and Cash Equivalents	The following tables set forth the Company's cash, cash equivalents and marketable securities (in thousands):
		As of December 31,
		2014			2013
	Cash - Demand deposits	$	471,916		$	225,035
	Cash equivalents - money market funds	373,119			129,193
	Cash equivalents - U.S. treasury bills	—			269,488
	Cash equivalents - Certificates of deposit - FDIC insured	—			240
	Cash and cash equivalents	$	845,035		$	623,956
Schedule of Marketable Securities
		As of December 31,
		2014			2013
	Certificates of deposit - FDIC insured	$	11,952		$	11,672
	Marketable securities	$	11,952		$	11,672
Schedule of Available-for-sale Securities	The following is a summary of the Company's available-for-sale securities measured a amortized costs, gross unrealized gains, gross unrealized losses and fair value (in thousands):
	As of December 31, 2014		Amortized Cost			Gross Unrealized Gain			Gross Unrealized Loss				Fair Value
	Certificates of deposit – FDIC insured		$	11,960		$	—		$	(8	)		$	11,952
	Marketable Securities		$	11,960		$	—		$	(8	)		$	11,952
	As of December 31, 2013		Amortized Cost			Gross Unrealized Gain			Gross Unrealized Loss				Fair Value
	Certificates of deposit – FDIC insured		$	11,680		$	—		$	(8	)		$	11,672
	Marketable Securities		$	11,680		$	—		$	(8	)		$	11,672
Schedule of Marketable Securities	As of December 31, 2014, the Company's marketable securities had the following remaining contractual maturities (in thousands):
		Amortized Cost			Fair Value
	Less than one year	$	11,960		$	11,952
Schedule of Fair Value Measurements of the Company's Cash Equivalents and Available-for-sale Securities	The following table sets forth the basis of fair value measurements for the Company's cash equivalents and available-for-sale securities (in thousands):
		As of December 31, 2014
		Level 1			Level 2			Level 3				Fair Value
	Cash equivalents:
	Money market funds	$	373,119		$	—		$	—			$	373,119
	Marketable securities:
	Certificates of deposit- FDIC insured	—			11,952			—				11,952
		$	373,119		$	11,952		$	—			$	385,071
		As of December 31, 2013
		Level 1			Level 2			Level 3				Fair value
	Cash equivalents:
	U.S. treasury bills	$	269,488		$	—		$	—			$	269,488
	Money market funds	129,193			—			—				129,193
	Certificates of deposit - FDIC insured	—			240			—				240
	Marketable securities:
	Certificates of deposit - FDIC insured	—			11,672			—				11,672
		$	398,681		$	11,912		$	—			$	410,593

Balance_Sheet_Components_Table

Balance Sheet Components - (Tables)	12 Months Ended
	Dec. 31, 2014
Balance Sheet Related Disclosures [Abstract]
Schedule of Property Plant and Equipment	Property and equipment, net consists of the following (in thousands):
		As of December 31,
		2014			2013
	Equipment	$	13,363		$	11,827
	Leasehold improvements	9,951			5,493
	Furniture and fixtures	1,278			1,278
	Construction in progress	19,461			14,592
		44,053			33,190
	Less: Accumulated depreciation and amortization	(11,577		)	(7,719		)
		$	32,476		$	25,471
Schedule of Accounts Payable and Accrued Liabilities	Accrued liabilities consist of the following (in thousands):
		As of December 31,
		2014			2013
	Accrued payroll and employee related expenses	$	19,645		$	20,500
	Accrued discounts and rebates	18,125			906
	Accrued clinical related	14,806			17,062
	Accrued royalty to Celera (see Note 5)	10,646			949
	Accrued value added taxes	7,395			7,041
	Accrued outside services	5,114			5,077
	Accrued contract manufacturing	2,380			1,556
	Accrued marketing	1,288			—
	Accrued property and equipment purchases	934			4,039
	Accrued inventory	101			7,592
	Accrued other	7,845			6,466
		$	88,279		$	71,188
Schedule of Deferred Revenue	Deferred revenue consists of the following (in thousands):
	Current portion:	As of December 31,
		2014			2013
	Deferred revenue related to the Agreement (see Note 5)	$	11,656		$	7,505
	Deferred revenue from sales to collaboration partner (see Note 5)	7,117			76
		$	18,773		$	7,581
	Non-current portion:	As of December 31,
		2014			2013
	Deferred revenue related to the Agreement (see Note 5)	$	34,885		$	52,025

Intangible_Assets_Tables

Intangible Assets - (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Future Annual Amortization Expense	As of December 31, 2014, the future annual amortization expense for the Company's intangible assets is expected to be as follows (in thousands):
	Fiscal Year	Future Amortization of Intangible Assets
	2015	$	728
	2016	730
	2017	728
	2018	728
	2019	728
	Thereafter	5,088
	Total	$	8,730

Stockholders_Equity_Tables

Stockholders' Equity - (Tables)	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Schedule of Stock Option Activity	The following table summarizes stock option activity related to shares of common stock under the Company's stock option plans (in thousands, except per share amounts and years data):
			Options Outstanding
			Number of Options			Weighted Average Exercise Price per Share				Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value
	Balance at December 31, 2013		5,111			$	23.54
	Exercised		(1,682	)		11.93
	Granted		1,142			91.68
	Forfeited or expired		(371	)		59.84
	Balance at December 31, 2014		4,200			43.5				5.7		$	332,507
	Vested and expected to vest at December 31, 2014		4,073			$	41.72			6.6		$	328,684
Schedule of Restricted Stock Unit Activity	The following table summarizes restricted stock unit activity under the Company's 2014 Plan (in thousands, except per share amounts and years data):
			Number of Options			Weighted Average Grant Date Fair Value				Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value
	Outstanding at December 31, 2013		—			$	—
	Granted		211			114.98
	Vested and released		(13	)		121.89
	Forfeited		(10	)		100.09
	Outstanding and unvested at December 31, 2014		188			$	115.32			2		$	23,052
	Expected to vest at December 31, 2014		163			$	115.61			1.9		$	19,960
Schedule of components of share-based compensation	The components of stock-based compensation recognized in the Company's consolidated statements of operations were as follows (in thousands):
			Years Ended								Six			Year Ended June 30,
			December 31,								Months Ended
											December 31,
			2014				2013				2012			2012
	Cost of goods sold		$	1,453			$	436			$	—		$	—
	Research and development		22,710				24,041				5,357			6,947
	Selling, general and administrative		29,578				25,733				2,079			2,926
	Total stock-based compensation		$	53,741			$	50,210			$	7,436		$	9,873
Schedule of fair value assumptions used to calculate fair value of options	The fair value of each stock option is estimated using the Black Scholes option-pricing model. The expected term of stock options granted represents the period of time that stock options are expected to be outstanding.  The Company generally does not expect substantially different exercise or post-vesting termination behavior among its employee or non-employee population. As such, for the majority of stock options granted and the Company's Employee Stock Purchase Plan, the Company generally calculates and applies an overall expected term assumption based on historical data. In certain cases, the Company uses a shorter expected term for performance-based stock options based on a combination of historical data and management's estimates of the period of time that options will be outstanding. The risk-free interest rate is based on a zero-coupon U.S. Treasury bond whose maturity period equals the expected term of the Company's options.
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	Employee stock options (1):
	Expected dividend yield	—			—			—			—
	Expected stock price volatility (2)	46.9% - 67.4%			50.9% - 84.8%			51.5% - 85.5%			88	%
	Risk free interest rate (2)	0.7% - 1.8%			0.5% - 1.5%			0.3% - 0.8%			1	%
	Expected life (years) (2)	2.52 - 5.04			2.52 - 5.20			2.60 - 5.20			5
	Non-employee stock options:
	Expected dividend yield	—			—			—			—
	Expected stock price volatility	79	%		79	%		89	%		84% - 89%
	Risk free interest rate	2.6	%		1.9	%		3.89	%		2.00% - 3.89%
	Expected life (years)	10			10			8			8.10 – 10.00
	(1) The above table includes assumptions used in the valuation of performance-based stock option grants for which the Company set performance criteria during the period.
	(2) Amounts for the year ended June 30, 2012 are presented on a weighted average basis.
Schedule of outstanding, exercisable and vested stock options	A summary of outstanding, exercisable and vested stock options as of December 31, 2014 is as follows (in thousands, except per share amounts):
			Options Outstanding												Exercisable						Exercisable and Vested
	Range of Exercise Prices		Number of Shares			Weighted Average Remaining Contractual Life		Weighted Average Exercise Price Per Share				Aggregate Intrinsic Value			Number of Shares	Weighted Average Remaining Contractual Life	Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value		Number of Shares	Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value
	$0.75 - $6.49		837			4.28		$	2.57						837	4.28	$	2.57			822	$	2.5
	$6.52 - $12.00		851			5.41		$	7.73						831	5.43	$	7.67			815	$	7.61
	$12.10 - $32.38		863			6.78		$	20.28						796	6.76	$	20.28			489	$	18.62
	$36.73 - $86.78		924			7.72		$	68.11						924	7.72	$	68.11			437	$	66.52
	$87.19 - $102.22		1,013			9.11		$	96.07						91	8.58	$	90.62			91	$	90.62
	$102.77 - $151.48		521			9.26		$	119.51						44	8.69	$	113.87			43	$	113.87
			5,009			7.03		$	49.67			$	364,377		3,523	6.18	$	28.62	$	329,982	2,697	$	22.11	$	270,222
Schedule of weighted average fair value assumptions under employee stock purchase plan	Compensation cost is estimated using the Black Scholes option-pricing model using the weighted average assumptions noted in the following table:
		Years Ended						Six			Year Ended
		December 31,						Months Ended			June 30,
								December 31,
		2014			2013			2012			2012
	Expected dividend yield	—			—			—			—
	Stock price volatility	49	%		48	%		50	%		54	%
	Risk free interest rate	0.3	%		0.16	%		0.16	%		0.15	%
	Expected life (years)	1.59			1.1			0.68			1.14

