Segment Information - Geographic Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Revenues from external customers by geographic area
Total revenues	$ 781.5	$ 794.4
Total Tyvaso
Revenues from external customers by geographic area
Total revenues	457.5	466.3
Tyvaso DPI
Revenues from external customers by geographic area
Total revenues	330.3	302.5
Nebulized Tyvaso
Revenues from external customers by geographic area
Total revenues	127.2	163.8
Remodulin
Revenues from external customers by geographic area
Total revenues	126.6	138.2
Orenitram
Revenues from external customers by geographic area
Total revenues	135.6	120.7
Unituxin
Revenues from external customers by geographic area
Total revenues	53.6	58.2
Adcirca
Revenues from external customers by geographic area
Total revenues	2.9	6.0
Other
Revenues from external customers by geographic area
Total revenues	5.3	5.0
U.S.
Revenues from external customers by geographic area
Total revenues	744.2	749.6
U.S. \| Total Tyvaso
Revenues from external customers by geographic area
Total revenues	442.9	441.1
U.S. \| Tyvaso DPI
Revenues from external customers by geographic area
Total revenues	330.3	302.5
U.S. \| Nebulized Tyvaso
Revenues from external customers by geographic area
Total revenues	112.6	138.6
U.S. \| Remodulin
Revenues from external customers by geographic area
Total revenues	108.8	120.2
U.S. \| Orenitram
Revenues from external customers by geographic area
Total revenues	135.6	120.7
U.S. \| Unituxin
Revenues from external customers by geographic area
Total revenues	49.0	56.9
U.S. \| Adcirca
Revenues from external customers by geographic area
Total revenues	2.9	6.0
U.S. \| Other
Revenues from external customers by geographic area
Total revenues	5.0	4.7
ROW
Revenues from external customers by geographic area
Total revenues	37.3	44.8
ROW \| Total Tyvaso
Revenues from external customers by geographic area
Total revenues	14.6	25.2
ROW \| Tyvaso DPI
Revenues from external customers by geographic area
Total revenues	0.0	0.0
ROW \| Nebulized Tyvaso
Revenues from external customers by geographic area
Total revenues	14.6	25.2
ROW \| Remodulin
Revenues from external customers by geographic area
Total revenues	17.8	18.0
ROW \| Orenitram
Revenues from external customers by geographic area
Total revenues	0.0	0.0
ROW \| Unituxin
Revenues from external customers by geographic area
Total revenues	4.6	1.3
ROW \| Adcirca
Revenues from external customers by geographic area
Total revenues	0.0	0.0
ROW \| Other
Revenues from external customers by geographic area
Total revenues	$ 0.3	$ 0.3