United Therapeutics (UTHR) 10-Q 29 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 22, 2013
Document and Entity Information
Entity Registrant Name	UNITED THERAPEUTICS Corp
Entity Central Index Key	1082554
Document Type	10-Q
Document Period End Date	30-Sep-13
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		50,226,603
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$322,230	$154,030
Marketable investments	394,612	325,175
Accounts receivable, net of allowance of none for 2013 and 2012	130,642	116,626
Other current assets	35,641	35,385
Inventories, net	49,617	37,254
Total current assets	932,742	668,470
Marketable investments	321,940	305,726
Marketable investments and cash-restricted	5,355	5,377
Goodwill and other intangibles, net	14,614	16,408
Property, plant and equipment, net	449,942	453,685
Deferred tax assets, net	149,648	150,147
Other assets	53,416	26,782
Total assets	1,927,657	1,626,595
Current liabilities:
Accounts payable and accrued expenses	97,510	83,188
Convertible notes	212,967
Other current liabilities	158,432	93,567
Total current liabilities	468,909	176,755
Convertible notes		204,667
Mortgages payable-noncurrent	70,298	70,343
Other liabilities	80,335	79,967
Total liabilities	619,542	531,732
Commitments and contingencies:
Temporary equity	47,915	10,882
Stockholders' equity:
Common stock, par value $.01, 245,000,000 shares authorized, 62,802,440 and 62,082,007 shares issued, and 50,177,388 and 50,165,953 shares outstanding at September 30, 2013 and December 31, 2012, respectively	628	621
Additional paid-in capital	1,029,718	1,015,835
Accumulated other comprehensive loss	-15,063	-14,957
Treasury stock at cost, 12,625,052 and 11,916,054 shares at September 30, 2013 and December 31, 2012, respectively	-513,437	-470,998
Retained earnings	758,354	553,480
Total stockholders' equity	1,260,200	1,083,981
Total liabilities and stockholders' equity	1,927,657	1,626,595
Preferred stock
Stockholders' equity:
Preferred stock
Series A junior participating preferred stock
Stockholders' equity:
Preferred stock

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Accounts receivable, allowance (in dollars)	$0	$0
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, shares authorized	245,000,000	245,000,000
Common stock, shares issued	62,802,440	62,082,007
Common stock, shares outstanding	50,177,388	50,165,953
Treasury stock, shares	12,625,052	11,916,054
Preferred stock
Preferred stock, par value (in dollars per share)	$0.01	$0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Series A junior participating preferred stock
Preferred stock, par value (in dollars per share)	$0.01	$0.01
Preferred stock, shares authorized	100,000	100,000
Preferred stock, shares issued	0	0

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues:
Net product sales	$300,006	$240,917	$820,647	$665,692
Other	2,219	1,551	7,320	6,567
Total revenues	302,225	242,468	827,967	672,259
Operating expenses:
Research and development	72,749	65,155	177,796	135,911
Selling, general and administrative	94,111	68,626	236,832	161,673
Cost of product sales	30,716	27,968	92,349	81,632
Total operating expenses	197,576	161,749	506,977	379,216
Operating income	104,649	80,719	320,990	293,043
Other (expense) income:
Interest income	868	1,138	2,716	3,225
Interest expense	-4,540	-4,384	-13,496	-12,149
Other, net	202	31,020	323	31,600
Total other (expense) income, net	-3,470	27,774	-10,457	22,676
Income before income taxes	101,179	108,493	310,533	315,719
Income tax expense	-38,494	-30,382	-105,659	-94,532
Net income	$62,685	$78,111	$204,874	$221,187
Net income per common share:
Basic (in dollars per share)	$1.25	$1.52	$4.10	$4.20
Diluted (in dollars per share)	$1.17	$1.46	$3.90	$4.11
Weighted average number of common shares outstanding:
Basic (in shares)	50,014	51,514	50,007	52,626
Diluted (in shares)	53,688	53,590	52,570	53,849

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$62,685	$78,111	$204,874	$221,187
Other comprehensive income:
Foreign currency translation gain (loss)	1,809	1,185	-854	797
Defined benefit pension plan:
Actuarial gain arising during period, net of tax			51	64
Less: amortization of actuarial gain and prior service cost included in net periodic pension cost, net of tax	255	131	767	391
Total defined benefit pension plan, net	255	131	818	455
Unrealized (loss) gain on available-for-sale securities, net of tax	-12	72	-70	109
Other comprehensive income (loss), net of tax	2,052	1,388	-106	1,361
Comprehensive income	$64,737	$79,499	$204,768	$222,548

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income	$204,874	$221,187
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	23,506	19,855
Provision for inventory obsolescence	-75	1,455
Current and deferred income tax expense	105,659	94,532
Share-based compensation expense	142,584	40,568
Amortization of debt discount and debt issue costs	9,412	8,902
Amortization of discount or premium on investments	3,066	3,303
Other	1,183	8,823
Excess tax benefits from share-based compensation	-5,807	-2,084
Changes in operating assets and liabilities:
Accounts receivable	-15,244	-19,516
Insurance proceeds receivable		-31,000
Inventories	-11,634	-4,790
Other assets	4,554	-6,385
Accounts payable and accrued expenses	12,633	-7,120
Other liabilities	-153,865	-109,311
Net cash provided by operating activities	320,846	218,419
Cash flows from investing activities:
Purchases of property, plant and equipment	-18,497	-90,650
Purchases of held-to-maturity investments	-438,633	-348,001
Investments in privately-owned companies	-30,766
Maturities of held-to-maturity investments	349,275	439,987
Net cash (used in) provided by investing activities	-138,621	1,336
Cash flows from financing activities:
Payments to repurchase common stock	-42,438	-130,925
Proceeds from the exercise of stock options	19,896	9,689
Issuance of stock under employee stock purchase plan	2,734
Excess tax benefits from share-based compensation	5,807	2,084
Net cash used in financing activities	-14,001	-119,152
Effect of exchange rate changes on cash and cash equivalents	-24	146
Net increase in cash and cash equivalents	168,200	100,749
Cash and cash equivalents, beginning of period	154,030	162,676
Cash and cash equivalents, end of period	322,230	263,425
Supplemental schedule of cash flow information:
Cash paid for interest	4,782	4,563
Cash paid for income taxes	119,632	75,046
Non-cash Investing activity:
Non-cash additions to property, plant and equipment	$3,054	$4,775

Organization_and_Business_Desc

Organization and Business Description	9 Months Ended
	Sep. 30, 2013
Organization and Business Description
Organization and Business Description	1. Organization and Business Description
	United Therapeutics Corporation is a biotechnology company focused on the development and commercialization of unique products to address the unmet medical needs of patients with chronic and life-threatening conditions. As used in these notes to the consolidated financial statements, unless the context otherwise requires, the terms “we”, “us”, “our,” and similar terms refer to United Therapeutics Corporation and its consolidated subsidiaries.
	We have three commercial products approved by the United States Food and Drug Administration (FDA): Remodulin® (treprostinil) Injection (Remodulin), Tyvaso® (treprostinil) Inhalation Solution (Tyvaso) and Adcirca® (tadalafil) tablets (Adcirca). Remodulin has also been approved in various other countries.

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2013
Basis of Presentation
Basis of Presentation	2. Basis of Presentation
	The accompanying unaudited consolidated financial statements have been prepared in accordance with the rules and regulations of the United States Securities and Exchange Commission (SEC) for interim financial information. Accordingly, they do not include all of the information required by United States generally accepted accounting principles (GAAP) for complete financial statements. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the accompanying notes to the consolidated financial statements contained in our Annual Report on Form 10-K for the year ended as of December 31, 2012, as filed with the SEC on February 26, 2013.
	In our management’s opinion, the accompanying consolidated financial statements contain all adjustments, including normal, recurring adjustments, necessary to fairly present our financial position as of September 30, 2013, results of operations and comprehensive income for the three- and nine-month periods ended September 30, 2013 and 2012, and cash flows for the nine-month periods ended September 30, 2013 and 2012. Interim results are not necessarily indicative of results for an entire year. Certain prior year amounts have been reclassified to conform to current period presentation.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2013
Inventories
Inventories	3. Inventories
	Inventories are stated at the lower of cost (first-in, first-out method) or market (current replacement cost) and consist of the following, net of reserves (in thousands):
		September 30,		December 31,
		2013		2012
	Raw materials	$	18,709	$	13,603
	Work-in-progress	13,738		11,708
	Finished goods	17,170		11,943
	Total inventories	$	49,617	$	37,254