Income_Taxes_Tables

Income Taxes - (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of components of income taxes	The components of the provision for income taxes are as follows (in thousands):
		Years Ended								Six			Year Ended
		December 31,								Months Ended			June 30,
										December 31,
		2014				2013				2012			2012
	Current:
	Federal	$	31,938			$	30,879			$	2,047		$	26
	State	4,294				202				599			—
	Foreign	91				45				1			13
	Total provision for income taxes	36,323				31,126				2,647			39
	Income before taxes	$	122,447			$	98,136			$	120,180		$	12,025
	Tax rate	29.66		%		31.72		%		2.2		%	0.33		%
Schedule of geographical breakdown of consolidated net income (loss) before income taxes by income tax jurisdiction	The following is a geographical breakdown of consolidated income before income taxes by income tax jurisdiction (in thousands):
		Years Ended								Six			Year Ended
		December 31,								Months Ended			June 30,
										December 31,
		2014				2013				2012			2012
	United States	$	100,270			$	70,254			$	69,563		$	(4,596	)
	Foreign	22,177				27,882				50,617			16,621
	Income before taxes	$	122,447			$	98,136			$	120,180		$	12,025
Schedule of deferred tax assets	Net deferred tax assets (liabilities) are summarized as follows (in thousands):
			As of December 31,
			2014				2013
	Deferred tax assets:
	Net operating loss carryforwards		$	4,546			$	3,552
	Tax credit carryforwards		25,978				26,110
	Capitalized research and development costs		200				230
	Depreciation and amortization		775				916
	Partnership investment		4,922				—
	Stock-based compensation		16,320				9,712
	Reserves and accruals		18,039				18,557
	Gross deferred tax assets		70,780				59,077
	Less: valuation allowance		(70,350		)		(58,679		)
	Net deferred tax assets		430				398
	Deferred tax liabilities:
	Depreciation		(430		)		(398		)
	Net Deferred tax assets		$	—			$	—
Schedule of statutory income tax	The provision for income taxes differs from the amount determined by applying the U.S. statutory income tax rate of 35% for the year ended December 31, 2014, year ended December 31, 2013, the six months ended December 31, 2012, and year ended June 30, 2012 to the income before income taxes as summarized below (in thousands):
		Years Ended								Six			Year Ended
		December 31,								Months Ended			June 30,
										December 31,
		2014				2013				2012			2012
	Tax provision (benefit) at statutory rate	$	42,857			$	34,347			$	42,064		$	4,209
	State Tax, net of federal benefit	3,156				202				389			—
	Research and development and orphan drug credits	(16,944		)		(21,774		)		—			(529		)
	Deferred tax assets benefited (not benefited)	7,151				28,376				(35,181		)	(5,727		)
	Stock-based compensation	4,532				5,261				1,056			2,009
	Other	3,238				744				(629		)	38
	Federal – alternative minimum tax	—				—				2,047			26
	Foreign taxes greater than (less than) U.S. rates	(7,667		)		(16,030		)		(7,099		)	13
		$	36,323			$	31,126			$	2,647		$	39
Schedule of activity related to gross unrecognized tax benefits	The following table summarizes the activity related to the Company's gross amounts of unrecognized tax benefits (in thousands):
		Years Ended								Six			Year Ended
		December 31,								Months Ended			June 30,
										December 31,
		2014				2013				2012			2012
	Beginning balance	$	15,976			$	2,845			$	2,307		$	1,726
	Additions based on tax positions related to current year	11,520				10,075				538			581
	Additions (reduction) for tax positions of prior years	(623		)		3,056				—			—
	Ending balance	$	26,873			$	15,976			$	2,845		$	2,307

Commitments_and_Contingencies_

Commitments and Contingencies - (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments	As of December 31, 2014, future minimum lease payments under non-cancelable operating leases are as follows (in thousands):
		Operating Lease Commitments
	2015	$	2,226
	2016	2,161
	2017	2,112
	2018	857
	2019	882
	Thereafter	2,890
	Total	$	11,128

Basic_and_Diluted_Net_Income_P1

Basic and Diluted Net Income Per Share - (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share, Basic and Diluted [Abstract]
Computation of Basic and Diluted Net Income Per Share	The computations of basic and diluted net income per share are as follows (in thousands, except per share amounts):
		Years Ended				Six		Year Ended
		December 31,				Months Ended		June 30,
						December 31,
		2014		2013		2012		2012
	Numerator:
	Net income	$	86,124	$	67,010	$	117,533	$	11,986
	Denominator:
	Weighted average common shares-basic	75,247		72,777		69,676		68,728
	Effect of dilutive securities:
	Employee stock options	2,873		4,237		4,607		3,781
	Employee stock purchase plan	16		69		125		108
	Restricted stock units	15		—		—		—
	Weighted average common shares - diluted	78,151		77,083		74,408		72,617
	Net income per share:
	Basic	$	1.14	$	0.92	$	1.69	$	0.17
	Diluted	$	1.1	$	0.87	$	1.58	$	0.17
	Potentially dilutive securities excluded from net income per share - diluted because their effect is anti-dilutive	1,243		848		445		441

Segment_Information_Tables

Segment Information - (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Schedule of Revenue from External Customers	he following table summarizes total revenue from external customers by geographic region, which consists of product revenue, net. IMBRUVICA first came to market on November 13, 2013.
		Years Ended				Six		Year Ended
		December 31,				Months Ended		June 30,
						December 31,
		2014		2013		2012		2012
	United States	$	492,418	$	13,573	$	—	$	—
	Other	—		—		—		—
	Total	$	492,418	$	13,573	$	—	$	—

Quarterly_Results_Unaudited_Ta

Quarterly Results (Unaudited) - (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following table is in thousands, except per share amounts:
		Quarters Ended
		March 31,			June 30,			September 30,		December 31,
		2014			2014			2014		2014
	Total revenue	$	119,377		$	113,020		$	207,140	$	290,192
	Total costs and expenses	$	101,152		$	150,224		$	158,771	$	197,201
	Net income (loss) from operations	$	18,225		$	(37,204	)	$	48,369	$	92,991
	Net income (loss)	$	18,275		$	(37,057	)	$	41,422	$	63,484
	Net income (loss) per share: (1)
	Basic	$	0.24		$	(0.49	)	$	0.55	$	0.84
	Diluted	$	0.23		$	(0.49	)	$	0.53	$	0.81
	Shares used in computation of net income (loss) per share:
	Basic	74,754			75,139			75,392		75,692
	Diluted	78,064			75,139			78,025		78,471
		Quarters Ended
		March 31,			June 30,			September 30,		December 31,
		2013			2013			2013		2013
	Total revenue	$	2,846		$	54,684		$	79,088	$	123,551
	Total costs and expenses	$	55,810		$	42,653		$	25,662	$	38,120
	Net income (loss) from operations	$	(52,964	)	$	12,031		$	53,426	$	85,431
	Net income (loss)	$	(51,911	)	$	12,351		$	42,333	$	64,237
	Net income (loss) per share: (1)
	Basic	$	(0.73	)	$	0.17		$	0.58	$	0.87
	Diluted	$	(0.73	)	$	0.16		$	0.55	$	0.82
	Shares used in computation of net income (loss) per share:
	Basic	70,933			72,953			73,316		73,868
	Diluted	70,933			77,194			77,659		77,917
	(1) Basic and diluted net income (loss) per share amounts are computed independently for each of the quarters presented.  Therefore, the sum of quarterly basic and diluted net income (loss) per share information may not equal annual basic and diluted net income (loss) per share.

