Segment Information - Geographic Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues from external customers by geographic area
Total revenues	$ 677.7	$ 506.9
Total Tyvaso
Revenues from external customers by geographic area
Total revenues	372.5	238.4
Tyvaso DPI
Revenues from external customers by geographic area
Total revenues	227.5	118.7
Nebulized Tyvaso
Revenues from external customers by geographic area
Total revenues	145.0	119.7
Remodulin
Revenues from external customers by geographic area
Total revenues	128.0	121.4
Orenitram
Revenues from external customers by geographic area
Total revenues	106.2	88.2
Unituxin
Revenues from external customers by geographic area
Total revenues	58.4	49.1
Adcirca
Revenues from external customers by geographic area
Total revenues	6.4	7.3
Other
Revenues from external customers by geographic area
Total revenues	6.2	2.5
U.S.
Revenues from external customers by geographic area
Total revenues	641.5	469.7
U.S. | Total Tyvaso
Revenues from external customers by geographic area
Total revenues	361.2	234.4
U.S. | Tyvaso DPI
Revenues from external customers by geographic area
Total revenues	227.5	118.7
U.S. | Nebulized Tyvaso
Revenues from external customers by geographic area
Total revenues	133.7	115.7
U.S. | Remodulin
Revenues from external customers by geographic area
Total revenues	108.3	93.2
U.S. | Orenitram
Revenues from external customers by geographic area
Total revenues	106.2	88.2
U.S. | Unituxin
Revenues from external customers by geographic area
Total revenues	53.4	44.3
U.S. | Adcirca
Revenues from external customers by geographic area
Total revenues	6.4	7.3
U.S. | Other
Revenues from external customers by geographic area
Total revenues	6.0	2.3
ROW
Revenues from external customers by geographic area
Total revenues	36.2	37.2
ROW | Total Tyvaso
Revenues from external customers by geographic area
Total revenues	11.3	4.0
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	11.3	4.0
ROW | Remodulin
Revenues from external customers by geographic area
Total revenues	19.7	28.2
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	5.0	4.8
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	$ 0.2	$ 0.2