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Measurements
Fair Value Measurements	4. Fair Value Measurements
	Assets and liabilities subject to fair value measurements are required to be disclosed within a fair value hierarchy. The fair value hierarchy ranks the quality and reliability of inputs used to determine fair value. Accordingly, assets and liabilities carried at, or permitted to be carried at, fair value are classified within the fair value hierarchy in one of the following categories based on the lowest level input that is significant in measuring fair value:
	Level 1—Fair value is determined by using unadjusted quoted prices that are available in active markets for identical assets and liabilities.
	Level 2—Fair value is determined by using inputs other than Level 1 quoted prices that are directly or indirectly observable. Inputs can include quoted prices for similar assets and liabilities in active markets or quoted prices for identical assets and liabilities in inactive markets. Related inputs can also include those used in valuation or other pricing models such as interest rates and yield curves that can be corroborated by observable market data.
	Level 3—Fair value is determined by using inputs that are unobservable and not corroborated by market data. Use of these inputs involves significant and subjective judgment.
	Assets and liabilities subject to fair value measurements are as follows (in thousands):
		As of September 30, 2013
		Level 1			Level 2		Level 3		Balance
	Assets
	Money market funds (1)	$	123,688		$	—	$	—	$	123,688
	Federally-sponsored and corporate debt securities (2)	—			716,530		—		716,530
	Available-for-sale equity investment	378			—		—		378
	Total assets	$	124,066		$	716,530	$	—	$	840,596
	Liabilities
	Convertible notes due 2016 (3)	$	425,250		$	—	$	—	$	425,250
	Contingent consideration (4)	—			—		6,784		6,784
	Total liabilities	$	425,250		$	—	$	6,784	$	432,034
		As of December 31, 2012
		Level 1			Level 2		Level 3		Balance
	Assets
	Money market funds (1)	$	77,436		$	—	$	—	$	77,436
	Federally-sponsored and corporate debt securities (2)	—			630,698		—		630,698
	Available-for-sale equity investment	473			—		—		473
	Total assets	$	77,909		$	630,698	$	—	$	708,607
	Liabilities
	Convertible notes due 2016 (3)	$	—		$	316,250	$	—	$	316,250
	Contingent consideration (4)	—			—		6,730		6,730
	Total liabilities	$	—		$	316,250	$	6,730	$	322,980
	(1)         Included in “cash and cash equivalents”, “marketable investments” and “marketable investments and cash—restricted” on the accompanying consolidated balance sheets.
	(2)         Included in current and non-current marketable investments on the accompanying consolidated balance sheets. The fair value of these securities is principally measured or corroborated by trade data for identical securities or comparable securities in which related trading activity is not sufficiently frequent to be considered a Level 1 input. See also Note 5—Investments—Marketable Investments—Held-to-Maturity Investments to these consolidated financial statements.
	(3)         Included in convertible notes on the accompanying consolidated balance sheets. Refer to Note 9—Debt—Convertible Notes Due 2016 for details. As of December 31, 2012, the fair value of our 1.0 percent Convertible Senior Notes due September 15, 2016 (2016 Convertible Notes) was estimated using other than Level 1 observable inputs.  A market has developed for our 2016 Convertible Notes and we believe the level of trading activity is now sufficiently active to become the principal basis for measuring their fair value. As a result, our 2016 Convertible Notes have been transferred from Level 2 to Level 1.
	(4)         Included in other liabilities on the accompanying consolidated balance sheets. The fair value of contingent consideration has been estimated using probability weighted discounted cash flow models (DCF). The DCFs incorporate Level 3 inputs including estimated discount rates that we believe market participants would consider relevant in pricing and the projected timing and amount of cash flows, which are estimated and developed, in part, based on the requirements specific to each acquisition agreement. We analyze and evaluate these fair value measurements quarterly to determine whether valuation inputs continue to be relevant and appropriate or whether current period developments warrant adjustments to valuation inputs and related measurements. Any increases or decreases in discount rates would have an inverse impact on the corresponding fair value, while increases or decreases in expected cash flows would result in corresponding increases or decreases in fair value. As of both September 30, 2013 and December 31, 2012, the cost of debt and weighted average cost of capital used to discount projected cash flows relating to our contingent consideration ranged from 6.6 percent to 17.2 percent, respectively.
	Reconciliations of the beginning and ending balances of Level 3 liabilities for the three-and nine-month periods ended September 30, 2013 are presented below (in thousands):
		Contingent
		Consideration
	Balance July 1, 2013—Asset (Liability)	$	(6,693	)
	Transfers into Level 3	—
	Transfers out of Level 3	—
	Total gains/(losses) realized/unrealized:
	Included in earnings	—
	Included in other comprehensive income	(91		)
	Purchases	—
	Sales	—
	Issuances	—
	Settlements	—
	Balance September 30, 2013—Asset (Liability)	$	(6,784	)
	Amount of total gains/(losses) for the three-month period ended September 30, 2013 included in earnings that are attributable to the change in unrealized gains or losses related to outstanding liabilities	$	—
		Contingent
		Consideration
	Balance January 1, 2013—Asset (Liability)	$	(6,730	)
	Transfers into Level 3	—
	Transfers out of Level 3	—
	Total gains/(losses) realized/unrealized:
	Included in earnings	—
	Included in other comprehensive income	(54		)
	Purchases	—
	Sales	—
	Issuances	—
	Settlements	—
	Balance September 30, 2013—Asset (Liability)	$	(6,784	)
	Amount of total gains/(losses) for the nine-month period ended September 30, 2013 included in earnings that are attributable to the change in unrealized gains or losses related to outstanding liabilities	$	—
	Fair Value of Financial Instruments
	The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable, and accrued expenses approximate fair value because of their short maturities. The fair values of our marketable investments and our 2016 Convertible Notes are reported above within the fair value hierarchy. The recorded value of our mortgage loan approximates its fair value as it bears a variable rate of interest that we believe approximates the market rate of interest for debt with similar credit risk profiles, terms and maturities. Refer to Note 9—Debt—Mortgage Financing for details.

Investments

Investments	9 Months Ended
	Sep. 30, 2013
Investments
Investments	5. Investments
	Marketable Investments
	Held-to-Maturity Investments
	Marketable investments classified as held-to-maturity consist of the following (in thousands):
		Amortized		Gross			Gross			Fair
		Cost		Unrealized			Unrealized			Value
				Gains			Losses
	Government-sponsored enterprises at September 30, 2013	$	421,890	$	342		$	(10	)	$	422,222
	Corporate notes and bonds at September 30, 2013	294,284		125			(101		)	294,308
	Total	$	716,174	$	467		$	(111	)	$	716,530
	Reported under the following captions on the consolidated balance sheet at September 30, 2013:
	Current marketable investments	$	394,612
	Noncurrent marketable investments	321,562
		$	716,174
		Amortized		Gross			Gross			Fair
		Cost		Unrealized			Unrealized			Value
				Gains			Losses
	Government-sponsored enterprises at December 31, 2012	$	350,043	$	261		$	(35	)	$	350,269
	Corporate notes and bonds at December 31, 2012	280,385		184			(140		)	280,429
	Total	$	630,428	$	445		$	(175	)	$	630,698
	Reported under the following captions on the consolidated balance sheet at December 31, 2012:
	Current marketable investments	$	325,175
	Noncurrent marketable investments	305,253
		$	630,428
	The following table summarizes gross unrealized losses and the length of time marketable investments have been in a continuous unrealized loss position (in thousands):
		As of September 30, 2013					As of December 31, 2012
		Fair		Gross			Fair			Gross
		Value		Unrealized			Value			Unrealized
				Loss						Loss
	Government-sponsored enterprises:
	Continuous unrealized loss position less than one year	$	52,522	$	(10	)	$	72,727		$	(35	)
	Continuous unrealized loss position greater than one year	—		—			—			—
		52,522		(10		)	72,727			(35		)
	Corporate notes and bonds:
	Continuous unrealized loss position less than one year	$	99,131	$	(101	)	$	90,960		$	(140	)
	Continuous unrealized loss position greater than one year	—		—			—			—
		99,131		(101		)	90,960			(140		)
	Total	$	151,653	$	(111	)	$	163,687		$	(175	)
	We attribute the unrealized losses on held-to-maturity securities as of September 30, 2013 and December 31, 2012 to the variability in related market interest rates. We do not intend to sell these securities, nor is it more likely than not that we will be required to sell them prior to the end of their contractual terms. Furthermore, we believe these securities do not expose us to undue market risk or counterparty credit risk. As such, we do not consider these securities to be other than temporarily impaired.
	The following table summarizes the contractual maturities of held-to-maturity marketable investments (in thousands):
		September 30, 2013
		Amortized		Fair
		Cost		Value
	Due in less than one year	$	394,612	$	394,863
	Due in one to two years	321,562		321,667
	Due in three to five years	—		—
	Due after five years	—		—
	Total	$	716,174	$	716,530
	Equity Investments
	We own less than one percent of the common stock of a public company. Our investment is classified as available-for-sale, reported at fair value based on the quoted market price, and included on the accompanying consolidated balance sheets in noncurrent marketable investments.
	Cost Method Investments
	As of September 30, 2013, we maintain in the aggregate, non-controlling equity investments of approximately $38.0 million in privately-held corporations. We account for these investments at cost since we do not have the ability to exercise significant influence over these companies and their fair values are not readily determinable. The fair value of these investments has not been estimated at September 30, 2013, as we have not identified any events or developments indicating that their carrying amounts may be impaired. We include these investments within other assets on our accompanying consolidated balance sheets.

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2013
Goodwill and Other Intangible Assets
Goodwill and Other Intangible Assets	6. Goodwill and Other Intangible Assets
	Goodwill and other intangible assets comprise the following (in thousands):
		As of September 30, 2013							As of December 31, 2012
		Gross		Accumulated			Net		Gross		Accumulated			Net
				Amortization							Amortization
	Goodwill (1)	$	10,626	$	—		$	10,626	$	10,530	$	—		$	10,530
	Other intangible assets (1):	—
	Technology, patents and trade names	4,965		(3,475		)	1,490		4,859		(2,825		)	2,034
	Customer relationships and non-compete agreements	4,860		(2,698		)	2,162		4,749		(2,232		)	2,517
	Contract-based	2,020		(1,684		)	336		2,020		(693		)	1,327
	Total	$	22,471	$	(7,857	)	$	14,614	$	22,158	$	(5,750	)	$	16,408
	(1)         Includes foreign currency translation adjustments.
	Total amortization relating to other intangible assets for the five succeeding years and thereafter is presented below (in thousands):
	Year ending December 31,
	2014	$	1,362
	2015	1,070
	2016	552
	2017	368
	2018	—
	Thereafter	—
		$	3,352

Supplemental_Executive_Retirem

Supplemental Executive Retirement Plan	9 Months Ended
	Sep. 30, 2013
Supplemental Executive Retirement Plan
Supplemental Executive Retirement Plan	7. Supplemental Executive Retirement Plan
	We maintain the United Therapeutics Corporation Supplemental Executive Retirement Plan (SERP) to provide retirement benefits to certain senior members of our management team. To help fund our expected obligations under the SERP, we maintain the United Therapeutics Corporation Supplemental Executive Retirement Plan Rabbi Trust Document (Rabbi Trust). The balance in the Rabbi Trust was $5.1 million as of September 30, 2013 and December 31, 2012. The Rabbi Trust is irrevocable and SERP participants have no preferred claim on, nor any beneficial ownership interest in, any assets of the Rabbi Trust. The investments in the Rabbi Trust are classified as restricted marketable investments and cash on our consolidated balance sheets.
	Net periodic pension cost consists of the following (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013		2012
	Service cost	$	1,352		$	1,078		$	4,055	$	3,236
	Interest cost	396			369			1,188		1,106
	Amortization of prior service cost	207			207			621		620
	Amortization of net actuarial loss	199			—			596		—
	Net pension expense	$	2,154		$	1,654		$	6,460	$	4,962
	Reclassifications related to the SERP from accumulated other comprehensive income to the statement of operations by line item and the tax impact of these reclassifications is presented below (in thousands):
	Component Reclassified from Accumulated Other Comprehensive Income (1)	Three Months			Nine Months Ended
		Ended September			September 30, 2013
		30, 2013
	Amortization of prior service cost:
	Research and development	$	79		$	234
	Selling, general and administrative	128			387
	Total	207			621
	Amortization of net actuarial loss:
	Research and development	75			224
	Selling, general and administrative	124			372
	Total	199			596
	Total amortization of prior service cost and net actuarial loss:	406			1,217
	Tax benefit	(134		)	(404		)
	Total, net of tax	$	272		$	813
	(1)         Refer to Note 12—Accumulated Other Comprehensive Income.