Transition_Period_Comparative_1

Transition Period Comparative Data (unaudited) - (Tables)	12 Months Ended
	Dec. 31, 2014
Income Statement [Abstract]
Comparable Financial Statements	Transition Period Comparative Data (unaudited)
		(in thousands, except per share data)
		Six Months Ended December 31,
		2012			2011
					(unaudited)
	Statement of Operations Data:
	Revenue:
	License and milestone revenue	$	155,000		$	77,605
	Collaboration services revenue	5,658			335
	Total revenue	160,658			77,940
	Costs and expenses:
	Research and development	46,639			23,324
	Less: Excess Amounts related to Research and development (See Note 5)	(17,306		)	—
	Research and development, net	29,333			23,324
	Selling, general and administrative	12,093			7,294
	Less: Excess Amounts related to Selling, general and administrative (See Note 5)	(819		)	—
	Selling, general and administrative, net	11,274			7,294
	Total costs and expenses	40,607			30,618
	Income from operations	120,051			47,322
	Interest income	137			68
	Other expense, net	(8		)	(24		)
	Income before income taxes	120,180			47,366
	Income tax provision	(2,647		)	(5,651		)
	Net income	$	117,533		$	41,715
	Net income per share:
	Basic	$	1.69		$	0.61
	Diluted	$	1.58		$	0.58
	Weighted average shares used to compute net income (loss) per share:
	Basic	69,676			68,491
	Diluted	74,408			71,312
	Statement of Cash Flows Data:
	Net cash provided by (used in) operating activities	$	110,694		$	123,904
	Net cash (used in) provided by investing activities	(6,386		)	13,063
	Net cash provided by financing activities	5,229			5,490
	Increase in cash and cash equivalents	$	109,537		$	142,457

Description_of_the_Company_and1

Description of the Company and Basis of Presentation - (Narrative) (Details)	Dec. 31, 2014
	country
Accounting Policies [Abstract]
Number of countries in which pharmaceutical is approved	40
Number of countries within the european union in which pharmaceutical is approved	28

Significant_Accounting_Policie3

Significant Accounting Policies - (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013
Organization and Summary of Accounting Policies
Receivable from collaboration partners		$26,970,000	$51,957,000
Sales discounts, goods, percentage		2.00%
Maximum total excess amounts plus interest	225,000,000
Vesting period for Restricted Stock Units		2 years 7 days
IMBRUVICA [Member]
Organization and Summary of Accounting Policies
Inventory, estimated useful life		24 months
Advertising expense		4,400,000	300,000
Janssen [Member]
Organization and Summary of Accounting Policies
Receivable from collaboration partners			50,200,000
Selling, General and Administrative Expenses [Member]
Organization and Summary of Accounting Policies
Collaborative agreement, cost sharing percentage		50.00%
Selling, General and Administrative Expenses [Member] | Janssen [Member]
Organization and Summary of Accounting Policies
Collaborative agreement, cost sharing percentage		50.00%
Furniture and Fixtures [Member]
Organization and Summary of Accounting Policies
Estimated useful life		5 years
Minimum [Member]
Organization and Summary of Accounting Policies
Estimated useful life		2 years
Maximum [Member]
Organization and Summary of Accounting Policies
Estimated useful life		5 years
Collaboration and License Agreement with Janssen Biotech Inc [Member]
Organization and Summary of Accounting Policies
Receivable from collaboration partners		27,000,000
Percent of cost sharing arrangement Janssen share	60.00%	60.00%
Percent of cost sharing arrangement by company	40.00%	40.00%
Maximum cost sharing amount incurred	50,000,000
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Receivable and Product Sales, Milestone Payment One [Member]
Organization and Summary of Accounting Policies
Receivable from collaboration partners		20,000,000
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Receivable and Product Sales, Milestone Payment Two [Member]
Organization and Summary of Accounting Policies
Receivable from collaboration partners		3,900,000
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Value Added Tax [Member]
Organization and Summary of Accounting Policies
Receivable from collaboration partners		1,700,000
Customer Concentration Risk [Member] | Customer A [Member] | Accounts Receivable [Member]
Organization and Summary of Accounting Policies
Concentration risk, percentage		25.00%	26.00%
Customer Concentration Risk [Member] | Customer B [Member] | Accounts Receivable [Member]
Organization and Summary of Accounting Policies
Concentration risk, percentage		22.00%	26.00%
Customer Concentration Risk [Member] | Customer C [Member] | Accounts Receivable [Member]
Organization and Summary of Accounting Policies
Concentration risk, percentage		19.00%	16.00%
Customer Concentration Risk [Member] | Customer D [Member] | Accounts Receivable [Member]
Organization and Summary of Accounting Policies
Concentration risk, percentage		15.00%
Certificates of Deposit [Member]
Organization and Summary of Accounting Policies
Securities received as collateral		300,000	300,000
Restricted Stock Units (RSUs) [Member]
Organization and Summary of Accounting Policies
Vesting period for Restricted Stock Units		4 years
Standby Letters of Credit [Member]
Organization and Summary of Accounting Policies
Letter of credit secured by a certificate of deposit		$300,000

Significant_Accounting_Policie4

Significant Accounting Policies - Schedule of Inventory (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounting Policies [Abstract]
Raw materials	$0	$8,007
Work-in-process	27,591	3,489
Finished goods	6,855	1,107
Inventory, Net	$34,446	$12,603

Product_Revenue_Net_Schedule_o

Product Revenue, Net - Schedule of Product Revenue, Net (Details) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Revenues [Abstract]
Product revenue, gross		$553,143	$14,968
Government rebates, return reserve and other		-34,502	-1,024
Chargebacks and cash discounts		-26,223	-371
Product revenue, net	$0	$492,418	$13,573	$0

Product_Revenue_Net_Schedule_o1

Product Revenue, Net - Schedule of Provisions, Credits and Payments (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Provisions and Credits/Payments for Product Revenues, Net Adjustments [Roll Forward]
Beginning Balance	$1,206	$0
Provision related to current period sales	60,725	1,395
Credits/payments	-35,196	-189
Ending Balance	$26,735	$1,206

Product_Revenue_Net_Schedules_

Product Revenue, Net - Schedules of Customers Who Represented 10% or More of the Company's Product Revenue, Net (Details) (Sales Revenue, Product Line [Member], Customer Concentration Risk [Member])	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Customer A [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	30.00%	24.00%
Customer B [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	20.00%	15.00%
Customer C [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	15.00%	12.00%
Customer D [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	14.00%	20.00%
Customer E [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	11.00%	12.00%

Accounts_Receivable_Net_Schedu

Accounts Receivable, Net - Schedule of Accounts Receivable, Net (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Valuation Allowance [Line Items]
Accounts receivable, gross	$72,921	$11,345
Accounts receivable, net	64,297	11,044
Allowance for doubtful accounts [Member]
Valuation Allowance [Line Items]
Allowance for doubtful accounts	-14	0
Allowance for chargebacks related to government programs [Member]
Valuation Allowance [Line Items]
Allowance for doubtful accounts	-7,105	-72
Allowance for cash discounts [Member]
Valuation Allowance [Line Items]
Allowance for doubtful accounts	($1,505)	($229)

Collaboration_and_Other_Agreem2

Collaboration and Other Agreements - License Agreement with Janssen Biotech, Inc (Narrative) (Details) (USD $)	1 Months Ended	6 Months Ended		12 Months Ended
	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Janssen's share of U.S. pre-tax commercial profits	50.00%
Maximum total excess amounts plus interest	$225,000,000
Incremental interest rate on outstanding balance	2.00%		2.00%
Maximum percentage of interest on outstanding excess amount (in percent)	5.00%
Maximum interest on excess amount	25,000,000
Estimated weighted average cost of capital (in percent)	12.00%
Minimum license royalty rates (in percent)	30.00%
Maximum license royalty rates (in percent)	40.00%
Collaboration services revenue		5,658,000	335,000	17,311,000	11,596,000	4,385,000
Deferred revenue - non-current portion				34,885,000	52,025,000
Cost of goods sold		0		40,410,000	3,501,000	0
Receivables from Collaboration Partners, Current				26,970,000	51,957,000
Accounts Payable				79,799,000	3,388,000
Pharmacyclics, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Janssen's share of U.S. pre-tax commercial profits	50.00%
Janssen [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue - non-current portion				34,885,000	52,025,000
Accounts Payable				79,800,000
Value added taxes payable				300,000
Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration services revenue		4,878,000		17,164,000	10,970,000	4,017,000
Janssen [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Janssen's share of U.S. pre-tax commercial profits	50.00%
Total excess amounts funded by Janssen				138,300,000
Total Excess Amounts Funded by Janssen				134,300,000
Interest on outstanding excess amount				4,000,000
Receivables from Collaboration Partners, Current					50,200,000
Licenses [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-Refundable Upfront Payment Upon Execution	70,600,000
Committee Services [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-Refundable Upfront Payment Upon Execution	15,000,000
Services revenue recognized period	17 years
Development Services [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-Refundable Upfront Payment Upon Execution	64,400,000
Services revenue recognized period	9 years
Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-Refundable Upfront Payment Upon Execution	150,000,000
Maximum milestone payments	825,000,000		825,000,000
Percent of cost sharing arrangement Janssen share	60.00%			60.00%
Percent of cost sharing arrangement by company	40.00%			40.00%
Company's annual cap of development and commercial costs	50,000,000
Deferred revenue total under cost sharing agreement				46,500,000
Receivables from Collaboration Partners, Current				27,000,000
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Receivable and Product Sales, Milestone Payment One [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Receivables from Collaboration Partners, Current				20,000,000
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Receivable and Product Sales, Milestone Payment Two [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Receivables from Collaboration Partners, Current				3,900,000
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Value Added Tax [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Receivables from Collaboration Partners, Current				1,700,000
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Janssen [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Janssen's share of U.S. pre-tax commercial profits				50.00%
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Continued Development Progress [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum milestone payments	250,000,000		250,000,000
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Achievement of Regulatory Progress [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum milestone payments	225,000,000		225,000,000
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Regulatory Approval [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum milestone payments	350,000,000		350,000,000
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Achievement of Approval , Regulatory, and Development Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum milestone payments				220,000,000
Revenue Recognition, Milestone Method, Cumulative Revenue Recognized				605,000,000
Counterparty's Share of Pre-tax Commercial Profits [Member] | Janssen [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Accounts Payable				76,700,000
Cost-sharing Under the Agreement [Member] | Janssen [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Accounts Payable				2,800,000
Pharmacyclics Product [Member] | Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration services revenue				4,200,000
IMBRUVICA [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cost of goods sold					$5,000,000

