COLLABORATION, LICENSE AND OTHER STRATEGIC AGREEMENTS - Assets Acquired and Liabilities Assumed Related to the Asset Acquisition (Details) - Perosphere Pharmaceuticals Inc. - USD ($) $ in Millions		3 Months Ended
	Jan. 16, 2019	Mar. 31, 2019
Assets:
Cash	$ 2.6
Operating lease right-of-use asset	0.8
Property and equipment	1.4
IPR&D	74.9	$ 74.9
Total Assets	79.7
Liabilities:
Accrued severance liabilities	(1.7)
Deferred revenue	(6.4)
Operating lease liability	(0.8)
Total Liabilities	$ (8.9)