Share_Tracking_Award_Plans

Share Tracking Award Plans	9 Months Ended
	Sep. 30, 2013
Share Tracking Award Plans
Share Tracking Award Plans	8. Share Tracking Award Plans
	We maintain the United Therapeutics Corporation Share Tracking Awards Plan, adopted in June 2008 (2008 STAP) and the United Therapeutics Corporation 2011 Share Tracking Awards Plan, adopted in March 2011 (2011 STAP). We refer to the 2008 STAP and the 2011 STAP collectively as the “STAP” and awards granted and/or outstanding under either of these plans as “STAP awards.” STAP awards convey the right to receive in cash an amount equal to the appreciation of our common stock, which is calculated as the positive difference between the closing price of our common stock on the date of exercise and the date of grant. STAP awards generally vest in equal increments on each anniversary of the date of grant over a four-year period and expire on the tenth anniversary of the date of grant.
	The STAP liability balance was $156.8 million and $75.4 million at September 30, 2013 and December 31, 2012, respectively, and has been included within other current liabilities on our consolidated balance sheets.
	In estimating the fair value of STAP awards, we are required to use inputs that materially impact the determination of fair value and the amount of compensation expense (benefit) to be recognized. These inputs include the price of our common stock, the expected volatility of the price of our common stock, the risk-free interest rate, the expected term of STAP awards, the expected forfeiture rate and the expected dividend yield.
	The table below includes the assumptions used to measure the fair value of STAP awards:
		September 30,		September 30,
		2013		2012
	Expected volatility	34.2	%	35.8	%
	Risk-free interest rate	1.1	%	0.5	%
	Expected term of awards (in years)	4.1		3.9
	Expected forfeiture rate	9.4	%	7	%
	Expected dividend yield	0	%	0	%
	A summary of the activity and status of STAP awards is presented below:
		Number of		Weighted-			Weighted		Aggregate
		Awards		Average			Average		Intrinsic
				Exercise			Remaining		Value
				Price			Contractual		(in Thousands)
							Term
							(in Years)
	Outstanding at January 1, 2013	7,962,375		$	49
	Granted	3,347,544		57.34
	Exercised	(1,705,088	)	43.44
	Forfeited	(147,197	)	55.28
	Outstanding at September 30, 2013	9,457,634		$	52.86		7.6		$	245,837
	Exercisable at September 30, 2013	3,612,863		$	47.17		6.4		$	114,459
	Expected to vest at September 30, 2013	4,968,749		$	55.8		8.8		$	114,553
	The weighted average fair value of STAP awards granted during the nine-month periods ended September 30, 2013 and 2012 was $24.70 and $21.26, respectively.
	Share-based compensation expense recognized in connection with the STAP is as follows (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Research and development	$	30,463		$	11,790		$	58,027		$	14,932
	Selling, general and administrative	29,945			14,404			59,706			18,061
	Cost of product sales	1,064			865			2,381			1,143
	Share-based compensation expense before taxes	61,472			27,059			120,114			34,136
	Related income tax (benefit)	(20,593		)	(9,909		)	(40,238		)	(12,501		)
	Share-based compensation expense, net of taxes	$	40,879		$	17,150		$	79,876		$	21,635
	Share-based compensation capitalized as part of inventory	$	358		$	462		$	681		$	608
	Cash paid to settle STAP awards exercised during the nine-month periods ended September 30, 2013 and 2012, was $31.2 million and $25.7 million, respectively.

Debt

Debt	9 Months Ended
	Sep. 30, 2013
Debt
Debt	9. Debt
	Convertible Notes Due 2016
	In October 2011, we issued $250.0 million in aggregate principal value 1.0 percent Convertible Senior Notes due September 15, 2016 (2016 Convertible Notes). The 2016 Convertible Notes are unsecured, unsubordinated debt obligations that rank equally with all of our other unsecured and unsubordinated indebtedness. We pay interest semi-annually on March 15 and September 15 of each year. The initial conversion price is $47.69 per share and the number of underlying shares used to determine the aggregate consideration upon conversion is approximately 5.2 million shares.
	Conversion can occur: (1) any time after June 15, 2016; (2) during any calendar quarter that follows a calendar quarter in which the price of our common stock exceeds 130 percent of the conversion price for at least 20 days during the 30 consecutive trading-day period ending on the last trading day of the quarter; (3) during the ten consecutive trading-day period following any five consecutive trading-day period in which the trading price of the 2016 Convertible Notes is less than 95 percent of the closing price of our common stock multiplied by the then current number of shares underlying the 2016 Convertible Notes; (4) upon specified distributions to our shareholders; (5) in connection with certain corporate transactions; or (6) in the event that our common stock ceases to be listed on the NASDAQ Global Select Market, the NASDAQ Global Market or the New York Stock Exchange, or any of their respective successors.
	The closing price of our common stock exceeded 130 percent of the conversion price of the 2016 Convertible Notes for more than 20 trading days during the 30 consecutive trading day period ended September 30, 2013. Consequently, the 2016 Convertible Notes are convertible at the election of their holders. As this conversion right is outside of our control, the 2016 Convertible Notes have been classified as a current liability on our consolidated balance sheet at September 30, 2013. We are required to calculate this contingent conversion provision at the end of each quarterly reporting period. Therefore, the convertibility and classification of our 2016 Convertible Notes may change depending on the price of our common stock.
	At September 30, 2013, the aggregate conversion value of the 2016 Convertible Notes exceeded their par value by $163.3 million using a conversion price of $78.85, the closing price of our common stock on September 30, 2013.
	Upon conversion, holders of our 2016 Convertible Notes are entitled to receive: (1) cash equal to the lesser of the par value of the notes or the conversion value (the number of shares underlying the 2016 Convertible Notes multiplied by the then current conversion price per share); and (2) to the extent the conversion value exceeds the par value of the notes, shares of our common stock. In the event of a change in control, as defined in the indenture under which the 2016 Convertible Notes have been issued, holders can require us to purchase all or a portion of their 2016 Convertible Notes for 100 percent of the notes’ par value plus any accrued and unpaid interest.
	The terms of the 2016 Convertible Notes provide for settlement wholly or partially in cash. Consequently, we are required to account for their liability and equity components separately so that the subsequent recognition of interest expense reflects our non-convertible borrowing rate. Accordingly, we estimated the fair value of the 2016 Convertible Notes without consideration of the conversion option as of the date of issuance (Liability Component). The excess of the proceeds received over the estimated fair value of the Liability Component totaling $57.9 million has been recorded as the conversion option (Equity Component) and a corresponding offset has been recognized as a discount to the 2016 Convertible Notes to reduce their net carrying value. A portion of the Equity Component equal to the unamortized discount as of September 30, 2013 has been reclassified to temporary equity because one of the contingent conversion criteria had been met at September 30, 2013, as disclosed above. Refer to Note 10—Temporary Equity. We are amortizing the discount over the five-year period ending September 15, 2016 (the expected life of the Liability Component) using the interest method and an effective rate of interest of 6.7 percent, which corresponded to our estimated non-convertible borrowing rate at the date of issuance.
	Interest expense incurred in connection with our convertible notes consisted of the following (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013		2012
	Contractual coupon rate of interest	$	625		$	625		$	1,875	$	1,875
	Discount amortization	2,801			2,626			8,300		7,790
	Interest expense—convertible notes	$	3,426		$	3,251		$	10,175	$	9,665
	Components comprising the carrying value of the 2016 Convertible Notes include the following (in thousands):
		September 30,			December 31,
		2013			2012
	Principal balance	$	250,000		$	250,000
	Discount, net of accumulated amortization of $20,905 and $12,605	(37,033		)	(45,333		)
	Carrying amount	$	212,967		$	204,667
	Convertible Note Hedge and Warrant Transactions
	In connection with the issuance of our 2016 Convertible Notes, we entered into separate convertible note hedge and warrant transactions with Deutsche Bank AG London (DB London) to reduce the potentially dilutive impact of the conversion of our convertible notes. Pursuant to the convertible note hedge, we purchased call options to acquire up to approximately 5.2 million shares of our common stock with a strike price of $47.69. The call options become exercisable upon conversion of the 2016 Convertible Notes, and will terminate upon the maturity of the 2016 Convertible Notes or the first day the 2016 Convertible Notes are no longer outstanding, whichever occurs first. We also sold DB London warrants to acquire up to approximately 5.2 million shares of our common stock with a strike price of $67.56. The warrants will expire incrementally on a series of expiration dates subsequent to the maturity date of our 2016 Convertible Notes. Both the convertible note hedge and warrant transactions will be settled on a net-share basis. If the conversion price of our 2016 Convertible Notes remains between the strike prices of the call options and warrants, our shareholders will not experience any dilution in connection with the conversion of our 2016 Convertible Notes; however, to the extent that the price of our common stock exceeds the strike price of the warrants on any or all of the series of related incremental expiration dates, we will be required to issue shares of our common stock to DB London.
	Mortgage Financing
	In December 2010, we entered into a Credit Agreement with Wells Fargo Bank, National Association (Wells Fargo) and Bank of America, N.A., pursuant to which we obtained a $70.0 million mortgage loan (the 2010 Credit Agreement). The 2010 Credit Agreement matures in December 2014 and is secured by certain of our facilities in Research Triangle Park, North Carolina and Silver Spring, Maryland. Annual principal payments are based on a twenty-five year amortization schedule using a fixed rate of interest of 7.0 percent and the outstanding debt bears a floating rate of interest per annum based on the one-month LIBOR, plus a credit spread of 3.75 percent, or approximately 3.9 percent as of September 30, 2013. Alternatively, we have the option to change the rate of interest charged on the loan to 2.75 percent plus the greater of: (1) Wells Fargo’s prime rate, or (2) the federal funds effective rate plus 0.05 percent, or (3) LIBOR plus 1.0 percent.  We can prepay the loan balance without being subject to a prepayment premium or penalty. As of September 30, 2013, the principal balance under the 2010 Credit Agreement was $67.8 million. The 2010 Credit Agreement contains financial covenants, and as of September 30, 2013, we were in compliance with these covenants.
	Line of Credit
	On September 26, 2013, we entered into a Credit Agreement with Wells Fargo providing for a $75.0 million revolving loan facility, which may be increased by up to an additional $75.0 million provided certain conditions are met (the 2013 Credit Agreement). At our option, amounts borrowed under the 2013 Credit Agreement will bear interest at either the one-month LIBOR rate plus a 0.50 percent margin, or a fluctuating base rate excluding any margin. In addition, we will be subject to a monthly commitment fee of 0.06 percent per annum on the average daily unused balance of the facility. Amounts borrowed under the 2013 Credit Agreement are secured by certain of our marketable investments. As of September 30, 2013, we have not drawn on the facility, which has a one-year term. The 2013 Credit Agreement does not contain any financial covenants.
	Interest Expense
	Details of interest expense presented on our consolidated statements of operations are as follows (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013		2012
	Interest expense	$	4,540		$	4,384		$	13,496	$	13,054
	Less: interest capitalized	—			—			—		(905		)
	Total interest expense	$	4,540		$	4,384		$	13,496	$	12,149