Collaboration_and_Other_Agreem3

Collaboration and Other Agreements - License Agreement with Les Laboratories Servier (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Estimated cost, termination of collaboration and license agreement	$88,279	$71,188
Collaborative Arrangement, Product [Member] | Servier [Member}
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Estimated cost, termination of collaboration and license agreement	$800

Collaboration_and_Other_Agreem4

Collaboration and Other Agreements - License Agreement with Novo Nordisk (Narrative) (Details) (Collaboration and License Agreement with Novo Nordisk [Member], USD $)	1 Months Ended
	Oct. 31, 2012
Collaboration and License Agreement with Novo Nordisk [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-Refundable Upfront Payment Upon Execution	$5,000,000
Maximum milestone payments	$55,000,000

Collaboration_and_Other_Agreem5

Collaboration and Other Agreements - License Agreement with Celera Corporation (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payment for HDAC Inhibitor	two-thirds
Milestone Payment For HDAC Inhibitor Percentage	66.66%
Milestone payment for Factor VIIa	one-third
Milestone Payment For Factor VIIa Percentage	33.33%
Celera Corporation Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum milestone payments	$97,000,000
Potential future milestone payments to be paid to Celera after regulatory approval	90.00%
Collaborative agreement, termination terms, days written notice to terminate agreement	60 days
Collaborative agreement, termination terms, days of written notice that breaching party has to cure a breach in contract before termination	90 days
IMBRUVICA [Member] | Celera Corporation Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalty Expense	$27,400,000	$1,000,000

Collaboration_and_Other_Agreem6

Collaboration and Other Agreements - Schedule of Collaborative and License Arrangements (Summary) (Details) (USD $)	3 Months Ended								6 Months Ended		12 Months Ended
In Thousands, 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, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue									$155,000	$77,605	$220,000	$235,000	$77,605
Total revenue	290,192	207,140	113,020	119,377	123,551	79,088	54,684	2,846	160,658	77,940	729,729	260,169	81,990
Janssen [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue									154,878		237,164	245,970	74,622
Servier [Member}
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue									93		139	159	7,157
Novo Nordisk [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue									5,631		8	454	0
Other Entities [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration Services and Other Revenue									56		0	13	211
Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue									$160,658		$237,311	$246,596	$81,990

Collaboration_and_Other_Agreem7

Collaboration and Other Agreements - Schedule of Collaborative and License Arrangements (Revenue Recognized Under Agreements) (Details) (USD $)	3 Months Ended								6 Months Ended		12 Months Ended
In Thousands, 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, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
License and milestone revenue									$155,000	$77,605	$220,000	$235,000	$77,605
Collaboration services revenue									5,658	335	17,311	11,596	4,385
Total revenue	290,192	207,140	113,020	119,377	123,551	79,088	54,684	2,846	160,658	77,940	729,729	260,169	81,990
Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
License and milestone revenue									150,000		220,000	235,000	70,605
Collaboration services revenue									4,878		17,164	10,970	4,017
Total revenue									154,878		237,164	245,970	74,622
Collaboration and License Agreement with Les Laboratories Servier [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
License and milestone revenue									0		0	0	7,000
Collaboration services revenue									93		139	159	157
Total revenue									93		139	159	7,157
Collaboration and License Agreement with Novo Nordisk [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
License and milestone revenue									5,000		0	0	0
Collaboration services revenue									631		8	454	0
Total revenue									$5,631		$8	$454	$0

Collaboration_and_Other_Agreem8

Collaboration and Other Agreements - Schedule of Collaborative and License Arrangements (License and Milestone Revenue Recognized) (Details) (USD $)	6 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
License and milestone revenue	$155,000	$77,605	$220,000	$235,000	$77,605
Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
License revenue	0		0	0	70,605
License and milestone revenue	150,000		220,000	235,000	70,605
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Regulatory Approval [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cumulative milestone payments triggered under collaboration	0		170,000	60,000	0
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Achievement of Regulatory Progress [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cumulative milestone payments triggered under collaboration	0		50,000	125,000	0
Collaboration and License Agreement with Janssen Biotech Inc [Member] | Continued Development Progress [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cumulative milestone payments triggered under collaboration	$150,000		$0	$50,000	$0

Collaboration_and_Other_Agreem9

Collaboration and Other Agreements - Schedule of Collaborative and License Arrangements (Expenses Charged to Collaboration) (Details) (USD $)	6 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development, net	$29,333	$23,324	$172,459	$85,133	$54,537
Excess Amounts	-17,306	0	0	-85,732	0
Excess Amounts	-819	0	0	-30,405	0
Selling, general and administrative, net	11,274	7,294	167,955	73,611	15,575
Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development, net	23,045		114,906	41,612	24,891
Selling, general and administrative, net	1,854		93,885	8,388	1,066
Collaboration Expense, Unadjusted [Member] | Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development, net	57,690		155,027	175,567	43,272
Selling, general and administrative, net	2,426		88,110	28,118	1,070
Increase (Decrease) for Cost Sharing [Member] | Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Increase (decrease) for cost sharing	-17,339		-40,121	-48,223	-18,381
Selling, general and administrative, net	247		5,775	10,675	-4
Excess Amounts [Member] | Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Excess Amounts	-17,306		0	-85,732	0
Excess Amounts	($819)		$0	($30,405)	$0

Recovered_Sheet1

Collaboration and Other Agreements - Schedule of Collaborative and License Arrangements (Company's Net Profit(Loss)) (Details) (USD $)	6 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Product revenue, net	$0		$492,418	$13,573	$0
Less: 50% of Pharmacyclics' U.S. cost of goods sold	0		-40,410	-3,501	0
Less: Pharmacyclics' share of world-wide research and development expenses under the Agreement	-29,333	-23,324	-172,459	-85,133	-54,537
Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Less: Pharmacyclics' share of world-wide research and development expenses under the Agreement	-23,045		-114,906	-41,612	-24,891
IMBRUVICA [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Less: 50% of Pharmacyclics' U.S. cost of goods sold				-5,000
IMBRUVICA [Member] | Parent Company [Member] | Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Product revenue, net	0		246,209	0	0
Less: 50% of Pharmacyclics' U.S. cost of goods sold	0		-20,205	0	0
Pharmacyclics' 50% share of U.S. net product revenue, less cost of goods sold	0		226,004	0	0
Less: Pharmacyclics' share of U.S. commercial expenses under the Agreement	-1,073		-70,597	-8,006	-1,058
Pharmacyclics' share of U.S. pre-tax profits from the commercialization of IMBRUVICA under the Agreement	-1,073		155,407	-8,006	-1,058
Less: Pharmacyclics' share of outside-U.S. pre-tax commercial loss under the Agreement	-781		-23,288	-382	-8
Pharmacyclics' share of worldwide pre-tax profits from the commercialization of IMBRUVICA under the Agreement	-1,854		132,119	-8,388	-1,066
Less: Pharmacyclics' share of world-wide research and development expenses under the Agreement	-23,045		-114,906	-41,612	-24,891
Pharmacyclics' share of IMBRUVICA related pre-tax net profit under the Agreement	($24,899)		$17,213	($50,000)	($25,957)

Recovered_Sheet2

Collaboration and Other Agreements - Schedule of Collaborative and License Arrangements (Company's Share of US Net Product Revenue Less COGS) (Details) (USD $)	1 Months Ended	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Product revenue, net		$0	$492,418	$13,573	$0
Cost of goods sold		0	40,410	3,501	0
Net Product Revenue Less Cost of Goods Sold			452,008
Janssen's share of U.S. pre-tax commercial profits	50.00%
Total costs of collaboration (Janssen's 50% share under the Agreement)		0	226,004	0	0
Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Pharmacyclics' 50% share of U.S. net product revenue less cost of goods sold			226,004
Janssen [Member] | Collaboration and License Agreement with Janssen Biotech Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Janssen's share of U.S. pre-tax commercial profits			50.00%
Total costs of collaboration (Janssen's 50% share under the Agreement)			$226,004

Recovered_Sheet3

Collaboration and Other Agreements - Schedule of Collaborative and License Arrangements (Excess Amounts Recorded Under Agreement) (Details) (USD $)	6 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Collaboration and Other Agreements [Abstract]
Research and development	$17,306	$0	$0	$85,732	$0
General and administrative	819	0	0	30,405	0
Total Excess Amounts	$18,125		$0	$116,137	$0

Cash_Cash_Equivalents_and_Mark2

Cash, Cash Equivalents and Marketable Securities - Schedule of Cash and Cash Equivalents (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2012	Jun. 30, 2011
In Thousands, unless otherwise specified
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$845,035	$623,956	$307,433	$197,896	$87,757
Demand Deposits [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	471,916	225,035
Money Market Funds [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	373,119	129,193
US Treasury Securities [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	0	269,488
Certificates of Deposit [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$0	$240

