Summary of Significant Accounting Policies (Details 4)	12 Months Ended
	Dec. 31, 2012
Revenue Recognition
Shelf life of Remodulin and Tyvaso sold to customers, minimum	1 year
Inventory holding period of Remodulin and Tyvaso, low end of range	30 days
Inventory holding period of Remodulin and Tyvaso, high end of range	60 days
Maximum exchanges of Remodulin and Tyvaso as compared to the total volume of units sold (as a percent)	1.00%
Income taxes
Minimum percentage of likelihood of realization of recognized tax benefit	50.00%