Temporary_Equity

Temporary Equity	9 Months Ended
	Sep. 30, 2013
Temporary Equity
Temporary Equity	10. Temporary Equity
	Temporary equity includes securities that: (1) have redemption features that are outside our control; (2) are not classified as an asset or liability; (3) are excluded from permanent stockholders’ equity; and (4) are not mandatorily redeemable. Amounts included in temporary equity relate to securities that are redeemable at a fixed or determinable price.
	Components comprising the carrying value of temporary equity include the following (in thousands):
		September 30,		December 31,
		2013		2012
	Reclassification of Equity Component (1)	$	37,033	$	—
	Common stock subject to repurchase (2)	10,882		10,882
	Total	$	47,915	$	10,882
	(1)         Represents the reclassification of the Equity Component equal to the unamortized discount of our 2016 Convertible Notes as of September 30, 2013 from additional paid-in capital to temporary equity. As of September 30, 2013, our 2016 Convertible Notes were convertible at the election of their holders as noted above in Note 9—Debt—Convertible Notes Due 2016.
	(2)         In connection with our amended 2007 agreement with Toray Industries Inc. (Toray), we issued 400,000 shares of our common stock and provided Toray the right to request that we repurchase the shares at a price of $27.21 per share.

Stockholders_Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2013
Stockholders' Equity
Stockholders' Equity	11. Stockholders’ Equity
	Earnings Per Common Share
	Basic earnings per share is computed by dividing net income by the weighted average number of shares of common stock outstanding during the period. Diluted earnings per share is computed by dividing net income by the weighted average number of shares of common stock outstanding during the period, adjusted for the potential dilutive effect of other securities if such securities were converted or exercised.
	The components of basic and diluted earnings per common share comprise the following (in thousands, except per share amounts):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Net income (numerator)	$	62,685		$	78,111		$	204,874		$	221,187
	Denominator:
	Weighted average outstanding shares — basic	50,014			51,514			50,007			52,626
	Effect of dilutive securities (1):
	Convertible notes	1,822			662			1,389			136
	Warrants	397			—			—			—
	Stock options and employee stock purchase plan	1,455			1,414			1,174			1,087
	Weighted average shares — diluted	53,688			53,590			52,570			53,849
	Earnings per common share:
	Basic	$	1.25		$	1.52		$	4.1		$	4.2
	Diluted	$	1.17		$	1.46		$	3.9		$	4.11
	Stock options and warrants excluded from calculation (2)	10,088			11,026			10,485			11,761
	(1)         Calculated using the treasury stock method.
	(2)         Certain stock options and warrants were excluded from the computation of diluted earnings per share because their impact would be anti-dilutive.
	Stock Option Plan
	We may grant stock options to employees and non-employees under our equity incentive plan. We estimate the fair value of stock options using the Black-Scholes-Merton valuation model, which requires us to make assumptions that can materially impact the estimation of fair value and related compensation expense. These assumptions include the expected volatility of our common stock, the risk-free interest rate, the expected term of stock option awards and the expected dividend yield. We did not grant any stock options during the nine-month periods ended September 30, 2013 and 2012.
	A summary of the activity and status of employee stock options during the nine-month period ended September 30, 2013 is presented below:
		Number of		Weighted-			Weighted		Aggregate
		Options		Average			Average		Intrinsic
				Exercise			Remaining		Value
				Price			Contractual		(in thousands)
							Term
							(Years)
	Outstanding at January 1, 2013	4,551,050		$	38.95
	Granted	—		—
	Exercised	(609,361	)	30
	Forfeited	(3,528	)	10.51
	Outstanding and exercisable at September 30, 2013	3,938,161		$	40.36		4.7		$	151,583
	Total share-based compensation expense related to employee stock options is as follows (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Selling, general and administrative	$	12,709		$	4,042		$	21,875		$	6,371
	Related income tax benefit	(4,258		)	(1,480		)	(7,328		)	(2,333		)
	Share-based compensation expense net of taxes	$	8,451		$	2,562		$	14,547		$	4,038
	Employee and non-employee stock option exercise data is summarized below (dollars in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Number of options exercised	310,673			246,401			665,363			386,515
	Cash received	$	9,799		$	6,575		$	19,896		$	9,689
	Employee Stock Purchase Plan
	In June 2012, our shareholders approved the United Therapeutics Corporation Employee Stock Purchase Plan (ESPP), which has been structured to comply with Section 423 of the Internal Revenue Code (Section 423). The ESPP provides eligible employees the right to purchase shares of our common stock at a discount through elective accumulated payroll deductions at the end of each offering period. Offering periods, which began in September 2012, occur in consecutive six-month periods commencing on September 5th and March 5th of each year. During the nine-month period ending September 30, 2013, we issued 55,070 shares of our common stock for $2.7 million. Eligible employees may contribute up to 15 percent of their base salary, subject to certain annual limitations as defined in the ESPP. The purchase price of the shares is equal to the lower of 85 percent of the closing price of our common stock on either the first or last trading day of a given offering period. In addition, the ESPP provides that no eligible employee may purchase more than 4,000 shares during any offering period. The ESPP has a 20-year term and limits the aggregate number of shares that can be issued to 3.0 million.
	Share-based compensation expense related to the ESPP for the three-month periods ended September 30, 2013 and September 30, 2012 was $204,100 and $63,900, respectively. For the nine-month periods ended September 30, 2013 and September 30, 2012 compensation expense was $594,300 and $63,900, respectively.
	We estimate the fair value of the shares of our common stock to be purchased under the ESPP using the Black-Scholes-Merton model. Our approach in determining and estimating inputs for the ESPP is similar to the methodology we employ in valuing our STAP awards.
	Share Repurchases
	Periodically, our Board of Directors may authorize repurchases of our common stock. In February 2013, our Board of Directors authorized a share repurchase program for up to $420.0 million in aggregate repurchases of our common stock in open market or privately negotiated transactions, from time to time at our discretion. The one-year repurchase period began on March 4, 2013. As of September 30, 2013, we have acquired 708,998 shares of our common stock at an aggregate cost of $42.4 million.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income	12. Accumulated Other Comprehensive Income
	The following table includes changes in accumulated other comprehensive income (loss) by component, net of tax (in thousands):
		Defined Benefit			Foreign			Unrealized			Total
		Pension Plan(1)			Currency			Gains and
					Translation			(Losses) on
					Losses			Available-for-
								Sale Securities
	Balance, January 1, 2013	$	(11,540	)	$	(3,876	)	$	459		$	(14,957	)
	Other comprehensive income (loss) before reclassifications	51			(854		)	(70		)	(873		)
	Amounts reclassified from accumulated other comprehensive income	767			—			—			767
	Net current-period other comprehensive income (loss)	818			(854		)	(70		)	(106		)
	Balance, September 30, 2013	$	(10,722	)	$	(4,730	)	$	389		$	(15,063	)
	(1)         Refer to Note 7—Supplemental Executive Retirement Plan which identifies the captions within our consolidated statement of operations where reclassification adjustments were recognized and their associated tax impact.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Taxes
Income Taxes	13. Income Taxes
	Income tax expense for the three- and nine-month periods ended September 30, 2013 and 2012 is based on the estimated effective tax rate for the entire year. The estimated annual effective tax rate can be subject to adjustment in subsequent quarterly periods if components used in its estimation are revised. The estimated annual effective tax rates as of September 30, 2013 and 2012 were 34 percent and 31 percent, respectively.
	We expect to utilize all of our general business tax credits in 2013.
	We are subject to federal and state taxation in the United States and various foreign jurisdictions. Currently, our 2010 tax year is subject to examination by the Internal Revenue Service and our tax years from 2009 to 2011 are subject to examination by state taxing authorities.
	We are unaware of any positions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly increase or decrease within the next 12 months.

Segment_Information

Segment Information	9 Months Ended
	Sep. 30, 2013
Segment Information
Segment Information	14. Segment Information
	We currently operate as one operating segment. However, our chief operating decision makers regularly review revenues, cost of revenues and gross profit data as a primary measure of performance for each of our three commercial products.
	Revenues, cost of revenues and gross profit for each of our commercial products were as follows (in thousands):
		Three Months Ended September 30,
	2013	Remodulin		Tyvaso		Adcirca		Total
	Revenues	$	132,322	$	120,306	$	47,378	$	300,006
	Cost of revenues	13,549		14,245		2,922		30,716
	Gross profit	$	118,773	$	106,061	$	44,456	$	269,290
	2012
	Revenues	$	120,811	$	88,302	$	31,804	$	240,917
	Cost of revenues	13,963		11,796		2,209		27,968
	Gross profit	$	106,848	$	76,506	$	29,595	$	212,949
		Nine Months Ended September 30,
	2013	Remodulin		Tyvaso		Adcirca		Total
	Revenues	$	371,314	$	324,409	$	124,924	$	820,647
	Cost of revenues	40,439		44,125		7,785		92,349
	Gross profit	$	330,875	$	280,284	$	117,139	$	728,298
	2012
	Revenues	$	341,755	$	239,578	$	84,359	$	665,692
	Cost of revenues	43,956		32,073		5,603		81,632
	Gross profit	$	297,799	$	207,505	$	78,756	$	584,060
	For the three-month periods ended September 30, 2013 and 2012, net revenues from our three U.S.-based distributors represented 76 percent and 79 percent, respectively, of our total net operating revenues.
	For the nine-month periods ended September 30, 2013 and 2012, net revenues from our three U.S.-based distributors represented 77 percent and 79 percent, respectively, of our total net operating revenues.