Cash_Cash_Equivalents_and_Mark3

Cash, Cash Equivalents and Marketable Securities - Schedule of Marketable Securities (Cash and Cash Equivalents) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets, Fair Value Disclosure [Abstract]
Certificates of deposit - FDIC insured	$11,952	$11,672
Available-for-sale Securities, Current	$11,952	$11,672

Cash_Cash_Equivalents_and_Mark4

Cash, Cash Equivalents and Marketable Securities - Schedule of Available-for-sale Securities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	$11,960	$11,680
Gross Unrealized Gain	0	0
Gross Unrealized Loss	-8	-8
Fair Value	11,952	11,672
Certificates of deposit – FDIC insured
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	11,960	11,680
Gross Unrealized Gain	0	0
Gross Unrealized Loss	-8	-8
Fair Value	$11,952	$11,672

Cash_Cash_Equivalents_and_Mark5

Cash, Cash Equivalents and Marketable Securities - Schedule of Marketable Securities (Remaining Contractual Maturities) (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Assets, Fair Value Disclosure [Abstract]
Amortized Cost	$11,960
Fair Value	$11,952

Cash_Cash_Equivalents_and_Mark6

Cash, Cash Equivalents and Marketable Securities - Schedule of Fair Value Measurements of the Company's Cash Equivalents and Available-for-sale Securities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Cash and Cash Equivalents [Line Items]
Fair Value	$11,952	$11,672
Quoted Prices in Active Markets for Identical Assets (Level 1)
Cash and Cash Equivalents [Line Items]
Assets, Fair Value Disclosure	373,119	398,681
Quoted Prices in Active Markets for Identical Assets (Level 1) | US Treasury Bill Securities [Member]
Cash and Cash Equivalents [Line Items]
Cash Equivalents Fair Value Disclosure		269,488
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money Market Funds [Member]
Cash and Cash Equivalents [Line Items]
Cash Equivalents Fair Value Disclosure	373,119	129,193
Quoted Prices in Active Markets for Identical Assets (Level 1) | US Treasury Securities [Member]
Cash and Cash Equivalents [Line Items]
Cash Equivalents Fair Value Disclosure		0
Fair Value	0	0
Significant Other Inputs (Level 2)
Cash and Cash Equivalents [Line Items]
Assets, Fair Value Disclosure	11,952	11,912
Significant Other Inputs (Level 2) | US Treasury Bill Securities [Member]
Cash and Cash Equivalents [Line Items]
Cash Equivalents Fair Value Disclosure		0
Significant Other Inputs (Level 2) | Money Market Funds [Member]
Cash and Cash Equivalents [Line Items]
Cash Equivalents Fair Value Disclosure	0	0
Significant Other Inputs (Level 2) | US Treasury Securities [Member]
Cash and Cash Equivalents [Line Items]
Cash Equivalents Fair Value Disclosure		240
Fair Value	11,952	11,672
Significant Unobservable Inputs (Level 3)
Cash and Cash Equivalents [Line Items]
Assets, Fair Value Disclosure	0	0
Significant Unobservable Inputs (Level 3) | US Treasury Bill Securities [Member]
Cash and Cash Equivalents [Line Items]
Cash Equivalents Fair Value Disclosure		0
Significant Unobservable Inputs (Level 3) | Money Market Funds [Member]
Cash and Cash Equivalents [Line Items]
Cash Equivalents Fair Value Disclosure	0	0
Significant Unobservable Inputs (Level 3) | US Treasury Securities [Member]
Cash and Cash Equivalents [Line Items]
Cash Equivalents Fair Value Disclosure		0
Fair Value	0	0
Estimate of Fair Value
Cash and Cash Equivalents [Line Items]
Assets, Fair Value Disclosure	385,071	410,593
Estimate of Fair Value | US Treasury Bill Securities [Member]
Cash and Cash Equivalents [Line Items]
Cash Equivalents Fair Value Disclosure		269,488
Estimate of Fair Value | Money Market Funds [Member]
Cash and Cash Equivalents [Line Items]
Cash Equivalents Fair Value Disclosure	373,119	129,193
Estimate of Fair Value | US Treasury Securities [Member]
Cash and Cash Equivalents [Line Items]
Cash Equivalents Fair Value Disclosure		240
Fair Value	$11,952	$11,672

Balance_Sheet_Components_Sched

Balance Sheet Components - Schedule of Property Plant and Equipment (Details) (USD $)	6 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		$44,053,000	$33,190,000
Construction in Progress, Gross		19,461,000	14,592,000
Less: Accumulated depreciation and amortization		-11,577,000	-7,719,000
Property, Plant and Equipment, Net		32,476,000	25,471,000
Depreciation, Depletion and Amortization	600,000	3,900,000	2,200,000	600,000
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		13,363,000	11,827,000
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		9,951,000	5,493,000
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		$1,278,000	$1,278,000

Balance_Sheet_Components_Sched1

Balance Sheet Components - Schedule of Accounts Payable and Accrued Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Balance Sheet Related Disclosures [Abstract]
Accrued payroll and employee related expenses	$19,645	$20,500
Accrued discounts and rebates	18,125	906
Accrued clinical related	14,806	17,062
Accrued royalty to Celera	10,646	949
Accrued value added taxes	7,395	7,041
Accrued outside services	5,114	5,077
Accrued contract manufacturing	2,380	1,556
Accrued marketing	1,288	0
Accrued property and equipment purchases	934	4,039
Accrued inventory	101	7,592
Accrued other	7,845	6,466
Accrued Liabilities, Current	$88,279	$71,188

Balance_Sheet_Components_Sched2

Balance Sheet Components - Schedule of Deferred Revenue (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Revenue Arrangement [Line Items]
Deferred revenue - current portion	$18,773	$7,581
Deferred revenue - non-current portion	34,885	52,025
Janssen [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue - current portion	11,656	7,505
Deferred revenue - non-current portion	34,885	52,025
Collaboration Partner [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue - current portion	$7,117	$76

Intangible_Assets_Narrative_De

Intangible Assets - (Narrative) (Details) (USD $)	6 Months Ended	12 Months Ended			0 Months Ended
	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012	Apr. 15, 2014
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$0	$520,000	$0	$0
Accumulated amortization		500,000
Technology-Based Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Technology assets acquired					$9,300,000
Expected useful life for technology assets					13 years

Intangible_Assets_Schedule_of_

Intangible Assets - Schedule of Future Annual Amortization Expense (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]
2015	$728
2016	730
2017	728
2018	728
2019	728
Thereafter	5,088
Total	$8,730

Stockholders_Equity_Common_and

Stockholders' Equity - Common and Preferred Stock Narrative (Details) (USD $)	1 Months Ended	6 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Statement [Line Items]
Issuance of common stock (in shares)	2,200,000
Issue price (in dollars per share)	$94.20
Proceeds from issuance of common stock	$201,000	$0	$0	$201,023	($559)
Number of preferred stock authorized (in shares)			1,000,000	1,000,000
Number of preferred stock authorized (in shares)			$0.00	$0.00
Preferred Stock [Member]
Statement [Line Items]
Number of preferred stock authorized (in shares)			1,000,000
Number of preferred stock authorized (in shares)			$0.00

Stockholders_Equity_Stock_Plan

Stockholders' Equity - Stock Plans Narrative (Details) (USD $)	6 Months Ended		12 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2014		Dec. 31, 2013		Jun. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period or equity incentive awards			2 years 7 days
Number of performance options granted (in shares)			0.8
Number of Performance Restricted Stock Units Granted with Performance Goals Not Set			0.1
Capitalized stock based compensation	$0		$900,000		$200,000		$0
Option pricing model used	Black Scholes option-pricing model	[1]	Black Scholes option-pricing model	[1]	Black Scholes option-pricing model	[1]	Black Scholes option-pricing model	[1]
Weighted average grant date fair value for employee options granted under the Company's stock option plans (in dollars per share)	$43.55		$59.28		$55.32		$11.44
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	45,800,000		196,600,000		145,500,000		17,300,000
Excess tax benefit from stock-based compensation arrangements			34,877,000		30,033,000
Fair value of options vested	3,700,000		43,300,000		37,400,000		5,600,000
Equity Incentive Award Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance and available for grant under 2014 plan			2
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs related to non vested employee options			87,600,000
Weighted average period of recognition of compensation costs			2 years 7 months 6 days
Additional Paid-in Capital [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess tax benefit from stock-based compensation arrangements			$34,877,000		$30,033,000
2014 Equity Incentive Award Plan [Member] | Equity Incentive Award Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period or equity incentive awards			10 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			4 years
[1]	The above table includes assumptions used in the valuation of performance-based stock option grants for which the Company set performance criteria during the period.

