Collaboration, License and Other Arrangements - Allocation of Consideration to the Assets and Liabilities (Details) - Alpine Immune Sciences Inc - USD ($) $ in Millions		12 Months Ended
	May 20, 2024	Dec. 31, 2024
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total cash consideration paid to Alpine	$ 4,957.5
Less: Expense related to unvested equity awards	(197.6)
Transaction costs	40.7
Total consideration allocated	4,800.6
Cash and cash equivalents	31.9
Current marketable securities	209.5
Long-term marketable securities	48.5
Deferred tax asset	105.5
Total other assets	19.5
Total liabilities	(37.5)
Total identifiable assets acquired, net	377.4
Acquired in-process research and development expense	4,423.2	$ 4,400.0
Vested and Unvested Equity Awards
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total cash consideration paid to Alpine	420.6
Common Stock
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total cash consideration paid to Alpine	$ 4,536.9