Litigation

Litigation	9 Months Ended
	Sep. 30, 2013
Litigation
Litigation	15. Litigation
	Sandoz Inc.
	In February 2012, we received a Paragraph IV Certification Notice Letter (the Original Notice Letter) from Sandoz Inc. (Sandoz) advising that Sandoz had submitted an abbreviated new drug application (ANDA) to the FDA requesting approval to market a generic version of the 10 mg/mL strength of Remodulin.  In December 2012, we received notice (the Second Notice Letter) that Sandoz had amended its previously filed ANDA to request additional approval to market generic versions of the 1 mg/mL, 2.5 mg/mL, and 5 mg/mL strengths of Remodulin. In the Original Notice Letter and the Second Notice Letter, Sandoz stated that it intends to market a generic version of Remodulin before the expiration of the following patents relating to Remodulin: U.S. Patent No. 5,153,222, which expires in October 2014; U.S. Patent No. 6,765,117, which expires in October 2017; and U.S. Patent No. 7,999,007, which expires in March 2029.  Each of these patents is listed in the Orange Book.
	We responded to the Original Notice Letter by filing a lawsuit in March 2012 against Sandoz in the U.S. District Court for the District of New Jersey alleging patent infringement.  We responded to the Second Notice Letter by filing an additional lawsuit in January 2013 for patent infringement in the U.S. District Court for the District of New Jersey.  Sandoz has filed its answer to our complaints in both lawsuits, and has also filed counterclaims in each action alleging that the patents at issue in the litigation are invalid or will not be infringed by the commercial manufacture, use or sale of the proposed product described in Sandoz’s ANDA submission.  We have filed answers to the counterclaims in both lawsuits.
	Under the Hatch-Waxman Act, the FDA is automatically precluded from approving Sandoz’s ANDA with respect to each concentration of Remodulin for up to 30 months from receipt of the Notice Letter corresponding to each concentration or until the issuance of a district court decision that is adverse to us, whichever occurs first.  We intend to vigorously enforce our intellectual property rights relating to Remodulin.

Inventories_Tables

Inventories (Tables)	9 Months Ended
	Sep. 30, 2013
Inventories
Schedule of inventories, net of reserves	Inventories are stated at the lower of cost (first-in, first-out method) or market (current replacement cost) and consist of the following, net of reserves (in thousands):
		September 30,		December 31,
		2013		2012
	Raw materials	$	18,709	$	13,603
	Work-in-progress	13,738		11,708
	Finished goods	17,170		11,943
	Total inventories	$	49,617	$	37,254

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Measurements
Schedule of assets and liabilities subject to fair value measurements	Assets and liabilities subject to fair value measurements are as follows (in thousands):
		As of September 30, 2013
		Level 1			Level 2		Level 3		Balance
	Assets
	Money market funds (1)	$	123,688		$	—	$	—	$	123,688
	Federally-sponsored and corporate debt securities (2)	—			716,530		—		716,530
	Available-for-sale equity investment	378			—		—		378
	Total assets	$	124,066		$	716,530	$	—	$	840,596
	Liabilities
	Convertible notes due 2016 (3)	$	425,250		$	—	$	—	$	425,250
	Contingent consideration (4)	—			—		6,784		6,784
	Total liabilities	$	425,250		$	—	$	6,784	$	432,034
		As of December 31, 2012
		Level 1			Level 2		Level 3		Balance
	Assets
	Money market funds (1)	$	77,436		$	—	$	—	$	77,436
	Federally-sponsored and corporate debt securities (2)	—			630,698		—		630,698
	Available-for-sale equity investment	473			—		—		473
	Total assets	$	77,909		$	630,698	$	—	$	708,607
	Liabilities
	Convertible notes due 2016 (3)	$	—		$	316,250	$	—	$	316,250
	Contingent consideration (4)	—			—		6,730		6,730
	Total liabilities	$	—		$	316,250	$	6,730	$	322,980
	(1)         Included in “cash and cash equivalents”, “marketable investments” and “marketable investments and cash—restricted” on the accompanying consolidated balance sheets.
	(2)         Included in current and non-current marketable investments on the accompanying consolidated balance sheets. The fair value of these securities is principally measured or corroborated by trade data for identical securities or comparable securities in which related trading activity is not sufficiently frequent to be considered a Level 1 input. See also Note 5—Investments—Marketable Investments—Held-to-Maturity Investments to these consolidated financial statements.
	(3)         Included in convertible notes on the accompanying consolidated balance sheets. Refer to Note 9—Debt—Convertible Notes Due 2016 for details. As of December 31, 2012, the fair value of our 1.0 percent Convertible Senior Notes due September 15, 2016 (2016 Convertible Notes) was estimated using other than Level 1 observable inputs.  A market has developed for our 2016 Convertible Notes and we believe the level of trading activity is now sufficiently active to become the principal basis for measuring their fair value. As a result, our 2016 Convertible Notes have been transferred from Level 2 to Level 1.
	(4)         Included in other liabilities on the accompanying consolidated balance sheets. The fair value of contingent consideration has been estimated using probability weighted discounted cash flow models (DCF). The DCFs incorporate Level 3 inputs including estimated discount rates that we believe market participants would consider relevant in pricing and the projected timing and amount of cash flows, which are estimated and developed, in part, based on the requirements specific to each acquisition agreement. We analyze and evaluate these fair value measurements quarterly to determine whether valuation inputs continue to be relevant and appropriate or whether current period developments warrant adjustments to valuation inputs and related measurements. Any increases or decreases in discount rates would have an inverse impact on the corresponding fair value, while increases or decreases in expected cash flows would result in corresponding increases or decreases in fair value. As of both September 30, 2013 and December 31, 2012, the cost of debt and weighted average cost of capital used to discount projected cash flows relating to our contingent consideration ranged from 6.6 percent to 17.2 percent, respectively.
Schedule of reconciliations of the beginning and ending balances of Level 3 assets and liabilities	Reconciliations of the beginning and ending balances of Level 3 liabilities for the three-and nine-month periods ended September 30, 2013 are presented below (in thousands):
		Contingent
		Consideration
	Balance July 1, 2013—Asset (Liability)	$	(6,693	)
	Transfers into Level 3	—
	Transfers out of Level 3	—
	Total gains/(losses) realized/unrealized:
	Included in earnings	—
	Included in other comprehensive income	(91		)
	Purchases	—
	Sales	—
	Issuances	—
	Settlements	—
	Balance September 30, 2013—Asset (Liability)	$	(6,784	)
	Amount of total gains/(losses) for the three-month period ended September 30, 2013 included in earnings that are attributable to the change in unrealized gains or losses related to outstanding liabilities	$	—
		Contingent
		Consideration
	Balance January 1, 2013—Asset (Liability)	$	(6,730	)
	Transfers into Level 3	—
	Transfers out of Level 3	—
	Total gains/(losses) realized/unrealized:
	Included in earnings	—
	Included in other comprehensive income	(54		)
	Purchases	—
	Sales	—
	Issuances	—
	Settlements	—
	Balance September 30, 2013—Asset (Liability)	$	(6,784	)
	Amount of total gains/(losses) for the nine-month period ended September 30, 2013 included in earnings that are attributable to the change in unrealized gains or losses related to outstanding liabilities	$	—

Investments_Tables

Investments (Tables)	9 Months Ended
	Sep. 30, 2013
Investments
Schedule of marketable investments classified as held-to-maturity	Marketable investments classified as held-to-maturity consist of the following (in thousands):
		Amortized		Gross			Gross			Fair
		Cost		Unrealized			Unrealized			Value
				Gains			Losses
	Government-sponsored enterprises at September 30, 2013	$	421,890	$	342		$	(10	)	$	422,222
	Corporate notes and bonds at September 30, 2013	294,284		125			(101		)	294,308
	Total	$	716,174	$	467		$	(111	)	$	716,530
	Reported under the following captions on the consolidated balance sheet at September 30, 2013:
	Current marketable investments	$	394,612
	Noncurrent marketable investments	321,562
		$	716,174
		Amortized		Gross			Gross			Fair
		Cost		Unrealized			Unrealized			Value
				Gains			Losses
	Government-sponsored enterprises at December 31, 2012	$	350,043	$	261		$	(35	)	$	350,269
	Corporate notes and bonds at December 31, 2012	280,385		184			(140		)	280,429
	Total	$	630,428	$	445		$	(175	)	$	630,698
	Reported under the following captions on the consolidated balance sheet at December 31, 2012:
	Current marketable investments	$	325,175
	Noncurrent marketable investments	305,253
		$	630,428
Summary of gross unrealized losses and the length of time marketable investments have been in a continuous unrealized loss position	The following table summarizes gross unrealized losses and the length of time marketable investments have been in a continuous unrealized loss position (in thousands):
		As of September 30, 2013					As of December 31, 2012
		Fair		Gross			Fair			Gross
		Value		Unrealized			Value			Unrealized
				Loss						Loss
	Government-sponsored enterprises:
	Continuous unrealized loss position less than one year	$	52,522	$	(10	)	$	72,727		$	(35	)
	Continuous unrealized loss position greater than one year	—		—			—			—
		52,522		(10		)	72,727			(35		)
	Corporate notes and bonds:
	Continuous unrealized loss position less than one year	$	99,131	$	(101	)	$	90,960		$	(140	)
	Continuous unrealized loss position greater than one year	—		—			—			—
		99,131		(101		)	90,960			(140		)
	Total	$	151,653	$	(111	)	$	163,687		$	(175	)
Summary of the contractual maturities of held-to-maturity marketable investments	The following table summarizes the contractual maturities of held-to-maturity marketable investments (in thousands):
		September 30, 2013
		Amortized		Fair
		Cost		Value
	Due in less than one year	$	394,612	$	394,863
	Due in one to two years	321,562		321,667
	Due in three to five years	—		—
	Due after five years	—		—
	Total	$	716,174	$	716,530