Stockholders_Equity_Schedule_o

Stockholders' Equity - Schedule of Stock Option Activity (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014
Number of Options
Balance at the beginning of the period (in shares)	5,111
Exercised (in shares)	-1,682
Granted (in shares)	1,142
Forfeited or expired (in shares)	-371
Balance at the end of the period (in shares)	4,200
Options Vested and expected to vest (in shares)	4,073
Weighted Average Exercise Price per Share
Balance at the beginning of period (in dollars per share)	$23.54
Exercised (in dollars per share)	$11.93
Granted (in dollars per share)	$91.68
Forfeited and expired (in dollars per share)	$59.84
Balance at the end of period (in dollars per share)	$43.50
Options Vested and expected to vest (in dollars per share)	$41.72
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	5 years 8 months 12 days
Vested and expected to vest, Weighted Average Remaining Contractual Term (in Years)	6 years 7 months 10 days
Options Outstanding, Aggregate intrinsic Value	$332,507
Vested and expected to vest, Aggregate Intrinsic Value	$328,684

Stockholders_Equity_Schedule_o1

Stockholders' Equity - Schedule of Restricted Stock Unit Activity (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at the beginning of the period (in shares)	0
Granted (in shares)	211
Vested and released (in shares)	-13
Forfeited (in shares)	-10
Outstanding at the end of the period (in shares)	188
Expected to vest at the end of the period (in shares)	163
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at the beginning of the period (in dollars per share)	$0
Granted (in dollars per share)	$114.98
Vested and released (in dollars per share)	$121.89
Forfeited (in dollars per share)	$100.09
Outstanding at the end of the period (in dollars per share)	$115.32
Expected to vest at the end of the period (in dollars per share)	$115.61
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Restricted stock units outstanding, Weighted Average Remaining Contractual Term (in Years)	2 years 7 days
Restricted stock units Expected to vest, Weighted Average Remaining Contractual Term (in Years)	1 year 11 months 1 day
Restricted stock units outstanding and unvested, Aggregate Intrinsic Value	$23,052
Restricted stock units expected to vest, Aggregate Intrinsic Value	$19,960

Stockholders_Equity_Schedule_o2

Stockholders' Equity - Schedule of components of share-based compensation (Details) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense recognized	$7,436	$53,741	$50,210	$9,873
Cost of Sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense recognized	0	1,453	436	0
Research and Development Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense recognized	5,357	22,710	24,041	6,947
Selling, General and Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense recognized	$2,079	$29,578	$25,733	$2,926

Stockholders_Equity_Schedule_o3

Stockholders' Equity - Schedule of assumptions used to calculate the fair value (Details)	6 Months Ended		12 Months Ended
	Dec. 31, 2012		Dec. 31, 2014		Dec. 31, 2013		Jun. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option pricing model used	Black Scholes option-pricing model	[1]	Black Scholes option-pricing model	[1]	Black Scholes option-pricing model	[1]	Black Scholes option-pricing model	[1]
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	[1]	0.00%	[1]	0.00%	[1]	0.00%	[1]
Stock price volatility							88.00%	[1],[2]
Risk free interest rate							1.00%	[1],[2]
Expected life (years)							5 years	[1],[2]
Non-employee stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%		0.00%		0.00%		0.00%
Stock price volatility	89.00%		79.00%		79.00%
Risk free interest rate	3.89%		2.60%		1.90%
Expected life (years)	8 years		10 years		10 years
Minimum [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price volatility	51.50%	[1],[2]	46.90%	[1],[2]	50.90%	[1],[2]
Risk free interest rate	0.30%	[1],[2]	0.70%	[1],[2]	0.50%	[1],[2]
Expected life (years)	2 years 7 months 6 days	[1],[2]	2 years 6 months 7 days	[1],[2]	2 years 6 months 7 days	[1],[2]
Minimum [Member] | Non-employee stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price volatility							84.00%
Risk free interest rate							2.00%
Expected life (years)							8 years 1 month 6 days
Maximum [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price volatility	85.50%	[1],[2]	67.40%	[1],[2]	84.80%	[1],[2]
Risk free interest rate	0.80%	[1],[2]	1.80%	[1],[2]	1.50%	[1],[2]
Expected life (years)	5 years 2 months 12 days	[1],[2]	5 years 14 days	[1],[2]	5 years 2 months 12 days	[1],[2]
Maximum [Member] | Non-employee stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price volatility							89.00%
Risk free interest rate							3.89%
Expected life (years)							10 years
PurchasePlan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%		0.00%		0.00%		0.00%
Stock price volatility	50.00%		49.00%		48.00%		54.00%
Risk free interest rate	0.16%		0.30%		0.16%		0.15%
Expected life (years)	8 months 5 days		1 year 7 months 2 days		1 year 1 month 6 days		1 year 1 month 20 days
[1]	The above table includes assumptions used in the valuation of performance-based stock option grants for which the Company set performance criteria during the period.
[2]	Amounts for the year ended June 30, 2012 are presented on a weighted average basis.

Stockholders_Equity_Schedule_o4

Stockholders' Equity - Schedule of outstanding, exercisable and vested stock options (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Aggregate intrinsic Value	$332,507,000
Exercisable, Number of Shares (in shares)	3,523
Exercisable, Weighted Average Remaining Contractual Life (in years)	6 years 2 months 5 days
Exercisable, Weighted Average Exercise Price Per Share (in dollars per share)	$28.62
Exercisable, Aggregate intrinsic Value (in dollars)	329,982
Exercisable and Vested, Number of Shares (in shares)	2,697
Exercisable and Vested, Weighted Average Exercise Price Per Share (in dollars per share)	$22.11
Exercisable and Vested, Aggregate intrinsic Value (in dollars)	270,222
Range of Exercise Prices $0.75 - $6.49
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercisable, Number of Shares (in shares)	837
Exercisable, Weighted Average Remaining Contractual Life (in years)	4 years 3 months 11 days
Exercisable, Weighted Average Exercise Price Per Share (in dollars per share)	$2.57
Exercisable and Vested, Number of Shares (in shares)	822
Exercisable and Vested, Weighted Average Exercise Price Per Share (in dollars per share)	$2.50
Exercise Price Range Lower Range (in dollars per share)	$0.75
Exercise Price Range Upper Range (in dollars per share)	$6.49
Range of Exercise Prices $6.52 - $12.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercisable, Number of Shares (in shares)	831
Exercisable, Weighted Average Remaining Contractual Life (in years)	5 years 5 months 5 days
Exercisable, Weighted Average Exercise Price Per Share (in dollars per share)	$7.67
Exercisable and Vested, Number of Shares (in shares)	815
Exercisable and Vested, Weighted Average Exercise Price Per Share (in dollars per share)	$7.61
Exercise Price Range Lower Range (in dollars per share)	$6.52
Exercise Price Range Upper Range (in dollars per share)	$12
Range of Exercise Prices $12.10 - $32.38
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercisable, Number of Shares (in shares)	796
Exercisable, Weighted Average Remaining Contractual Life (in years)	6 years 9 months 4 days
Exercisable, Weighted Average Exercise Price Per Share (in dollars per share)	$20.28
Exercisable and Vested, Number of Shares (in shares)	489
Exercisable and Vested, Weighted Average Exercise Price Per Share (in dollars per share)	$18.62
Exercise Price Range Lower Range (in dollars per share)	$12.10
Exercise Price Range Upper Range (in dollars per share)	$32.38
Range of Exercise Prices $36.73 - $86.78
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercisable, Number of Shares (in shares)	924
Exercisable, Weighted Average Remaining Contractual Life (in years)	7 years 8 months 19 days
Exercisable, Weighted Average Exercise Price Per Share (in dollars per share)	$68.11
Exercisable and Vested, Number of Shares (in shares)	437
Exercisable and Vested, Weighted Average Exercise Price Per Share (in dollars per share)	$66.52
Exercise Price Range Lower Range (in dollars per share)	$36.73
Exercise Price Range Upper Range (in dollars per share)	$86.78
Range of Exercise Prices $87.19 - $102.22
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercisable, Number of Shares (in shares)	91
Exercisable, Weighted Average Remaining Contractual Life (in years)	8 years 6 months 29 days
Exercisable, Weighted Average Exercise Price Per Share (in dollars per share)	$90.62
Exercisable and Vested, Number of Shares (in shares)	91
Exercisable and Vested, Weighted Average Exercise Price Per Share (in dollars per share)	$90.62
Exercise Price Range Lower Range (in dollars per share)	$87.19
Exercise Price Range Upper Range (in dollars per share)	$102.22
Range of Exercise Prices $102.77 - $151.48
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercisable, Number of Shares (in shares)	44
Exercisable, Weighted Average Remaining Contractual Life (in years)	8 years 8 months 8 days
Exercisable, Weighted Average Exercise Price Per Share (in dollars per share)	$113.87
Exercisable and Vested, Number of Shares (in shares)	43
Exercisable and Vested, Weighted Average Exercise Price Per Share (in dollars per share)	$113.87
Exercise Price Range Lower Range (in dollars per share)	$102.77
Exercise Price Range Upper Range (in dollars per share)	$151.48
Total Time Based and Performance Based Options [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares (in shares)	5,009
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	7 years 11 days
Options Outstanding, Weighted Average Exercise Price Per Share (in dollars per share)	$49.67
Options Outstanding, Aggregate intrinsic Value	$364,377
Total Time Based and Performance Based Options [Member] | Range of Exercise Prices $0.75 - $6.49
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares (in shares)	837
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	4 years 3 months 11 days
Options Outstanding, Weighted Average Exercise Price Per Share (in dollars per share)	$2.57
Total Time Based and Performance Based Options [Member] | Range of Exercise Prices $6.52 - $12.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares (in shares)	851
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	5 years 4 months 28 days
Options Outstanding, Weighted Average Exercise Price Per Share (in dollars per share)	$7.73
Total Time Based and Performance Based Options [Member] | Range of Exercise Prices $12.10 - $32.38
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares (in shares)	863
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	6 years 9 months 11 days
Options Outstanding, Weighted Average Exercise Price Per Share (in dollars per share)	$20.28
Total Time Based and Performance Based Options [Member] | Range of Exercise Prices $36.73 - $86.78
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares (in shares)	924
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	7 years 8 months 19 days
Options Outstanding, Weighted Average Exercise Price Per Share (in dollars per share)	$68.11
Total Time Based and Performance Based Options [Member] | Range of Exercise Prices $87.19 - $102.22
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares (in shares)	1,013
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	9 years 1 month 10 days
Options Outstanding, Weighted Average Exercise Price Per Share (in dollars per share)	$96.07
Total Time Based and Performance Based Options [Member] | Range of Exercise Prices $102.77 - $151.48
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares (in shares)	521
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	9 years 3 months 4 days
Options Outstanding, Weighted Average Exercise Price Per Share (in dollars per share)	$119.51

