Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012 distributor	Sep. 30, 2011 distributor	Sep. 30, 2012 segment distributor product	Sep. 30, 2011 distributor
Segment Information
Number of operating segments			1
Number of commercial products			3
Revenues, cost of revenues and gross profit
Revenues	$ 240,917	$ 201,020	$ 665,692	$ 546,784
Cost of revenues	27,968	22,676	81,632	63,577
Gross profit	212,949	178,344	584,060	483,207
Number of U.S.-based distributors for majority of the entity's revenues	3	3	3	3
Percentage of revenues from U.S.-based distributors for majority of the entity's revenues	79.00%	81.00%	79.00%	82.00%
Remodulin
Revenues, cost of revenues and gross profit
Revenues	120,811	114,918	341,755	323,016
Cost of revenues	13,963	12,659	43,956	36,860
Gross profit	106,848	102,259	297,799	286,156
Tyvaso
Revenues, cost of revenues and gross profit
Revenues	88,302	66,330	239,578	175,835
Cost of revenues	11,796	8,735	32,073	23,551
Gross profit	76,506	57,595	207,505	152,284
Adcirca
Revenues, cost of revenues and gross profit
Revenues	31,804	19,772	84,359	47,933
Cost of revenues	2,209	1,282	5,603	3,166
Gross profit	$ 29,595	$ 18,490	$ 78,756	$ 44,767