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2013
Goodwill and Other Intangible Assets
Schedule of goodwill and other intangible assets	Goodwill and other intangible assets comprise the following (in thousands):
		As of September 30, 2013							As of December 31, 2012
		Gross		Accumulated			Net		Gross		Accumulated			Net
				Amortization							Amortization
	Goodwill (1)	$	10,626	$	—		$	10,626	$	10,530	$	—		$	10,530
	Other intangible assets (1):	—
	Technology, patents and trade names	4,965		(3,475		)	1,490		4,859		(2,825		)	2,034
	Customer relationships and non-compete agreements	4,860		(2,698		)	2,162		4,749		(2,232		)	2,517
	Contract-based	2,020		(1,684		)	336		2,020		(693		)	1,327
	Total	$	22,471	$	(7,857	)	$	14,614	$	22,158	$	(5,750	)	$	16,408
	(1)         Includes foreign currency translation adjustments.
Future amortization of other intangible assets	Total amortization relating to other intangible assets for the five succeeding years and thereafter is presented below (in thousands):
	Year ending December 31,
	2014	$	1,362
	2015	1,070
	2016	552
	2017	368
	2018	—
	Thereafter	—
		$	3,352

Supplemental_Executive_Retirem1

Supplemental Executive Retirement Plan (Tables)	9 Months Ended
	Sep. 30, 2013
Supplemental Executive Retirement Plan
Components of net periodic benefit cost recognized	Net periodic pension cost consists of the following (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013		2012
	Service cost	$	1,352		$	1,078		$	4,055	$	3,236
	Interest cost	396			369			1,188		1,106
	Amortization of prior service cost	207			207			621		620
	Amortization of net actuarial loss	199			—			596		—
	Net pension expense	$	2,154		$	1,654		$	6,460	$	4,962
Schedule of components reclassified from accumulated other comprehensive income	Reclassifications related to the SERP from accumulated other comprehensive income to the statement of operations by line item and the tax impact of these reclassifications is presented below (in thousands):
	Component Reclassified from Accumulated Other Comprehensive Income (1)	Three Months			Nine Months Ended
		Ended September			September 30, 2013
		30, 2013
	Amortization of prior service cost:
	Research and development	$	79		$	234
	Selling, general and administrative	128			387
	Total	207			621
	Amortization of net actuarial loss:
	Research and development	75			224
	Selling, general and administrative	124			372
	Total	199			596
	Total amortization of prior service cost and net actuarial loss:	406			1,217
	Tax benefit	(134		)	(404		)
	Total, net of tax	$	272		$	813
	(1)         Refer to Note 12—Accumulated Other Comprehensive Income.

Share_Tracking_Award_Plans_Tab

Share Tracking Award Plans (Tables) (Share tracking award plans (STAP))	9 Months Ended
	Sep. 30, 2013
Share tracking award plans (STAP)
Awards granted under the STAP
Schedule of assumptions to estimate the fair value of STAP awards
		September 30,		September 30,
		2013		2012
	Expected volatility	34.2	%	35.8	%
	Risk-free interest rate	1.1	%	0.5	%
	Expected term of awards (in years)	4.1		3.9
	Expected forfeiture rate	9.4	%	7	%
	Expected dividend yield	0	%	0	%
Summary of activity and status of STAP awards
		Number of		Weighted-			Weighted		Aggregate
		Awards		Average			Average		Intrinsic
				Exercise			Remaining		Value
				Price			Contractual		(in Thousands)
							Term
							(in Years)
	Outstanding at January 1, 2013	7,962,375		$	49
	Granted	3,347,544		57.34
	Exercised	(1,705,088	)	43.44
	Forfeited	(147,197	)	55.28
	Outstanding at September 30, 2013	9,457,634		$	52.86		7.6		$	245,837
	Exercisable at September 30, 2013	3,612,863		$	47.17		6.4		$	114,459
	Expected to vest at September 30, 2013	4,968,749		$	55.8		8.8		$	114,553
Schedule of share-based compensation expense recognized in connection with the STAP	Share-based compensation expense recognized in connection with the STAP is as follows (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Research and development	$	30,463		$	11,790		$	58,027		$	14,932
	Selling, general and administrative	29,945			14,404			59,706			18,061
	Cost of product sales	1,064			865			2,381			1,143
	Share-based compensation expense before taxes	61,472			27,059			120,114			34,136
	Related income tax (benefit)	(20,593		)	(9,909		)	(40,238		)	(12,501		)
	Share-based compensation expense, net of taxes	$	40,879		$	17,150		$	79,876		$	21,635
	Share-based compensation capitalized as part of inventory	$	358		$	462		$	681		$	608

Debt_Tables

Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Debt
Schedule of components of interest expense incurred in connection with the entity's convertible notes	Interest expense incurred in connection with our convertible notes consisted of the following (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013		2012
	Contractual coupon rate of interest	$	625		$	625		$	1,875	$	1,875
	Discount amortization	2,801			2,626			8,300		7,790
	Interest expense—convertible notes	$	3,426		$	3,251		$	10,175	$	9,665
Schedule of information about carrying amount of the 2016 Convertible Notes	Components comprising the carrying value of the 2016 Convertible Notes include the following (in thousands):
		September 30,			December 31,
		2013			2012
	Principal balance	$	250,000		$	250,000
	Discount, net of accumulated amortization of $20,905 and $12,605	(37,033		)	(45,333		)
	Carrying amount	$	212,967		$	204,667
Schedule of components of interest expense presented on the entity's consolidated statements of operations	Details of interest expense presented on our consolidated statements of operations are as follows (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013		2012
	Interest expense	$	4,540		$	4,384		$	13,496	$	13,054
	Less: interest capitalized	—			—			—		(905		)
	Total interest expense	$	4,540		$	4,384		$	13,496	$	12,149

Temporary_Equity_Tables

Temporary Equity (Tables)	9 Months Ended
	Sep. 30, 2013
Temporary Equity
Schedule of components of temporary equity	Components comprising the carrying value of temporary equity include the following (in thousands):
		September 30,		December 31,
		2013		2012
	Reclassification of Equity Component (1)	$	37,033	$	—
	Common stock subject to repurchase (2)	10,882		10,882
	Total	$	47,915	$	10,882
	(1)         Represents the reclassification of the Equity Component equal to the unamortized discount of our 2016 Convertible Notes as of September 30, 2013 from additional paid-in capital to temporary equity. As of September 30, 2013, our 2016 Convertible Notes were convertible at the election of their holders as noted above in Note 9—Debt—Convertible Notes Due 2016.
	(2)         In connection with our amended 2007 agreement with Toray Industries Inc. (Toray), we issued 400,000 shares of our common stock and provided Toray the right to request that we repurchase the shares at a price of $27.21 per share.

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Common Share
Schedule of components of basic and diluted earnings per share	The components of basic and diluted earnings per common share comprise the following (in thousands, except per share amounts):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Net income (numerator)	$	62,685		$	78,111		$	204,874		$	221,187
	Denominator:
	Weighted average outstanding shares — basic	50,014			51,514			50,007			52,626
	Effect of dilutive securities (1):
	Convertible notes	1,822			662			1,389			136
	Warrants	397			—			—			—
	Stock options and employee stock purchase plan	1,455			1,414			1,174			1,087
	Weighted average shares — diluted	53,688			53,590			52,570			53,849
	Earnings per common share:
	Basic	$	1.25		$	1.52		$	4.1		$	4.2
	Diluted	$	1.17		$	1.46		$	3.9		$	4.11
	Stock options and warrants excluded from calculation (2)	10,088			11,026			10,485			11,761
	(1)         Calculated using the treasury stock method.
	(2)         Certain stock options and warrants were excluded from the computation of diluted earnings per share because their impact would be anti-dilutive.
Stock Options
Stock Option Plan
Schedule of stock option activity
		Number of		Weighted-			Weighted		Aggregate
		Options		Average			Average		Intrinsic
				Exercise			Remaining		Value
				Price			Contractual		(in thousands)
							Term
							(Years)
	Outstanding at January 1, 2013	4,551,050		$	38.95
	Granted	—		—
	Exercised	(609,361	)	30
	Forfeited	(3,528	)	10.51
	Outstanding and exercisable at September 30, 2013	3,938,161		$	40.36		4.7		$	151,583
Schedule of share-based compensation expense related to employee stock options	Total share-based compensation expense related to employee stock options is as follows (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Selling, general and administrative	$	12,709		$	4,042		$	21,875		$	6,371
	Related income tax benefit	(4,258		)	(1,480		)	(7,328		)	(2,333		)
	Share-based compensation expense net of taxes	$	8,451		$	2,562		$	14,547		$	4,038
Summary of employee and non-employee stock option exercise data	Employee and non-employee stock option exercise data is summarized below (dollars in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Number of options exercised	310,673			246,401			665,363			386,515
	Cash received	$	9,799		$	6,575		$	19,896		$	9,689

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income
Schedule of changes in accumulated other comprehensive income (loss) by component, net of tax	The following table includes changes in accumulated other comprehensive income (loss) by component, net of tax (in thousands):
		Defined Benefit			Foreign			Unrealized			Total
		Pension Plan(1)			Currency			Gains and
					Translation			(Losses) on
					Losses			Available-for-
								Sale Securities
	Balance, January 1, 2013	$	(11,540	)	$	(3,876	)	$	459		$	(14,957	)
	Other comprehensive income (loss) before reclassifications	51			(854		)	(70		)	(873		)
	Amounts reclassified from accumulated other comprehensive income	767			—			—			767
	Net current-period other comprehensive income (loss)	818			(854		)	(70		)	(106		)
	Balance, September 30, 2013	$	(10,722	)	$	(4,730	)	$	389		$	(15,063	)
	(1)         Refer to Note 7—Supplemental Executive Retirement Plan which identifies the captions within our consolidated statement of operations where reclassification adjustments were recognized and their associated tax impact.