Stockholders_Equity_Employee_S

Stockholders' Equity - Employee Stock Purchase Plan Narrative (Details) (USD $)	1 Months Ended	6 Months Ended	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	31-May-13	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average estimated grant date fair value of our employee stock purchase plan (in dollars per share)		$43.55	$59.28	$55.32	$11.44
PurchasePlan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price per share as a percent of fair market value			85.00%
Sales under the purchase plan		0.1	0.1	0.2	0.2
Average price on sales under purchase plan (in dollars per share)		$13.06	$80.55	$21.65	$5.19
Additional number of shares authorized under plan (in shares)	0.3
Shares available for future purchase under the Purchase Plan			0.5
Weighted average estimated grant date fair value of our employee stock purchase plan (in dollars per share)		$33.32	$36.79	$41.19	$6.38
Unrecognized compensation costs			$4.40
Weighted average period of recognition of compensation costs			1 year

Employee_Benefit_Plan_Narrativ

Employee Benefit Plan - (Narrative) (Details) (USD $)	6 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Employee Benefit Plan [Abstract]
Matching contribution	$0.10	$1.90	$1	$0.20

Income_Taxes_Schedule_of_compo

Income Taxes - Schedule of components of income taxes (Details) (USD $)	6 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Current:
Federal	$2,047		$31,938	$30,879	$26
State	599		4,294	202	0
Foreign	1		91	45	13
Total provision for income taxes	2,647	5,651	36,323	31,126	39
Income before taxes	$120,180	$47,366	$122,447	$98,136	$12,025
Tax rate	2.20%		29.66%	31.72%	0.33%

Income_Taxes_Schedule_of_geogr

Income Taxes - Schedule of geographical breakdown of consolidated net income (loss) before income taxes by income tax jurisdiction (Details) (USD $)	6 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Income Tax Examination [Line Items]
Income before taxes	$120,180	$47,366	$122,447	$98,136	$12,025
United States [Member]
Income Tax Examination [Line Items]
Income before taxes	69,563		100,270	70,254	-4,596
Foreign [Member]
Income Tax Examination [Line Items]
Income before taxes	$50,617		$22,177	$27,882	$16,621

Income_Taxes_Schedule_of_defer

Income Taxes - Schedule of deferred tax assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$4,546	$3,552
Tax credit carryforwards	25,978	26,110
Capitalized research and development costs	200	230
Depreciation and amortization	775	916
Partnership investment	4,922	0
Stock-based compensation	16,320	9,712
Reserves and accruals	18,039	18,557
Gross deferred tax assets	70,780	59,077
Less: valuation allowance	-70,350	-58,679
Net deferred tax assets	430	398
Depreciation	-430	-398
Net Deferred tax assets	$0	$0

Income_Taxes_Schedule_of_statu

Income Taxes - Schedule of statutory income tax (Details) (USD $)	6 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Income Tax Disclosure [Abstract]
Statutory income tax rate	35.00%		35.00%	35.00%	35.00%
Tax provision (benefit) at statutory rate	$42,064		$42,857	$34,347	$4,209
State Tax, net of federal benefit	389		3,156	202	0
Research and development and orphan drug credits	0		-16,944	-21,774	-529
Deferred tax assets benefited (not benefited)	-35,181		7,151	28,376	-5,727
Stock-based compensation	1,056		4,532	5,261	2,009
Other	-629		3,238	744	38
Federal – alternative minimum tax	2,047		0	0	26
Foreign taxes greater than (less than) U.S. rates	-7,099		-7,667	-16,030	13
Total provision for income taxes	$2,647	$5,651	$36,323	$31,126	$39

Income_Taxes_Schedule_of_activ

Income Taxes - Schedule of activity related to gross unrecognized tax benefits (Details) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$2,307	$15,976	$2,845	$1,726
Additions based on tax positions related to current year	538	11,520	10,075	581
Reduction for tax positions of prior years		-623
Additions for tax positions of prior years	0		3,056	0
Ending balance	$2,845	$26,873	$15,976	$2,307

Income_Taxes_Narrative_Details

Income Taxes - (Narrative) (Details) (USD $)	6 Months Ended	12 Months Ended			3 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012	Sep. 30, 2014
Tax Credit Carryforward [Line Items]
Valuation allowance, deferred tax asset, change in amount		$11.70	$26.80
Statutory income tax rate	35.00%	35.00%	35.00%	35.00%
Unrecorded deferred tax assets from stock option exercises		2.1
Undistributed earnings of foreign subsidiaries		65.9
Undistributed earnings, maximum estimated applicable effective tax rate		40.00%
Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax adjustments, settlements, and unusual provisions					0.3
Internal Revenue Service (IRS) [Member]
Tax Credit Carryforward [Line Items]
Net operating loss carry forward		9.4	10.1
Tax credit carryforward		9.1	6.9
Internal Revenue Service (IRS) [Member] | Orphan Drug Credit [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforward		71.1	48.6
State and Local Jurisdiction [Member]
Tax Credit Carryforward [Line Items]
Net operating loss carry forward		58	37.3
Tax credit carryforward		8.9	5.5
United States [Member]
Tax Credit Carryforward [Line Items]
Deferred tax assets, tax credit carryforwards, alternative minimum tax		$1.50	$2.40

Commitments_and_Contingencies_1

Commitments and Contingencies - Schedule of Future Minimum Lease Payments (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Operating Lease Commitments
2015	$2,226
2016	2,161
2017	2,112
2018	857
2019	882
Thereafter	2,890
Total	$11,128

Commitments_and_Contingencies_2

Commitments and Contingencies - (Narrative) (Details) (USD $)	6 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012	Dec. 31, 2015	Jan. 31, 2015	Feb. 28, 2015
		sqft				sqft	sqft
Loss Contingencies [Line Items]
Facility total leased space in square feet (in square feet)		132,176
Period for which option to extend lease term is available		5 years
Operating leases, rent expense	$0.60	$2.50	$1.80	$1
Noncancelable purchase obligation		85.9	34.8
Janssen [Member]
Loss Contingencies [Line Items]
Total excess amounts funded by Janssen		138.3
Cumulative Benefits Excess Amounts		134.3
Interest on outstanding excess amount		4
Switzerland [Member]
Loss Contingencies [Line Items]
Facility Total Leased Space in Square Feet, Current		8,000
South San Francisco, California [Member]
Loss Contingencies [Line Items]
New facility agreement, additional leased space (in square feet)		7,000
Corporate Headquarters, Building C [Member] | Subsequent Event [Member] | California [Member]
Loss Contingencies [Line Items]
Facility total leased space in square feet (in square feet)						36,000
Operating Leases, Rent Expense					0.5
Building [Member] | Subsequent Event [Member] | California [Member]
Loss Contingencies [Line Items]
Facility total leased space in square feet (in square feet)							10,000
Operating Leases, Rent Expense					$0.30
California [Member] | Corporate Headquarters, Building A [Member]
Loss Contingencies [Line Items]
Facility total leased space in square feet (in square feet)		79,776
California [Member] | Corporate Headquarters, Building B [Member]
Loss Contingencies [Line Items]
Facility total leased space in square feet (in square feet)		52,400

Basic_and_Diluted_Net_Income_P2

Basic and Diluted Net Income Per Share - (Details) (USD $)	3 Months Ended																6 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, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Numerator:
Net income	$63,484		$41,422		($37,057)		$18,275		$64,237		$42,333		$12,351		($51,911)		$117,533	$41,715	$86,124	$67,010	$11,986
Denominator:
Weighted average common shares-basic	75,692		75,392		75,139		74,754		73,868		73,316		72,953		70,933		69,676	68,491	75,247	72,777	68,728
Effect of dilutive securities:
Weighted average common shares - diluted	78,471		78,025		75,139		78,064		77,917		77,659		77,194		70,933		74,408	71,312	78,151	77,083	72,617
Net income per share:
Basic (in dollars per share)	$0.84	[1]	$0.55	[1]	($0.49)	[1]	$0.24	[1]	$0.87	[1]	$0.58	[1]	$0.17	[1]	($0.73)	[1]	$1.69	$0.61	$1.14	$0.92	$0.17
Diluted (in dollars per share)	$0.81	[1]	$0.53	[1]	($0.49)	[1]	$0.23	[1]	$0.82	[1]	$0.55	[1]	$0.16	[1]	($0.73)	[1]	$1.58	$0.58	$1.10	$0.87	$0.17
Potentially dilutive securities excluded from net income per share - diluted because their effect is anti-dilutive (in shares)																	445		1,243	848	441
Employee Stock Option [Member]
Effect of dilutive securities:
Employee stock options and purchase plan (in shares)																	4,607		2,873	4,237	3,781
Employee Stock Purchase Plan (ESPP) [Member]
Effect of dilutive securities:
Employee stock options and purchase plan (in shares)																	125		16	69	108
Employee stock purchase plan [Member]
Effect of dilutive securities:
Employee stock options and purchase plan (in shares)																	0		15	0	0
[1]	Basic and diluted net income (loss) per share amounts are computed independently for each of the quarters presented. Therefore, the sum of quarterly basic and diluted net income (loss) per share information may not equal annual basic and diluted net income (loss) per share.