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Information
Schedule of revenues, cost of revenues and gross profit for each of the entity's commercial product	Revenues, cost of revenues and gross profit for each of our commercial products were as follows (in thousands):
		Three Months Ended September 30,
	2013	Remodulin		Tyvaso		Adcirca		Total
	Revenues	$	132,322	$	120,306	$	47,378	$	300,006
	Cost of revenues	13,549		14,245		2,922		30,716
	Gross profit	$	118,773	$	106,061	$	44,456	$	269,290
	2012
	Revenues	$	120,811	$	88,302	$	31,804	$	240,917
	Cost of revenues	13,963		11,796		2,209		27,968
	Gross profit	$	106,848	$	76,506	$	29,595	$	212,949
		Nine Months Ended September 30,
	2013	Remodulin		Tyvaso		Adcirca		Total
	Revenues	$	371,314	$	324,409	$	124,924	$	820,647
	Cost of revenues	40,439		44,125		7,785		92,349
	Gross profit	$	330,875	$	280,284	$	117,139	$	728,298
	2012
	Revenues	$	341,755	$	239,578	$	84,359	$	665,692
	Cost of revenues	43,956		32,073		5,603		81,632
	Gross profit	$	297,799	$	207,505	$	78,756	$	584,060

Organization_and_Business_Desc1

Organization and Business Description (Details)	9 Months Ended
	Sep. 30, 2013
	item
Organization and Business Description
Number of commercial products approved	3

Inventories_Details

Inventories (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Inventories:
Raw materials	$18,709	$13,603
Work-in-progress	13,738	11,708
Finished goods	17,170	11,943
Total inventories	$49,617	$37,254

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Oct. 31, 2011
In Thousands, unless otherwise specified
Assets
Federally-sponsored and corporate debt securities	716,530	630,698
Discounted Cash Flow | Maximum
Liabilities
Cost of debt and weighted average cost of capital (as a percent)	17.20%	17.20%
Discounted Cash Flow | Minimum
Liabilities
Cost of debt and weighted average cost of capital (as a percent)	6.60%	6.60%
Convertible Notes Due 2016
Liabilities
Convertible Senior Notes, stated percentage	1.00%	1.00%	1.00%
Recurring fair value measurements | Level 1
Assets
Money market funds	123,688	77,436
Available-for-sale equity investment	378	473
Total assets	124,066	77,909
Liabilities
Convertible notes due 2016	425,250
Total liabilities	425,250
Recurring fair value measurements | Level 2
Assets
Federally-sponsored and corporate debt securities	716,530	630,698
Total assets	716,530	630,698
Liabilities
Convertible notes due 2016		316,250
Total liabilities		316,250
Recurring fair value measurements | Level 3
Liabilities
Contingent consideration	6,784	6,730
Total liabilities	6,784	6,730
Recurring fair value measurements | Balance
Assets
Money market funds	123,688	77,436
Federally-sponsored and corporate debt securities	716,530	630,698
Available-for-sale equity investment	378	473
Total assets	840,596	708,607
Liabilities
Convertible notes due 2016	425,250	316,250
Contingent consideration	6,784	6,730
Total liabilities	432,034	322,980

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (Contingent Consideration, USD $)	3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013
Contingent Consideration
Reconciliation of beginning and ending balances of Level 3 assets and liabilities
Beginning balance	($6,693)	($6,730)
Total gains/(losses) realized/unrealized
Included in other comprehensive income	-91	-54
Ending balance	($6,784)	($6,784)

Investments_Details

Investments (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Marketable investments classified as held-to-maturity:
Amortized Cost	$716,174	$630,428
Gross Unrealized Gains	467	445
Gross Unrealized Losses	-111	-175
Fair Value	716,530	630,698
Government-sponsored enterprises
Marketable investments classified as held-to-maturity:
Amortized Cost	421,890	350,043
Gross Unrealized Gains	342	261
Gross Unrealized Losses	-10	-35
Fair Value	422,222	350,269
Corporate notes and bonds
Marketable investments classified as held-to-maturity:
Amortized Cost	294,284	280,385
Gross Unrealized Gains	125	184
Gross Unrealized Losses	-101	-140
Fair Value	$294,308	$280,429

Investments_Details_2

Investments (Details 2) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
As reported on the consolidated balance sheets at the end of the period:
Current marketable investments	$394,612	$325,175
Noncurrent marketable investments	321,562	305,253
Total marketable investments	$716,174	$630,428

Investments_Details_3

Investments (Details 3) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Continuous unrealized loss position, Fair Value
Fair Value, Total	$151,653	$163,687
Continuous unrealized loss position, Gross Unrealized Loss
Gross Unrealized Loss, Total	-111	-175
Government-sponsored enterprises
Continuous unrealized loss position, Fair Value
Less than one year, Fair value	52,522	72,727
Fair Value, Total	52,522	72,727
Continuous unrealized loss position, Gross Unrealized Loss
Less than one year, Gross Unrealized Loss	-10	-35
Gross Unrealized Loss, Total	-10	-35
Corporate notes and bonds
Continuous unrealized loss position, Fair Value
Less than one year, Fair value	99,131	90,960
Fair Value, Total	99,131	90,960
Continuous unrealized loss position, Gross Unrealized Loss
Less than one year, Gross Unrealized Loss	-101	-140
Gross Unrealized Loss, Total	($101)	($140)

Investments_Details_4

Investments (Details 4) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Amortized Cost
Due in less than one year, Amortized Cost	$394,612
Due in one to two years, Amortized Cost	321,562
Total marketable investments	716,174	630,428
Fair Value
Due in less than one year, Fair Value	394,863
Due in one to two years, Fair Value	321,667
Fair Value	$716,530	$630,698
Equity Investments
Available-for-sale investment in common stock, less than a certain percentage	1.00%

Investments_Details_5

Investments (Details 5) (Privately-held corporations, USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Privately-held corporations
Cost Method Investments
Investments in equity of privately-held corporations	$38

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Goodwill and other intangible assets
Goodwill, Gross	$10,626	$10,530
Goodwill, Net	10,626	10,530
Other intangible assets, Accumulated Amortization	-7,857	-5,750
Other intangible assets, Net	3,352
Total intangible assets, Gross	22,471	22,158
Total intangible assets, Net	14,614	16,408
Amortization relating to other intangible assets
2014	1,362
2015	1,070
2016	552
2017	368
Other intangible assets, Net	3,352
Technology, patents and trade names
Goodwill and other intangible assets
Other intangible assets, Gross	4,965	4,859
Other intangible assets, Accumulated Amortization	-3,475	-2,825
Other intangible assets, Net	1,490	2,034
Amortization relating to other intangible assets
Other intangible assets, Net	1,490	2,034
Customer relationships and non-compete agreements
Goodwill and other intangible assets
Other intangible assets, Gross	4,860	4,749
Other intangible assets, Accumulated Amortization	-2,698	-2,232
Other intangible assets, Net	2,162	2,517
Amortization relating to other intangible assets
Other intangible assets, Net	2,162	2,517
Contract-based
Goodwill and other intangible assets
Other intangible assets, Gross	2,020	2,020
Other intangible assets, Accumulated Amortization	-1,684	-693
Other intangible assets, Net	336	1,327
Amortization relating to other intangible assets
Other intangible assets, Net	$336	$1,327

Supplemental_Executive_Retirem2

Supplemental Executive Retirement Plan (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Supplemental Executive Retirement Plan Disclosure
Marketable investments and cash-restricted	$5,355		$5,355		$5,377
Supplemental Executive Retirement Plan (SERP)
Supplemental Executive Retirement Plan Disclosure
Marketable investments and cash-restricted	5,100		5,100		5,100
Components of net periodic pension cost
Service cost	1,352	1,078	4,055	3,236
Interest cost	396	369	1,188	1,106
Amortization of prior service cost	207	207	621	620
Amortization of net actuarial loss	199		596
Net pension expense	$2,154	$1,654	$6,460	$4,962

Supplemental_Executive_Retirem3

Supplemental Executive Retirement Plan (Details 2) (USD $)	3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013
Reclassifications related to the SERP from accumulated other comprehensive income to the statement of operations
Amortization of prior service cost	$207	$621
Amortization of net actuarial loss	199	596
Total amortization of prior service cost and net actuarial loss	406	1,217
Tax benefit	-134	-404
Total, net of tax	272	813
Research and development
Reclassifications related to the SERP from accumulated other comprehensive income to the statement of operations
Amortization of prior service cost	79	234
Amortization of net actuarial loss	75	224
Selling, general and administrative
Reclassifications related to the SERP from accumulated other comprehensive income to the statement of operations
Amortization of prior service cost	128	387
Amortization of net actuarial loss	$124	$372

Share_Tracking_Award_Plans_Det

Share Tracking Award Plans (Details) (Share tracking award plans (STAP), USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Share tracking award plans (STAP)
Awards granted under the STAP
Share-based awards, vesting period	4 years
Grant expiration period from the grant date	10 years
Equity based compensation liability	$156,800,000		$75,400,000
Assumptions used to measure the fair value of STAP awards
Expected volatility (as a percent)	34.20%	35.80%
Risk-free interest rate (as a percent)	1.10%	0.50%
Expected term of awards	4 years 1 month 6 days	3 years 10 months 24 days
Expected forfeiture rate (as a percent)	9.40%	7.00%
Expected dividend yield (as a percent)	0.00%	0.00%
Share-based awards activity
Outstanding at the beginning of the period (in shares)	7,962,375
Granted (in shares)	3,347,544
Exercised (in shares)	-1,705,088
Forfeited (in shares)	-147,197
Outstanding at the end of the period (in shares)	9,457,634
Exercisable at the end of the period (in shares)	3,612,863
Expected to vest at the end of the period (in shares)	4,968,749
Share awards, Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$49
Granted (in dollars per share)	$57.34
Exercised (in dollars per share)	$43.44
Forfeited (in dollars per share)	$55.28
Outstanding at the end of the period (in dollars per share)	$52.86
Exercisable at the end of the period (in dollars per share)	$47.17
Expected to vest at the end of the period (in dollars per share)	$55.80
Share awards, Weighted Average Remaining Contractual Term
Outstanding at the end the period	7 years 7 months 6 days
Exercisable at the end of the period	6 years 4 months 24 days
Expected to vest at the end of the period	8 years 9 months 18 days
Share awards, Aggregate Intrinsic Value
Outstanding at the end of the period (in dollars)	245,837,000
Exercisable at the end of the period (in dollars)	114,459,000
Expected to vest at the end of the period (in dollars)	$114,553,000
Awards granted during the period, weighted average fair value (in dollars per share)	$24.70	$21.26

Share_Tracking_Award_Plans_Det1

Share Tracking Award Plans (Details 2) (Share tracking award plans (STAP), USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share-based compensation (benefit) expense recognized in connection with the STAP
Share-based compensation expense before taxes	$61,472,000	$27,059,000	$120,114,000	$34,136,000
Related income tax (benefit)	-20,593,000	-9,909,000	-40,238,000	-12,501,000
Share-based compensation expense, net of taxes	40,879,000	17,150,000	79,876,000	21,635,000
Share-based compensation capitalized as part of inventory	358,000	462,000	681,000	608,000
Cash payments on awards exercised during the period			31,200,000	25,700,000
Research and development
Share-based compensation (benefit) expense recognized in connection with the STAP
Share-based compensation expense before taxes	30,463,000	11,790,000	58,027,000	14,932,000
Selling, general and administrative
Share-based compensation (benefit) expense recognized in connection with the STAP
Share-based compensation expense before taxes	29,945,000	14,404,000	59,706,000	18,061,000
Cost of product sales
Share-based compensation (benefit) expense recognized in connection with the STAP
Share-based compensation expense before taxes	$1,064,000	$865,000	$2,381,000	$1,143,000

Debt_Details

Debt (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

Share data in Millions, except Per Share data, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Oct. 31, 2011

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2010

Sep. 30, 2013

Convertible senior notes

Convertible senior notes

Convertible senior notes

Convertible senior notes

Convertible Notes Due 2016

Convertible Notes Due 2016

Convertible Notes Due 2016

Revolving line of credit

Revolving line of credit

Revolving line of credit

Mortgage Financing

Mortgage Financing

Mortgage Financing

D

Maximum

One-month LIBOR

One-month LIBOR

Debt

Debt aggregate principal value

$250,000,000

Convertible Senior Notes, stated percentage

1.00%

1.00%

1.00%

Amount by which aggregate conversion value exceeds par value

163,300,000

Conversion price (in dollars per share)

$78.85

$47.69

Convertible debt, number of shares into which convertible

5.2

Percentage of conversion price that the closing sales price of the entity's common stock must exceed in order to make the notes convertible

130.00%

Number of trading days within 30 consecutive trading days in which closing price of the entity's common stock must exceed conversion price for notes to be redeemable

20

Trading-day period used to determine contingent conversion requirement on notes

30

Number of consecutive business days immediately after any five consecutive trading-day period during note measurement period

10

Number of consecutive trading-days during which the trading price of the convertible notes must be less than a given percentage of the entity's stock price to be convertible.

5

Percentage of trading price of the entity's common stock's closing price and the conversion rate, maximum

95.00%

Redemption price of convertible notes as a percentage of principal amount, due to change in control

100.00%

Equity component

57,900,000

Amortization schedule

5 years

Effective interest rate (as a percent)

6.70%

Interest expense incurred in connection with the entity's convertible notes

Contractual coupon rate of interest

625,000

625,000

1,875,000

1,875,000

Discount amortization

2,801,000

2,626,000

8,300,000

7,790,000

Interest expense-convertible notes

3,426,000

3,251,000

10,175,000

9,665,000

Carrying amount related to convertible notes

Principal balance

250,000,000

250,000,000

67,800,000

Convertible debt, discount to reduce net carrying value

-37,033,000

-45,333,000

Discount, accumulated amortization

20,905,000

12,605,000

Carrying amount

212,967,000

204,667,000

Mortgage Financing

Mortgage loan under credit agreement

70,000,000

70,000,000

Amortization schedule, period for calculation of monthly installments

25 years

Amortization schedule, fixed interest rate for calculation of principal payments (as a percent)

7.00%

Debt, floating rate of interest basis

one month LIBOR

one month LIBOR

Debt, floating rate of interest, basis spread (as a percent)

0.50%

3.75%

Debt, interest rate at period end (as a percent)

3.90%

Debt, interest rate, alternative option (as a percent)

2.75%

Debt, interest rate, alternative option, spread over federal funds effective rate (as a percent)

0.05%

Debt, interest rate, alternative option, basis

LIBOR

Debt, interest rate, alternative option, spread over basis (as a percent)

1.00%

Unused commitment fee (as a percent)

0.06%

Debt, maturity term

1 year

Maximum borrowing capacity

75,000,000

Additional increase in borrowing capacity of the line of credit available at the entity's option

75,000,000

Interest expense

Interest expense

4,540,000

4,384,000

13,496,000

13,054,000

Less: interest capitalized

-905,000

Total interest expense

$4,540,000

$4,384,000

$13,496,000

$12,149,000

Debt_Details_2

Debt (Details 2) (Convertible Notes Due 2016, USD $)	9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013
Sale of warrant
Share warrant, number of shares	5.2
Share warrant, exercise price (in dollars per share)	$67.56
Purchased call options | Long
Purchase of call options
Convertible note hedge, approximate number of shares that can be purchased	5.2
Convertible note hedge, exercise price (in dollars per share)	$47.69

Temporary_Equity_Details

Temporary Equity (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Temporary equity
Total	$47,915	$10,882
Temporary equity component in convertible note due 2016
Temporary equity
Reclassification of Equity Component	37,033
Temporary equity common stocks subject to repurchase
Temporary equity
Common stock subject to repurchase	$10,882	$10,882
Common stock issued (in shares)	400,000
Repurchase price (in dollars per share)	$27.21

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Numerator:
Net income	$62,685	$78,111	$204,874	$221,187
Denominator:
Weighted average outstanding shares-basic	50,014	51,514	50,007	52,626
Effect of dilutive securities:
Convertible notes (in shares)	1,822	662	1,389	136
Warrants (in shares)	397
Stock options and employee stock purchase plan (in shares)	1,455	1,414	1,174	1,087
Weighted average shares-diluted	53,688	53,590	52,570	53,849
Earnings per common share:
Basic (in dollars per share)	$1.25	$1.52	$4.10	$4.20
Diluted (in dollars per share)	$1.17	$1.46	$3.90	$4.11
Stock options and warrants excluded from calculation (in shares)	10,088	11,026	10,485	11,761

Stockholders_Equity_Details_2

Stockholders' Equity (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock option activity
Exercised (in shares)	-310,673	-246,401	-665,363	-386,515
Stock Options
Stock option activity
Outstanding at the beginning of the period (in shares)			4,551,050
Exercised (in shares)			-609,361
Forfeited (in shares)			-3,528
Outstanding at the end of the period (in shares)	3,938,161		3,938,161
Employee stock options, Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)			38.95
Exercised (in dollars per share)			30
Forfeited (in dollars per share)			10.51
Outstanding at the end of the period (in dollars per share)	40.36		40.36
Employee stock options, Weighted Average Remaining Contractual Term
Outstanding at the end the period			4 years 8 months 12 days
Employee stock options, Aggregate Intrinsic Value
Outstanding at the end of the period (in dollars)	151,583		151,583

Stockholders_Equity_Details_3

Stockholders' Equity (Details 3) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share-based compensation expense related to outstanding awards
Share-based compensation expense			$142,584,000	$40,568,000
Stock Options
Share-based compensation expense related to outstanding awards
Related income tax benefit	-4,258,000	-1,480,000	-7,328,000	-2,333,000
Share-based compensation expense, net of taxes	8,451,000	2,562,000	14,547,000	4,038,000
Employee Stock Purchase Plan (ESPP)
Share-based compensation expense related to outstanding awards
Offering period			6 months
Common stock issued in connection with ESPP, Amount			2,700,000
Maximum percentage of compensation employees may contribute for ESPP	15.00%		15.00%
Percentage of the lower of the fair market value of common stock on the first or last trading-day of a given offering period			85.00%
Number of eligible employees who may purchase more than 4000 shares			0
Maximum number of shares each eligible employees may purchase in any given offering period			4,000
Term of employee stock purchase plan			20 years
Maximum number of shares authorized to be issued Aggregate number of shares authorized to be issued	3,000,000		3,000,000
Common stock issued in connection with ESPP			55,070
Share-based compensation expense	204,100	63,900	594,300	63,900
Selling, general and administrative | Stock Options
Share-based compensation expense related to outstanding awards
Share-based compensation expense before taxes	$12,709,000	$4,042,000	$21,875,000	$6,371,000

Stockholders_Equity_Details_4

Stockholders' Equity (Details 4) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Employee and non-employee stock option exercise data
Number of options exercised (in shares)	310,673	246,401	665,363	386,515
Cash received	$9,799	$6,575	$19,896	$9,689

Stockholders_Equity_Details_5

Stockholders' Equity (Details 5) (USD $)	0 Months Ended	1 Months Ended	9 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 04, 2013	Feb. 28, 2013	Sep. 30, 2013
Share Repurchase
Authorized aggregate repurchases of common stock		$420
Period over which shares may be purchased under share repurchase program	1 year
Repurchased shares of common stock			708,998
Cost of shares repurchased			$42.40

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Changes in accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period			($14,957)
Other comprehensive income (loss) before reclassifications			-873
Amounts reclassified from accumulated other comprehensive income			767
Other comprehensive income (loss), net of tax	2,052	1,388	-106	1,361
Balance at the end of the period	-15,063		-15,063
Defined Benefit Pension Plan
Changes in accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period			-11,540
Other comprehensive income (loss) before reclassifications			51
Amounts reclassified from accumulated other comprehensive income			767
Other comprehensive income (loss), net of tax			818
Balance at the end of the period	-10,722		-10,722
Foreign Currency Translation Losses
Changes in accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period			-3,876
Other comprehensive income (loss) before reclassifications			-854
Other comprehensive income (loss), net of tax			-854
Balance at the end of the period	-4,730		-4,730
Unrealized Gains and (Losses) on Available-for-Sale Securities
Changes in accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period			459
Other comprehensive income (loss) before reclassifications			-70
Other comprehensive income (loss), net of tax			-70
Balance at the end of the period	$389		$389

Income_Taxes_Details

Income Taxes (Details)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Income Taxes
Estimated Annual Effective Income Tax Rate	34.00%	31.00%

Segment_Information_Details

Segment Information (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
			segment
			item
Segment Information
Number of operating segments			1
Number of commercial products			3
Revenues, cost of revenues and gross profit
Revenues	$300,006	$240,917	$820,647	$665,692
Cost of revenues	30,716	27,968	92,349	81,632
Gross profit	269,290	212,949	728,298	584,060
Remodulin
Revenues, cost of revenues and gross profit
Revenues	132,322	120,811	371,314	341,755
Cost of revenues	13,549	13,963	40,439	43,956
Gross profit	118,773	106,848	330,875	297,799
Tyvaso
Revenues, cost of revenues and gross profit
Revenues	120,306	88,302	324,409	239,578
Cost of revenues	14,245	11,796	44,125	32,073
Gross profit	106,061	76,506	280,284	207,505
Adcirca
Revenues, cost of revenues and gross profit
Revenues	47,378	31,804	124,924	84,359
Cost of revenues	2,922	2,209	7,785	5,603
Gross profit	$44,456	$29,595	$117,139	$78,756

Segment_Information_Details_2

Segment Information (Details 2) (Net revenues, Customer concentration, Three U.S.-based distributors)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
	item	item	item	item
Net revenues | Customer concentration | Three U.S.-based distributors
Segment Information
Number of U.S.-based distributors	3	3	3	3
Concentration risk, percentage	76.00%	79.00%	77.00%	79.00%