Segment_Information_Schedule_o

Segment Information - Schedule of Revenue from External Customers (Details) (USD $)	3 Months Ended								6 Months Ended		12 Months Ended
In Thousands, 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, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$290,192	$207,140	$113,020	$119,377	$123,551	$79,088	$54,684	$2,846	$160,658	$77,940	$729,729	$260,169	$81,990
Product Revenues, Net [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									0		492,418	13,573	0
Product Revenues, Net [Member] | United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									0		492,418	13,573	0
Product Revenues, Net [Member] | Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									$0		$0	$0	$0

Quarterly_Results_Unaudited_Sc

Quarterly Results (Unaudited) - Schedule of Quarterly Financial Information (Details) (USD $)	3 Months Ended																6 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, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$290,192		$207,140		$113,020		$119,377		$123,551		$79,088		$54,684		$2,846		$160,658	$77,940	$729,729	$260,169	$81,990
Total costs and expenses	197,201		158,771		150,224		101,152		38,120		25,662		42,653		55,810		40,607	30,618	607,348	162,245	70,112
Net income (loss) from operations	92,991		48,369		-37,204		18,225		85,431		53,426		12,031		-52,964		120,051	47,322	122,381	97,924	11,878
Net income	$63,484		$41,422		($37,057)		$18,275		$64,237		$42,333		$12,351		($51,911)		$117,533	$41,715	$86,124	$67,010	$11,986
Basic (in dollars per share)	$0.84	[1]	$0.55	[1]	($0.49)	[1]	$0.24	[1]	$0.87	[1]	$0.58	[1]	$0.17	[1]	($0.73)	[1]	$1.69	$0.61	$1.14	$0.92	$0.17
Diluted (in dollars per share)	$0.81	[1]	$0.53	[1]	($0.49)	[1]	$0.23	[1]	$0.82	[1]	$0.55	[1]	$0.16	[1]	($0.73)	[1]	$1.58	$0.58	$1.10	$0.87	$0.17
Basic (in shares)	75,692		75,392		75,139		74,754		73,868		73,316		72,953		70,933		69,676	68,491	75,247	72,777	68,728
Diluted (in shares)	78,471		78,025		75,139		78,064		77,917		77,659		77,194		70,933		74,408	71,312	78,151	77,083	72,617
[1]	Basic and diluted net income (loss) per share amounts are computed independently for each of the quarters presented. Therefore, the sum of quarterly basic and diluted net income (loss) per share information may not equal annual basic and diluted net income (loss) per share.

Transition_Period_Comparative_2

Transition Period Comparative Data (unaudited) - (Details) (USD $)	3 Months Ended																6 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, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012
Revenue:
License and milestone revenue																	$155,000	$77,605	$220,000	$235,000	$77,605
Collaboration services revenue																	5,658	335	17,311	11,596	4,385
Total revenue	290,192		207,140		113,020		119,377		123,551		79,088		54,684		2,846		160,658	77,940	729,729	260,169	81,990
Costs and expenses:
Research and development																	46,639	23,324	172,459	170,865	54,537
Less: Excess Amounts related to Research and development																	-17,306	0	0	-85,732	0
Research and development, net																	29,333	23,324	172,459	85,133	54,537
Selling, General and Administrative Expense, Including Excess Amounts from Collaborative Agreements																	12,093	7,294	167,955	104,016	15,575
Less: Excess Amounts related to Selling, general and administrative																	-819	0	0	-30,405	0
Selling, general and administrative																	11,274	7,294	167,955	73,611	15,575
Total costs and expenses	197,201		158,771		150,224		101,152		38,120		25,662		42,653		55,810		40,607	30,618	607,348	162,245	70,112
Income from operations	92,991		48,369		-37,204		18,225		85,431		53,426		12,031		-52,964		120,051	47,322	122,381	97,924	11,878
Interest income																	137	68	440	341	178
Other expense, net																	-8	-24	-374	-129	-31
Income before income taxes																	120,180	47,366	122,447	98,136	12,025
Income tax provision																	-2,647	-5,651	-36,323	-31,126	-39
Net income	63,484		41,422		-37,057		18,275		64,237		42,333		12,351		-51,911		117,533	41,715	86,124	67,010	11,986
Net income per share:
Basic (in dollars per share)	$0.84	[1]	$0.55	[1]	($0.49)	[1]	$0.24	[1]	$0.87	[1]	$0.58	[1]	$0.17	[1]	($0.73)	[1]	$1.69	$0.61	$1.14	$0.92	$0.17
Diluted (in dollars per share)	$0.81	[1]	$0.53	[1]	($0.49)	[1]	$0.23	[1]	$0.82	[1]	$0.55	[1]	$0.16	[1]	($0.73)	[1]	$1.58	$0.58	$1.10	$0.87	$0.17
Weighted average shares used to compute net income (loss) per share:
Basic (in shares)	75,692		75,392		75,139		74,754		73,868		73,316		72,953		70,933		69,676	68,491	75,247	72,777	68,728
Diluted (in shares)	78,471		78,025		75,139		78,064		77,917		77,659		77,194		70,933		74,408	71,312	78,151	77,083	72,617
Statement of Cash Flows Data:
Net cash provided by (used in) operating activities																	110,694	123,904	183,767	88,772	86,087
Net cash (used in) provided by investing activities																	-6,386	13,063	-23,449	-20,313	15,809
Net cash provided by financing activities																	5,229	5,490	60,761	248,064	8,243
Increase in cash and cash equivalents																	$109,537	$142,457	$221,079	$316,523	$110,139
[1]	Basic and diluted net income (loss) per share amounts are computed independently for each of the quarters presented. Therefore, the sum of quarterly basic and diluted net income (loss) per share information may not equal annual basic and diluted net income (loss) per share.

Related_Party_Transactions_Nar

Related Party Transactions - (Narrative) (Details) (Former Director, USD $)	1 Months Ended	12 Months Ended	2 Months Ended	12 Months Ended
In Millions, except Share data, unless otherwise specified	Nov. 30, 2011	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013
Related Party Transaction
Consulting expense to related party		$0.10
Lump sum consulting fee under agreement	0.1
Consulting fee agreement period (in years)	2 years
Number of options granted previously to related party in connection with consulting services (in shares)	330,000
Stock option maximum exercise period	3 years
Legal Counsel [Member]
Related Party Transaction
Amount of transaction with related parties			0.4	3.7	2.9
Legal Counsel [Member] | Accrued Liabilities [Member]
Related Party Transaction
Amount payable to related parties				$1.30	$0.90

Subsequent_Events_Narrative_De

Subsequent Events - (Narrative) (Details) (USD $)	12 Months Ended	0 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Jan. 22, 2015
Subsequent Event [Line Items]
Vesting period for Restricted Stock Units	2 years 7 days
Consulting Agreement Out of Pocket Expenses [Member] | Director [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Accounts Payable, Related Parties		$0.10
Restricted Stock Units (RSUs) [Member]
Subsequent Event [Line Items]
Vesting period for Restricted Stock Units	4 years
Restricted Stock Units (RSUs) [Member] | Consulting Agreement [Member] | Director [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Restricted stock units issued to a director		10,000
Vesting period for Restricted Stock Units		4 years
Accounts Payable, Related Parties		$1.60

Schedule_II_Valuation_and_Qual1

Schedule II - Valuation and Qualifying Accounts and Reserves - (Details) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2012	Dec. 31, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at End of Period		$70,350	$58,679		$70,350
Income Tax Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	70,001	58,679	31,915	79,161	70,350
Additions	0	11,671	26,764	0
Write-offs/Adjustments	-38,086	0	0	-9,160
Allowance for Doubtful Accounts, Cash Discounts and Other Programs [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	0	301	0	0	8,610
Additions	0	26,641	371	0
Write-offs/Adjustments	0	-18,332	-70	0
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	0	0	0	0	14
Additions	0	14	0	0
Write-offs/Adjustments	$0	$0	$0	$0